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.

So, what, in my opinion, constitutes a life in crisis for a young adult?  A few examples that come to mind are being diagnosed with a serious illness, being forced into the role of full-time caregiver for a family member, or losing one's home due to fire or flood.  Some students of mine were forced to take on many more work hours to help pay for home expenses, while others dealt with legal issues. 

When I think back to previous semesters, it seemed as though about one in ten students was contending with a major problem such that it was affecting their studies.  Let us say then, to be very conservative, that 5% of college students will experience a major crisis during any given semester (I would prefer to consult a real study for this, but I do not know that such a study has ever been carried out).  A semester is 4 months long, while a typical college degree is 36 months long (three years). 

If, for any given semester, a student has a 5% chance of encountering a crisis in his or her life, then the statistical likelihood of encountering at least one such situation at some point during one's three-year degree is about 37% (this is found using a simple probability calculation under the assumption that all students have an equal chance of finding themselves in a situation of crisis).

I was fortunate to be part of the 63% category as a young adult student.  Although I faced challenges during my academic years as a young adult, none were so grave that they interfered significantly with my studies.  The first time I had to contend with serious adult concerns I was already a serious adult.  Looking back now, I can appreciate how lucky I was.

How prepared is an eighteen-year-old to accompany a parent to their medical visits and manage their pharmaceutical prescriptions?  Many adolescents are forced to 'grow up fast' due to circumstances outside of their control, but the trauma attached to such events can be quite heavy.  In the short term, my students experiencing trying circumstances see their educational experience suffer and watch their marks drop.  The long term effects of trauma can stay with them beyond adolescence and well into adulthood.

Here is another question: How likely is a young adult with the weight of the world on his or her shoulders to seek therapy to help them through trying times?  I suspect it is not very likely, as time and money are both scarce commodities for most people in such instances.  But without therapy, many of these young adults will struggle to regain their personal balance, and are at an increased risk of suffering from a wide range of mental health issues.

While a college cannot solve all of the personal issues that its students are contending with, there must be, and almost always are, services available at the college where students can seek assistance (student services).  Teachers can help by pointing students towards such services, but also by being understanding, and as empathetic as possible.

I suppose the real question is, "If there are more students by percentage in dire straits with nowhere to turn than ever before, why is this so?"

The most obvious first place to turn for an answer might be the fact that both parents now work, so have less time to spend with their young children and young adults too.  Furthermore, "The picket fence American Dream" is difficult to attain even with two incomes, such that now, many young students need to help pay the bills at home.  Decades ago, the solution was simple: kids dropped out of school if money was tight.  Today, this is not a viable option for students, as it represents career suicide.

I suspect that another factor causing some young adults to be placed in crushing circumstances, is the fact that we now live in a much more individualistic society.  By that, I mean that decades ago, a struggling young adult whose parents were deceased or not in a position to help would receive assistance from somewhere else within their community.  Perhaps an uncle, aunt, or grandparent would come to the rescue.  A family friend might have opened their door, or maybe a religious community could have been of service.

One of the hardest parts of my job is watching young adults fall through the cracks.  We, as a society, need to be aware of how challenging the lives of many of our young adults truly are.  With adequate support, and some luck, those struggling adolescents will emerge through their tough challenges, and transition into adulthood with a limited amount of scarring.  My wish to such students is that in the future, their greatest stress will be brought upon by an upcoming mechanics final exam.

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.

The idea of a space elevator came out of Russia in 1895, but was really just a figurative dream.  Yuri Artsutanov proposed a physical model for the structure in 1960.  Artsutanov showed how if an extremely long ribbon were extended from the surface of the Earth somewhere along the equator to a large satellite beyond GEO, the centripetal acceleration due to the spin of the planet would counteract its gravitational pull.  This ribbon would be in tension, providing a vertical railroad to be scaled by climbers containing payloads. 

In 1975, the feasibility of such a model was analyzed in depth by Jerome Pearson.  Pearson determined that while the setup would be physically possible, no known material could withstand the tension that would manifest in the ribbon due to the counteracting forces.  Indeed, a suitable material, we may call “Unobtanium”, would require a strength to density ratio fifty times greater than that of steel.  Steel is a hard material to lap fifty times over in a race.

In 1991, Sumio Iijima discovered Carbon nanotubes, which, if synthesized properly, could one day solve the material challenge that has long plagued the space elevator project.  Still in its infancy, carbon nanotube technology is evolving at a steady pace today, and may be able to meet the space elevator ribbon’s specifications in a couple of decades.  The current design for the space elevator, detailed by Bradley Edwards in 2003, includes climbers whose wheels grip the ribbon on both sides, and whose electric motor receives energy via laser from the Earth.

There are more than one hundred scientists and engineers in the world today doing research directly related to the space elevator; I am one of them.   My Master’s thesis in Mechanical Engineering was entitled: “Space Elevator Dynamics” (it is available at the McGill University library and in my parents’ living room).  I studied how the structure would move.  The ribbon itself would oscillate like a very long elastic band.  It would also sway back and forth due to external forces such as the wind in the Earth’s atmosphere and lunar gravitational fluctuations. 

Also, when climbers scale the ribbon to bring payloads to space, they would cause the ribbon to sway due to what is known as the Coriolis force.  Although understanding the dynamic behaviour of this amazing structure seems a bit premature today, it will be essential before construction, potentially some decades from now.  Other areas of research include laser-beaming technology and the avoidance of the orbiting space junk mentioned earlier.

Perhaps another hundred or so engineers and enthusiasts are participating in what is known as the space elevator games.  Two challenges with million-dollar prizes were issued by NASA.  The first contest is a material challenge.  The prize would be awarded to a team producing a ribbon that exceeds the strength per unit density of the top commercially available material by 50%.  No team has come close to attaining the mark thus far. 

However, the second challenge, which involves building laser-powered climbers and racing them up one kilometre of ribbon, at an average rate of at least 2 m/s, was met by a Seattle-based company in 2009.  Although the actual ribbon of the space elevator will likely span 100,000 km, we have to start somewhere.  The desired climbing rate for a climber will be in the neighbourhood of 60 m/s, making a trip to GEO a weeklong transit (with spectacular views).

The enormous material challenge facing the space elevator ribbon is one that will be met over time.  Carbon nanotube technology is being developed for many other uses, such as the aviation industry. 

The only other huge technological hurdle for the space elevator appears to be surviving the onslaught of orbital debris (both manmade and celestial) that will likely be on or near the path of the ribbon on a regular basis.  The debris breaks down into two categories.  The larger items, say twenty five centimetres in diameter, can be easily detected by radar.  If one were to fall in the path, the ribbon would need to be manoeuvred properly to avoid the collision.  The space elevator design calls for the ribbon to be fastened to an oil tanker that floats in the ocean.  On occasion, this mobile base will need to move some kilometres so as to bring the ribbon out of harm’s way. 

Smaller debris (the second category), which cannot be detected, will occasionally pierce the ribbon.  The ribbon must be designed in such a way that small holes weaken it locally, but do not sever it.  The details concerning space debris avoidance were recently tackled by a wonderful organization called ISEC (more on them soon).

There is a small shopping list of other engineering problems that must be addressed.  In addition to carrying payloads, climbers will have the task of repairing and even thickening the ribbon as they ascend it.  Other risks to the structure include lightning and hurricanes at the base; situating the ribbon surface connection in a calm climate somewhere along the equator will minimize the likelihood of such occurrences.

So, with a conceptual design seemingly devised, and a set of a few challenges mapped out, why might we have to wait until the year 2050 or later to see construction of the space elevator commence?  There are a few reasons. 

One deterrent is the large capital required now, for a return on investment that is very far away.  The only way that companies will invest in technologies related to the space elevator is if they also yield spin-off technologies that are relevant for an application today. 

Another reason why the project is moving decidedly slowly is that one hundred scientists and engineers are not nearly enough.  What is needed is a larger pool of researchers, but also a large infrastructure in which they can work.  ISEC (the International Space Elevator Consortium) is currently attempting to create this infrastructure.  ISEC organizes the annual space elevator conference in the United States, but also tracks the progress made at space elevator conferences held in Europe and Japan.  Incidentally, the 2011 Space Elevator Conference will be held August 12-14 at the Microsoft campus in Redmond, Washington.  

Finally, what is needed is greater public awareness for the project.  When I give seminars on the space elevator, be it to my physics class or to the general public, the majority of audience members have never heard of the concept.

Arthur C. Clarke’s Science Fiction, “Fountains of Paradise,” follows the building of the first space elevator, and the many challenges surrounding it.  The impact of the space elevator on society was depicted as dramatic, and, the impact of the real one will no doubt be so.  Without question, the space elevator would have the kind of effect on space exploration and exploitation that the internet has had on communication.  And, let us not forget that the internet was made possible by space exploitation. 

I will be paying very close attention to this project over the coming decades, and you may wish to also.  In my experience as a teacher, few ideas have captured the imagination of my students like this one.