They've simulated a vacuum tube, and found that it works.
Specific points that you'd want to address if you were purporting to rebut Hyperloop criticisms:
* Because Musk's plan can't leverage existing last-mile infrastructure the way HSRs do, it delivers riders from one very inconvenient location to another, adding 1-2 hours of additional transit time to SF-LA.
* Because (by Musk's own admission) destructive disruptions of his pod-in-tube runs are catastrophic in a way that they aren't with HSRs, his plan requires TSA-style airport security, adding an additional 15-30 minutes to every trip.
* The cost estimates for the Hyperloop captured only its capex costs and not its operating expenses, so that the per-ticket prices derived from its proposed cost bore no relation to its actual cost structure.
* That the tunneling and viaduct cost estimates given in the Hyperloop proposal were so low that they constituted a revolutionary breakthrough in urban planning and structural engineering in their own right; in other words, if he can dig a Hyperloop-capable tunnel for the price his plan suggests, or run an elevated tube as cheaply as he suggests, why waste time with Hyperloops? The answer would be that he can't do either of those things.
* That the routing he proposes, particularly with regards to mountain passes, are wildly optimistic, and that a realistic routing will result in a longer run and significantly increased costs.
* That the forces involved on passengers in the Hyperloop exceed the tolerances allowed for existing HSRs in ways that are likely to make motion sickness a signficant problem.
This article appears to address none of them, and your comment appears to be premised on the idea that those criticisms hadn't been made.
WRT destructive disruptions, I believe there was a section dealing with sudden tube repressurization. If the failure mode is effective, it seems like an attack would be less destructive than one on a train, due to the smaller pod size.
If CapEx is much lower, and energy cost is lower, the ticket price should be lower, unless the maintenance cost is much higher (it may be due to exotic requirements, but it's not fair to say that what he's describing bears no relation to actual cost structure - it's just not complete).
No idea about the routing/tunneling estimates. Were his per-mile tunnel cost estimates much lower than normal?
The motion sickness complaint seems like it would have legs, since there won't be any view of the horizon - your eyes will be reporting a static environment outside your body, and your inner ear will be doing very much the opposite. Then again, planes experience turbulence and mild G forces and have the same characteristic for most passengers of not seeing the horizon. Maybe motion sickness was a much larger problem in the past, based on the presence of barf bags at every seat.
Musk's plan specifically calls for TSA-style security.
Your third point is nonresponsive to the argument. The ticket cost will reflect opex, but Musk's plan doesn't include it.
Yes, his per-mile tunnel cost estimates were extremely low.
Airplanes occasionally experience motion-sickness-inducing G's. Hyperloop pods will every trip. You'd at least want to know if the design is a vomit comet before you sank billions into it, would be the right point to make here.
The whole Hyperloop thing is back of the napkin wank.
I don't see how poorly chosen station locations invalidates the plan, though - those are just proposals, perhaps because it would be much more involved to estimate land prices within the city. It'll make it much more expensive than the figures they mention, but that doesn't make the overall concept much less interesting, since the land rights will almost certainly still be much cheaper than an on-the-ground solution like the current HSR that we seem to be willing to build.
One critique of Musk's plan pointed out that the Shinkansen trains were essentially a frivolous novelty until they were brought into city centers. The same thing was true of Southwest Airlines trying to service NYC from Idlewild. You have to terminate transit lines at places people want to go.
Also, the bar you're trying to set for critiquing the Hyperloop is too high. An argument against Musk's plan need not show that it's impossible to build. Rather, the bar is simply that an unproven new technology must have significantly better cost and performance characteristics than HSR. Nobody is going to drop many tens of billions of dollars to build this thing "just because".
The Hyperloop concept at least can point out the folly of pie-in-the-sky projections.
But the rest of it, the ridiculous route proposed, the estimates of right-of-ways and construction costs, and the comparison to the CA HSR plans that are going forward -- invited explicitly by Musk -- those parts of the plan are ipso facto nonsensical. That's why some people think it's just a tactical salvo of disinformation aimed at fragmenting what political support CA HSR has.
They invalidate the plan as an alternative to the HSR plan, which doesn't avoid the issue of connecting places people actually are to places people actually want to get, which is kind of an important part of any mass transit proposal.
Firstly, the article in question is about the technical feasibility of hyperloop, which is in question because it's not something that's ever been done before and it's a non-trivial application of aerodynamics et al. Secondly, if you insist on changing the subject from one of technical feasibility to one of economic feasibility you can't just spew a bunch of opinions without backing any of them up. This article isn't meant to address the economics of hyperloop and implying that it should is unfair.
Also, none of these are my opinions; they're opinions distilled from published critiques of Musk's plans. I didn't simply make them up.
If a technical article about how facebook is able to scale was posted to HN and then someone made the comment: "Everyone knows that scaling java services is easy, the real problem is that facebook doesn't have a clue how to monetize effectively." people would jump all over them. Regardless of whether or not the criticism of facebook's monetization strategies was accurate. When you make a fundamental technical error on that scale it immediately red flags whatever point you are trying to make, and if the rest of your post is just assertions and opinions with no backup then your post should be ignored, and rightly so.
If you want to talk about multi-billion dollar high technology projects and you don't care about getting the details right then I suggest you go to the bar and discuss things with the other patrons there. If you want to have a serious discussion though then you better come to the table with the correct facts.
Edit: I'm not trying to rebut or argue about any of the challenges. I'm just saying I find it highly unlikely any of them are 50+ billion dollar problems.
A somewhat cynical but I think on-the-money assessment of the Hyperloop is that it isn't at all a real proposal, but rather a sleight of hand to reduce buy-in to the CA HSR plan, which Musk opposes. That being the case, investing money in further studies seems like a dumb plan. Extraordinary claims require extraordinary evidence, and there are extraordinary claims in Musk's proposal with no evidence backing them up, so the onus is probably on him.
Absolutely. People familiar with the tech industry should recognize this pattern: Announce a vaporware [1] product as part of a FUD [2] campaign against the enemy.
When considered in this way, Musk's actions with Hyperloop make a lot of sense. This is a classic FUD move against CA HSR.
[1] http://en.wikipedia.org/wiki/Vaporware
[2] http://en.wikipedia.org/wiki/Fear,_uncertainty_and_doubt
Even if Musk's Hyperloop proposal remains only a proposal, if nothing else it should give people serious pause about the existing plan, and hopefully force a revision of it. The route through Palmdale is utterly pointless, tacks on a dozen minutes to a trip that's already too long, and exists largely to satisfy NIMBYs and give fat checks to a bunch of property speculators. That particular element of the HSR plan reeks of cowardice, corruption and graft. Consider this as an alternative:
http://www.cahsrblog.com/2013/06/the-truth-about-tejon/
Musk's opposition to the existing plan is well reasoned and rational. Calling it FUD is itself a sort of FUD.
No one is saying they were. The parent and grandparent are saying the Hyperloop announcement is FUD.
> if nothing else it should give people serious pause about the existing plan, and hopefully force a revision of it.
So, at the very least, the uncertainty and doubt parts of FUD?
Edit: s/fear/doubt
It's a battery-powered hovercraft inside of a soft vacuum tube (soft vacuum being within reasonable reach of cheap pumps), with boost segments to get it up to speed.
Usually, vacuum concepts rely purely magnetic levitation & propulsion. The fact that it's an air cushion vehicle in a soft vacuum IS the novel concept here.
However, there is still plenty of air in the tube to be an issue at the proposed speeds thus making Hyperloop cheaper and more complex than a traditional vacume transport.
I meet a lot of curmudgeonly planners who like to downplay the potential impacts of new technology (hyperloop, self-driving cars, etc.), but I'm open to the possibility of truly disruptive tech. Still, I have a hard time imagining that the land acquisitions will be that much cheaper for hyperloop.
The assumptions regarding land use were pretty well covered in the PDF Elon Musk released.