
The limits of Hyperloop - curtis
https://mappingignorance.org/2018/02/07/the-limits-of-hyperloop/
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curtis
The author thinks that the physics of Musk's original hyperloop proposal
aren't going to work out, at least with today's technology -- in particular he
focuses on the difficulty of building a suitable axial compressor without a
major advance in technology.

As a lay-person I can't really evaluate his argument. But even if he's right,
I think he may be drawing too strong a conclusion. To my knowledge all of the
current experimental hyperloop systems have already dropped one aspect of
Musk's original proposal: instead of using air bearings they're all using
maglev systems now. I am expecting that sometime soon we'll also see variants
on hyperloop which dispense with the static air column in the tube and instead
are designed around the idea of blasting the air through the tube at the same
velocity as the car. Of course you've got drag throughout the entire tube, but
on the other hand if the air in the tube is a not-quite-hard vacuum as in the
original hyperloop proposal, there's maybe not that much drag when you add it
all up.

