It's impressive because these students are breaking new ground. One competitor just said they didn't know anything about batteries in vacuum, just for one example, and had to bring in an expert on that, among other challenges.
It's specifically not a vacuum, but rather a low pressure system.
> Just as aircraft climb to high altitudes to travel through less dense air, Hyperloop encloses the capsules in a reduced pressure tube. The pressure of air in Hyperloop is about 1/6 the pressure of the atmosphere on Mars. This is an operating pressure of 100 Pascals, which reduces the drag force of the air by 1,000 times relative to sea level conditions and would be equivalent to flying above 150,000 feet altitude. A hard vacuum is avoided as vacuums are expensive and difficult to maintain compared with low pressure solutions.
You're using faulty definitions there. Even outer space is not a 'true' vacuum. Any pressure lower than atmospheric pressure is considered a partial vacuum.
100 Pascals in a lab would be considered a 'medium' vacuum. And in a tube the size of an actual full-size hyperloop, even that will probably be extremely difficult and expensive to achieve.
I think the hyperloop will end up being technologically unviable mostly because of the cost and the limitations of technology (like the expansion joints that will be required on a decently long track), but I hope I'm wrong on that. It may lead to new innovations which will be good.
You're right, I'm using vacuum as a layman's term, and shorthand for "hard vacuum" as mentioned in the paper. [0] The paper refers to the Hyperloop system as a "a low pressure (vs. almost no pressure) system".
A true vacuum is literally impossible. It's not a category that can exist in nature, because particles aren't actually little balls that bounce around. Every volume has some probability of a particle being in it in the great universal configuration space. It can have an expected number of particles < 1, but never zero.
No. There's enough air pressure to potentially lift and cushion the pod in the pipe (at least in the original plan). However most pod designs (I think) use magnetic levitation for lift.
Why is that impressive?