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.