tag:blogger.com,1999:blog-82620154105508008612024-03-13T22:35:14.045-04:00The Engineer`s PulseLearning science is one of the hardest things a person can do. It often forces us to shift the way in which we see the world. The process is demanding, but is ultimately rewarding, because it allows us to interact with nature in a deeper, more meaningful way. If we continue down this road, we become empowered with the means to shape our environment - we become engineers.The Engineerhttp://www.blogger.com/profile/05080325091689417696noreply@blogger.comBlogger215125tag:blogger.com,1999:blog-8262015410550800861.post-13980136590620613562023-12-06T12:56:00.000-05:002023-12-06T12:56:30.877-05:00My Fall Mechanics Class - thanks for the escape!<p>Oftentimes, as the end of year draws near, I take a moment to reflect on its high points. For me, there were several, most notably, the publication of my first book (<i>Getting Physics: Nature's Laws as a Guide to Life</i>, link on the right side of the page, makes a great Christmas gift, wink wink). But, this year has been a rough one for me, particularly the past couple of months, for many reasons I will not elaborate on, but if I must list a theme, let's go with 'targeted attacks on minority communities'.</p><p>Of course, I am not alone. In these difficult moments, we need to try extra hard to be in the moment, and escape the weight of this general malaise. The classroom is a setting that can offer such an escape. Many students feel that the classroom is a place they would like to escape from, but consider this...</p><p>Many years ago, a student of mine was in crisis. I could see on their face that something was not right, and we had a chat. They said something that stuck with me: "The classroom is an escape, a brief respite from my troubles." I totally get that, particularly with physics, because physics does not care about the day we are having or whether there is peace in the Middle East. The laws of nature exist outside and above all of our troubles.</p><p>In a recent bout with COVID, I was watching too much Netflix, as one does (mostly movies I have already seen cause that's how I roll). I rewatched <i>Jurassic World</i>. There are two brothers who enter a theme park with dinosaurs. One's glee boils over, while the other stares at his phone. How can one not be completely in awe? That is how I feel when students get bored in physics class... Not that they all do, but of course, some do. Maybe most do some of the time? How can I know for sure?</p><p>At the front of the class, <i>I</i> get immersed in physics, and <i>I</i> get to spend time with a fun bunch of young adults. <i>I</i> get to escape things that exist outside the classroom. I want all of my students to experience the same feeling. I have spent my whole career figuring out how to do that while also maximizing their academic growth - and I still have much to learn.</p><p>Normally, I say goodbye to my students at the end of the year and inherit new groups in the Winter semester, and <i>try again</i>. But for my Mechanics class, there was a last-minute reshuffling, and no one could take this group of honours students of mine for their next course (Waves, Optics, and Modern Physics). In the shuffle, <b>the course fell to me</b>. </p><p>I now have this opportunity (has only happened twice before in my career) to teach the same body of students another course. I hope they will be happy to hear this news. My take on it, in general, is that it should be avoided. Students should see a discipline from many angles. Also, too much familiarity can be a problem. For example, students might think it is okay to break lab equipment cause "He's a nice guy, and he knows us," etc. Anyway, as I said, they are a fun bunch of young adults and I look forward to trying again. A second chance to get to know the Universe and escape our Earthly troubles in the process.</p>The Engineerhttp://www.blogger.com/profile/05080325091689417696noreply@blogger.com0tag:blogger.com,1999:blog-8262015410550800861.post-37617467295784184702023-07-11T13:14:00.001-04:002023-07-11T13:18:49.736-04:00In the Light of Other Suns<p>The <b>Eighth Interstellar Symposium</b>, entitled "In the Light of Other Suns" is underway this week at my alma mater, McGill University, in Montreal, Quebec. Hosted by the Interstellar Research Group and Professor Andrew Higgins, the space conference includes studies of various challenges associated with interstellar flight... and there are many!</p><p>Last night, I was fortunate enough to be in a sold out auditorium for a panel discussion amongst experts with varying backgrounds. The six hundred in attendance sat attentively as a wide range of questions were addressed, from "How much might the transit depicted in Avatar 2 cost?" to "Is it ethical to have a child on a planet that is not Earth, virtually guaranteeing that they will never set foot on their species' origin planet?" The answer to the former is on the order of petadollars (billions of billions of dollars), and the answer to the second is "We don't know."</p><p>The experts have no illusions that people will be travelling to Alpha Centauri in the coming decades. They anticipate microsatellites being propelled at relativistic speeds (>0.1<i>c</i>) to take pictures of exoplanets in that timeframe. Starships with people might be a hundred years away. So, why are distinguished professors studying them today?</p><p>The economic answer is that long term projects overcome incremental hurdles that enable spinoff technologies in the present. But there are so many more reasons, like the plain fact that we are an aspirational species. NASA technologist Les Johnson, irked by the question of economic returns associated with interstellar flight, posited that humans wanting to know things is reason enough (a comment that elicited enthusiastic applause).</p><p>Current engineering studies examine photonic propulsion and the highly reflective surfaces required to reach dizzying speeds. Others look at the stability of a tiny satellite's trajectory while being bombarded with photons or collisions with space dust when moving at some fraction of <i>c</i>.</p><p>I was expecting to hear more about Breakthrough Starshot, the aforementioned mission to snap photos of exoplanets and send them back to Earth. It seems that the interstellar community is becoming less focused on this one particular mission, instead looking at energy propulsion in a broader sense. The possibility of a one month transit to Mars was discussed; the spaceship would use a 1<i>g</i> acceleration for the first half of the trip (lasers pushing it from Earth) followed by a 1<i>g</i> deceleration during the second half (lasers pushing it from Mars). So ya, it would require laser arrays deployed on the Martian surface, but don't worry, studies have looked into the feasibility of that too.</p><p>Is it a space symposium for dreamers? Absolutely. But power to them (the photonic kind). A technical engineering conference that can fill a large auditorium is doing something right. </p>The Engineerhttp://www.blogger.com/profile/05080325091689417696noreply@blogger.com0tag:blogger.com,1999:blog-8262015410550800861.post-5151483788351818572023-03-22T11:13:00.002-04:002023-03-22T11:13:59.529-04:00My first TV appearance!<p>I'm excited to announce that I will be interviewed by Mutsumi Takahashi on CTV's Montreal noon newscast this coming Tuesday, March 28. We will discuss my book, <i><a href="https://www.amazon.ca/dp/B0BSJJDNWF">Getting Physics</a></i>, and how I use it to help make physics relatable for students.</p><p>I have done radio interviews before, but TV is a new thing for me. Looking forward to it!</p>The Engineerhttp://www.blogger.com/profile/05080325091689417696noreply@blogger.com0tag:blogger.com,1999:blog-8262015410550800861.post-84025189792200700042023-03-04T15:59:00.001-05:002023-03-04T15:59:24.897-05:00A Thought About Teaching<p>If we are born a seed, then when I meet students in college, they are plants with deep roots. On my best day, I can be a star that shines light on the garden before me, inspiring a direction in which to sprout. If that is not a good reason to get dressed in the morning and go to work, then I don't know what is.</p>The Engineerhttp://www.blogger.com/profile/05080325091689417696noreply@blogger.com2tag:blogger.com,1999:blog-8262015410550800861.post-58160516409217274322023-03-02T09:34:00.001-05:002023-03-02T09:34:12.159-05:00My first book launch<p>Next Thursday, March 3, 5:00 pm, I will be having my first book launch event at Vanier College (in the STEM Centre, D-301) for <i>Getting Physics: Nature's Laws as a Guide to Life</i>. I would love to see science enthusiasts there, particularly current and former students of mine. </p><p>I am thinking about how the event should run. I have been to book signings before and they always include some readings from the newly published book. My hope is that some of my current and former students could share some of the reading duties with me. After all, this book was written with them in mind. The schedule I envision is:</p><p>5:00 - 5:30 pm: hors d'ouevres and schmooze</p><p>5:30 - 6:00 pm: speeches and short readings from book</p><p>6:00 - 6:30 pm: book purchase and signing</p><p>My college issued a <a href="https://www.vaniercollege.qc.ca/newsroom/book-launch-march-9th-stephen-cohens-getting-physics-natures-laws-as-a-guide-to-life/">press release yesterday</a>, so I am also hoping to make the rounds with local Montreal media.</p><p>It will be my pleasure to share this moment with readers of this blog who happen to live in my city. There will be no book tour, so I am contemplating ways to reach a wider audience. For now, I am starting with my stomping grounds, and seeing where it goes from there.</p>The Engineerhttp://www.blogger.com/profile/05080325091689417696noreply@blogger.com0tag:blogger.com,1999:blog-8262015410550800861.post-7344755478255096582023-01-20T07:43:00.002-05:002023-01-20T13:42:42.372-05:00"Getting Physics" NOW AVAILABLE!<p><span style="font-family: inherit;"> After years of work, my first book, <i>Getting Physics: Nature's Laws as a Guide to Life</i>, is finally available. I will almost certainly never devote more time to any single project than I did this one. It is a labour of love, and I am so happy to share it with readers all around the world.</span></p><p><span style="font-family: inherit;">The link to purchase it through Amazon is here: <a href="https://www.amazon.ca/dp/B0BSJJDNWF?ref_=pe_3052080_397514860" target="_blank">GETTING PHYSICS</a>.</span></p><p><span style="font-family: inherit;">I am not sure what else to write in this post. This blog is the place where I learned how to write about physics. Some of the contents of this book include paragraphs I wrote in 2010, the year <i>The Engineer's Pulse</i> was launched. I am feeling incredibly nostalgic right about now. The only thing that makes sense to me is to simply copy/paste the acknowledgement section of <i>Getting Physics</i> here:</span></p><p align="center" class="MsoNormal" style="text-align: center; text-indent: 0cm;"><span style="font-family: inherit;"><b><span>Acknowledgements</span></b><span style="mso-ansi-language: EN-CA; mso-bidi-font-family: "Times New Roman"; mso-fareast-font-family: "Times New Roman";"><o:p></o:p></span></span></p><p class="MsoNormal"><span style="font-family: inherit;"><span style="text-indent: 0cm;">Momentum
for the manuscript began when eleven Vanier College students volunteered to
read through a chapter or two and provide detailed comments. I want to
thank Bastienne D.C., Peter D., Kamil C., Maria-Sara F., Quassandra D., Daniel
M., Carolynn B., Will E., Alin B., Aashiha B., and Myriam L., because their
feedback improved the book immensely. </span></span></p><p class="MsoNormal" style="text-indent: 0cm;"><span style="font-family: inherit;"><o:p></o:p></span></p><p class="MsoNormal"><span style="font-family: inherit;">There are two more
experienced authors that helped point me in the right direction early on as I
navigated the journey that is ‘publishing a book’. Thank you, Alex
Rosenblatt and Brahm Canzer.<o:p></o:p></span></p><p class="MsoNormal"><span style="font-family: inherit;">I must also thank
Kristie Stuckey, whose keen eye and countless iterations led to the lovely
figures contained herein.<o:p></o:p></span></p><p class="MsoNormal"><span style="font-family: inherit;">Pearl Levine provided
a round of editing that was much appreciated (she also bakes amazing brownies). Stef Caron used a fine comb and did a final,
skillful pass through.<o:p></o:p></span></p><p class="MsoNormal"><span style="font-family: inherit;">I have more colleagues
at Vanier College to thank for their feedback and moral support along the way
than I can fit here. I want to give a shout out to the Vanier College
Physics Department, whose combined wisdom helped refine the lens through which
I see physics. I also wish to thank
Nicholas Park, <span lang="EN" style="background: white; border: 1pt none windowtext; padding: 0cm;">Jean-François Brière</span>, and Sameer Bhatnagar for reviewing portions of the book.
Similarly, I have been encouraged to write about physics by many friends, like
Jon, Corey, Lorne, Peter, Tom, Rob, Jer, Christian, and Jeff to name a few.<o:p></o:p></span></p><p class="MsoNormal"><span style="font-family: inherit;">I have had the honor
of teaching more than 1,500 students. My interactions with them helped
shape me as an educator. Their curiosity and resilience through adversity
inspired me to keep pushing forward in my career.<o:p></o:p></span></p><p class="MsoNormal"><span style="font-family: inherit;">I would have little
connection to academic content, nor any practical skills without the teacher
interactions I had as a student. My fundamentals in math were solidified
in college thanks to Denis Sevee and Frank Lovasco. Professor Andrew Higgins
served as a model for how to communicate physics with gusto. Gerard
Carrier and Alpha Ross showed me the ropes in the space industry, upping my technical
engineering game. Finally, my mentor, Professor Arun Misra, taught me
most of what I know about physics and engineering. He introduced me to
orbital mechanics, space elevators, space conferences, and how to write
technical papers; most importantly, he personified how to approach one’s career
and human interactions with integrity. He has been my Mr. Miyagi.<o:p></o:p></span></p><p class="MsoNormal"><span style="font-family: inherit;">Before any of this
could happen, Mom, Dad, Jamie, you gave me a foundation upon which to build a
life. I was brought up in this nurturing family, even though my mother is
not exactly sure where her science author son emerged from.<o:p></o:p></span></p><p>
<span><span style="font-family: inherit;">Val. We were kids and then we grew into ourselves
side by side. You are my anchor in this life. At this point, I
suppose you <i>get physics</i> whether you like it or not.</span></span></p>The Engineerhttp://www.blogger.com/profile/05080325091689417696noreply@blogger.com0tag:blogger.com,1999:blog-8262015410550800861.post-32172464620765975712022-11-25T08:45:00.003-05:002022-11-25T08:48:31.966-05:00Published in Scientific American!<p>This morning marks a big moment in my career. I have long wished to be a popularizer of science, and there are few better venues for this than <i>Scientific American</i>. I had originally submitted a very technical article about space elevators to them, but they asked for something more 'fun', so I rewrote it. I am so pleased with the result: <a href="https://www.scientificamerican.com/article/space-elevators-are-less-sci-fi-than-you-think/"><span style="color: red;">Space Elevators are Less Sci-Fi than you Think</span></a>. I feel quite elated on this November morning.</p>The Engineerhttp://www.blogger.com/profile/05080325091689417696noreply@blogger.com7tag:blogger.com,1999:blog-8262015410550800861.post-81014656958209831272022-08-05T13:54:00.002-04:002022-08-07T11:37:41.602-04:00The Journey that is 'Publishing a Book'<p style="text-align: justify;">Have you ever tried to publish a book? If yes, I wonder if your experience tested your might the way mine has. I have nearly crossed the finish line, but what a long and arduous road it has been (the publishing part, not the writing part). If you are thinking about publishing a book, perhaps the following bits of wisdom gleaned throughout my soul-crushing journey will be of some benefit to you.</p><p style="text-align: justify;">There are two main avenues to publication: to work with a publishing house or to go about it independently. In the case of my forthcoming book, <i>Getting Physics</i>, I experienced <b>both</b>. That, in and of itself, is an indicator that things did not go smoothly...</p><p style="text-align: justify;"><b>My first mistake: Writing the book before choosing the avenue for publication</b></p><p style="text-align: justify;">If you intend to publish with a publishing house, it is far more efficient to make a book proposal, which includes a synopsis, proposed table of contents, marketing ideas, and perhaps two chapters, before completing a manuscript. It turns out that even if you decide to publish independently, a book proposal is an excellent idea. If you will be your own boss, you ought to provide yourself with a roadmap that considers the big picture.</p><p style="text-align: justify;">Having written the book first, I backtracked and prepared a book proposal, and this process led me to modify my manuscript. Armed with my book proposal, I now wished to find a publisher that was interested in my book.</p><p style="text-align: justify;">I did some research, and found that the best way to get a good publisher is to get a literary agent. They work on your behalf, meeting with established publishers, many of whom only consider works that arrive via such an agent. It turns out that enticing a literary agent is about as hard as enticing a good publisher.</p><p style="text-align: justify;"><b>My second mistake: Having pride</b></p><p style="text-align: justify;">I diligently prepared a list of literary agents that fit my work (non-fiction, popular science), got their contact info, and noted the package they wished to receive (usually a book proposal or a query, which is a much shorter synopsis of the project). I sent in five tailored packages and waited for a response. And waited. I checked my email and junk mail more often than I care to admit. Nothing.</p><p style="text-align: justify;">I moved on from getting representation and began reaching out directly to publishers. Again, I researched publishing houses with non-fiction pop-sci experience. This time, I had a list of fifteen. I sent out packages in groups of three. I sometimes did get a reply, but it was never the green light I wanted. There were some helpful back and forth exchanges, including brief explanations of why my book was not the <i>right fit</i>. The main issue was that it was too lay to be a textbook, but too technical to be a lay book. Well, that is exactly what I was going for: a book that would be challenging but accessible for a physics novice, and a light, enjoyable read for seasoned physicists. I wrote it because that type of book did not exist, and it was the kind of thing my students needed; but the fact that it did not exist made publishers hesitant to sign a contract with a first-time science author not named Bill Nye.</p><p style="text-align: justify;">With my pride swallowed and humble pie consumed, I remained committed to the project, and to working with a publishing house. This set me up for my biggest mistake.</p><p style="text-align: justify;"><b>My third mistake: Signing on with an unestablished publisher</b></p><p style="text-align: justify;">A colleague told me about her friend who had recently published with a new publishing house who shall go nameless. I sent them a package and received a contract offer shortly thereafter. I examined the contract and sent it to an author friend, who saw no major red flags. I contacted one of the publisher's authors who spoke highly of his experience (his book was in sociology, not a natural science, but still, this gave me confidence to move forward). I signed the contract, and celebrated my victory.</p><p style="text-align: justify;">I completed a bunch of paperwork and tailored my manuscript to the publisher's standards within a month. I recorded a promo video per their request. Then, I waited months with little contact. Eventually, they admitted that they could not find a content editor for science! In the meantime, they decided to copy-edit (format) the book, and worry about finding a content editor afterwards. The formatting process went on for months. The final look of the book was not bad, but getting there required so much input from me (they clearly did not know what they were doing). Months later, they still did not have a content editor for me, and I decided to part ways with them. Both the publisher and I wasted nearly 18 months that felt like 36 in this process that almost caused me to give up on the book entirely.</p><p style="text-align: justify;">The only good thing to come out of all of this is that the publisher's ineptitude forced me to learn a lot about publishing books. This positioned me well to take on my latest (and, knock on wood, final) avenue for publication: KDP (Kindle Direct Publishing), which is run by Amazon. The support at KDL via both online tools and actual humans you can call and who call you back within minutes or hours, was incredible (feedback with publishers happens on timescales of weeks and months). Within weeks, the paperback was completed, and as I write, a proof hardcopy is on its way to my home by way of, well, Amazon.</p><p style="text-align: justify;">I am not saying that all small publishers are bad, or that established ones only deal with established authors. Everyone's publication journey is unique, and not all are fiascos like the one I have detailed here. Still, I hope that some of this information will benefit another budding author on their road to publication.</p><p style="text-align: justify;">My book has been a labor of love along a dirt road littered with shards of broken glass. I hope that many will enjoy it once it becomes available.</p>The Engineerhttp://www.blogger.com/profile/05080325091689417696noreply@blogger.com1tag:blogger.com,1999:blog-8262015410550800861.post-29199763507190611732022-01-07T10:42:00.003-05:002022-01-10T09:05:08.247-05:00David Suzuki's 'The Sacred Balance'<p>Like many, I have seen an uptick in my reading quota over the past couple of years. My diet has included about 25% fiction, 25% biography, and 50% science non-fiction. My favourite fiction was Matt Haig's <i>The Midnight Library</i> and my favourite non-fiction was probably David Suzuki's <i>The Sacred Balance</i>. I had never read any of Suzuki's work, and although this one is more than a decade old, it seemed to be his defining work, so I went with it.</p><p>Suzuki is a prominent figure in Canada; he has been a leader in the sustainability movement for most of my life. While my personal interest is in space exploration, there is no question that sustainability is the most pressing issue of our time.</p><p>The premise of the book is quite simple: while science is a powerful tool and a culmination of our collective creativity and curiosity, it has a tendency to be fragmented, failing to view ecosystems as a whole. The findings of science has led to short-term increases in standard of living, increasing lifespan and comfort, but it has come at a major cost to the prosperity of our species in the long-term. We are simply not thoughtful enough to use science conservatively; our economic system is based on unsustainable growth, and all political systems, thus far, have failed to prioritize the long-term. Science, when perverted by runaway capitalism, is nothing short of a slowly burning fire on the global scale with nothing to put it out. So, you know, this was a fun read in the midst of a global pandemic.</p><p>The thesis of the book is that we will not be able to control our planet with science for the foreseeable future. If we wish to <i>have</i> a foreseeable future, we need to model our behaviour after civilizations that have lived in harmony with the sustaining features of Earth for hundreds of years: namely, indigenous people. This does not mean we must abandon science and technology. It simply means we must refocus it. We must rethink our socio-political and economic systems; they must have sustainability sewed into their fabric. In a finite system, growth is madness. Growth is suicide.</p><p>The first half of the book focuses on the science of our sustaining systems and their interconnections: air, water, soil, solar energy, and biodiversity. It is in this latter chapter that the writing flourishes. A strong case is made that decrease in biodiversity hurts <i>all</i> species in the long run - it is a precursor to mass extinction. Biodiversity becomes a measure of the long-term prosperity of our species, like placing a stethoscope to our existence on this planet.</p><p>The second half of the book is where its strength lies. It talks about love and spirituality, the joys of being alive, the vitality that we are granted once our requirements of air, water, food, and warmth are met. The final chapter is about restoring balance, not with further attempts to engineer our planet, but by allowing the ecosystems of Earth time to fix themselves - by getting out of the way. We will need engineering to allow comfortable lives for our roughly eight billion population. But it must be long-term-focused. It must get out of the way. This final chapter is about how we can get there. It highlights stories of individuals, who become grassroot movements, who have come to effect macroscopic change. Their stories must become a beacon for us. They are truly motivational. This motivation will be crucial in the way forward.</p><p>Last semester, a colleague of mine taught a sustainability course. The experience left him disheartened because the students in the course did not believe humanity had the wherewithal to change. They lacked faith in our species, and who can blame them? In their lifetimes, world leaders have only set us in the wrong course, and these leaders often reflect the wants of the societies they represent. I understand my colleague's sadness. As a teacher, the students' morale is our morale. And frankly, if today's young people have thrown in the towel, we are indeed a lost species.</p><p>One shining light, from my point of view, has been some sweeping change that we have seen over the last couple of years, in our response to a very different existential crisis: COVID-19. Damn it! I almost completed an article without bringing it up! Maybe next time... But seriously, we saw a threat, and pivoted. It was not pretty, and not without hardship, but as a species confronting a dangerous threat, we tried to make changes to adapt to the situation. </p><p>Perhaps you have heard of the frog-in-the-pot analogy... A pandemic, to us, is like a frog that is dropped into a pot of boiling water. We are that frog, still trying to climb out, the hot droplets of water striking our tushies. </p><p>Our present situation, where our finite resources are being exacerbated, represents a different threat. In this one, we are a frog in slightly warm water that is continuously being warmed further. It will eventually boil. In this scenario, a frog would likely meet its demise. It would not instinctively react and jump out of the pot. But we have an advantage over the frog. We have tools, like a thermometer, and we understand the reasons for the warming of the water. We can forecast, with limited but reasonable accuracy, the rate of warming that will occur if conditions go unchanged. Armed with this, we can be smarter than a frog. We can evolve our thinking, act responsibly, and earn the right to wield the powerful tools that science has unleashed.</p><p>It is essential that we react to our biosphere crisis with the same resolve as we did the pandemic. We <i>can</i> do it. At the very least, we <i>can</i> try. But a sweeping response will only happen if a critical mass of people at all levels of society truly understand the severity of the situation. They need to embrace the obvious truth that this threat is every bit as serious as a pandemic. Its solutions are less <i>scientifically</i> complex than engineering a vaccine. We just need to learn to get out of the way. We need to exist within nature rather than attempt to manipulate it. It is less about new science than it is about smart design.</p><p>We all know that science and technology can be abused. We usually focus on the upside: agriculture nourishes the masses, electricity gives us light, warmth and comfort, and modern medicine reduces suffering and extends life. But these are the very things that have allowed our population to balloon. This larger population then demands the same kind of comfort, which means more brut engineering. While this ballooning sounds like the opposite of extinction, it has taken an unprecedented toll on our sustaining systems in the blink of an eye. </p><p>One way or another, this graph will come down. But how will that journey look? Will the descent entail pain and hardship? Will it end at zero? Or will we allow Earth's natural mechanisms the time needed to stabilize itself? Will we be here to see it happen? Will today's children come to know a world whose sacred balance has been restored? Countless humans today have not given up. Please be one of them.</p>The Engineerhttp://www.blogger.com/profile/05080325091689417696noreply@blogger.com0tag:blogger.com,1999:blog-8262015410550800861.post-37963786826331924102021-12-07T15:17:00.002-05:002021-12-13T20:07:04.593-05:00As 2021 Winds Down in My ClassroomAs I rev up for that final push through exam season, I am reflecting on this past semester.<div><br /></div><div>This semester followed more than one year of online learning. I felt relieved to know we were coming back. I could not spend another semester teaching from this chair in my home. The experience is ultimately deflating, because you know how ineffective it is for most students. Online learning was a necessary evil that I hope to never experience again. The one silver lining was observed very clearly yesterday morning as I cleared snow and ice off my car for the drive to the college.</div><div><br /></div><div>This semester saw some very apprehensive students show up at the college. The incoming cohort was generally less prepared than usual for college. The second year science students, having spent their entire college education to that point online, were perhaps even more unprepared. College can feel overwhelming at times, even for students who had adequate high school preparation. This semester saw more students give up than I have ever seen in my 12 years as a teacher.</div><div><br /></div><div>As midterm assessments were returned, some students were crushed, and stopped attending. I felt awful for them. I do not fault them for it. I look at it another way: realizing the adversity that <i>all</i> students have faced over the past couple of years leaves me feeling extra proud of the ones who have stuck around. They are the ones who will be sweating it out in three-hour exams next week. I hope they take pride in showing all they have learned.</div><div><br /></div><div>As for me, I remain committed to what seems like my mission in life: to help people 'get physics'. I look forward to the years ahead spent in the classroom. Career-wise, I am also excited about two things happening outside the classroom.</div><div><br /></div><div>Over the past week, SERG (the Space Elevator Research Group) has reformed. It includes three Vanier College students. Over the coming months, we will be undertaking a new space elevator dynamical study. It will involve the addition of a station at the geosynchronous altitude. I am excited for that to get underway. More updates to come on this project in 2022.</div><div><br /></div><div>And then, there is my book, <i>Getting Physics</i>. The publication process has been, well, lengthy, thus far. I was hoping it would be published by end of 2021. At this point, I will settle for <i>sometime</i> in 2022. I appreciate all of the words of encouragement I have received via email and LinkedIn. I am so excited to get this book into the hands of readers in the near future.</div><div><br /></div><div>After years of teaching, it has become evident to me that you do not need to be a physicist to <i>get physics</i>. Physicists will dive deeper than the rest of us, but there is much depth to physics even at the surface. The fundamentals of physics are accessible to nearly anyone who wants to know them. Ask my students this semester, who can describe all kinds of phenomena, from a car crash to a vibrating guitar string. They are only beginning their journey into the sciences. They are not experts yet, but the seeds have been planted.</div><div><br /></div><div>I want to wish you all a wonderful holiday season and much happiness in 2022.</div>The Engineerhttp://www.blogger.com/profile/05080325091689417696noreply@blogger.com0tag:blogger.com,1999:blog-8262015410550800861.post-70872636212664386422021-11-01T17:37:00.000-04:002021-11-01T17:37:13.556-04:00Disrupting Earth's Orbital Mechanics<p>After today's physics class, which involved orbital mechanics, I began thinking about ways in which humans could affect the Earth's spin rate or its path around the Sun.</p><p><b>Jumping all at once:</b></p><p>If all humans congregated at one place on Earth (7+ billion people in one city, while maintaining social distancing, of course), and then jumped simultaneously, there would be some repercussions. The energy of all that mass shifting in a short time could lead to an Earthquake, for example. But, that is not the sort of effect I am interested in.</p><p>Would Earth's path around the Sun be affected? The answer is, surprisingly, not in the slightest. The problem is that we would eventually land back where we started. The net mass of the system consisting of Earth and us will not have changed. As we are part of the total system that is in orbit, the forces exchanged during both the jump and landing would be internal to that system. It is not possible to change the system's velocity without a force exchange with something<i> external</i> to the system. For example, an asteroid collision could have some small effect on the Earth's orbit.</p><p><b>Running all at once:</b></p><p>OK. So, jumping failed. Maybe by running, we can impact the planet's spin rate. Imagine that we (the human population) were to gather somewhere on the equator, like Singapore. We collectively decide that we wish to change the length of a day on this planet. We decide to run along the direction of the Earth's spin with the expectation that it might slow the rotation down (there are not enough hours in a day, they say).</p><p>With our first step, we propel ourselves forward (the Earth pushes us in the direction we move via static friction), so we impart an equal static friction onto the surface of Earth in the opposite direction. However, every subsequent time that our foot strikes the ground, it slows us down before speeding us up again. In fact, if we maintain our jogging speed, each step results in a net linear impulse of zero (on us and the Earth), which means that each step has zero net effect on the angular momentum of either.</p><p>It seems we suffer from the same problem as we did while jumping. Our initial acceleration from rest gives a tiny net angular impulse to Earth, but it will undo itself when we decelerate, just as our jump was only temporary in the previous scenario.</p><p>The only way to accomplish either of the intended effects (disrupt orbital path or spin rate) is to do something more permanent, like sending payloads to space. These do indeed impart small net impulses onto the Earth. I could calculate their magnitudes, but I don't feel like it.</p><p><b>Blowing up the planet:</b></p><p>Frustrated with our wasted efforts, we decide to blow the planet up from the inside. It splits into two halves. Each hemisphere will orbit the Sun, but the precise orbit of each half will depend on the direction in which the planet splits apart. Regardless, the Earth gets the last laugh... The center of mass consisting of each of the hemispheres will remain in the original orbit, because again, the explosion is ultimately an exchange of forces that are internal to the system.</p>The Engineerhttp://www.blogger.com/profile/05080325091689417696noreply@blogger.com0tag:blogger.com,1999:blog-8262015410550800861.post-46546555402069025022021-07-05T12:50:00.011-04:002021-08-18T13:22:53.881-04:00A Goldilocks Universe<p>Anyone with experience in astronomy has encountered the term 'Goldilocks planet'. It pertains to a planet that is not too near a star, nor too far, such that it may have liquid water on the surface. Many scientists believe that this is a necessary pre-cursor for life. Earth is the only Goldilocks planet in our solar system, but exoplanet searches have identified others across this galaxy.</p><p>This morning I was thinking about the Universe, and noting that there could be no Goldilocks planets without, what we might call 'Goldilocks stars'. I would define a Goldilocks star as one that has a main sequence that endures for billions of years at the least. There are countless such stars in our galaxy.</p><p>Why are billions of years of stable star output important? It is because such is the timeframe that it takes for the development of life (itself an unlikely event) on a planet (which itself may take hundreds of millions of years to develop into a potential host for life).</p><p>A star's main sequence describes its stable state where the gravity that holds it together is in balance with the internal pressure that pushes it outward. It is achieved during the period of time when the core of the star is largely a mass of protons zooming about (these protons are denoted as H-1, as they are hydrogen isotopes that lack a neutron, known as 'protium' as they are effectively just protons). Energy is created via nuclear fusion when these protons collide and enter into what is known as the unfortunately named 'p-p cycle'.</p><p>A complete p-p cycle is a complex series of nuclear fusion reactions that eventually convert six protons into two protons and one Helium atom. Each link in the fusion chain spits out other matter including positrons, neutrinos, and gamma particles. Most importantly, the fusion reaction releases thermal energy because the nuclear by-products have less mass than the nuclear fuel - the fusion process produces energy <i>E</i> in the amount of <i>dm</i> multiplied by the speed of light squared (Einstein's uber famous equation) where <i>dm</i> is the quantity of annihilated mass.</p><p>The big picture is far less complex than the details: hydrogen fuel converts to helium and releases energy at a specified rate until it runs out. The amount of time that this dance will play out for is determined by just one thing: the star's mass.</p><p>Red Dwarfs are small stars and are the most common; they can burn for trillions of years. Yellow Dwarfs (like the Sun) are medium-sized and less common but not uncommon; these burn for billions of years. Supergiants are far more massive than the Sun and are far less common; these burn for just millions of years before they exhaust their fuel supply.</p><p>Given the brief period of time (in cosmological terms) that Supergiants undergo their main sequence, it is unlikely that its planets can ever harbor life. We can deem these stars <i>too big</i>. We do not yet know whether Red Dwarfs can sustain life on the planets that orbit them. These stars might be <i>too small</i>. We do know for certain that planets orbiting Yellow Dwarfs can harbor life (we know of one clear example of this). These stars, it seems, are <i>just right: </i>Goldilocks stars.</p><p>But it all comes back to that p-p cycle. The rate at which our Sun burns through its fuel depends upon the probability that a p-p cycle can be completed. Smashing two protons (H-1) together does not guarantee that a deuteron (H-2) will be synthesized (step one in the p-p cycle)... Far from it! It is actually <i>extremely</i> unlikely. The probability that it will occur is on the order of 1 in 10 to the power of 26! The reason that the Sun produces energy at such a high rate is that despite the low fusion rate, there are some 10 to the power of 57 protons zooming about.</p><p>It is the 1 in 10 to the 26 rate that confounds me. I mean, like, why that rate? Each proton-proton collision is a quantum event. The particular fusion rate seems so random, arbitrary even. But it is ultimately critical to our existence. If this rate were, say, ten times higher than it is, our Sun would have burned out long before life emerged on this planet.</p><p>Physics reveals many instances where the conditions of the Universe, its matter and the laws that govern how it interacts, seem to be <i>just right</i>. If the strong nuclear force that binds the nucleus of an atom were slightly weaker, the electrostatic repulsion of protons would exceed it and prevent the existence of any atom not called Hydrogen. No atomic variety means no life, just as no long-burning stars means no life.</p><p>One can imagine a universe not so perfectly tuned; a universe where life is impossible instead of improbable. We may live on a Goldilocks planet that orbits a Goldilocks star, but if we widen our gaze, we see that we reside in a Goldilocks universe. Not that it matters, but it is a funny coincidence that like Goldilocks herself, I ate porridge for breakfast today. I mixed it with leftover brownies. It became<i> just right</i>. </p>The Engineerhttp://www.blogger.com/profile/05080325091689417696noreply@blogger.com2tag:blogger.com,1999:blog-8262015410550800861.post-71478267330232139762021-06-19T09:01:00.003-04:002021-06-19T14:19:00.452-04:00AATIP Reveals Compelling Videos of UFOs<p>Some weeks ago, as my class was discovering notions of relativity, a student asked what I thought of the bizarre videos that were making its rounds on the internet - they reveal what appears to be some kind of unusual aerial vehicle. I watched these black and white videos with curiosity. In the background, you can hear some excited voices expressing genuine confusion about what they are witnessing. With final exams looming and little free time, I did not pursue this rabbit hole any further. Then weeks later, a friend we'll call 'Phil', asked what I thought about the UFOs.</p><p>Tom is a staunch believer in the scientific method and a skeptic when it comes to conspiracies and the like. But he found these videos to be very compelling. He informed me about Luis Elizondo and the Advanced Aerospace Threat Identification Program (AATIP) and suggested I watch his recent interviews. I did. I also came across a clip of Barack Obama giving credence to the notion that the highest levels of American intelligence have come across aerial vehicles whose origins confound them. It appears that AATIP is indeed a genuine Pentagon program and they <i>will</i> issue an official response to the aforementioned videos.</p><p>I impressed upon Phil that I am typically not drawn into stories of this nature due to the extreme unlikelihood of alien visitation. However, if these videos were real artifacts, free of manipulations, they reveal technology that is far beyond current human capability. The aerial vehicle in the videos:</p><p>1. Has no visible means of propulsion and whatever <i>does</i> propel it shows no sign of interacting with the environment.</p><p>2. Transfers from air to water without disturbing the water.</p><p>3. Banks extremely sharp turns at impossibly high speeds.</p><p>Let us, for instance, analyze point 3. The vehicle is tracked at speeds in excess of Mach 5 (five times the speed of sound in air, so about 1,650 m/s). In order to not experience violent accelerations in excess of 5g (about 50 m/s/s), the minimum radius that its circular path would require is 36 km! Points 1 and 2 are even more bewildering.</p><p>If these videos are authentic, how did the vehicles get here undetected by our radio astronomers? Elizondo theorizes they emerged from the deep ocean. Phil asked me where we should purchase our aluminum hats.</p><p>Passing on the hats for the moment, I went to the library later that day, and returned home with <i>They Are Already Here: UFO Culture and Why we See Saucers</i>, by Sarah Scoles. The book is a historical account of the human obsession with UFOs and the possibility of alien intelligence, from Roswell and Area 51 to AATIP. The title to the book is misleading: the author confides on the last pages that she remains unconvinced that any interplanetary intelligence has ever visited Earth, and that the plethora of reported human encounters with aliens are either honest mistakes or fabrications.</p><p>I am interested in honest mistakes, as they force us to apply the scientific method within this thought-provoking context. These range from explainable celestial events, to high-tech military operations, and a wide range of optical illusions. I also understand and do not fault claims of UFOs that are entirely psychological, whether they be drug-induced or convincing dreams. </p><p>On the other hand, fabrications offend me. They are an affront to my senses. They degrade the entire process of discovery. Muddying the evidence, manipulating the data, unfalsifiable claims masked as truths... These acts of dishonesty, whatever their motivation, highlight the fly in the ointment, which is human corruption. Such acts of deceit serve only to spoil the earnest endeavor of identifying UFOs. One key take-away from Scoles' book is that distinguishing genuine science from hoaxes is half the battle in the search for alien intelligence.</p><p>When it comes to the matter of extra-terrestrials, we must be extra skeptical of information emanating from sources who have a vested interest in making the first human contact with them. One such player is Robert Bigelow, a wealthy American who has initiated numerous 'scientific teams' whose primary outputs have been UFO fabrications. When I discovered that Bigelow has a connection to AATIP, I began to doubt the authenticity of the internet videos.</p><p>It is improbable that we have been or will ever be visited by interplanetary beings during our species' tenure on this pale blue dot. The chances that intelligent life exists in our neighborhood of this galaxy during the small window of time comprising human existence are very low. But not zero. And that is what distinguishes the topic of aliens from other human obsessions, like paranormal activity. The former is entirely conceivable according to our current understanding of nature. </p><p>Evidence that confirms the existence of aliens would cause a dramatic shift in our understanding of the universe and our place in it. That is why this conversation is so alluring.</p><p>I await the Pentagon's response to the videos that have captured the attention of so many. If their assessment does not support the alien intelligence theory (and I highly doubt that it will), conspiracy-theorists will be unmoved. Government history <i>does</i> include cover-ups, which merely confirms the general prevalence of human weakness. This history of dishonesty injects doubt into the UFO conversation. </p><p>I will not be buying an Aluminum hat just yet.</p>The Engineerhttp://www.blogger.com/profile/05080325091689417696noreply@blogger.com0tag:blogger.com,1999:blog-8262015410550800861.post-59196894421450991452021-06-08T09:16:00.006-04:002021-06-10T11:51:47.509-04:00Enforced Rotation of Tarzan Rope (Solution)<p>The semester has ended, and alas, nobody posted a solution to the difficult problem I posed months ago (see problem <a href="https://theengineerspulse.blogspot.com/2021/01/enforced-rotation-of-tarzan-rope-problem.html">here</a>). In short, we have a rope that is suspended from the top and is being moved along a circular path in the horizontal plane with constant angular velocity. Aerodynamic effects shall be neglected. We are seeking a lateral deflection function. Here is my solution...</p><p>With a problem such as this, we must begin with a physical model. My hand drawing is seen below (I apologize for the crude sketch, but the summer me exerts less effort):</p><p></p><div class="separator" style="clear: both; text-align: center;"><div class="separator" style="clear: both; text-align: center;"><a href="https://lh3.googleusercontent.com/-IOSyflP2F9M/YL9i8IMp8_I/AAAAAAAAFmk/TLm99UCzWf8OpjiqkYd0XpVnGToJ4FFSACLcBGAsYHQ/image.png" style="margin-left: 1em; margin-right: 1em;"><img alt="" data-original-height="491" data-original-width="852" height="184" src="https://lh3.googleusercontent.com/-IOSyflP2F9M/YL9i8IMp8_I/AAAAAAAAFmk/TLm99UCzWf8OpjiqkYd0XpVnGToJ4FFSACLcBGAsYHQ/image.png" width="320" /></a></div></div><br />The solid blue line represents the rope whose profile we aim to determine. At some location (<i>x</i>, <i>y</i>), we will apply Newton's second law to a single mass element d<i>m</i>. My free body diagram is on the right side. There are two external forces acting on the element; one is real and the other, a pseudo-force. The real force, d<i>Fg</i>, is gravitational, while the centrifugal load, d<i>Fc</i>, is a pseudo-force as it is effectively an inertial term. Finally, tension acts internally, pulling this element in both directions tangent to the rope's profile at (<i>x</i>, <i>y</i>). The upward pointing tension is (correctly) assumed slightly higher than the downward one, by some amount d<i>T</i>. One useful, though limiting facet of the assumed model, is that, at a given vertical location <i>x</i>, each element simply displaces horizontally - in reality, it also shifts up vertically, ever so slightly. This simplification allows an elegant solution, but whose accuracy is limited as we shall see.<p></p><p>Applying Newton's second law to that element on both axes, we get:</p><p>d<i>Fc</i> = d<i>T</i>sin<i>θ </i><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><i> <span> </span></i>(1)</p><p>d<i>Fg</i> = d<i>T</i>cos<i>θ</i><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> <span> <span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span></span></span>(2)</p><p>We can express the elemental forces as:</p><p class="MsoNormal"><span lang="FR-CA">d<i>Fc = </i>d<i>m(</i></span><i>ω</i><i><sup><span lang="FR-CA">2</span></sup></i><i><span lang="FR-CA">y)</span></i><i><span lang="FR-CA"><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> <span> </span><span> </span><span> </span><span> </span><span> </span><span> </span></span></span></i>(3)</p><p>
</p><p class="MsoNormal"><span lang="FR-CA">d<i>Fg = </i>d<i>m(</i></span><i>g)</i><i><span lang="FR-CA"><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><o:p></o:p></span></i><i> <span> <span> </span><span> </span><span> </span><span> </span> <span> </span></span></i>(4)</p><p class="MsoNormal">The angular velocity of the enforced circular motion is denoted by <i>ω. </i>If we divide equation 1 by equation 2 and then divide equation 3 by equation 4, we get the relationship</p><p class="MsoNormal">tan<i>θ = </i><i>ω</i><i><sup><span lang="FR-CA">2</span></sup></i><span lang="FR-CA"><i>y/g</i><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><i> </i>(5)</span></p><p class="MsoNormal"><span lang="FR-CA">The key realization to move forward is that the derivative d<i>y</i>/d<i>x</i> = tan</span><i>θ. </i>This yields the governing equation:</p><p class="MsoNormal">d<i>y</i>/d<i>x = </i><i>ω</i><i><sup><span lang="FR-CA">2</span></sup></i><span lang="FR-CA"><i>y/g<span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span></i></span>(6)</p><p class="MsoNormal"><i><o:p></o:p></i></p><p>The particular solution to equation 6, after having applied the boundary condition <i>y</i>(0) = <i><span lang="FR-CA">R<sub>0</sub></span></i>, the radius of the enforced circular path, is given by:</p><p></p><p class="MsoNormal"><i><span lang="FR-CA" style="mso-ansi-language: FR-CA;">y(x) = R<sub>0</sub></span></i><span lang="FR-CA" style="mso-ansi-language: FR-CA;">exp</span><i><span style="mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;">(xω</span></i><i><sup><span lang="FR-CA" style="mso-ansi-language: FR-CA; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;">2</span></sup></i><span lang="FR-CA"><i>/g)</i><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><span style="font-style: italic;"> </span><i> </i>(7)</span></p><p class="MsoNormal"><span lang="FR-CA">This solution is quite interesting. We first notice that the density and area of cross-section of the rope have no effect on the shape it takes. This is not surprising because both external forces were proportional to the elemental mass. The more important takeaway here is that the lateral deflection becomes exponential. The faster we spin the top of the rope, the more dramatic the curve. This makes sense, but there is a serious flaw: the rope has a finite length. As this function is exponential, there is no limit to the lateral deflection it describes. As the imposed angular velocity increases, the lateral deflection can quickly become greater than the total length of the rope, which is physically impossible. </span></p><p class="MsoNormal"><span lang="FR-CA">I suspect that I ran into this problem because, in my original model, I neglected the gain in altitude that a particle driven laterally inevitably experiences. For fun, I included this effect in a subsequent attempt. After a page of work, I saw that numerical tools would be required to solve. Again, it's summer, and I am content to move on and not pursue this problem further, especially when a closed solution appears impossible. </span></p><p class="MsoNormal"><span lang="FR-CA">Equation 7 may be a good approximation of the rope's profile for fairly slow rotation rates. An experiment is difficult to conduct for multiple reasons. While air effects lead to a three dimensional profile, so to would inertial effects when it comes to establishing planar motion. In principle, it may be possible to enforce the theoretical equilibrium configuration as well as a uniform angular velocity for all string elements, but it is not practical. Failure to do this would inevitably lead to a helical 3D profile.</span></p><p class="MsoNormal"><span lang="FR-CA">You may be thinking I did all that work for nothing. It is important to realize that simplified approaches teach us a lot about complex problems. They give confidence to the more strenuous, complex solutions that follow them.</span></p><p class="MsoNormal"><span lang="FR-CA">And now, out of my cave. Summer beckons.</span></p><p></p>The Engineerhttp://www.blogger.com/profile/05080325091689417696noreply@blogger.com0tag:blogger.com,1999:blog-8262015410550800861.post-10490928807295338732021-01-24T18:09:00.002-05:002021-01-24T18:09:32.719-05:00Enforced Rotation of Tarzan Rope (Problem)<p>I had so much fun with the <a href="https://theengineerspulse.blogspot.com/2020/12/a-tarzan-rope-in-wind-problem.html">rope problem</a> I posted to start off 2021 (which was subsequently solved by Anthony Attia - see his <a href="https://theengineerspulse.blogspot.com/2021/01/a-tarzan-rope-in-wind-solution.html">elegant solution</a> here), that I want to continue to explore this theme. While that problem seemed tough (seeking the steady state profile of a uniform rope pinned at its top end and suspended vertically in a uniform horizontal wind), it turned out to be fairly simple. It was almost disappointing. To remedy the situation, consider an even more intriguing problem...</p><p>Imagine a Tarzan rope (bulk density 'p') that you suspend vertically in uniform surface gravity 'g'. You then take the top end of the rope with length 'L' and move it with uniform circular motion in the horizontal plane (radius 'R' and angular frequency 'w'). Ignoring aerodynamic effects (because that would cause a 3D problem and have no clean analytical solution), what profile will the rope assume? That is, if we froze the video at any given instant, what lateral deflection function, y(x), describes the rope's shape? Treat the rope like a string (cannot support shear loads).</p><p>I spent some time on the problem, and it turns out to be even more interesting that I expected. I will not give any hints this time. I am curious to see if anyone will post a solution. If you do, please provide a description of how you did it.</p><p>I am excited to share my solution, but I will be patient, and see what, if anything, gets submitted here.</p>The Engineerhttp://www.blogger.com/profile/05080325091689417696noreply@blogger.com0tag:blogger.com,1999:blog-8262015410550800861.post-41219104270484603632021-01-23T11:50:00.004-05:002021-11-15T12:09:29.313-05:00A Tarzan Rope in the Wind (Solution)<p>This is very exciting: a former student of mine, Anthony Attia, has submitted a solution to the <a href="https://theengineerspulse.blogspot.com/2020/12/a-tarzan-rope-in-wind-problem.html">Tarzan rope problem</a> I posted some weeks ago. Anthony was in my Mechanics class at Vanier College in 2016. He is now pursuing undergraduate studies in mechanical engineering and simultaneously doing a stage at my former employer, MDA Space.</p><p>As is the case with some students, Anthony and I have stayed in touch since he graduated from college. This post, however, is the <i>first</i> one in more than ten years of this blog's existence that someone other than me has written; it is about time. Watch as Anthony analyzes a uniform rope, pinned at the top and vertically suspended, subjected to a horizontal uniform wind.</p><p>The following text appears here with Anthony Attia's consent:</p><p>___________________________________________________________________________________</p><p></p><p class="MsoNormal" style="text-align: justify;"><a name="_Hlk62160809"></a>When
faced with a complex physical phenomenon, it is quite common to simplify the
problem to a point where an analytical solution can be formulated. The
simplification is done by stating assumptions throughout the approach. The more
assumptions we take, the more likely our approximated answer will diverge from
the true value. As students of science, it is our duty to ensure that we are
equipped with enough knowledge to apply the proper assumptions.<o:p></o:p></p>
<p class="MsoNormal" style="text-align: justify;">Tarzan’s rope problem can be as complex as we
want it to be. We can treat the rope as either flexible or rigid, we can treat
the wind force as a function of time or a constant, we can consider the effects
of cold temperature on the characteristic properties of air or we can neglect
them. For the sake of maintaining my sanity and that of the reader’s, we shall
treat the rope as a pinned rigid body who is subjected to a constant drag force
that is acting in the horizontal direction. An important fact about assumptions
is that there cannot be an incorrect one per say, however, every single one of
them must be justified. <o:p></o:p></p><p class="MsoNormal" style="text-align: justify;">In my preliminary analysis, I will assume the rope to be rigid, effectively assuming that the profile of the rope will be linear when displaced. Generally, this assumption would not be valid with a rope, but I will make it anyway and check the extent to which it was good later.</p>
<p class="MsoNormal" style="text-align: justify;">With that in mind, we can begin
trying to find the velocity of the wind, by relating the drag force <i>F<span style="font-size: x-small;">D</span></i> and the weight <i>W</i><span style="mso-fareast-font-family: "Times New Roman"; mso-fareast-theme-font: minor-fareast;">. Consider the model below, which depicts the scenario:</span></p><p class="MsoNormal" style="text-align: justify;"></p><div class="separator" style="clear: both; text-align: center;"><a href="https://lh3.googleusercontent.com/-vrFmk8JiAC8/YAxF7btTVTI/AAAAAAAAFJE/GW1KC3v3Kus4vvTHXdvF3X4sRDG8QfIQwCLcBGAsYHQ/image.png" style="margin-left: 1em; margin-right: 1em;"><img alt="" data-original-height="285" data-original-width="239" height="240" src="https://lh3.googleusercontent.com/-vrFmk8JiAC8/YAxF7btTVTI/AAAAAAAAFJE/GW1KC3v3Kus4vvTHXdvF3X4sRDG8QfIQwCLcBGAsYHQ/image.png" width="201" /></a></div><span style="mso-fareast-font-family: "Times New Roman"; mso-fareast-theme-font: minor-fareast;">Given that the net
drag force is acting on the center of gravity in the horizontal direction and
the weight is acting in the vertical direction, the ratio of these forces, </span><i style="text-align: justify;">F<span style="font-size: x-small;">D</span>/W</i><span style="mso-fareast-font-family: "Times New Roman"; mso-fareast-theme-font: minor-fareast;">, ends up being equal to tan(</span><i style="text-align: justify;">θ).</i><span style="text-align: justify;"> We can take</span> the sum of all torques about the
pin and put them equal to zero. Then, using the following <span style="font-family: inherit;">definitions, we may express the wind speed as a function of the other parameters.</span><div><span style="background-color: white;"><span style="font-family: inherit;"><br /></span></span></div><div><span style="background-color: white;"><span style="font-family: inherit;">Surface gravity: <i>g</i></span></span></div><div><span style="background-color: white; font-family: inherit;">Air density: <i>p</i></span></div><div><span style="background-color: white; font-family: inherit;">Wind speed: V</span></div><div><span style="background-color: white; font-family: inherit;">Rope angle: </span><i style="text-align: justify;">θ</i></div><div><span style="background-color: white; font-family: inherit;">Rope mass: <i>m</i></span></div><div><span style="background-color: white; font-family: inherit;">Rope diameter: <i>d</i></span></div><div><span style="background-color: white; font-family: inherit;">Rope length: <i>L</i></span></div><div><span style="background-color: white; font-family: inherit;">Rope shape (cylinder) coefficient of drag: <i>C<span style="font-size: x-small;">d</span></i></span></div><div><p></p>
<p class="MsoNormal" style="text-align: justify;"><span style="mso-fareast-font-family: "Times New Roman"; mso-fareast-theme-font: minor-fareast;">The wind speed is then given by: </span></p><p class="MsoNormal" style="text-align: justify;"></p><div class="separator" style="clear: both; text-align: center;"><a href="https://lh3.googleusercontent.com/-3Lnhy8cvzuU/YAxL8BqeuMI/AAAAAAAAFJg/zNYbG2OTfMUg08O6DrOLcP1vFVNATyisACLcBGAsYHQ/image.png" style="margin-left: 1em; margin-right: 1em;"><img alt="" data-original-height="49" data-original-width="164" height="63" src="https://lh3.googleusercontent.com/-3Lnhy8cvzuU/YAxL8BqeuMI/AAAAAAAAFJg/zNYbG2OTfMUg08O6DrOLcP1vFVNATyisACLcBGAsYHQ/w209-h63/image.png" width="209" /></a></div><br /><span style="mso-fareast-font-family: "Times New Roman"; mso-fareast-theme-font: minor-fareast;"><div class="separator" style="clear: both; text-align: left;"><span style="text-align: justify;">Knowing this, we may begin computations to determine the wind speed that causes a specific rope deflection. Assuming some reasonable 'Tarzan rope' values, it takes a 15 m/s wind to rotate the rope by 30</span><span style="text-align: justify;">°. This seems reasonable. But, we can only feel so much confidence in this result, as it is based on an assumption that may not be justifiable.</span></div></span><p></p>
<p class="MsoNormal" style="text-align: justify;">Say, however, that
we now want to treat the rope as a flexible body; how would we proceed? Before
answering that question, we must properly understand the behavior of weight and
drag. In the previous figure, the drag force was lumped into a single vector whose
line of action passes through the center of mass of the rope. <span style="mso-spacerun: yes;"> </span>Let us do a quick thought experiment: if we
were walking headwind, would our entire body feel pushed by the drag force or
just a single point? The answer is the former. So, why did we draw a single
vector? That vector is actually the resultant or net drag force acting on the
rope. If we were to properly illustrate the aerodynamic force that the body is
subjected to, we would have to draw many smaller vectors that are acting on the
entire exposed surface. These types of forces are called distributed load: though they act on every point of the body, we may sometimes use a single vector to
represent the resulting effect (note that gravity is similarly distributed and then a resultant is used). Every segment of the rope has a mass equal to <i>dm</i> and the sum of all segment masses will yield
the total mass <i>m</i><span style="mso-fareast-font-family: "Times New Roman"; mso-fareast-theme-font: minor-fareast;">. Now, to solve the
flexible body problem, we must assess a differential segment </span><i>dm</i> that is exposed to a differential drag of <i>dF<span style="font-size: x-small;">d</span></i> by drawing its free body diagram.</p><div class="separator" style="clear: both; text-align: center;"><a href="https://lh3.googleusercontent.com/-H6i0TWZ71V0/YAxHXg6C5vI/AAAAAAAAFJQ/b9N_6FUv0WsNK-6ceJ6wTiVINIo03m0OwCLcBGAsYHQ/image.png" style="margin-left: 1em; margin-right: 1em;"><img alt="" data-original-height="281" data-original-width="324" height="240" src="https://lh3.googleusercontent.com/-H6i0TWZ71V0/YAxHXg6C5vI/AAAAAAAAFJQ/b9N_6FUv0WsNK-6ceJ6wTiVINIo03m0OwCLcBGAsYHQ/image.png" width="277" /></a></div><p></p>
<p class="MsoNormal" style="text-align: justify;">Newton’s second law in x and in y
yields:</p><p class="MsoNormal" style="text-align: justify;"></p><div class="separator" style="clear: both; text-align: center;"><a href="https://lh3.googleusercontent.com/-5zXNe8yKnD4/YAxOZaXv34I/AAAAAAAAFJw/594sqOTMVxY19ODQrnIz6WWxhTdgvdA_QCLcBGAsYHQ/image.png" style="margin-left: 1em; margin-right: 1em;"><img alt="" data-original-height="91" data-original-width="356" height="76" src="https://lh3.googleusercontent.com/-5zXNe8yKnD4/YAxOZaXv34I/AAAAAAAAFJw/594sqOTMVxY19ODQrnIz6WWxhTdgvdA_QCLcBGAsYHQ/w299-h76/image.png" width="299" /></a></div><p></p>
<p class="MsoNormal"><span style="mso-fareast-font-family: "Times New Roman"; mso-fareast-theme-font: minor-fareast;">These equations simplify to:</span></p><p class="MsoNormal"><span style="mso-fareast-font-family: "Times New Roman"; mso-fareast-theme-font: minor-fareast;"></span></p><div class="separator" style="clear: both; text-align: center;"><div class="separator" style="clear: both; text-align: center;"><a href="https://lh3.googleusercontent.com/-7liZrLT51kg/YAxUPTLO9LI/AAAAAAAAFKI/ez1hMeW-AHk9Wvz9UFgpDA__-hIq1nrdgCLcBGAsYHQ/image.png" style="margin-left: 1em; margin-right: 1em;"><img alt="" data-original-height="94" data-original-width="116" height="94" src="https://lh3.googleusercontent.com/-7liZrLT51kg/YAxUPTLO9LI/AAAAAAAAFKI/ez1hMeW-AHk9Wvz9UFgpDA__-hIq1nrdgCLcBGAsYHQ/w117-h94/image.png" width="117" /></a></div></div><p></p>
<p class="MsoNormal"><span style="mso-fareast-font-family: "Times New Roman"; mso-fareast-theme-font: minor-fareast;">Equalizing the two equation we get:<o:p></o:p></span></p>
<p class="MsoNormal" style="text-align: center;"></p><div class="separator" style="clear: both; text-align: center;"><a href="https://lh3.googleusercontent.com/-_t1pSbbgDiQ/YAxO4oCIJKI/AAAAAAAAFJ8/7jOS-ETbhWIZuWDkP_jdWpC0zgamfRN5ACLcBGAsYHQ/image.png" style="margin-left: 1em; margin-right: 1em;"><img alt="" data-original-height="28" data-original-width="135" height="28" src="https://lh3.googleusercontent.com/-_t1pSbbgDiQ/YAxO4oCIJKI/AAAAAAAAFJ8/7jOS-ETbhWIZuWDkP_jdWpC0zgamfRN5ACLcBGAsYHQ/w138-h28/image.png" width="138" /></a></div><span style="text-align: left;"><div><span style="text-align: left;"><br /></span></div>It is evident that the equation obtained
for the flexible body problem is the same as the rigid body problem, however,
it is in a differential form. To remove the differentials, we must apply an
integrating operator to the equation. If we do so, the same expression linking the angle to the wind speed is obtained.</span></div><div><br /></div><div>We conclude that both approaches lead to
the same answer, but one requires an understanding of calculus, whilst the
other requires only an understanding of mechanics. As one of my professors used
to say, the simplest solution is often the best solution!</div><div><span style="text-align: left;"><br /></span></div><div><span style="text-align: left;">___________________________________________________________________________________</span></div><div><span style="text-align: left;"><br /></span></div><div><span style="text-align: left;">It gives me much pride to see a former student of mine express himself as he does here. I get the same result on my end as that which he found. The reason that the rigid body assumption works is because, due to the symmetry of the scenario, the uniformity of the fields and rope, the rope's profile must be linear.</span></div><div><span style="text-align: left;"><br /></span></div><div><span style="text-align: left;">In this problem, we have the weight force and the drag force. They act vertically, and horizontally, respectively, onto each element. While weight acts on dm elements, and drag acts on dA elements, both are uniform: we may think of each as a uniform field. Effectively, they combine to form a uniform net field, and the rope simply aligns itself with it. Though I initially thought the rope would have some curvature, it does not. I am almost disappointed that the result is so simple. I will try to pose a problem that has a stranger result in my next post.</span></div><div><span style="text-align: left;"><br /></span></div><div><span style="text-align: left;">Still, what I really want to emphasize here, is something greater than the problem itself. I am thrilled that <i>The Engineer's Pulse</i> just had its first guest writer; he happens to be a fine engineer in the making.<br /></span><br /><p></p></div>The Engineerhttp://www.blogger.com/profile/05080325091689417696noreply@blogger.com0tag:blogger.com,1999:blog-8262015410550800861.post-12198387172933836032020-12-26T11:30:00.006-05:002020-12-26T17:28:19.561-05:00A Tarzan Rope in the Wind (Problem)<p>With all of my grades entered, my mind can turn off for two weeks. In my case, that means exploring my curiosity. Today, that resulted in a fascinating mechanics problem.</p><p>My kids have a Tarzan rope in the backyard - a rope suspended vertically and hanging freely. I noticed this morning that it had been displaced significantly by the wind: it was now draped over a swing that hangs nearby. "That must have been <i>some</i> wind," I thought. Rope has a small ratio of surface area to mass, which means it should not be overly affected by aerodynamic drag forces. With some physics, I should be able to estimate the minimum speed of last night's wind.</p><p>To make the exercise worthwhile, I have no intention of simply solving a numerical problem: <i>boring</i>. Instead, I will solve a generalized problem before specifying any parameters. Before doing so, I will make some assumptions that will hopefully render the problem to one that can be solved without numerical software.</p><p>I will assume that the wind is lateral and constant. This may lead to an overestimate of the wind, because it is possible that some sort of driving frequency was present in the wind, causing the fundamental mode of the rope to resonate somewhat. Still, it is probably a fair assumption. Also, the fact that the wind force is not time variant will reduce the governing dynamics from what could have been a partial differential equation to an ordinary one. This is because the lateral displacement of the rope (y) varies along the vertical rope's length (x). A time-varying displacement would make the solution vary according to y(x,t), a multivariable function. Now, I can begin my search for the single variable function, y(x). I will also assume what appears to be true: the rope is uniform in terms of its properties and cross-sectional geometry across its whole length.</p><p>At this point I could probably Google "steady-state lateral deformation of a vertically suspended uniform rope exposed to a uniform and constant lateral wind", but I strongly doubt anything useful will turn up. So, because I can (I hope) solve this problem, I am diving into it head first.</p><p>Yup, it's boxing day, but instead of looking for deals on stuff, I am entertaining myself for free as my wife shakes her head (well, she doesn't, but that is only because she thinks I am up to something more important).</p><p>Before beginning this analysis, I must determine what approach to take. It is clear that with a constant wind speed at all locations of the rope at all times, the rope will reach a steady state y(x). So, I am in search of an equilibrium position. This simplifies things considerably from a typical first principles analysis. Rather than applying Newton's second law for all of the infinitesimally small segments of rope, dx, I can do this using the first law. That is because acceleration has been removed from the scenario.</p><p>I could do a quick first pass using an assumed modes shortcut. If I assume that the shape of the rope will follow a specific y(x), I could quickly establish a single algebraic equation in which wind speed is the only unknown. Here, I would effectively be starting with an assumed solution, but if my guessed shape happens to be good, the answer it gives could be surprisingly accurate. It is a good moment to pause and ask ourselves the following question: If we were forced to assume the shape that a constant wind would impose upon the freely suspended rope, what mathematical function might it follow?</p><p>Four possibilities immediately come to mind:</p><p>(1) Linear</p><p>(2) 1/4 sine wave</p><p>(3) Some sort of polynomial </p><p>(4) Some sort of exponential</p><p>I will not reveal here which of the above options my intuition leans towards. I will leave that as a fun mental exercise for the reader. I will dissect each of the above options in my solutions post.</p><p>Alternatively, I could use a more generalized approach - one that requires no shape assumption. The downside here would be that an ordinary differential equation would require solving. It would probably be solvable analytically, without the use of numerical tools. The type of y(x) function that would result would either confirm or negate the choice of assumed function used in the shortcut approach described above. I guess I should be rigorous, and explore both options. I could then note the extent to which the quicker method is valid.</p><p>I suppose this is where I leave you, for now. If you are a mechanics savvy reader and are up to the challenge, feel free to post your solution for y(x) in the comments (you can use any approach you like, but please state the one used). To ensure we use the same variables, express your y(x) in terms of the following variables:</p><p>Surface gravity: g</p><p>Air density: p</p><p>Wind speed: v</p><p>Rope mass: M</p><p>Rope diameter: D</p><p>Rope length: L</p><p>Rope elastic modulus: E</p><p>Rope shear modulus: G</p><p>Rope shape (cylinder) coefficient of drag: Cd</p><p>It is likely than one or more of the above parameters will <i>not</i> appear in your solution for y(x). It is also possible that some additional assumption on your part will be required, though at this time I cannot think of one.</p><p>Alright, now for the hard part, if I do not get overwhelmed by laziness: working out the detailed solutions. See you on the other side of 2020.</p>The Engineerhttp://www.blogger.com/profile/05080325091689417696noreply@blogger.com2tag:blogger.com,1999:blog-8262015410550800861.post-6663921235760159882020-11-19T14:26:00.010-05:002020-11-19T15:42:32.299-05:00The Smoke of Wildfires Travels to Canada<span style="font-family: arial;">The 2020 wildfires in California have devastated parts of that state, but they also serve as a symbol for the socio-political fire that is consuming America. One clear similarity between the two scenarios is that the current environmental conditions favour devastation. The likelihood of the physical fires increases as the globe warms, and high winds paired with low precipitation spurn it onward. The socio-political fire that rages on in the United States is a direct result of a tribalistic political environment, which threatens to overthrow democracy in that country. <br /><br />There are, of course, some important differences between how these fires are being handled. The physical fires are combatted by waterbombers and firefighters. Fire chiefs have done everything in their power to prevent its spread. The divisions in the United States – the deep discord among its citizens – has been and continues to be exacerbated by the outgoing President. The fire chief is stoking the fire as he contemplates his next move. We are witnessing the fall of Rome. <br /><br />As Canadians, I may consider myself a passive observer of the 24/7 drama channels, like CNN. But I have good reason for staying tuned, despite its obvious negative effects on my mental health. There are serious existential risks to our species that we must face, from the aforementioned climate change, to the current (and next) pandemic. Neither of these threats lead to our extinction in the short term, but they require our serious attention to limit their harmful effects in the long term. <br /><br />Various branches of government must work alongside scientists to combat these fires from spreading. But instead of that, the leader (did I mention outgoing?) of the American government is questioning the expertise of the scientists, and even worse, causing his mob of supporters to doubt scientists. That is like halting efforts to stop the fires in California because we distrust that water molecules consist of two atoms of Hydrogen and one of Oxygen (I can actually imagine President Trump arguing that the Oxygen atom helps the fire breath as his minions nod their heads). Worse still, the smoke that blows from his mouth travels around the world, infecting non-Americans as well. <br /><br />Assuming that President-elect Joe Biden is indeed sworn into office in January, the next question becomes: Can America reassert its place in the world, become a voice of reason, and help us homo sapiens become responsible custodians of Earth? <br /><br />Perhaps Canadians can instead ask themselves: "What can we do to help make this possible?" I have a few suggestions. Let's: <br /><br />1) Be our best selves. We need not enter into Facebook yelling contests with conspiracy theorists. Let the FBI worry about them. Just act kindly - be respectful and act with integrity. <br /><br />2) Promote the virtues of democracy and show up to vote when it is our turn. We can also encourage our leaders to be their best selves. <br /><br />3) Clean our own house. Canada is great but it is far from perfect. We must lead by example and do what is undeniably right. We must continue to strive for equality across race and gender. <br /><br />4) Act responsibly towards the environment as individuals and ask our leaders to hold corporations and institutions to this same standard. <br /><br />Who knows? The age of reason and enlightenment may not be out of reach. Getting there, however, will mean fighting back against the many fires that threaten to consume us. It means trusting the experts who have earned such distinction. It means electing officials who serve our best interests. Most of all, it means thinking locally and globally; it is not and has never been a choice between one or the other. A fire anywhere on this planet is a fire everywhere on this planet; we have just one planet.<br /><br />I fear that Americans may be so divided that no leader can sew the country back together in four or even eight years. I mitigate this fear by turning off CNN and going for a walk. </span>The Engineerhttp://www.blogger.com/profile/05080325091689417696noreply@blogger.com0tag:blogger.com,1999:blog-8262015410550800861.post-89944048464629157462020-11-02T15:53:00.004-05:002020-12-01T10:37:58.241-05:00The Benefits of a Decade Blogging<p> I founded this blog in October, 2010, which feels like an eternity ago.</p><p>After ten years of blogging, I can speak to the positive impacts it has had on my career. Though I originally started the blog as an outlet for my ideas on science and engineering, it quickly evolved into a space where I write for my students; after all, I became a physics professor at Vanier College in 2010 also.</p><p>Blogging has:</p><p>(1) Helped me consolidate my own ideas</p><p>(2) Made me a better teacher</p><p>(3) Given me a bank of topical content at the right level to pass on to my students (incidentally, this has become a cornerstone of my teaching approach, whereby new content is introduced before class, conceptually - students then write their reflections and submit them - and I then assign their best questions back to them so they may discuss them in groups)</p><p>(4) Been a launchpad to some speaking and radio gigs</p><p>(5) Made me a better writer</p><p>This last benefit has enabled me to produce a manuscript for my first book about the fundamentals of physics. A couple of publishers have shown some interest in it recently. I am hopeful to sign a publishing deal sometime in 2021.</p><p>Ah, 2010 was long ago indeed. The blog has aged with me, but also my children - my eldest had just turned one when I wrote my first post, which was fittingly entitled "My Daughter the Physicist". Reminiscing further, humanity seemed in better shape then. Two years into President Obama's first term, there was reason for optimism. I still remain hopeful that we can right the fragile ship on which we sail, but along with many of you, I am growing worried of the future (like, two days in the future, when a racist, misogynistic, reason-defying narcissist is hoping to see his time in the White House extended by four more years).</p><p>I pray that in 2030, humanity will have found its stride, and have become responsible custodians of this planet. It is within our capability. Until then, I will continue to write, for there is indeed a sixth benefit to doing so: it is so much fun.</p>The Engineerhttp://www.blogger.com/profile/05080325091689417696noreply@blogger.com0tag:blogger.com,1999:blog-8262015410550800861.post-85597174133348972162020-10-02T07:57:00.003-04:002020-12-01T10:51:18.667-05:00How do I Feel About This?<p>Humans on this planet woke up to the very not fake news that the sitting President of the United States has contracted the COVID-19 virus.</p><p>Like anyone with a reasonable amount of education and any semblance of a moral compass, I have no desire to witness, albeit from across a border, four more years of lies, deceit and fear-mongering. Let me also clearly state that I sincerely hope the President recovers from this illness. What is more, I do not even think he <i>deserved</i> to get the virus - no one deserves it. Some might invoke karma, because after all, this is a man who hid the dangers of the disease from those he claims to represent. In my head, I am not really going there. My thoughts this morning are moving in a completely other direction...</p><p>Obviously, this only hurts his re-election campaign. Even if his symptoms are mild, his supporters will have a hard time calling this a total hoax (it was announced by his highness on his royal twitter platform). One way or another, his diagnosis gives the optics of weakness - his perceived strength and bravado is the one thing some might say he had 'going for him'. Of course, if his health suffers for a couple of weeks or more, then it seems to me that the election is a moot point (though we have all been proven wrong by this man in the past).</p><p>If indeed, this virus spells the end of the sitting President's reign, that is, without question, a good thing from the point of view of the vast majority of humans on this planet. But as <i>this particular </i>human sits typing away this morning, he cannot help but feel strangely about it.</p><p>Before this news, I, along with most Canadians that I know, felt a great deal of anxiety over the four weeks leading up to the U.S. election - these feelings were independent of the fact that the world seems to be on fire, sometimes in a literal sense. If the chances that Joe Biden will be the President in 2021, instead of the alternative, increased dramatically overnight, that is undoubtedly a good thing, and it does provide me with a certain sense of relief, or even, dare I say, cautious optimism. But the prevailing thought I am overcome with is that I would have preferred it not happen this way.</p><p>I would like to have seen sensible Americans do the right thing in massive numbers based on the information before them. I wanted my faith in my neighbours to the South restored. I wanted the overwhelming majority of Americans to choose the reasonable human instead of the bully, the ignorant fool, the small-minded racist, the petty mysoginist... Need I go on?</p><p>Alas, the scale may have tipped over last night. Biden may just win this thing by default. The right thing might happen, but for the wrong reason. It reminds me of a completely analogous situation - an even more serious one that also affects us on a global scale: climate change.</p><p>I have no doubt that humans will eventually move away from fossil fuels to power their lives. All powerplants will be solar, all combustion engines will convert to electric, and most food consumption will go vegan. Sadly, these changes will happen for the wrong reasons.</p><p>These grandiose modifications, so necessary for the viability of life as we know it on this planet, will be made not because they are the right thing to do. They will happen because they are economically preferable. The cost of vegan will be cheaper than raising cattle only to kill and distribute their parts. The cost of solar energy production will become far less than that obtained by the burning of coal (it is comparable today).</p><p>The fight against climate change may be a victory one day (that is, it may not be a runaway train with no end in sight, and be limited to a minor global catastrophe), yes, but it will reflect that our species cares deeply about our world economy and not our world. It will leave me shaking my head at our backwardness.</p><p>As a hopeful person, I yearn to see my fellow humans step up to the plate, and make the noble choice. The President's contraction of COVID may have, in a sense, denied Americans that opportunity. The outcome may well be positive, because the more suitable candidate may win, but it may not be a victory that Americans can be truly proud of.</p><p>I sincerely hope that us fickle humans come to our senses - that we become responsible custodians of this planet. I want it to happen so much, that I would accept almost any avenue required to get there. But I would prefer that our path to responsibility, accountability and sustainability be paved by the good will of humans rather than their obsession with the almighty dollar.</p>The Engineerhttp://www.blogger.com/profile/05080325091689417696noreply@blogger.com0tag:blogger.com,1999:blog-8262015410550800861.post-74083217695415915952020-08-18T09:36:00.002-04:002020-08-18T09:37:22.665-04:00Back to School in the Post-COVID World<p><span style="font-family: inherit;">Somewhere across the spectrum of difficulties our society
faces in the post-COVID world lies the education of our children. As a parent and a teacher, I am currently
operating under the assumption that, come the Fall, Secondary V and lower will
be attending classes in person, while the majority of those in CEGEP and higher
will be resuming their studies online.
Given what we know about COVID-19, it appears that the socio-economic
fallout associated with keeping children home is the worse of two evils when
compared to the health risks attached to attending classes in person.</span></p><p class="MsoNormal"><span style="font-family: inherit;"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family: inherit;">My primary concern with the resumption of learning
activities that await our students in a matter of weeks is that the already
wide chasm that exists between so-called strong and weak students will widen,
perhaps dramatically.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family: inherit;">In my ten years of CEGEP teaching, I have observed the
following: our best students get better every year, and our struggling students
struggle more. Anecdotally, I attribute
these changes to increased access to technology. Where a strong student might use Wikipedia to
examine the link between black holes and general relativity, a less motivated
student might spend an afternoon on Instagram.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family: inherit;">Indeed, the resources available to our children are
mind-boggling. Self-directed learners (there are a handful in every class) could arguably work their way through elementary and high school on their own
armed with only a list of content, a tablet, and an internet connection. In this thought experiment, such students
suffer socially, but may emerge unscathed academically.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family: inherit;">My fear is that going forward, our students’ academic diet
will be dominated by screen learning.
While this is evident for online learning, our younger students who sit
in classrooms by day could experience a similar, though less dramatic
shift. Consider a teacher who is
mandated to bring their students to a hand-washing station once per hour. This process eats up fifteen minutes each
time. Where is this lost hour per day
recouped? Kahn Academy YouTube videos
from home? Flashy learning Apps that
utilize Smart Gaming?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family: inherit;">The motivated student whose parent can spend time alongside
them may well eat this content up. But
what of her classmate, who would, quite understandably, prefer to play street
hockey or watch an entire season of Friends, and whose parents arrive home
exhausted around dinner time? Scenarios
such as this make it clear that the educational landscape, which already
favours wealthier families, is about to stratify even further. <o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family: inherit;">Oh, and what about the teachers?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family: inherit;">A common word that echoes through school administrations is <i>equity</i>. Equity across a given course means that
regardless of which section of say, a Mechanics class that a student is
registered in, they will experience a similar degree of difficulty, cover
roughly the same content to the same depth, and ultimately have an equal chance
of passing. Many departments succeed in
this by meeting regularly in curriculum committees and sharing teaching
materials. <o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family: inherit;">However, this does not ensure that the learning experience
is <i>equal</i> across different sections in all courses. Academic freedom
means that each teacher is free to select their preferred pedagogical approaches
for the courses they teach. This freedom
is crucial to the teaching profession, as it allows a teacher to tailor the
learning experience to their own unique strengths. There is, however, a downside to this
necessary freedom.<o:p></o:p></span></p>
<div style="text-align: left;"><span style="font-family: inherit;">Back in March, when education abruptly moved online, the
learning experience became, for lack of a better term, the Wild West. Some teachers threw massive streams of video
content at their students, some gave their students regular feedback, and some
teachers, I can only assume, replaced their morning coffee with gin and held
wildly entertaining Zoom sessions.</span></div><div style="text-align: left;"><span style="font-family: inherit;"><br /></span><span style="line-height: 107%;"><span style="font-family: inherit;">Fortunately, us teachers have had more time to
prepare for this Fall (although it must be said that, with weeks to go,
there has been little flow of information from the provincial government thus
far). Many educators will adapt to the
new boundaries inherent to teaching in 2020 and beyond. My hope is that our students, regardless of
their socio-economic class, can adapt along with us. </span></span></div>
The Engineerhttp://www.blogger.com/profile/05080325091689417696noreply@blogger.com0tag:blogger.com,1999:blog-8262015410550800861.post-74024126203410597552020-06-24T10:22:00.001-04:002020-06-24T10:22:30.898-04:00Things Must not Return 'Back to Normal'<div>I had written a short post regarding the return to somewhat normal life after three months of quarantine. As I was about to post it here on my blog, I decided it would benefit from a larger audience, and so I sent it as an op-ed to the Montreal Gazette. They decided to publish it (it is in the June 25, 2020, print edition); the online link is <a href="https://montrealgazette.com/opinion/opinion-after-covid-19-lets-not-go-back-to-normal">here</a>.</div><div><br /></div><div>In summary, my hope is that as certain aspects of life get back to normal, I sincerely hope that some key lessons learned on our three month long quarantine reflection will endure. Things must not go back to how they were. Black Lives Matter, buying local, minimal commuting... These positive movements were inevitable, but COVID-19 accelerated them. The hurt brought upon by the pandemic cannot be undone, but it can stand for something if we maintain the positive changes that it has brought about.</div><div><br /></div><div>I extend my best wishes to you and your families and friends. I remain hopeful that our species can learn to live justly among ourselves and sustainably atop this beautiful planet.<br /></div>The Engineerhttp://www.blogger.com/profile/05080325091689417696noreply@blogger.com0tag:blogger.com,1999:blog-8262015410550800861.post-61300759623528541512019-05-06T08:55:00.000-04:002019-05-06T08:55:48.540-04:00Meet S.E.R.G.Towards the end of 2018, I decided to try to form a small research team of college students to join in on my space elevator research. I managed to recruit three such students. This turned out to be the beginning of S.E.R.G. (Space Elevator Research Group), a lab that aims to study various mechanical aspects of the Space Elevator.<br />
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<a href="https://3.bp.blogspot.com/-vuhJmXktgnE/XNAn3KAyjeI/AAAAAAAAC-Y/DXefGca1TsE-7UuU33ykk45uUe2zP-ifQCLcBGAs/s1600/SERG_May_2019.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1067" data-original-width="1600" height="266" src="https://3.bp.blogspot.com/-vuhJmXktgnE/XNAn3KAyjeI/AAAAAAAAC-Y/DXefGca1TsE-7UuU33ykk45uUe2zP-ifQCLcBGAs/s400/SERG_May_2019.jpg" width="400" /></a></div>
<div style="text-align: center;">
<span style="font-size: x-small;"><b>From left to right: Professor Arun Misra (McGill University), <br />Richard Ziegahn, Raffael Rinaldi, Tristan Vieira, and Stephen Cohen (Vanier College)</b></span></div>
<div style="text-align: center;">
<br /></div>
<div style="text-align: left;">
Over the course of the past four months, I have met with the three students every so often to help guide them through our research. Besides learning some fundamentals associated with space elevator mechanics, their focus has been to write a code that will explore something new. On my end, I have been delighted with how little support they have needed to get as far as they have.</div>
<div style="text-align: left;">
<br /></div>
<div style="text-align: left;">
Without getting into the details of our research, I just feel the need to express that they are doing the work I would be doing if I had the time to do it. It is not unusual for students to aid researchers in this way; it is unusual that the students are 18-19 years old. I was 24 when I published my first paper - these students will be published before they start university. They will all begin undergraduate studies in various engineering disciplines later this year.</div>
<div style="text-align: left;">
<br /></div>
<div style="text-align: left;">
Last week, the three students shared their contributions to our research project at a tech/science fair. Also in attendance, was my mentor-turned-collaborator, Professor Arun Misra. Indeed, the five of us will be jointly published in the proceedings of the International Astronautical Congress that will be held in Washington D.C. this coming October. Misra and I are sure to be there - the other three will join us, but only if they can cut classes for a few days. This unique opportunity may actually justify doing so.</div>
<div style="text-align: left;">
<br /></div>
<div style="text-align: left;">
I must admit that I was initially unsure as to how much any college-level students could contribute to real-world research. The 21st century seems to have equipped these resourceful students with enough tools to contribute a great deal. I am encouraged by this, and am seeking funding that will allow me to grow and maintain S.E.R.G. for years to come.</div>
The Engineerhttp://www.blogger.com/profile/05080325091689417696noreply@blogger.com1tag:blogger.com,1999:blog-8262015410550800861.post-88811474145575920522019-02-01T10:51:00.001-05:002019-02-01T10:51:03.251-05:00How Powerful we Have BecomeThe bad news is:<br />
<br />
1. Homosapiens are fallible<br />
2. Our planet's stability is fragile<br />
3. We have attained a significant level of technological maturity<br />
<br />
Our technology is powerful enough to alter our biosphere. It did not happen in one year - it took one century. The most dramatic changes occurred over the past few decades. Unquestionably, if we continue along, status quo, this planet will become both unstable, and unrecognizable in a few more decades. We will render ourselves powerless to stop it. We will reduce in population size, not by choice, but by attrition.<br />
<br />
Bottom line: our social and ethical maturity has not kept pace with that of our technology.<br />
<br />
The good news is:<br />
<br />
1. The future is unwritten<br />
2. We can learn from our mistakes<br />
3. New technologies can actually help if they are tempered with reasonable behaviour<br />
<br />
I have faith in this species to which I belong. As individuals, we are, by and large, quite dignified in our actions most of the time. As a collective, we can be better, though we are, at times, worse. Even when 10% act horrifically, if some of them command significant sway, it takes the other 90% to simply hold them at bay.<br />
<br />
Bottom line: we must allow civilization to mature from a sociological standpoint, and make the kinds of decisions that give us the right to deem ourselves an intelligent species. The Engineerhttp://www.blogger.com/profile/05080325091689417696noreply@blogger.com0tag:blogger.com,1999:blog-8262015410550800861.post-20652290947037524752019-01-17T10:49:00.002-05:002019-01-21T18:57:32.797-05:00What Would Happen if the World's Most Powerful Nation Elected a Narcissist?D. T.'s two-year journey into our collective consciousness may be described as a reality show where the bumbling star is a walking study of narcissistic personality disorder.<br />
<br />
I have tried very hard not to allow T - - - P's name to grace this blog, which is where beautiful ideas of science and engineering are supposed to be explored, but I cannot write about general relativity and the standard model (that is what I was hoping to do today) without first getting this nonsense out of the way. Once through, I hope to be able to emerge from this fog and think clearly. Some Americans might identify with that last sentence, and deem it applicable to the past three years of their lives.<br />
<br />
It seems that this sad man has infiltrated our minds to the point where otherwise reasonable people have developed <i>CNN</i> addictions, tuning in for hours every day to witness the "Gotcha!" moment. They want to know as soon as possible that the bully's alleged criminal activity has caused him to be stripped of his powers, and left him somewhere that he can no longer harm the planet.<br />
<br />
And harm the planet he has, in almost every conceivable way.<br />
<br />
At first, I thought his worst long term offence would be to remove the United States from <span class="st"><i>The</i> <i>Paris Agreement</i> that was established <i></i><i></i>at the United Nations Framework Convention on Climate Change (UNFCCC)</span>. He has also attempted, and sometimes succeeded at tearing up other precautionary measures that seek to protect our fragile biosphere from us hominids. Then, when he did all of that, it occurred to me that these would not be his most long term devastating affronts to the species.<br />
<br />
This frightened tiger's legacy will likely be his battle against truth. Any scientist with any care in the world should fear a future where regular people think facts are worthy of debate. This man's presidency coincides with the introduction of the idea of the 'Alternative Fact'. I still do not know what such a term means, but I do know what it attempts to accomplish. This man who brags about his love for the uneducated has attempted to uneducate the educated, so he may love us all.<br />
<br />
My message is simple: I care too much about myself, my family, my friends, and my students to let that happen. D. T.'s time is short, and humanity's struggle to find its way is seemingly endless. Our spirit is indefatigable. Our collective efforts cannot be undermined by one narcissist and a few of his minions. It is insulting for them to think that it might.<br />
<br />
This brief but seemingly eternal fog will lift, and as an engineer, I cannot help but propose a solution for how it might end without violence. I will close this rant by elucidating a potential solution...<br />
<br />
The reason I refer to D. T. as a frightened tiger is because he is without critical thought, and he is presently cornered by his own absurdity. What he has done thus far in such situations is to deny, deter and distract. The only thing that might distract America sufficiently such that he may briefly escape this mess and go golfing is a far bigger mess he has the power to impose.<br />
<br />
Here is how violence may be averted:<br />
<br />
Someone must distract the frightened tiger, perhaps until Michael Cohen appears at the House Oversight Committee (currently set for February 7, get your popcorn ready), a day that may well lead to D. T.'s conviction. It is essential that this event not be derailed by some horrific plot that intends to deter and distract. I hope that some responsible adults who are not his minions have a close eye on him and his arsenal of weapons today and over the coming days. Perhaps they can lie to him (it needs to be people he trusts, like right-wing media) that everything will be fine for him, so there is no need to do anything rash. <br />
<br />
Then, when the dust settles, and D. T. possesses no power to speak of, a new leader must emerge. He or she need not be bold, nor charismatic. For all I care, he or she may be camera shy. It is critical that the new leader be an adult who is committed to unity and has a steadfast determination to maintain civility during the transition from absolute chaos to more regular levels of chaos.<br />
<br />
Perhaps, with some vision and leadership, the leaders of this world will help guide our species to an age of reason - this planet requires this of us if we are to inhabit it in such great numbers for an extended period of time. Despite the many backwards steps we have all witnessed in recent years, and not just in America, I remain hopeful that this ship's course may be righted; all we need are some courageous captains, and a majority of willing passengers possessing critical thought and the resolve to visit voting stations when it counts. Further, they need to keep a close eye on the captains they elect, and hold them accountable should they lack the resolve it takes to navigate this complex and delicate ocean. <br />
<br />
I would like to fund a wall in the shape of a circle. I propose that D. T. spend the remainder of his life inside the confines of this wall to protect the rest of us from him. And while I am dreaming, can his new home block twitter access?<br />
<br />
**************<br />
<br />
P. S. : I have already written two volumes out of a planned four in a Popular Science Book Series (in March, I intend to mail out a Book Proposal seeking a literary agent for representation), and I can proudly state that the only leaders I have referred to in any way in the text are people of true substance, like Carl Sagan.The Engineerhttp://www.blogger.com/profile/05080325091689417696noreply@blogger.com0