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Is it possible that an underwater train can travel from New York to Paris in less than a hour in the future? And is it also possible to travel faster than Mac 5?
- Derek (age 12)
Yes, it is indeed possible that a train could go from New York to Paris
in under an hour, but I'd keep that train away from the water. Maybe a
tube with the air taken out under the sea is a good place for such a
train. Water is very heavy and would slow down such a train. It would
waste lots of energy creating shock waves in either water or air if it
were traveling in anything but vacuum. I'd imagine such a project would
be both expensive and also difficult to market to the public. People
are afraid enough of flying on airplanes. Taking them deep under the
sea in an evacuated tube would make them simultaneously afraid of
suffocating and drowning. As it is, the Concorde supersonic airplane
has been retired more for economic reasons than anything else -- there
wasn't enough demand for it to justify the cost of flying the planes.
Underwater tunnels are used routinely for train and auto traffic.
Accidents happen, though and fires in these tunnels have created
setbacks. Nonetheless, it would be nice to have some mode of
transportation from New York to Paris which economizes on fuels.
Travel faster than 5 times the speed of sound is most certainly
possible, but again at an expense of energy. There's the unavoidable
sonic boom, and friction with the air going past will heat up the skin
of an airplane traveling that fast. Astronauts and satellites in
low-earth orbit go around the earth once every 90 minutes or so, and
you can figure out what that is in terms of the speed of sound (of
course the speed of sound means a lot less if there isn't much air).
(republished on 07/11/06)
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