Montreal's Revamped Planetarium Worth a Visit

Just because your dad teaches physics and writes science articles as a hobby doesn't necessarily mean that he will take you on a field trip to a planetarium - but it certainly does increase the odds.  I took my four-year-old to Montreal's relocated Planetarium this past weekend and would recommend it to others.

Chief Technical Editor of Climb

When I look at other fellow engineers, there is one trait that we tend to share besides the obvious ones (affinity for Star Wars, unwarranted big egos, etc): lots of extra-curricular activities.  Most engineers that I know play in a sports league and are involved in multiple projects outside of their actual profession.

I play on a soccer team, drum in bands from time to time, and manage this blog.  Well, I now do something else - this week I was asked to be the new Chief Technical Editor of Climb, the Space Elevator Journal affiliated with ISEC (the International Space Elevator Consortium).

Cover shot of Climb, Vol. 1 (courtesy of lulu.com)

Orienteering is all About Finding Your Way

As a thirty-one-year old, it is refreshing to do something for the first time.  Such was the case last weekend when I went orienteering with my family at a large green space near my home.

For the uninitiated, orienteering is a sport whereby individuals or teams locate 'x' number of checkpoints in a specific order in an open space in as little time as possible equipped with only a map and a compass.

Groups of people of all levels of experience showed up last week: there were four levels of maps and corresponding checkpoints ranging from 'first-timers' to 'advanced'.  Much like the 'spice level' I that I tend to select at an Indian restaurant, we chose level 1.  It was easy to identify the level 4 orienteers - they were the ones popping in and out of thick forest as though the trees and bushes were not there (they were also the ones sweating).

If you want to be a bad-ass orienteer, you need a bad-ass hat

Homogeneity is Overrated: the PQ can Keep Their Charter

I am so sick and tired of the elected leaders of this province I live in called Quebec.  Today, the leaders of the Parti Quebecois (PQ) have put forth a Charter of Secularism which, among other things, forbids public servants from wearing religious garb while performing their duties.  As an educator at the college level, I am a public servant, and though I almost never wear a kippa in my day to day life, I don't see what business it is of this provincial government if I should decide to do so one day.

The minister in charge of what I would call the charter of division, Bernard Drainville, defends the proposed changes to civil servant dress code as follows: "If the state is neutral, those working for the state should be equally neutral in their image."

When one sports a religious symbol, one's capacity to perform one's duties is undiminished.  If the population is so offended by workers wearing such symbols, then what they need is a lesson in tolerance; they do not need legislation that reinforces such xenophobia.

When I look at the richness of the matter that is around us, I see heterogeneity.  I see hundreds of different kinds of atoms that intermingle in countless ways, forming compounds, each exhibiting unique properties.  The diversity of matter can serve as a model for society.  It saddens me that Pauline Marois, Quebec's Premier, sees multiculturalism as a threat to her Quebecois ether.

I want to live in a society where one's belief system is outside state jurisdiction.  Those behind this charter would likely deem it to be progressive, but it is clearly regressive.  It's aim is unmistakable: to make those whose heritage is not Quebec feel unwelcome.

I could rant on and on about this, but I need to prepare a lecture on mixtures.  As a civil servant, I will fulfill my duty, and focus only on homogeneous ones.

The Wright Brothers Stood on Cayley's Shoulders

Sir Isaac Newton famously expressed that in order to make his numerous contributions to science, he stood on the shoulders of giants.  This seems to be a modest claim given the huge individual leaps of intellect he made.  A book that I recently read, "The Man who Discovered Flight: George Cayley and the First Airplane," by Richard Dee, had me thinking about the notion of how we are always continuing the work of our predecessors.

When any of us think about the first airplane, we invariably think of the Wright Brothers and their historic achievement; few have ever even heard of George Cayley.  Cayley's contributions to aviation were numerous, but they preceded the Wright Brothers' flight by about a century.  Consider this excerpt from Dee's book:

"Within the course of six scribbled pages in his notebook, Cayley had shown that man-made flight by wing was a theoretical possibility, but practically, with engineering constraints as they were at the time, it was a non-starter.  So having discovered that it could happen and then almost immediately proving that it couldn't happen yet, what next?"

Elon Musk's Hyperloop is Bold and Ambitious

Perhaps you've heard of the recently proposed revolutionary transportation system dubbed the Hyperloop.  No?  Google it.  The vast majority of posts on the topic that I have read go beyond mere skepticism and describe the project as just short of impossible.  What is it about dreamers that brings out the haters?

The Hyperloop was described by its inventor, Elon Musk, as "a cross between a Concord, a rail gun and an air hockey table."  Picture those hollow tubes that shuttle documents through offices by way of air pressure (in movies - I've never actually seen one in real life, but I assume they exist).  Now enlarge the diameter of the tube, replace the tiny capsules with pods containing passengers, and have the ends connect two distant cities, and you begin to grasp Musk's intriguing mass-transit system.

The initial proposal calls for a train that links Los Angeles and San Francisco - the specs call for a thirty-five minute shuttle time each way.  The distance between the two cities is about 600 km.  Is this beginning to sound like a high-school mechanics problem?  Let's spice it up a bit and stipulate a 0.2 g acceleration from rest to cruise and 0.2 g deceleration from cruise to rest.  Try to calculate the cruise speed...

Why Has the Ozone Layer Continued to Deplete?

I've taken an eight-week break from blogging.  It's been the first long break since I began the blog in 2010.  The absence is owed not to having little to write about, but rather to having so little time to write it in.

Today, I'd like to write about an often misunderstood phenomenon: ozone layer depletion.

In my experience, the public at large believes that climate change and ozone layer depletion are very much connected, when in fact, the two are independent threats to life as we know it on Earth. 

Climate change, a.k.a. global warming, is a gradual increase in the average temperature of Earth's atmosphere brought about by the greenhouse effect, whereby certain gases, like carbon dioxide and methane, trap heat in the atmosphere.  Global warming is a much larger problem than ozone layer depletion as it can set off a multitude of other changes to our biosphere and it will be far more difficult to avoid.  It is in many ways the grim story of the 20th century that will inevitably haunt the 21st.

The fact that ozone layer depletion will not haunt us too badly in the 21st century and beyond is truly a success story.  It is a rare example where mankind acted responsibly as a species for our own preservation.

Polarization in Light and Politics

The essence of an electromagnetic (EM) wave is defined by two key parameters: its frequency and the strength (amplitude) of its electric field (E).  The strength of the magnetic field (B) is not a 'free variable' - it is given by E/c, where c is the speed of light.  Light is just one variety of EM wave.  It, like all others, is self-sustaining because the oscillating electric field produces an oscillating magnetic field and vice versa.  The relationship between the orientations of these fields and the direction of wave travel is shown below:

Figure 1: EM Wave Field Orientations (courtesy of: astronomy.swin.edu.au)

Here, the wave propagates in the x-direction, the electric field oscillates in the z-direction, and the magnetic field oscillates in the y-direction.  The electric and magnetic field vectors are always perpendicular to one another and exist in a plane that is itself perpendicular to the direction of travel of the light wave.  If the light wave is headed towards you, then you can be sure that the magnetic and electric field vectors span a plane that faces you.  The field vectors are separated by a right angle.

Wikipedia, a Surprisingly Reliable Science Resource

At first, an active encyclopedia written by and large on a volunteer basis sounds like an ill-conceived plan.  Considering that so much content on the internet is incorrect, the Wikipedia experiment was bound to fail.  But then, something strange happened: it actually worked.

The internet community, which can always be counted on for lewd YouTube comments dripping of ignorance and disrespect, somehow came together to compile a mass of information that is almost always factual (obviously, different parts of the community are at play here).  Yes, some donor money goes to pay tens of employees to overlook things, and do some fact-checking, but Wikipedia remains a database composed by tens of thousands of anonymous members of our global village, and is perhaps one of the best things to come out of the internet age.

Written mostly by amateurs, who have free time to spare, the volume of information grows at a staggering rate: thousands of pages per hour.  This kind of productivity at no cost, but reasonable quality, helps to explain why Wikipedia has flourished and the Encyclopedia Britannica has become all but irrelevant; oh, and did I mention it's free?

But here is the million-dollar question: "Do I encourage my science students to use Wikipedia?"

What Kind of Star are you?

Despite constituting the vast majority of the matter in the universe, stars are surprisingly simplistic.  A star spends nearly all of its life in hydrostatic equilibrium, whereby gravity pulls it inward as thermal pressure pushes it outward.  This state is known as the main sequence, during which countless Hydrogen atoms fuse to form Helium ones, and release energy in the process.

OK, that might not seem simple.  But, a star is simplistic in the sense that its entire future is quite predictable given its mass when this thermonuclear fusion process begins.  We can predict how long this steady radiation will endure based on this mass.  One might think that more massive stars have more fuel to burn, and will burn for longer as a result.  Though more mass does mean more fuel, it also means higher temperature and pressure, which means a greater fusion rate.  Massive stars actually live a far shorter life than less massive ones - lifetime is roughly proportional to M^(-2.5), where M is mass.

In the graph shown below, the approximate time a star spends in its main sequence is shown as a function of its mass ratio to the Sun.