Creating a vacuum in a long pipe will be extremely difficult. There are just too many technical problems that will need to be overcome. I don't think many people realize that the the expertise involved in making such a hull will surpass that of the Space Station.
Just think of the large-scale piping systems we already have now. They are prone to leaks, distortion, vandalism, terrorism, technical failures. All these problems have to be overcome and an almost 100% safety level achieved.
My personal opinion is that, for all the hype :), it cannot be done, at least not at the speeds and distances which have been touted.
I respectively disagree
a hard vacumn is not required.
just a lower pressure in front than behind.
pneumatic tubes have been used for small parcel (money, letters sales receipts)
for a hundred years.
just scale it up.
if 750mph isn't dooable?
so what.
75 mph would work.
"just scale it up"
I think this oversimplifies things a little. :)
mouse- elephant
guppy- whale
chihuahua- great dane.
I don't see the problem