

How Does Elon Musk's Hyperloop Work? - abdinoor
http://www.abdinoor.com/2013/07/16/elon-musk-and-the-hyperloop/

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satellitecat
Yesterday there was a post on here where Elon tweeted a reply to someone that
his guess was the closest yet:

[https://news.ycombinator.com/item?id=6046943](https://news.ycombinator.com/item?id=6046943)

He seems to verify that there will be "pods" 2m wide, so it sounds like this
will be tunnel- or tube-based.

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skastel
The real issue is the safety issue. Shutting down a vehicle moving at 2500
feet/sec without subjecting the occupants to unhealthy G-forces is going to be
rather difficult. But who knows, the human body can certainly withstand some
pretty intense shock:
[http://www.youtube.com/watch?v=s4tuvOer_GI](http://www.youtube.com/watch?v=s4tuvOer_GI)

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chiph
If it's any kind of open track, it'll have problems with sonic booms. 400
miles in 30 minutes is 800 mph, a speed which exceeds the speed of sound at
sea-level (~ 760mph). The neighbors aren't going to like that.

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abdinoor
Supersonic vehicles have been designed that minimize the size of the sonic
boom. For example, the Lockheed Martin SAI produces a sonic boom 1% as big as
the Concorde
([http://en.wikipedia.org/wiki/SAI_Quiet_Supersonic_Transport](http://en.wikipedia.org/wiki/SAI_Quiet_Supersonic_Transport)).

~~~
chiph
Hmm. Maybe it won't be a problem after all. The size of the sonic boom seems
to correlate positively with the size of the wing surface. Since a track (or
tube) based system wouldn't need much of a wing, it ought to have a pretty
small boom.

However, I do want to point out that rifle shots are supersonic and are
annoying to the neighbors, and they have no wings at all.

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FlyingAvatar
I'm pretty sure a subsonic rifle shot is still pretty loud. :)

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chiph
A friend has a rifle in 300 AAC Blackout. Subsonic ammo is far quieter than
supersonic -- but you'd still want hearing protection. With a suppressor
attached, it's quieter still -- you can fire it without wearing earplugs. But
it's not "Hollywood quiet" \- that's a movie myth.

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VuongN
We'll have to wait and see, but what I read was definitely plausible and
sound. Intriguing indeed.

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IanDrake
This is the most plausible and interesting interpretation I've heard yet.

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yoavshapira2
Good explanation!

