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Hyperloop

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621–630 of 983 posts

Re: Hyperloop

#621
post #591

Earlier quoted context omitted.

The R&D can't happen in government, but in some ways that's better - government projects are slower than this needs to be. What we need is for someone(s?) with deep pockets to bank-roll prototypes &c.

Sounds vaguely like maglev a couple of decades ago. It too was a neat idea on paper.

Development is underway in China apparently!

http://en.wikipedia.org/wiki/Vactrain

Re: Hyperloop

#622
"... each passenger will have access their own personal entertainment system."

Only a small point. Other than to display ghastly advertising, why not a dumb monitor that interfaces with your phone/tablet? It's not like you're going to be able to watch a movie. And if we're seven years into the future on this, I'll be wearing my Oculus Rift 4.0 anyway.

Maybe I'm just too disillusioned by the systems used in aircrafts with their awful interfaces, lag, etc.

Re: Hyperloop

#623

Earlier quoted context omitted.

I would be very surprised if the numbers really work out the way you claim: that the weight for carrying a passanger is similar for trains and a tube, and that the weight advantage of a tube comes essentially from 3x speed allowing for a one third the linear density of passengers. Do you have a cite?

No, this is just back-of-the envelope, admittedly. But the three factors that determine how many people you can move past a given point per unit of time are the frequency of the vehicles, the capacity of the vehicles, and the speed of the vehicles, so if you want to match the throughput of the proposed Hyperloop, but with rail traveling at 164mph, you have to either make the vehicles more frequent or higher-capacity,…

> the three factors that determine how many people you can move past a given point per unit of time are the frequency of the vehicles, the capacity of the vehicles, and the speed of the vehicles

Why is speed relevant?

Re: Hyperloop

#624

Appreciate Elon Musk for this idea. But do you really want a bus sized hunk of w(ever)tf this is made out of zipping by you at 700mph?

Lets be honest, the difference between 700mph and 80mph head across the median on is negligible. Either way you are almost certainly dead or crippled. Past a certain speed the only real difference is how large of an area your body is spread out over; dead is dead.

Re: Hyperloop

#625

Earlier quoted context omitted.

Turn down the nastiness. It's totally non-obvious that this isn't overshadowed by the weight of the tube. And it does carry a motor with it, just not one that's responsible for initial acceleration or for large air resistances.

Sorry if you perceived that as "nasty". The motor that it carries with it is about 146 horsepower. That's less than a Kawasaki Ninja street bike. The General Electric E60 locomotives currently in use on Amtrak crank out 6,250 hp (4,660 kW) and weigh 423,000 lb (192,000 kilograms). The weight of the tube doesn't really enter into it.

Flippant comments like "Did you actually read the PDF?" are exactly the kind of needless small escalations that destroys the tenor of commentary at HN. Any time you write that, you could be writing "It's discussed on page XX". If the comment doesn't deserve a cordial response, then just downvote and move along.

Re: Hyperloop

#626
post #575

Earlier quoted context omitted.

It's not clear to me that he is interested in being the one to build it. I think he wants somebody else to.

I'm sure he'd prefer someone else do it but then again he might have preferred that someone else would have conceived of and designed it -- or something similar. There's a chance, as with the leadership of Tesla, that no one else with the capability (or position/reputation) to execute will be found, and I'd be surprised if he were not heavily involved in seeing it through.

From what I understand he still sort of wants out of Tesla in the long term. SpaceX is his baby and he's only running Tesla because he feels that he has to. I suspect he isn't receptive to spreading himself out over a third project (he apparently doesn't do much work himself for SolarCity).

Re: Hyperloop

#627

Earlier quoted context omitted.

Look at the Armstrong limit (at 62,000´), a mayor problem to overcome if the tube is going to be at the equivalent pressure of 150,000´ http://en.wikipedia.org/wiki/Armstrong_Limit http://en.wikipedia.org/wiki/Time_of_useful_consciousness Also look at the TUC (time of useful consciousness) that it´s below 5 secs when flying that high. That means that you have less than 5 secs to put your oxigen mask on before you los…

From the linked article: At or above the Armstrong limit, exposed bodily liquids such as saliva, tears, and the liquids wetting the alveoli within the lungs — but not vascular blood (blood within the circulatory system) — will boil away without a pressure suit As mentioned above, we have been boarding planes without pressure suits for decades, and the hyperloop has two security advantages: it has a large supply of co…

> As mentioned above, we have been boarding planes without pressure suits for decades

The Armstrong Limit is at 62,000 feet. Jetliners fly at below 45,000 feet.

Re: Hyperloop

#628
post #180

Earlier quoted context omitted.

Interesting point that big government provoked the advancement of the hyperloop idea - counterintuitive idea, and clearly yes. but any idea like this will need government cooperation. The real test of big government will be how they respond to the hyperloop. magic response: "of course we may be wrong, we'll look into this immediately." and then they decide to build it. likely answer: praise, perhaps even an evaluatio…

The problem is that, at least with the CA high speed rail system, the design is all theoretical at the moment. It may be a brilliant idea, but but moving from the core ideas in the document to actual working, build-able products, can be a slow process. And given the state of where CA is on their project, that may not put them on the same window.

I can assure you that the CA system isn't "theoretical" anymore. Terminals are already being constructed in SF and Anaheim. Right-of-way acquisition has begun and construction is scheduled to begin in the Central Valley this year.

Re: Hyperloop

#629

Earlier quoted context omitted.

Unfortunately I walk a very fine line about what is sensitive and what is not. I really couldn't go any deeper than what I posted here.

Well, is it cool?

It's definitely cool. I left about a year ago to join a startup, but that had more to do with wanting to live in NYC again than the submarine company. Two interesting books: http://www.amazon.com/Dark-Waters-Insiders-Account-Undercove... and http://www.amazon.com/Blind-Mans-Bluff-Submarine-Espionage/d...

Re: Hyperloop

#630

None of this is to say that Hyperloop is a bad idea. The idea sounds very interesting and I'd rather spend sixty billion building a Hyperloop --even if it fails-- than the ridiculous California high speed rail project. Cost is probably off by an order of magnitude, if not more. Why? Unions and other groups. Building anything in this country costs massively more (and takes significantly longer) than one could imagine…

Wow, can you not abuse this wonderful idea for a political forum on unions , of all things?

There's a difference between theory on a piece of paper the the reality of building something. In the real world unions will be all over a project like this. Up every crevice. So will environmental groups and other special interest groups. None of this is good for any major civil engineering project.

I asked a question in my post. Can you name any new major civil engineering project in the US in the last fifty years? Refurbishing an existing project does not count. I am talking about something major, say, a new conventional railroad.

The reality is that these kinds of projects are just-about impossible to realize given our political and, yes, labor framework. So, yes, unions are very relevant because it matters not if the physics of the project is brilliant and utterly peer reviewed. The various externalities I mentioned almost guarantee that it cannot built.

I'd love to be wrong.

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