Friday, December 30, 2011

The Engineer's Pulse 2011 Year in Review

As the year winds down, it is an appropriate time to reflect on it, and also to plan for 2012.  At this time last year, I set some goals for my blog in 2011, and although not all were reached, the most important one was: I wrote articles consistently throughout the entire year.

The lesson that I take from this is that an ambitious goal may be reached by setting many small achievable ones.  In 2011, I posted 61 articles.  While some might call these posts, my readers will defend me when I say that my written pieces are not typical "posts" just as this site is not a typical "blog".  My articles are usually about 1,000 words, but sometimes 2,000 words.  If the average post is 1,200 words, then I wrote over 73,000 words on various topics within the realm of science and engineering over the course of this year.

It would seem daunting to commit to the goal of writing 73,000 words in a year, particularly if it were done on the side, like a hobby, as is the case for me.  I mean, this many words could easily fill a full fledged book.  I instead committed myself to write about one article per week.  As each article represents a very reasonable task on its own, the final result, while it appears grandiose when surveyed as a whole, was arrived at without much stress or concern.

I am happy to report that the audience for my blog grew steadily throughout the year.  To be sure, my articles have not gone viral - I remain jealous of the viewership of YouTube videos of cats rolling around in vomit, which easily generate millions of hits just days upon their uploading.  I suppose my site is more like a slowly growing bacteria; I like to think that my blog is going bacterial.

During the month of January 2011, I had just over 400 hits.  Over the last three months of this year, the blog averaged 3,000 hits.  While these numbers are not huge by any measure, I am still excited that thousands of people around the world are taking the time to read my words, which include some fairly in-depth discussions of reasonably complex content.  There are no cute cats on my site, nor is there anything gross or shocking.  Visitors to my blog have a head on their shoulders, and in general, have an earnest desire to be informed about new technologies and scientific discoveries.  I would describe my current audience as small but mighty.

All this being said, never before 2011 could I state that thousands of people have taken the time to consume anything that I produced.  And, although the comments board is not as busy as I'd hoped it would be this year, there have been many interesting and thoughtful comments posted by many.  Thanks to all who have taken the time to continue the discussions that I try to stimulate within my articles.  The nice thing about receiving just a few comments every week is that I can easily keep up with them, and post responses.  Please, keep them coming.

This year, I posted about topics ranging from aerospace to quantum physics to God.  And, despite all of the deep, existential discussions, which seem to me to be the most intriguing, the most read article of mine this year, was "Why Don't Airplanes Flap Their Wings?" which was read by 860 people.  This tells me that people want to know how every day technologies work.  I will continue to discuss technologies that we take for granted in 2012, and if a few more people understand the basic principles behind the tools with which they interact through a quick read on my site, then I am happy for it.

In the month of March, I had Aerospace Month.  As this was a relative success, I plan on having one or more themed months in 2012 - I am leaning towards an "Energy Month".

One other important addition in 2011 was the "For Physics Students" page, which I have been building.  In truth, "The Engineer's Pulse" has become much more student-centered than I had originally planned for.  Many of my favourite articles to write are inspired from content that I teach, and writing the articles empowers me to give clearer and more compelling lectures.  The truth is that even if this blog never becomes very 'popular', it will not have been a wasted effort, as it has proven itself to be an extremely useful teaching tool for me.

That being said, please do not hesitate to pass my articles along via whatever means (Facebook, Twitter, etc) to anyone whom you know that may find them interesting.  Do you know any science-minded students or tech-savvy adults?  Send them my way.

I wish all of you a prosperous 2012.  Oh, and by the way, I have seen the future, and I am glad to report that the world does not end.  On the downside, Donald Trump gets elected as the President of the United States.  Hmm, maybe that is the end that the Mayans were referring to all along.

Wednesday, December 21, 2011

Goldilocks Planets No Fairy Tale

Throughout the twentieth century, it was not all that uncommon to hear of graduate physics students running down the halls calling out, "We found a new one!"  Such a claim usually meant that a new elementary particle had been observed in the lab, be it the muon or gluon.  The count for such particles has remained at sixteen for some time.  The large hadron collider may soon allow the long theorized but ever evasive Higgs Boson to be observed, thereby raising the tally to seventeen.  This discovery would complete the list theorized by what is commonly referred to as the standard model.

These days, when physicists are found doing their celebratory dances, it is usually because a new planet has been discovered.  And, if that planet happens to be a Goldilocks planet, they really bust a move.

Goldilocks planets lie a distance from their star such that the surface temperature can allow for water in liquid form.  Like the porridge in the famous fairy tale, the surface temperature of such planets are not too hot or too cold; they are just right.  Planets in the "Goldilocks Zone" for a given star may be conducive for the evolution of life.  And, if other conditions are met, it is possible that other communicable societies currently call the surfaces of such planets their home.  However improbable this may be, the fact that it is not impossible is one reason why the discovery of such planets is cause for celebration among physicists and astronomers, and why it is thought-provoking for us all.

Thursday, December 15, 2011

Peter Hadfield Exposes McExperts

"McExpert" is perhaps my favourite word that I have learned this year.  The term, which seems to have been coined by former New Scientist journalist Peter Hadfield, describes a person who speaks authoritatively on subjects for which they have no expertise.  More specifically, it describes someone like, say, Glen Beck, who applies a fast-food approach to his own learning and then disseminates it to his disciples.

It might be reasonable to fault Beck's followers for being so gullible and for considering him a credible source, but to focus criticism on them rather than Beck would be like faulting misbehaving children rather than their neglectful parents.

Indeed, Beck is a classic McExpert; he is endowed with a super-sized ego, but is completely devoid of any reason or integrity.  The label is just so fitting - ten minutes listening to him is akin to downing a fast-food combo, which is calorie rich and nutrient deficient.

Wednesday, December 7, 2011

The Slow Death of Creationism

Creationism, the notion that all life on Earth was created at one instant around five thousand years ago and has not evolved since, is one of many baseless concepts in society that just refuses to die.

I recently came across a talk discussing the current status of creationism being taught in the classroom.  It appears that in the United States of America, creationism is alive and well in many states.  But, I must say, I do not know just how long this silliness can endure.

The very idea of teaching creationism in a science class is contradictory.  Science is an evidence-based field of study, and there is no evidence on which one can base the theory of intelligent design (another name for creationism).

Monday, December 5, 2011

Students in Crisis

In the few years that I have been teaching physics at college, I have never come across a greater number of distraught students than I have this semester, the Fall of 2011.  Of the seventy students I have taught or mentored, no less than fifteen have experienced a personal crisis at some point in the past four months - that translates to over 20%.

Though I am not a professor of sociology, I am well aware that this case study is in no way thorough.  An actual case study would involve a much larger group of students, pooling several class sections across many different educational institutions.  Also, my students did not fill out a survey.  I suppose the last weakness in my statistical assessment is that the situations that may constitute a crisis are defined subjectively here by me.

Placing these shortcomings aside, there is no denying that more than 20% of the students that I have encountered this semester have brought personal concerns to my attention that I deem to be severe for any adult to deal with, but particularly severe for a young adult between 17 and 20 years old (the typical age group of my students).  It is worth noting that there may be some students in my small sample group who experienced a crisis, but were not tallied in my count, as they did not decide to inform me of their problems.  So, the 20% figure is likely a low estimate.

Members of society who view collegiate students as unthoughtful, pot-smoking, lazy teenagers ought to revisit this unfair stereotype.  My sense is that for every student that is coasting through life with a sense of entitlement, there is at least one with his or her back against the wall.  Today's young adult student has bills, demanding jobs, and too often, family problems.  In my view, adults should consider a more empathetic view when framing college students.  Many of these eighteen-year-olds are not experiencing the prime of their lives.

Wednesday, November 16, 2011

Snell's Law for Light and Students

Optics, the study of visible light, is one of the earliest branches of science.  An introductory physics class will usually highlight what happens when a light ray encounters a new medium.  That is, a light ray may be travelling in a straight line unperturbed through medium 1, air, when it suddenly encounters medium 2, a thick plane of glass.  Before the light ray strikes the boundary, it is referred to as an incident ray.

The incident light ray will divide itself upon striking the new medium: some of the ray will reflect, and some of it will refract.  The reflection of a light ray is simple - it is no different than what happens to a billiard ball when it strikes a band.  Just as a billiard ball rebounds off of the flat border with an angle equal to that which it struck with, the angle of the reflected ray is equal to the angle of the incident one.

However, light can also permeate the new medium (an ability that no billiard ball possesses).  The portion of the light that passes through the boundary, continuing its travels into medium 2, is referred to as the refracted ray.  As shown in the figure below, the angle of each ray is measured with respect to an invisible 'normal' line, which is drawn perpendicular to the surface.

Monday, November 7, 2011

Water and Electricity Do Mix

*** Disclaimer: Do not wet your finger and plunge it into a live electrical outlet.  The title of this article was intended to be a play on words.  You know what?  If that was not already obvious to you, a severe electrical shock might do you some good.

Some science students are initially baffled when studying electricity.  This is not so surprising, as it is hard to relate to the concept of current, the rate of flow of charge.  The charge that is transported through an electrical circuit is composed of electrons - many of them.  I have never seen an electron, and while I have felt a charge by means of electric shock, I have trouble sensing exactly how many Coulombs are being transferred to me (or are they being taken from me?  I can never tell.).  I have an easier time visualizing, say, mass than I do visualizing charge, and I imagine this to be true for most people.

This is why it is appealing to explore the analogy between electrical current through a circuit and fluid flow rate through a system of pipes.  As a student, I could never remember whether current was constant through resistors connected in series or parallel.  The answer becomes obvious when one considers the flow rate of water through pipes rather than the current through wires.

Saturday, November 5, 2011

Entropy in Autumn

There are two things that I associate with the Fall season: Halloween and raking leaves.  While the former brings out my inner child who yearns for costumes and candy, the latter is the focus of this article, as it provides a wonderful illustration of the second law of thermodynamics.


Ah, the second law... Personally, I have never been particularly drawn to the study of thermodynamics, but I have always had an affinity for the second law and all of its fascinating philosophical implications.

The zeroth law of thermodynamics discusses thermal equilibrium, and in so doing, gives meaning to the term temperature.  The first law describes the conservation of energy, and dictates that energy cannot be created nor destroyed.  The second law says, in a variety ways, that no system can be 100% efficient, and as such, every system has losses. 

If you are curious, the reason that there is a zeroth law is that it was developed decades after the first two, but precedes them in terms of scientific principle, in that it lays a foundation for further study.  Rather than shift laws one and two up to two and three, it was decided that they be left alone, and that the new law be referred to as law zero.  This was a great choice, because it gave scientists the opportunity to use the term "zeroth", and as a result, sound very intelligent.

In summary, law zero says there will be lunch, law one says that it will not be free, and law two says that actually, you have to tip.

Thursday, October 27, 2011

Quantum Discomfort

Quantum physics has always been this mystical thing to me.  Throughout my years of academic studies in engineering, the word quantum may have been uttered by a professor, but it was never explored in any kind of depth.  Engineers are practical, and while quantum physics is fascinating, it is of little practical importance to most engineers at present.

A physics professor might say, "Classical physics is not theoretically sound, as it is only an approximation, and may only be accurately applied to things that do not move too fast and are not too small."  An engineering professor might then respond, "Most things are reasonably large and move reasonable slowly... In any case, any error less than 5% is good enough for me."

For nearly all engineers, the entire field of study may be ignored, and is.  For theoretical physicists on the other hand, it appears that there is not much outside quantum physics to ponder anymore.

In reality, for an object of reasonable size, the amount of error introduced by simply ignoring quantum aspects is negligible.  Still, this field of study is so fundamentally different from all of the science that came before it, that it is always categorized separately; that is, there is quantum physics, which centers around wave functions and probabilities, and then there is classical physics, which is everything else.

Quantum physics as a field of study was established in the mid-1920s with physicists such as Max Planck, Albert Einstein, Neils Bohr, and Werner Heisenberg.  The fundamental principle of quantum physics was discovered by Heisenberg, who showed that one could not be 100% certain of both the momentum and position of a given particle.  The law is known as the 'uncertainty principle', not to be confused with the 'what the heck is going on principle' commonly exemplified by certain physics students.  

Tuesday, October 18, 2011

Wavelengths and Personality Types

Light is a funny thing. 

It behaves like an electromagnetic wave (it has a phase - it can undergo interference), yet it also behaves like a stream of particles (it consists of photons, as proven by Einstein's photoelectric effect).  The split personality exhibited by light has bewildered scientists for one hundred years.  And, while we will never see a photon with our naked eye, our eyes would see nothing at all if not for light.  These photons reveal the nature of the matter around us, but keep their own true nature under wraps.

The light that reaches our pupils may come directly from a source or it may arrive after a series of reflections off of other surfaces; either way, the light emanates from a source, like the sun or a light bulb.  Both of these particular sources produce what is known as white light. 

All electromagnetic waves, whether they are radio waves or x-rays, have a wavelength associated with them.  Visible light fills a very narrow band within the electromagnetic spectrum: 400 nm to 700 nm.  All wavelengths in this range correspond to a particular colour.  Violet light has a wavelength of 400 nm, while that of red is 700 nm.  A rainbow will have these colours on either side (violet on the bottom, red on top), and all other colours in between ordered by wavelength.  White light is what you get if you superimpose all colours in the visible spectrum on top of one another.  Black, on the other hand, represents the absence of colour.

With this background information on light, we can properly appreciate why a red sports car looks like a red sports car.  It is less obvious than you might think...

The sun undergoes fusion, a nuclear reaction, which produces, among other things, white light.  These white light rays travel in all directions at about 300,000 km/s.  After travelling a little over eight minutes, some of these white light rays hit the red sports car that sits before you.  Then, something critical happens: some of the white light is reflected by the car's surface, but most of it is absorbed.  In fact, the surface absorbs every wavelength of light with the exception of its own, red, 700 nm.  The 700 nm wavelength of the light is reflected by the surface.  These reflected light rays head off in many directions, including yours.  Your brain interprets this wavelength to be red.

So, while the car may be red, we could not make this deduction if not for a source of light that contains, at a minimum, this particular wavelength.  It is kind of like that falling tree... If an object is not lit up by a source, does it have a colour?

The car's red colour gives it a certain character.  And, while one's personality is more complex than a single data point along a spectrum, colour codes for personality classification are often surprisingly telling.

Thursday, October 13, 2011

High Pressure Situations

A relatively small number of people deal with intense situations on a regular basis.  Overseas military, first responders and ER doctors are part of a select group that deal with high stress on a daily basis.  The rest of us can probably count on one hand the number of traumatic experiences that we have encountered in our modern, sheltered lives.  Personally, I can count this number on two fingers.

The first intense situation that I recall occurred when I was eighteen and living at home.  I started the backyard barbecue, and then went back inside the house while it warmed up.  When I looked back at the barbecue a few minutes later, it was a massive fireball.  I jumped to my feet, and ran towards the fire extinguisher.  As I approached the fire, I was fearful, realizing that the propane tank could have blown up at any moment.  Nevertheless, I sprayed out the blazing flames.

My one and only firefighting experience ended well.    Thinking back now, my actions that evening were instinctive; they involved no thought.  Intense situations do not leave one with much time to think.

Intense situation number two made yesterday a day I would like to forget.

Monday, October 3, 2011

Differential Equations Govern the Future

Mathematics is the language used to quantify anything in science.  Still, some aspect of the tool we call math is utilized in nearly every field from business, to sales, and of course, engineering.

The field of Mathematics may be divided into several branches like calculus, linear algebra, and statistics.  While all of these subjects are fascinating, let us focus on calculus, which can be summarized as "the study of change."  If no facet of the universe ever changed, we would have no use for calculus, but then again, such a universe could not support life altogether (life cannot exist without chemical reactions).

At its heart, calculus focuses on functions, which are equations describing how variables are related to one another.  The simplest kind of function consists of two variables; one variable is dependent, the other is independent.  If a taxi driver charges a customer $1.50 per minute, then the cost function for riding in the taxi would be C = 1.5t, where C is in dollars and t is in minutes.  Here, time is an independent variable, and cost is a dependent variable (as the cost depends on the duration of the cab ride).  In other words, cost is a function of time, or C = f (t).

The simple taxi function given above relates cost to time, but functions can describe the relationships between other dependent variables and time.  We could, for example, consider the temperature of a hot cup of coffee.  One can imagine that the coffee's temperature value would decrease as time goes on until it reaches the room's air temperature.  The key difference between the taxi function and the coffee function, is that the function for the ride in the taxi was specified by the taxi driver.  No one specified the temperature function of the coffee.  The coffee's temperature function is the result of a differential equation, which is also known as a governing equation - a law of nature, and in the case of the coffee, thermodynamics.

Friday, September 30, 2011

You can Count on Asimov

Isaac Asimov is on a short list of my favourite science authors.  The list has two names on it: Arthur C. Clarke and Isaac Asimov.  Both write excellent science fiction (Asimov's "I Robot" and Clarke's "Fountain's of Paradise" are my personal favourites) and both write excellent topical science articles and essays.  While Orson Scott Card writes some compelling sci-fi (Ender's Game is probably my favourite novel of all time), he is not a "popularizer" of science - it is rare to find an author that is skilled in both fiction and non-fiction.

Asimov may have been the most prolific author ever, having published upwards of four hundred pieces.  His direct style in story-telling and, at times, redundant style of communicating in non-fiction does not appeal to everyone, but it does appeal to me.

Asimov's largest volume of work involves the communication of science, but physics in particular.  I just finished reading "Asimov on Numbers," which involves mathematics, but really focuses on, well, numbers.  It is a collection of essays written over a period of many years, beginning in 1959.  Although all articles are between four and five decades old, they have aged well.  The only instances where the book feels old is when population and financial figures are discussed, as the absolute values of both have inflated significantly in the ensuing years.

I learned a lot in reading these essays, mostly about the history of mathematics (very fascinating) and the Earth's geography (which, as it turns out, can be described so well numerically).

Friday, September 23, 2011

A Big Day for Science Geeks

There are two interesting developments to discuss, so let's get right to them:


1. Today, several chunks of a decommissioned satellite will strike the surface of the Earth (hundreds of kilograms at hundreds of km/h)

For the past week, earthlings have been warned that a defunct satellite will enter the Earth's atmosphere on Friday, Sept 23, 2011.  Unlike small satellites, this one, the size of a bus, will not entirely burn up upon re-entry.  Although the simulation is hard to predict with high precision, it is certain that a significant portion of the satellite will survive the re-entry, and will find a terminal velocity in the region of 300 km/hr.  Like the weather, aerodynamic problems involving extreme heat transfer are difficult to solve with much accuracy long in advance.  The location of where on Earth these satellite chunks will land is still somewhat up in the air.

NASA explained last week that this should not worry us, as there is a 75% chance that the said pieces will hit water (gee, thanks for the geography lesson).  As of this morning, we now know that the satellite pieces will strike the Earth in its Southern Hemisphere.

This sort of thing happens roughly once per year...

Saturday, September 17, 2011

Guitar String Theory

I learned how to play the guitar about thirteen years ago, towards the end of high school, because I hypothesized that it would attract the ladies.  Fortunately for me, it attracted one lady in particular, and I ended up marrying her.  Although this case study was limited to one specimen, I think further investigation would lead to a strong correlation between guitars and ladies.

Over time, the guitar has become much more for me than a tool for garnering attention around a campfire.  The six-stringed instrument has sat on my lap for countless hours, as I figure out songs that I enjoy, perform them live, or just sit alone strumming nothing in particular.  It’s amazing what a wonderful diversion those twelve notes can provide.


I have written previously about how a pulse can travel along a string that is in tension.  What distinguishes the behaviour of a stringed instrument is that both ends of the strings are fixed.  The phenomenon that occurs when a taught string is plucked is known as a standing wave.  The note that we hear, its frequency, is dependent on four parameters for the given string: its length (L), tension (T), mass per unit length (µ), and mode number (n).  The frequency in Hz is given by the following equation:

f = [n/(2L)](T/µ)0.5

The Infrastructure is Crumbling, but Don't Panic

As a Montreal resident, I sometimes wonder if the roads are as bad in other major cities.  It seems as though the roads within the province of Quebec suffer from a contagious disease constrained within its borders.  The disease transforms an otherwise developed nation into Colombia with snow.

The moment you cross the border into the United States, the crater-sized potholes vanish and the uneven surfaces become smooth.  If you listen closely, you can hear the suspension system of your car breathe a sigh of relief as you leave Quebec.  If you happen upon a road imperfection while driving in the states, it will be most certainly preceded by one or two warning signs.  If every hole in Montreal's roads were well-marked, there would be no space left for the speed limit signs (which we don't follow anyway, but that's another story).

In truth, dodging potholes and bouncing around in one's car is part of the quebecois experience; the locals have grown accustomed to it.  What the public will never come to accept, however, are falling overpasses and tunnels.  Over the past five years, several such incidents have occurred in the city of Montreal.  In the summer of 2011, reports of a major structure crumbling in some way seemed to become a weekly tradition.  Due to the local media coverage of these incidences, the average Montrealer now knows what a gusset is, and could probably submit a decent draft for our next bridge's design.

Let's first examine why structures fail, and then look at why so many are failing these days in particular.

Friday, September 9, 2011

No 9/11 Conspiracy

The terrorist attacks that occurred in New York City ten years ago is all that anyone seems to be talking about these days.  Whatever the medium, wherever I turn, I am reminded of how the world changed on Sept 11, 2001.  Strangely, it seems that much of the conversation about this terrible event surrounds the possibility that it may have not been a terrorist attack at all.

As a scientist, I can appreciate the desire to question things and dig deeper for the truth when things do not seem to add up.  In the case of 9/11, as with the moon landing (which, of course, did happen), the "deniers" or conspiracy theorists are wasting their collective breath.

Tuesday, September 6, 2011

Death by Numbers: The Dangers of Exponential Growth


Physicist Dr. Albert Bartlett believes that man’s greatest shortcoming may be his inability to understand the exponential function.  A long time member of the faculty at the University of Colorado at Boulder (since 1950), Bartlett has given his famous lecture, “Arithmetic, Population, and Energy,” 1,600 times over the past fifty years.  Add to that millions of hits on YouTube, and it may be the most viewed lecture of all time. 

Dr. Bartlett, now nearing ninety years old, is still eager to inform others about the least discussed major issue that mankind faces: overpopulation.  While politicians move their mouths on topics from unemployment to global warming, not since Nixon has a leading politician uttered the word overpopulation.  Telling society that we are our own worst problem is not a popular thing to do; it is, on the other hand, a very responsible thing to do.  Overpopulation exacerbates both global warming as well as unemployment, not to mention poverty, at the local and global level.

Thursday, September 1, 2011

Even Superman Can’t Turn Back Time

I, like many men that are 30 going on 13, have always had an affinity for superheroes, and in particular, superhero movies.  There are so many reasons why this genre of movie appeals to me, but what I enjoy first and foremost is the notion of fantasy set in reality.  Among my favourites are The Watchmen, Batman (the original and the Dark Knight), and X-Men.

I must admit, there is a certain inherent fallacy to the notion of fantasy set in the real world.  Some stories, like that of Star Wars, avoid any real world association, as they are set far from the world we know in both time and space.  Fantasy set in reality presents an internal conflict for the viewer: “Do I just go with the fantasy and ignore reality, or do I go with the reality and question the fantasy?”
    
While the first option allows one to achieve the escapism that such films offer, my mind has trouble turning off completely, and I tend to walk a line somewhere between both options.  A premise such as that of The Matrix avoids this issue, as it offers a compelling reason for why the rules of the universe, the laws of physics, need not apply.

While nearly any sci-fi movie, if analyzed carefully enough, can be criticized for taking liberties with science, the award for “Most ridiculous violation of the laws of science in one scene” must go to the climactic finale of the first Superman film.  [As an aside, the award for “Most consistently false science throughout” may be shared by Armageddon and Independence Day.]

Saturday, August 27, 2011

The Science Class I Wish I Had

I recently read a book called The Science Class You Wish You Had to get motivated and inspired for the new school semester.  It is authored by two brothers, David and Arnold Brody; the former is a science historian, and the latter a professor of pathology.  The book, written in 1997, describes the seven most important scientific discoveries of all time, and gives insights into the lives of the scientists who made them.

According to the authors, the top seven scientific discoveries in history are:

  •  Gravity and the basic laws of physics (Newton)
  • The principle of relativity (Einstein)
  •  The big bang and the formation of the universe (Hubble)
  • The structure of the atom (Rutherford and Bohr) 
  • Evolution and the principle of natural selection (Darwin)
  • The cell and genetics (Flemming and Mendel)
  • The structure of the DNA molecule (Watson and Crick)

In the list above, we have one discovery in chemistry sandwiched between three in physics and three in biology.  In each case, the story behind how the discovery was made is as interesting as the discovery itself.  Noticeably absent from the list is quantum physics, but it would be hard to knock anything off this list.  The importance of quantum physics has become more apparent over the past fifteen years (when the book was published) – today’s list of top discoveries should perhaps be extended to eight.

The vast majority of man’s science discoveries have taken place in the twentieth century.  With the exception of Newtonian physics, all six of the others listed came to fruition in the 1900s.  It appears that the most exciting period of time to be a scientist was between 1850 and 1950.  The explosion of scientific knowledge that occurred during that period will probably never be matched.  Although our current tools and sheer numbers allow us to drive science forward at a greater pace than ever before, today’s science attempts to push boundaries, whereas yesterday’s science discovered what those boundaries were.

Wednesday, August 24, 2011

Returning to School

A few days ago, I posted the question, "Who is more anxious about returning to school, the teachers or the students?" A friend of mine commented, "The parents."

Getting back into the school schedule is a challenge for all involved, but in the first week, standing in front of my first class, I was reminded of how much I enjoy being there.  Meeting new young people, with their own unique perspectives on life, on science, is so refreshing for me.

I can't say that I am looking forward to all of the course prep and piles of correcting that await me - I am teaching three college physics courses this semester.  But, these sacrifices are worth it, because the payoff is the time spent in class discussing physics.  A learning environment is a truly fortunate place to find oneself in.

I can appreciate the nerves from the students' perspectives.  Being a full-time student is hard these days.  Many of them work over twenty hours per week during the semester.  Some do it to pay for luxuries like cars and cell phones, but many do it to pay for their schooling as well as their bills at home.

Remarkably, some of these eighteen-year-old full-time students are living on their own, paying their own way.  I have a tremendous amount of respect, but also some sympathy for students in this situation.  I never had it so hard, and I can't imagine being able to enjoy my college years if I were placed in such trying circumstances.

Finding a life balance is a hard task for anyone.  Students and teachers alike need to plan their schedules carefully to maintain their mental health - to at the very least, survive, and in the best case, thrive.

I am looking at my busy schedule, wondering if it will be feasible for me to undertake some volunteer work with the Robotics Club at Vanier College.  As I struggle with this somewhat trivial decision, I remain humbled by students that I pass by in the halls, many of whom face far more daunting decisions than I.

Wednesday, August 17, 2011

An Analytical Mind is Hard to Turn Off

Yesterday, as I watched my two-year-old daughter run along in the playground, I observed her pony-tail as it bobbed up and down.  Before I knew it, I was analyzing the motion of her hair as a function of time.  My mind raced through vibration textbooks and dynamics courses.  I decided that her pony-tail was similar to a one-degree-of-freedom system with base excitation, kind of like the chassis of a car as it drives along a bumpy road.

Considering the science behind a given situation is a regular occurrence for me, as I suppose it is for many scientists and engineers.  Once one has spent enough hours mastering a certain domain, that domain seems to find a special place in one’s brain, where it giddily awaits to be called upon.  Scientific thoughts appear in my mind at unexpected moments, and even turn up in my dreams – I can’t help it.

At a glance, this lack of control over my own thoughts can appear somewhat psychotic, but it is actually a common thing.  For example, try to hold the image of one simple thing in your mind, like for example, a grilled cheese sandwich.  Hold it there, and do not let anything else enter the picture you hold in your head.  OK, how long did you last, 5 seconds?  Less?

Total control of one’s thoughts is a tricky business, and is actually a skill that those who meditate try to develop.  I suppose it would be a necessary skill for a Jedi to master; how can one expect to control the thoughts of others if they cannot fully control those within their own minds?

Thursday, August 11, 2011

The 2011 Space Elevator Conference

It is that time of the year again.  Over the course of this weekend (Aug 12 - 14), space elevator enthusiasts will gather in Redmond, Washington to present new research on what may well be the most exciting engineering project of the 21st century.  Those with little or no knowledge about the space elevator may wish to check out my space elevator page (link above) before reading on.

The space elevator topic is the focus of three annual conferences; the two other conferences are held in Japan and Europe, respectively, while this weekend's event is the North American edition.  I had the opportunity to attend and speak at the 2009 Space Elevator Conference, and have kept in contact with the small but growing space elevator community in North America.

Although I will not be attending the conference this year, I am on the judging panel for the Pearson and Artsutanov prizes, which are awarded to the best papers.  This year, the theme for these papers is research that will lead towards a material suitable for the construction of the space elevator ribbon.  The material challenge remains the most daunting technological one for the overall project.  In a way, this is a very good thing, because it is not an isolated challenge - stronger and lighter materials are being developed continuously for non-space related use as well.

The entity that organizes the Space Elevator Conference in North America is called ISEC (International Space Elevator Consortium).  ISEC seeks to aid in making the space elevator a reality sooner than later, and has taken a bold step this year by creating the journal, Climb: it is the first scientific journal specific to the space elevator topic.  The journal will help to centralize the state of the art for the space elevator project, and will be particularly important for space elevator academics that cannot attend the conferences.  Those interested in the space elevator project should consider joining ISEC, as the very reasonable membership fee includes a copy of Climb.

For those attending the conference this year, I hope that you enjoy it.  The space elevator project needs a community, and the conference helps to grow and strengthen it.  For more information regarding this weekend's conference, please click on this link.

Friday, August 5, 2011

Man's Gift Also His Curse

As I walked through a quiet nature trail in Vancouver’s beautiful Stanley Park, I noticed a sign indicating that a few foreign plants were spreading within the nature reserve.  These plants threatened to overtake the park, and perhaps replace certain species of the plant life over the coming decades.

The signs were written as a kind of warning not to introduce new plants into the park, but it prompted me to consider the following question: What is wrong with a little bit of biological competition?  If one species of plant should dominate another, is it not simply survival of the fittest?  By trying to control the local plant life, I feel as though mankind is overstepping its boundaries.

Life at all levels is in a constant struggle for survival, and it is through this struggle that it adapts or dies out.  Natural selection is merely nature’s “tough love”.

If survival were easy for hominids, perhaps Homo sapiens would never have evolved – these big brains of ours, which allow us to both understand and shape the world, would not have been required.  But man did evolve, and, the high intelligence that we have inherited through millennia of adaptation has placed us in a unique, privileged, but I would also argue, overwhelmed situation.

Monday, July 25, 2011

Man Will Teleport When Pigs Fly (or Teleport)

I expect to see some pretty amazing technological developments over the coming decades, but I am certain that the teleportation of matter will not be one of them.

There are two particularly intriguing sci-fi notions that come up regularly in physics lectures as well as fantasy films, and they are time travel and teleportation.  I am often asked which feat will be accomplished first by man.  I believe that travelling instantaneously along the dimension of time is actually more feasible than doing so across a dimension of space. 

Einstein’s special relativity shows that the universe allows matter to travel forward in time (although travelling backwards in time may not be permissible).  All one must do to travel forward in time is move at a very high velocity, near the speed of light (300,000 km/s).  Einstein showed that accelerating mass to such extreme velocities requires a tremendous amount of energy; so, it is difficult and costly, but not outside the realm of possibility.

Imagine for a moment that a high speed train were to circle the equator at near light speed on a fixed path.  The clocks on the train would run slower, and the passengers would age slower than if they were sitting stationary on the Earth.  Unfortunately, the centripetal acceleration of the circular motion would not allow the train to stay on this fixed course (it would fly out into orbit).  Also, the frictional losses would be enormous.  The only practical place to perform forward time travel is likely in outer space, where there are no effects of friction.

Travelling backwards in time requires faster than light travel (tachyon speeds), but light speed seems to be a firm boundary that no matter can exceed.  In any case, if it were possible to travel backwards in time, we would expect to have met time travellers from the future at some point, and to my knowledge, we have not encountered any as of yet.  Back to the Future is a phenomenal film, but it is sheer fantasy.

Teleportation would be a real game-changer for mankind.  Transporting matter around the Earth (be it living or non-living) takes so much energy and time.  While teleportation would likely require vast amounts of energy, the time of travel would reduce to zero – once you clear customs.

While there is a scientific basis for how time travel can occur, there is none for teleportation.  The most realistic concept was depicted well in the 1986 re-make of The Fly

In the film, a scientist builds two pods (one for departure, and another for arrival).  However, the matter does not actually get transported from one pod to the other.  The matter inside the first pod is chemically analyzed and then vaporized.  Then, the information is sent to the second pod, which attempts to re-synthesize the same matter that was in the original pod.  Teleportation infers instantaneous transport, while what occurs in the film is a two-step process: decomposition and creation.

The scientist had created a chemical photocopier, not a transporter.  While the invention would be ground-breaking, no person would use it to get to work in the morning.  Rather than being transported, they would be killed and then newly regenerated at work – not a good way to start the day.  Oh, and be warned:  if a housefly happens to join you in pod 1, you will die a horrible death over the coming weeks.

On one hand, it really is too bad that teleportation will not be realized in the foreseeable future.  So much of life consists of moving stuff from one location to another.  I have a flight to Vancouver in a couple of days, and it would be nice to bypass the experience, arrive at my destination, and know with certainty that my luggage would too.

On the other hand, transport can be a lot of fun.  Imagine adolescence without road trips, or camping without canoeing.  Often, getting there is the best part.  Ralph Waldo Emerson had it right: “Life is a journey, not a destination”.  

Tuesday, July 19, 2011

The Internet's Energy Bill

It is easy to overlook some of the energy costs associated with our daily lives.  We pay close attention to the energy required by our car and home climate control as the consumption occurs directly before us, and the use hits our wallets hard.  Until recently, I had never thought about the energy costs associated with internet use.

I am not referring to the energy used by my home computer when accessing the internet – we are all well aware of this.  I am actually referring to the land-based processors that my server calls upon when using the internet.  It turns out that the amount of energy consumed by these massive centers is anything but negligible.  But, as these facilities are located so far from us, we give no thought the energy they consume.

The other reason we think nothing of the cost of the processors called upon for web-surfing is because we do not foot that bill.  These energy costs find their way to the companies that are responsible for the processing, and no company processes more than Google.

Every time you conduct a search on Google’s engine, processors far away crunch some numbers very quickly to yield millions of results for you and organize them in terms of relevance.  This processing comes at a cost: there is no such thing as a free search.

One percent of all power produced on Earth is consumed by internet processing centers.  That is comparable to the entire consumption of a small to medium-sized developed country.  The piece of the power plant pie devoted to internet processing is expected to grow significantly over the coming decades.  As such, companies like Google pay close attention to the cost of a kW-hr in the regions where they plan on setting up shop.

Our access to and sharing of information via the internet is a precious commodity that we often take for granted.  Those of us who are more environmentally conscious may become more selective about our internet use, as the link between energy use and global warming is well-known.  As for Google, I have a suggestion on how to save them a few Joules here and there: Do we really need millions of search results?

Thursday, July 14, 2011

A Quick Farewell to the Shuttle

In a matter of days, Atlantis will return from its final visit to the International Space Station (ISS).  Its return to Earth will represent the end of the American Space Shuttle Program.

It is fair to say that to this point, man has merely "dabbled" in space.  Man has seen very little of space, and only a small number of men and women have reached altitudes beyond our atmosphere.  Still, the shuttle program is the most impressive dabbling we have done to date, and we have NASA to thank for it.

Atlantis and its sister ships (Endeavour, Discovery, Challenger, and Colombia)  have been shuttling astronauts to and from the ISS on a regular basis like tourists to a far-out hotel.  In so doing, man has maintained a continuous presence in orbit, and have developed the ISS into a humble home.  The ISS is like a high tech country house, but one further off the beaten path than that of The Shining.

Over the coming years, America will need to hitch a ride on another nation's ship to access the ISS: the Russian Soyuz spacecraft is the only one that can carry a crew.  There are several other Russian, Japanese, and European ships that can shuttle supplies to the ISS.

In its storied history, the shuttle program saw many highs and lows.  The 1986 and 2003 disasters of Challenger (lift-off) and Colombia (re-entry) claimed the lives of 14 astronauts collectively.  The fact that 2 out of the 135 flights that the various shuttles took ended in disaster illustrates how dangerous manned spaceflight truly is.

In addition to being dangerous, the shuttle program has been expensive: 200 billion US dollars in total.  A typical transit (with return) to the ISS costs 500 million US dollars.  Given the current economic woes plaguing the United States along with most other nations, man's presence in space may begin to dwindle over time.

The retirement of the space shuttle severely diminishes man's access to space.  Imagine the mess an island city would be in if its most popular bridges were suddenly closed with no plans to build new ones (my local Montreal readers can relate to this circumstance).

Tuesday, July 5, 2011

Our Orbital Junkyard

The expression “Out of sight – out of mind” is often used to rationalize why people are comfortable contributing massive amounts of trash to their local landfills.  The issue of tossing out our junk is easily ignored, as the landfill is not in our backyard.  If it were, the amount of junk tossed by the average person would decrease drastically.

A little farther from our local landfill, tons upon tons of waste that does not make it to a designated land disposal site eventually floats to an undesignated water-based one.  Sadly, 20% of the Styrofoam that is produced finds its way into the ocean, where it slowly decomposes over hundreds of years.  Unbelievably, square kilometres of the stuff are floating in certain locales of our hydrosphere.  If this insult to our environment were floating in a lake in your neighbourhood, it would be hard to ignore.  As it floats hundreds of miles away, it is out of mind.

It is not surprising then that man continues to fill yet another of its reservoirs with waste: our orbital environment.  To quote the film Wall-E, “There’s plenty of space up in space!”  Indeed, what could be a better place to store our junk?  The space beyond our atmosphere is plentiful, and it is most certainly out of sight – unless of course you happen to be aboard the international space station, in which case even small space debris poses a life-threatening risk.

What is meant by space junk?

Most objects that orbit the Earth began on Earth.  While hundreds of satellites are currently operational, thousands of them are decommissioned.  Once satellites are no longer used, they are not physically brought down from orbit, as to do so is prohibitively expensive. 

Beyond our atmosphere there is no drag force, no fluid to push up against.  In a car, boat, train or plane, it is expensive to thrust forward, but free to press the brakes.  In space, slowing down by 100 m/s is just as expensive as speeding up by 100 m/s.  For this reason, satellites that are placed in orbit remain there indefinitely – all satellites are destined to be space junk eventually.

Saturday, June 25, 2011

Life as a Mass on an Inclined Plane

The motion of a mass on an inclined plane is perhaps the most classic introductory mechanics problem.  Over the years, as a student, and then later as a physics teacher, I have analyzed more than my fair share of these kinds of scenarios.  I must admit, as an engineer, I have yet to encounter a problem of this type in the field – I have never been asked to design a block or inclined plane, nor have I been asked to verify that Newton’s 325-year-old laws still apply to it.

Do I think all of the time that physics students spend examining masses on inclined planes is wasted?  Of course not – the simple scenario clearly illustrates the most important law of mechanics (Newton’s second law), and is a necessary stepping stone towards analyzing more complex situations.  

There is, I believe, a secondary usefulness to examining such systems that extends beyond the practical realm.  Let us take a close look at a mass as it slides up or down a banked surface; I contend that it serves as a powerful metaphor for life.

I know what you are thinking: this guy has drawn one too many free body diagrams.

Wednesday, June 15, 2011

A Scientific Road Map

Science is my favourite realm of study.  Although physics is the branch that I am most comfortable with, I find science as a whole very fascinating.  It seems to me that science can be broken down into five categories: physics, chemistry, biology, psychology and sociology – in that order.

How do these five pillars relate to one another?  What is their connection?  Consider the following simple organizational chart.


A Scientific Road Map

Monday, June 6, 2011

Christopher Hitchens on God and Religion


The real “miracle” is that we, 
who share genes with the original bacteria that began life on the planet, 
have evolved as much as we have.            
- Christopher Hitchens, God is not Great

After reading an article of mine, which discussed God’s role in the universe, a friend recommended that I read the work of Christopher Hitchens.  He is an intellectual, a journalist, and a proud atheist.  He famously enters debates with religious leaders or advocates, and clearly comes out ahead (a quick YouTube search will confirm as much).  On top of having a sharp mind, he has a cunning wit, and does not hold back for fear of insulting those on the other side of the debate, or those who watch such debates intently.

I recently came upon Hitchens’ 2007 book, “God is not Great: How Religion Poisons Everything”.  It turns out that Hitchens is every bit as forward as a writer as he is as a speaker.  He devotes nearly the entire book to debunking various religious myths; from west to east, no religion is spared.  The theme throughout is the notion that freedom of thought and expression have been repressed by barbaric religious leaders throughout mankind’s history, and it is time that such bullying come to an end.

Friday, June 3, 2011

Summer School

In the month of June, as most students are beginning to think about summer camp, or a temporary job, some students are beginning a new semester of school.  Whether they are retaking a failed class or trying to get ahead in their studies, summer school is not how most adolescents would like to spend their summer.

I have an unusually high interest in the notion of summer school this year because, for the first time, I will be teaching a class during these hot months.

Summer courses are much like fall or winter courses.  The classrooms are the same, but tend to have fewer students in them, and are filled with much hotter air.  Most institutions I know of, mine included, have no air conditioning.  I plan on wearing sandals to work. 

I suppose the main difference between regular semester courses and summer ones is that students sitting in class during the summer do not want to be there.  Let me rephrase that ... However much a student wants to be in a classroom under normal circumstances, they want to be there in the summer less.

Tuesday, May 31, 2011

Go Nuclear or Go Home

My previous article gave electric cars a conditional two thumbs up as a way of reducing man’s level of carbon dioxide emissions.  The condition is that fossil-fuel-based energy production, which represents about 70% of the total current global energy production, is phased out as EVs are phased in.

A complete makeover of our power plant infrastructure is a daunting task from an economic perspective.  The amount of energy consumed by man is already tremendous, and the demand is going to increase dramatically as certain populous countries develop and cars begin to go electric.  If fossil fuel power plants are to be shut down, what can they be replaced with?

At present, there is only one alternative that can meet the high demand: nuclear power plants.  Solar and wind, while renewable and green, are only effective in certain locations and even then do not give nearly as much bang for your buck.  Put simply, we cannot, at present, expect to meet more than 20% of our global energy production demands with wind and solar.  Perhaps, by the mid-twenty-first century, this percentage will be much higher. 

While nuclear plants do create radioactive waste, the waste can be contained, in contrast to coal plants, which release CO2 directly into the atmosphere.  The sheer amount of waste in the case of nuclear is comparatively so much less because it is 750,000 times more mass efficient then coal.  One kilogram of coal, when burned, can power a 100-Watt light bulb for eight hours.  The fission of one kilogram of enriched uranium can power the same bulb for 690 years.

As an aside, try to imagine the effort involved in acquiring the billions of tons of coal that are burned globally each year.  How can this inefficient practice be cost-effective?  The only reason that the energy produced per dollar by way of coal burning is similar to that by way of nuclear reactor is because the coal miners are not justly compensated for their work.
 

Monday, May 23, 2011

Electric Cars Alone Solve Nothing

There was a time when, in my view, the subject of this article would have seemed too trivial to bother with – how naive I was.  Thanks in large part to misinformation campaigns by oil pushers, the public at large remains grossly oblivious to climate change issues. 

When false science permeates the media it leads to confusion among many, which can lead to frustration on their part.  The long-term consequence of misinformation is an apathetic society.  Apathy is a sad but accurate description of how a large proportion of the North American population feel about climate change.

The electric car on its own is not really a green solution.  Traditional gas-guzzling cars have internal combustion engines that convert fossil fuels into energy to power them, while outputting significant amounts of carbon dioxide into the atmosphere in the process.  Carbon dioxide is a greenhouse gas, so-named because it transforms the Earth’s surface into a greenhouse, trapping sunlight in, and gradually causing the surface temperature to increase.

What many fail to recognize is that an electric car, which requires no fuel, does require electrical energy; the first law of thermodynamics stipulates that the energy must come from somewhere.  Electric car batteries are charged by plugging them into the local electrical grid, like a cell phone battery.  The big question is then what powers your grid?  Globally, the answer is fossil fuels 70% of the time.  If you live in an area that is powered by coal for example, you are no further ahead environmentally by swapping for an electric vehicle.  You are simply diverting the CO2 spewing from your car engine to your local power plant.

On the other hand, if you live in an area that gets its power from a non-fossil fuel source (nuclear, hydro, solar, wind...), then you are indeed reducing your carbon footprint effectively.  If you are in this 30% minority, you should commend your government for it.  If we are serious about curbing our carbon output, then as electric cars are phased onto our roads, fossil fuels must be phased out of energy production.

Thursday, May 19, 2011

Are we Just Bags of Chemicals?

What am I?  There are many ways to answer this philosophical question, but let us take a scientific approach.

The universe is composed of indivisible building blocks.  An electron is one example of such a building block, and physicists today seek to find other yet unknown examples of such particles.  All matter in the universe is composed of atoms, which are composed of the aforementioned subatomic particles.  The over one hundred known elements (kinds of atoms) all originate in stars, where extremely high energy collisions occur between atoms.  These collisions cause atoms to fuse together to form bigger ones in a nuclear process known as fusion. 


Ninety nine percent of the fusion reactions in stars involve hydrogen and helium.  But, if not for the remaining 1% of collisions, which fill in the periodic table, there would of course be no carbon, and then, no organic matter, and no life.  Life is an unlikely and bewildering occurence in so many ways.

Chemicals are combinations of atoms that have bonded together.  While there are only about one hundred known elements, there are millions of known chemicals, each with specific properties.

A person is an organism, which is composed of many systems, which are collections of organs, made up of tissues, which consist of cells.  The biological building blocks of a person are cells.  While cells are living matter, they are matter just the same; cells are made up of the atoms, whose origins lie not in the heavens, but in the stars.  What are we?  As the very famous astrophysicist, Neil deGrasse Tyson, likes to put it, "We are stardust."

Thursday, May 5, 2011

Hawking's Grand Design

I read Stephen Hawking’s most recent book, “The Grand Design” (co-authored by Leonard Mlodinow), and highly recommend it, particularly to those who have never read a Hawking non-fiction before.  My only negative comment is that the book is short.  Even a slow reader like me can complete it in just a few hours.  Hawking, the rock-star physicist that he is, always leaves me wanting more.

“The Grand Design” was not well-received by religious groups, as it points out that God is not necessary for the universe to exist.  This comes as no surprise, as religious groups are particularly displeased whenever arguments are based on observation and reason. 

Friday, April 29, 2011

The Ins and Outs of Control

Control is a major branch of engineering, but one that rarely gets much credit, bowing to more popular fields like robotics and computers, both of which play important roles within many control systems.  Contrary to what the title for this article might suggest, my intention is not to communicate an in-depth understanding of the details of control theory.  My aim is to provide an introduction of what control systems are, and how they work.  But I just couldn’t resist the title, because as we will soon see, control is all about inputs and outputs.

These days, people want devices they can control.  However, we tend to ignore the fact that the actual control of such systems takes place behind the scenes, in a control box.  The systems that people interact with are autonomous – the user inputs the desired output, and the control system takes care of the rest.

Whether the system in question is the cruise control of a car or the heating of a home, the only parameter that users can manipulate is the input.  For the car, the input is the desired velocity to cruise at, and for the home, it is the desired air temperature.

The control of a given system can be broken down into three parts: input, transfer function, and output.  The input is what the user wants the controlled parameter to be while the output is its current value.  The transfer function is the guts of the control system, which aims to make the output equal to the input.  The output is recorded by some kind of sensor.

Sunday, April 24, 2011

Immobility in an Over-Constrained System

The most enduring quote in the fiction, Life of Pi, is perhaps: “To choose doubt as a philosophy of life is akin to choosing immobility as a means of transportation.”  There are many things that render us immobile in a philosophical sense.  Perhaps the most prevalent reason why people give up is because they are simply overwhelmed.

There is way too much to try and get right in this day and age.  You need to take care of your kids and/or parents, your significant other, and of course, yourself.  You need to exercise enough, eat right, maintain good hygiene, work, pay taxes, and get vaccinated (not necessarily in that order).  It is also recommended that you find a hobby, spend time with friends, and get involved in your community.  If you are a parent, the to-do list is compounded by things like hockey practice and meet-the-teacher night.  We sign up for so much in life, and then struggle to meet the demands they entail.

Engineering projects can find themselves in a predicament similar to that of overwhelmed people.  When constraints in a project begin to press up against one another, the engineer caught in the middle tends to feel suffocated.  The typical reaction to this is usually the most dangerous one: the engineer is rendered immobile.  I have been caught together with a team of engineers in a scenario of this type, and learned a very valuable lesson from it: indecision is in fact worse than a wrong decision.

Sunday, April 17, 2011

The Mechanics of Sports Injuries

“Oh crap!!!” is the first thought that runs through your head as you lay on the field/ice/court in excruciating pain immediately following a sports injury.  Whether it is an ankle sprain in soccer, a dislocated shoulder in football, or a broken wrist in basketball, sports-related injuries are painful and frustrating, but unfortunately, inevitable.


The second thought that runs through the injured athlete’s head is, “I wish I could take the last moment back.”  It is an appropriate thought to have, as whenever a collision occurs, the severity of the injury is dependent on just how short the duration of the collision was.  Although impacts in sport between two athletes appear instantaneous, there is actually a small amount of time over which they take place, which we will refer to as dt

Friday, April 8, 2011

The Engineer's Virtual Toolbox

 It was not that long ago that I was a science student applying to an undergraduate Mechanical Engineering program at McGill University.  In hindsight, I really did not know much about the profession of engineering at the time, and it is not hard to see why.  Introductory physics courses can give a student the impression that engineers spend their mornings drawing free body diagrams, and their afternoons predicting the accelerations of blocks sliding down a smooth inclined plane.

There is a lot to know about physics, and early on, a great deal of time must be spent learning theory, and applying it to solve simple problems.  As such, a student cannot be faulted for thinking that a few equations, pencil and paper, and a calculator, are all the tools necessary to complete real world engineering problems.

In real life, when one is designing anything from a bridge to a car, today’s engineering problems are solved with two overlapping methods.  The first method is analytical, and the second is numerical.

The analytical method is similar to the approach taught in science courses.  The complex problem is simplified via good approximations – it is transformed into something that can be solved with a pencil and paper.  Problem solving of this sort gives the engineer a rough estimate of what the result might look like in the end.  It gives a sense of direction for where the design might be headed; it is sometimes called a ‘first cut’, or an ‘order of magnitude solution’.

However, the majority of an engineer’s problem solving time is spent using numerical methods imbedded in virtual tools.  There are many software tools for every field of engineering that allow the user to solve very complex problems with a high degree of precision.  At the click of the mouse, a simulation calling on some governing equations of physics can be run on whatever design you have fed to the software in whatever environment you desire.  Want a picture of the stress distribution in the body of a roller coaster car as it travels along a track?  There is a virtual tool for that.  Want to see the temperature distribution within a satellite as it orbits the Earth?  There is a virtual tool for that too.

Tuesday, April 5, 2011

Not All Engineers Are Handy

I am an engineer, and I am not handy.

If you are the accountant in your family, you probably get financial questions from your friends and family members – particularly around tax season.  If you are the doctor in the family, you are probably inundated with medical questions from aging parents or in-laws, hoping to save themselves a trip to the clinic.  Although talking shop when not at work can be annoying, it is nice to be able to help family and friends by sharing your expertise with them.

If you are an engineer, you may receive a call from time to time from a friend when something of theirs breaks.  Engineers like to talk shop; unlike the doctor or accountant, engineers are excited that someone has taken an interest in what they do.

The thing is, not all engineers are endowed with practical abilities. 

There are two sides to engineering: theory and practice.  Most of University is spent acquiring theoretical knowledge.  Mechanical engineers, for example, take many math, mechanics, thermodynamics, and fluids courses.  Very little time is spent educating engineers on how to apply their knowledge in a “hands-on” kind of way.  They may do projects in heat transfer where they design the optimal spacing of a double window pane for a given winter climate, but they will not be required to install the window.

Friday, April 1, 2011

Resolving Conflicts With Newtonian Mechanics

The 2005 film, Crash, won the “Best Picture” award at the Oscars, and is one of the best dramas I have ever seen.  The movie follows several characters that are involved in negative interactions fuelled by racial differences and hate.

Watching these intense situations play out from a distance is thought-provoking and highly entertaining.  However, experiencing such conflicts first-hand is often very stressful.  One-on-one confrontations between strangers, colleagues, friends, and, worst of all, family members, can be extremely detrimental to one’s personal equilibrium. 

A person is like a particle moving along through space – if left to one’s own devices, one will continue along pleasantly, unaffected.  This is predicted by Newton’s first law of motion, which says that an object in motion will only change velocity if a non-zero net external force acts on it.  One way to think of Newton’s first law is that life would be dull if we just kept to ourselves.  Going through life with constant velocity is no fun; human contact makes for a far more interesting journey.

One of the characters in Crash goes so far as to suggest that people seek out conflicts because they are bored or lonely – as though colliding into one another is a mechanism that people use to confirm they are still alive.

A life that is completely devoid of conflict is boring.  On the other hand, a life that is filled with destructive interactions is too stressful.

Like particles floating in the air, or cars driving on the road, people moving through life will inevitably collide with one another.  Usually, these collisions are positive, like a friendly hello from a neighbour.  Sometimes, however, people collide in an explosive manner, like when colleagues disrespect one another.

Sunday, March 27, 2011

The Helicopter: A Fragile Fish

Helicopters do not have a lot going for them.  They are expensive to buy as well as operate, somewhat odd-looking, and, if movies like Die Hard 3 and Cliffhanger are reliable sources of information, they can be brought down with a hand gun or a rock or some rope... pretty much anything nearby.

Helicopters are fairly vulnerable pieces of hardware, but it takes more than a knock in the rotor to drop them out of the sky.

I have traveled by planes, trains and automobiles, but never by helicopter.  From an engineering standpoint, they scare me.  Where possible, it is good to avoid single-point-failure scenarios.  If one airplane engine were to fail, most airplanes can still be flown with the remaining engines.  If the main rotor blade of a helicopter were to fail mid-flight, down it goes.  The main rotor is responsible for the lift force, and without it, it is time to look for a good parachute (and then a good lawyer).

How does a helicopter navigate around?  The principal force is generated by the main rotor, which spins very quickly, displacing vast amounts of air in exchange for lift upwards.  If it wants to maintain altitude, the lift force upwards must be equal to the weight downwards. 

Wednesday, March 23, 2011

NASA vs. CSA

Nearly everyone on planet Earth has heard of the organization called NASA.  They may not know that NASA stands for National Aeronautics and Space Administration, but they do know that it runs the world’s most successful space program.  Though founded in 1958, NASA was immortalized in 1969, when it sent a man to the surface of the moon.  The event was the landmark of the twentieth century, and cemented the United States as the world leader in space exploration. 

The economic benefits that the United States reaped from its lunar landing cannot be overstated.  Leaders in aerospace are leaders in technology, and leaders in technology are economic superpowers.  If the American energy and auto industries matched the level of excellence of NASA, the United States would be technologically untouchable.

I would bet that the vast majority of Canadians haven’t a clue what CSA is.  The Canadian Space Agency is the Canadian equivalent of NASA, but the two organizations are hardly equivalent.  CSA is a fine organization.  They participate in the expensive practice of space exploration on a meagre budget; it is however the level of funding of national space organizations that determines the extent to which they may participate.

Here is an order of magnitude scale for the kind of aerospace related activity you can afford for a given amount of American dollars in 2011:

$100,000,000,000                 Manned interplanetary mission
$10,000,000,000                   Manned lunar mission
$1,000,000,000                     Unmanned rocket for satellite placement
$100,000,000                        Complete communications satellite or a 747 airplane
$10,000,000                         Space payload (eg, Satellite Antenna)
$1,000,000                           Basic helicopter
$100,000                              Half a tank of gas for a 747 airplane
$10,000                               One foot wide meteorite (collector’s item)
$1,000                                 Typical coach plane ticket with return
$100                                    Nike sneakers to jump as high as you can
$10                                      Movie ticket for Apollo 13
$1                                        Paper airplane

Friday, March 18, 2011

Breaking the Sound Barrier

The expression “sound barrier” refers to the speed of sound in a given medium.  In the field of aerospace, which studies motion through air and space, the medium in question is air.  Space is a vacuum, which is no medium at all.  Sound can only travel if there is a medium to carry its information from one neighbouring molecule to the next.  As such, sound does not travel outside our atmosphere, contrary to what silly movies like “Armageddon” would lead one to believe.

What is the speed of sound in air?  It is dependent on two factors associated with the air itself: its density and its bulk elasticity.  For standard atmospheric conditions, the speed of sound in air is about 340 m/s.

When an object travels through the air below this speed, its motion is said to be subsonic.  The term Mach number (M) refers to the ratio of a vehicle’s speed to the speed of sound of the medium it travels through.  A typical commercial airplane may travel around 170 m/s, or M = 0.5.  Jets travelling beyond 340 m/s are supersonic.  When an aeronautical engineer hears about Mach 4, he or she thinks of supersonic air travel, and not a Gillette razor. 

Monday, March 14, 2011

One-Way Mission to Mars

About four decades ago, Elton John sang, “Mars ain’t the kind of place to raise your kids ... In fact, it’s cold as hell.”  As Mars is the fourth planet from the Sun, this statement remains true today.  So, when the first human visitors land there some decades from now, they will probably have left their kids at home on Earth – and they will probably never see them again.

I am not predicting that the first manned mission to the planet Mars will fail.  I am merely predicting that the first trip to Mars will be a one-way trip. 

The brave souls who volunteer to take on this expedition will probably do so realizing that their lives will never be the same.  No more blue and green Earth.  They will most likely live out the remainder of their lives trying to survive on the inhospitable planet, while using any extra available time to establish some kind of home base for future human visitors to make use of.

Why will the first Mars settlers never walk among us again?  It is for the same reason that sending people to Mars is such a challenging endeavour in the first place: it takes a lot of fuel.  If we send the spacecraft with the quantity of fuel it will require to eventually lift off of Mars and return towards Earth, the entire original payload will be simply too heavy.

Thus, if a manned mission to Mars is to occur before an alternative method of space travel, such as the space elevator, is implemented, the trip will be one-way.  In all likelihood, an adventure to Mars will precede the space elevator’s construction.  Therefore, NASA had better start digging through its potential list of candidates, and identify anyone that is qualified to undertake the mission, comfortable with the concept of never returning to Earth, and also mentally sane.  The list will be a short one.

Wednesday, March 9, 2011

Why Don’t Airplanes Flap Their Wings?

The distance between the average person and their tools has grown a great deal over the past century.  There was a time when the average adult was fairly independent: they could grow and catch their own food, build their shelter, and manage their own health, albeit for their forty-year lifespan.  When the tools that were used in society were primitive, it was not difficult to understand how they worked, in a general sense.  Today’s tools are not primitive, and they continue to advance exponentially.

That being said, aircrafts have been taking flight for over a century.  The latter half of the twentieth century saw the friendly skies open up to even middle class passengers.  Air transit is now a typical form of transportation.  It is normal for a new technology to appear mysterious, even magical, to the common man.  However, one would expect the common man to comprehend the basics of a relatively old technology such as aviation.

I am fairly positive that more than 80% of the passengers aboard a given flight today haven’t a clue as to how the airplane is flying.  Perhaps they feel better chalking airplane travel up to magic.  I have news for you: the pilot is not a magician – he or she is just an operator of a well-tuned piece of engineering hardware.

Thursday, March 3, 2011

The Space Elevator: Past, Present, Future

There are two main reasons why, for the past sixty years, man has launched rockets from the surface of the Earth. 

The first reason is to place satellites into an orbit around our planet.  The moon is a Celestial body that orbits the Earth in an elliptical fashion at an average of about 380,000 km away from the Earth.  Other than this large body and other small space debris that orbit the Earth, all other bodies that do so were placed in their respective orbits by man to serve some purpose.  One can think of an orbit as a path that a falling object takes continuously around a larger body.  Much in the way that a baseball’s path curves to fall towards the Earth once it is thrown, an orbit is in a perpetual state of falling.  The difference is that the orbiting body is moving much faster than the baseball (think kilometres per second), and the baseball faces the resistance of air, whereas the drag forces in space are negligible. 

It boggles the mind, but we (and when I say we, I mean America and Russia) have transported thousands of satellites into space.  Most satellites are used for communication, be it internet, phone, or television, while some are used for Earth observation leading to weather prediction, the tracking of oil spills, and the marvel that is Google Earth.  Most satellites are located hundreds of kilometres above the surface of the Earth (note that an airplane’s altitude rarely exceeds 12 km) in an area known as LEO (Low Earth Orbit).  

Another popular zone is at the GEO (Geosynchronous) altitude of about 35,800 km altitude; this is a special altitude for which the orbital period of a satellite is the same as that of the Earth.  If one were to stand on the equator and stare up at an equatorial GEO satellite, one would observe no motion at all.  It would be as though the satellite were attached to the Earth by an invisible cord.  The typical operational life of a satellite is fifteen years.  As such, the majority of satellites currently in orbit are decommissioned and commonly referred to as space junk.

The other reason for which man sends payloads to space via rockets is for interplanetary travel.  Such ventures are done in the name of research, observation, exploration, and discovery.  Sometimes these payloads contain astronauts, as in some trips to the moon, but often these are unmanned missions, or probes, investigating, for example, Mars or Saturn’s moons.  The missions are very exciting, sometimes providing answers to important scientific questions, other times demonstrating what we can achieve when we put our minds to it; the 1969 moon landing was perhaps the defining moment, technologically speaking, of the twentieth century. 

An even more formidable task would be sending man on a return trip to Mars.  The greater distance to Mars as well as the greater Martian escape velocity means that the payload leaving the Earth would be much more massive than that for Apollo 11.  Also, the trip length (years instead of days) would make the challenge for the astronauts far greater.  However, it is the issue of the large mass which makes the Mars mission unrealistic today.  Transporting mass away from the Earth using rockets is prohibitively expensive.  The cost for satellite placement in GEO is in the area of $10,000 US per kilogram of payload; it is substantially greater for interplanetary travel. 

In today’s space industry, every gram is questioned.  In order for a payload to achieve the escape velocity required for interplanetary travel, over 90% of the mass leaving the Earth must consist of fuel; this is a chemical constraint associated with rocket travel.  For this reason and others, the rocket will probably not be the principal mode of travel used to escape the Earth’s gravity fifty years from now.  

The most promising upgrade from the conventional rocket appears to be the space elevator, which could reduce the cost to GEO to as low as one hundred or even ten dollars per kg (reducing satellite placement costs by at least a factor of one hundred).  An operational space elevator, which would carry no fuel, would open up space to mankind; it would bridge the gap between us and the vastness we see when we stare up at night, both figuratively and literally.