There are so many stupid lies flying around for well working systems. So let's have a good exorcism. I've had this hyperloop rant just waiting to be posted. So here we go:
I've seen so much physics-based arguments against hyperloop, so I'm not going to that route. Physics-based problems can mostly be solved, that is what hard-science research is for.
But this hyperloop has more serious issues. It's like making a near 100% efficient hovercraft that's fueled by only water, but it only works in searing hot sand-desert environment - and then we would try to fix the drought problem in desert areas to justify the hovercrafts viability, while completely ignoring the fact, that at night, deserts are extremely cold.
Anyway, the only issue I see in the hyperloop idea is this: there is absolutely no realworld solution to make this both SAFE AND COST-EFFICIENT. I'm going to get in to this in detail, just to be sure, so that the logistical and passenger safety related problems are seen in the right light. Because, for some reason, some people really don't see the full picture on this one.
Enough prologue, here are the facts:
To make the hyperloop work, there needs to be more than just one train running in the tube for it to be cost-efficient, so a connection between stations has to be two tubes, and thus, there needs to be a way of turning the trains. The only two solutions are:
Type 1. Make the tubes an isolated loop, and have the passengers get in and out in vacuum-sealed docking ports at stations. (This is cheap, but very prone to failures)
Type 2. Make every station have de-/pressurisation chambers, so trains can unload/load in normal 1ATM stations. (This is extremely costly, but fairly safe)
Because of the immense power held by the huge near-vacuum tubes, the speed of the trains, and the danger it holds for the people near them, which ever solution of the two is used, we need a 99% reliable safeguard when a problem in any of those trains happen, or in at any point in the tube or stations.
Reliable safety can only be archived by making automatic seals in set intervals in the tube and special fast-reacting seals on stations and near them. Compressed gas+friction-based braking systems will also be needed on the trains, adding to the cost. Slowing speed in near vacuum tube is not as easy as you would think - this also increases the weight and lowers the cost-efficiency of the train-units.
For the passengers to get out of a broken train-unit, or in case of tube failure, we need an emergency hatch to be reachable at any pressure-sealed point of the tube. Passengers can't just get out by opening a door and jump out, no matter the seriousness of the emergency. In hyperloop, hull break is to kill everybody by rupturing their lungs with sudden pressure change. Thus at least 4-12 small automatic and controlled valves to let in the outside air must be installed to instantly stabilize the pressure of a closed part of the tube to 1ATM. The valves have to be in every sealed part of the tube, so that the train-unit can even be exited, and there needs to be emergency hatch on both sides of every emergency vacuum seal in the tube. And the hatches need to be no less than 150 meters away, even by Europeon tunnel standards.
Everytime this hyperloop-system is, by design, and by hardware upkeep secessary, depressurised, for MAINTENANCE or, after an emergency, it stops working. THE WHOLE SYSTEM WILL BE AT 0% WORKING CONDITION WHILE IN MAINTENANCE. Can you think of a modern world mass-transportation track that would stop working for 1-2 weeks, just to do basic maintenance. Let's say that you can somehow save 100% of the energy that you used by making that insanely huge vacuum, working until the tubes are vacuumed again. You would still lose those 1-2 weeks. It's just not worth it.
hyperloop doesn't sound so cheap, fast or reliable now, does it? This is just in the bare minimum by the requirements for safety in mass-transportation by law. Now finally, we get to the juicy part: The "I don't give a shit, what does it cost, I'm willing to pay anything for a dream of "saving 30 minutes on a 2 hour commute"-part:
The juicy part is in part 2. That random law-anon will never do.
TLDR; hyperloop is a dangerous non-cost-efficient non-solution to non-problem. Saving 10-15% hours in transportation between cities, with horribly ignored safety concerns, is not something we should support, no matter how "elonmusked" the idea is. Bad ideas are some times just bad ideas.
-Science Anon #0216