Musk's Hyperloop

http://prattleat.us/post/5

by autotravis • 14 years ago

87 65 14 years ago

prattleat.us

mtgx2• 14 years ago

The real question is - will you have to go through TSA first to get in it?

kmfrk• 14 years ago

I'm sure people will find a way to lose my luggage.

SuperChihuahua2• 14 years ago

I believe that the Hyperloop is some sort of cannon. He has earlier revealed that it won't need a tube or tracks

Edit: Source to the no-tube from Elons twitter: "Will publish something on the Hyperloop in about four weeks. Will forgo patents on the idea and just open source it. Not a vac tunnel btw."

wwkeyboard• 14 years ago

And there goes my dream for a Futurama style Tube Transport System.

lowkey• 14 years ago

Are you sure he specifically said it wouldn't require any sort of tube? I was under the impression that Elon's Hyperloop would be a derivative of the concept of Evacuated Tube Transport - a capsule containing passengers launched inside a tube under vacuum (eliminating air resistance) and levitated using some sort of MagLev (eliminating rolling resistance).

The concept isn't entirely new but having someone with Musk's credibility and resources as a proponent may be the catalyst required to make it happen.

I distinctly recall seeing some PR material circling the internets a few months back from a consortium known as ET3.com The group claims to have been working on a similar project for the past decade.

omegant• 14 years ago

I don´t think is a vacuum tube, it seems more like a tube with railgun like propulsion(elevated via towers, like power lines, even using the same power lines routes), but the guiding is maybe based on aerodinamics. There must be some kind of sound contention because he says it is supersonic.

He also said that it would be energetically independent so he may be using the external part of the tube to install solar cells, and the tube itself may be used for accumulation (capacitation maybe?).It doesn´t need to be air tight, just somehow sound insulated. The steering or "levitation" inside the tube may be obtained via shock waves (note his actual experience with high energy aerodinamics due to the development in spaceX).

He surely is taking advantage of the knowledge gained in the R&D of SpaceX, Tesla and Solar city.

schiffern9• 14 years ago

Yeah, not a vac tube: https://twitter.com/elonmusk/status/224406502188916739

Think "cheap". The cheapest vacuum is right above us: at 35 km up there's only 1% the air pressure at the surface. It takes some energy to get there, but if you're on a rail you can recoup it on the way down.

mariusz79• 14 years ago

Well, by definition projectile used in any cannon will crash, so that's not it :)

SuperChihuahua2• 14 years ago

Not if you attach a "grasshopper" to the projectile :)

larrydag• 14 years ago

The cannon idea is really interesting. Musk's initiatives are all about reducing the cost of long term operation in order to disrupt the market. Most of the operational cost of air transportation is (I believe) in the take-off. If you eliminated the need for the aircraft itself to takeoff by projecting it with a rail-gun then this could theoretically reduce costs greatly. Essentially creating airline bullet gliders. Just a theory.

jivatmanx• 14 years ago

Forgoing patents on it is a bad idea if it means that a troll will immediately patent the idea after Musk releases it.

If only there were a GPL for patents...

mtgx2• 14 years ago

What about prior art?

politician2• 14 years ago

Actually, the problem is that someone will immediately acquire patents on trivial upgrades and logically-related extensions of the idea. The publication of the idea itself would be prior art.

astangl• 14 years ago

I would love it if this were true. I have been saying (only semi-tongue-in-cheek) for years that getting shot out of a cannon would be a great form of transportation, if only the bugs could get worked out (i.e., eliminate possibility of mid-air collisions). :-)

squid_ca• 14 years ago

The cynic in me is reminded of the Segway at this point. I'm not calling bullshit on this, but I'll wait to get excited when something is actually shown.

mertd• 14 years ago

There is a segway-esque secrecy around it. However if there is one person I would give the benefit of the doubt, that person would be Elon Musk, and he said they'll open source the project.

malandrew• 14 years ago

It sounds like a Lofstrom loop http://en.wikipedia.org/wiki/Launch_loop

schiffern9• 14 years ago

That was my leading theory, and "cross between a rail-gun and a Concorde" all but confirms it. Flight path like a Concorde, propulsion like a rail-gun. Exploit the natural vacuum above our heads without expensive tunnels.

Let's look at the attributes Elon has described publicly, and see how they compare to a launch loop:

https://www.youtube.com/watch?v=uegOUmgKB4E#t=43m13s

* could be cheaper than CA high-speed rail? Check (no right-of-way).

* "theoretically fastest way" from A-B? Check.

* can't crash? Check (w/ well-designed rails).

* immune to weather? Check.

* twice as fast as a plane? Check.

* lower energy cost than a car? Check.

* self-powering with solar panels? Check.

* stores power w/o batteries? Check.

https://www.youtube.com/watch?v=L-s_3b5fRd8#t=18m20s

* requires aerodynamic expertise? Check.

* "ground-based Concorde – as fast as a Concorde, but on the ground"? Arguably. All weight is supported by the ground, and cars take a Concorde-like path.

* rails are not needed? BZZT!! However, he may be talking about the "right-of-way" aspect of rails here.

http://www.businessweek.com/printer/articles/71590-elon-musk...

* leaves right when you arrive? Check (w/ individual pods).

https://twitter.com/elonmusk/status/224406502188916739

* isn't a vac tunnel? Check.

Of all the ideas that have been kicked around, the launch loop seems to fit best. Elon would certainly have been exposed to the idea when brainstorming for SpaceX.

My only question for the past few weeks has been, "How do you build the thing?" It doesn't inertially support itself in the air until the rotor is spun up, and the rotor can only be spun up when it's fully constructed between the endpoints. Catch-22!

There are basically three ways to do it, each with their own challenges.

Build it in the air. You would need huge numbers of lifting balloons (presumably of zero-pressure solar Montgolfier design, ala ARCA), and the portions of the system in the troposphere would be incredibly susceptible to adverse weather while under construction. You would want to have the entire thing already built, then unreel it as fast as possible. Smart tethering would reduce this risk, and the whole thing would need emergency descent parachutes for operation anyway. This seems like the least unworkable scheme, imho.

Build it in the water. Ocean currents and tides are now your problem instead of wind. The requirement to survive the corrosive salt water environment puts additional constraints on material selection. Oh, and you have to shut down all boat traffic from LA to SF. And your base station either has to be mobile (to start out in the ocean) or you have to start with a big arc out from the coastline and "tip it up" vertically. Do the math on how big the rotor endpoints would be (given reasonable assumptions about bending magnets), and you quickly realize that building them in place is the only option.

Build it over land. This seems the most unworkable – all the risk of having it fall (or worse, lose containment), and now you have to build tall towers every few thousand feet and string a high-tension support cable between them. Imagine explaining to homeowners that the "rail" we're building above their house will have parts moving at 10 km/s inside before it lifts off. Ouch.

keenerd• 14 years ago

Over water seems rather reasonable considering what we can do with cable laying ships.

Whatever method is used to get it up in the air, it'll need to be safely reversible. Over water bringing it down is much easier. And you'll have to bring it down for repairs. Every five minutes it will do a full loop.. Iron is fairly ductile, but those stresses will add up. And wikipedia says the kinetic energy involved is close to a small nuclear bomb. Back of the envelope math suggests the iron cylinder would be very thin. It will wear out sooner or later.

My guess is that Musk's big breakthrough is for a cheap and reversible deployment system.

I'm double checking my numbers now (and reading the original papers) but the entire contraption might weight a lot less than we are implicitly assuming. Like, light enough that a single large plane/blimp could support the entire cable/sheath system. And a small fleet of planes could safely tow the cable through the sky. Or a fleet of blimps could support the entire cable while it was stopped for maintenance. (Both would need a large number of well trained pilots, it would make the skycrane maneuver look simple.)

edit: The original paper talks about a ribbon 5cm wide and 7.6mm thick weighing 15.6 Gg. I dropped a kilo in the back of the envelope calculations. So it would need at least 100 very large aircraft to hold up. Still feasible, but more than a little crazy.

joezydeco• 14 years ago

10 km/sec. I'm still trying to wrap my head around that number. That's close to Mach 30, right?

Lerc2• 14 years ago

When hyperloop was first mentioned I considered the criteria required and worked on a matching result. I came up with something that deviates from later info by nevertheless I came up with something that matched.

Working on the principle that the speeds and efficiency mentioned means it has to avoid the friction of travelling through a medium. Since he had said "not a vac tunnel" I set my mind considering how the problem could be solved without relying on a vacuum. I figured, 'why not move the medium as well?'. Making a tube train travelling in a fluid medium would be interesting. Make the inner surface of the tube a hydrophobic surface. Use solar power along the length of the tube to accelerate the liquid. The speed would increase until the energy lost through friction with the sides reached equilibrium of the solar acceleration. If you can reduce the surface friction sufficiently, extremely high speeds should be possible.

Comparing against the checklist you did, a Hydrophobic torus full of high speed liquid gets a fair number of hits. The same aspect applies of energy storage as kinetic. It's a better match for 'ground based' but The same ground based aspect means it would get in the way. Building the liquid filled thing would be much easier, possibly implementable at smaller scales initially.

Mostly I think this just goes to show the interesting ideas you can come up with when given a set of constraints and a goal. I seem to vaguely recall a Mike Abrash anecdote about VGA fifos that applies here too.

I think I'd be a bit disappointed if it is a Lofstrom loop(but that's what it likely is) unless there is some significant innovation extending the idea. It's just like a vac tunnel with cool inertial skyhooks.

wololo• 14 years ago

> killing countless people daily

2.09% of deaths, according to http://en.wikipedia.org/wiki/List_of_causes_of_death_by_rate

Question: what would an Elon Musk of those even more common causes of death build?

w1ntermute• 14 years ago

For cardiovascular disease, how about a way to stop people stuffing their faces with greasy and fattening food?

whatusername• 14 years ago

So the Paleo Diet community (and Taubes/etc) would say that the greasy food is part of the solution (and that some perceptions of "fattening" food are wrong)

MiguelHudnandez• 14 years ago

* Gene therapy to make unhealthy foods taste terrible

* Nanobots or symbiotic parasites to maintain the body [1]

[1] http://en.wikipedia.org/wiki/Parasites_Lost

schiffern9• 14 years ago

A sexy, highly marketable e-cigarette.

TeMPOraL3• 14 years ago

That doesn't break very fast. My girlfriend loves e-cigarettes, but it's all fun until the endpoint (*-mizer, whatever they call it) burns out, which it does every week or three, and then there is a battery that tends to fail after around two to three months of usage. </anecdotal-evidence>

KevinEldon• 14 years ago

The OP suggests (jokingly?) that driverless cars and Musk's Hyperloop are somehow in competition. I don't see that. Cars today are about transportation and cabin conveniences. Why can't the two be separated over time? Your "car" takes your cabin to the train that takes your cabin to the high-speed rail (Hyperloop?) that takes you from Atlanta to Kansas City. Perhaps you switch cabins based on price to transport... maybe you rented a bigger one for local travel, but don't want to pay a higher price for long range travel... lots of ifs, but to me, this and/or scenario seems more likely than driverless cars vs. Hyperloops.

autotravis• 14 years ago

> Here I was getting excited about Google's work on driverless cars.

OP here, only competing for my (unfortunately limited) excitement. There is definitely room in this world for both.

lutusp2• 14 years ago

Since there are no details, we can only speculate. There are only a few practical implementations. At the top of the list is an evacuated tube.

The linked article says it's desirable to do this without requiring a right-of-way or moving people out of their homes. So that puts the tube below ground level -- well below.

Let's say an evacuated tube, below ground level, in California, between San Francisco and Los Angeles. This really isn't going to work, because (all other considerations aside) the route crosses any number of known geological faults that are in constant relative motion -- some creep past each other, some wait and then periodically move all at once in an earthquake. You can't build a subsurface tube that crosses geological faults.

I don't think this is a practical idea. But it's a nice one in principle.

schiffern9• 14 years ago

>At the top of the list is an evacuated tube.

Except for the small problem that Elon said it's not an evacuated tube: https://twitter.com/elonmusk/status/224406502188916739

lutusp2• 14 years ago

Yes, I noticed since I wrote the original, but that might be smoke. It's not obvious how the system would work without some sort of dedicated pathway that remains the same day after day. The word "tube" leaps to mind. :)

swalsh• 14 years ago

In the past, it sounded like he really wanted to see someone work on the idea, but was not interested in doing it himself. Now it seems he's coming around to the idea. This is really exciting.

endlessvoid94• 14 years ago

I suspect there is no hyper loop. I wouldn't put it past Elon to use his reputation to spur people to think big about these kinds of problems.

It's worked, too. The ideas people have had, just trying to "figure out" what the hyperloop might be, are very interesting and diverse.

pdenya• 14 years ago

I've never heard anything about Elon Musk that indicates he speaks lightly about things like this. He has an amazing track record and a habit of taking on huge problems. There is no reason to think that he's not working on a hyper loop.

Lerc2• 14 years ago

>The ideas people have had, just trying to "figure out" what the hyperloop might be, are very interesting and diverse.

Got any links to such ideas? I would love to see what other people have come up with.

Zenst• 14 years ago

Would this possibly be using a railgun to initiate takeoff speed (reducing fuel a lot) and then some for a plane that then obtains very high speed in very high orbits to then be able to land and use existing airports.

This is only logical given the prospect to use a railgun type launcher to eliminate booster rockets or reduce fuel for space flight. So would marry in with other avenues of research and as such be less of a risk and Musk don't like risk.

This at least would fit the criteria, maybe with the initial speed a form of electric powered plane, maybe Musk and Dyson could get together and invent a good electric jet engine (yes probably be ion based but still).

ekianjo3• 14 years ago

" This is over 100 years after the first mass-produced automobile was sold, with the announcement of (another) successful nano-scale teleportation experiment just the other day."

So what? This is 40 years after the first Man walked on the Moon and we are still all living on Earth. It's been about 60 years we have discovered the double-helix structure of the DNA and we still have yet to see revolutions in medical practice coming from it. What is your point, exactly ? There are clear reasons why no huge technology leaps take place at once. Most innovation is progressive, iterative and it is very likely that you will not see a drastic change of technology within your lifetime.

tsewlliw• 14 years ago

Perhaps I am just much more impressed with the last 30 years than you. I'm not a point-by-point rebuttal man, but its very tempting. Try thinking about the massive changes if you don't limit radical progress to being in a straight line going the direction you want.

ekianjo3• 14 years ago

I guess you are referring about the computing revolution? There are definitely impressive things about it but it has not significantly changed our lives yet. Only the communication parts and shopping, for the most. Institutions, behaviors and culture have not changed significantly yet, if not for a minority of the population. Do not take me wrong, I also think there is a tremendous potential for innovation and progress, my point is just that it takes time. I am not THAT impressed with the past 10-20 years at least where innovation has been very slow overall across all industries, in my opinion. I do not know about you, but I think the introduction of fossil fuels in the 19th and 20th century as well as the spread of electricity, radio and television were definitely MORE life-changing that what we experience nowadays.

jacquesm2• 14 years ago

Cars were doing 100 Mph on the German autobahn in the 60's, they're not much quicker today and most drive a lot slower than that.

There is progress, but on the transportation front from a practical point of view the biggest one so far is the electric bicycle.

rehack• 14 years ago

Elon Musk is Leonardo Da Vinci of the present times. More power to him.

Uchikoma• 14 years ago

Sounds like the Segway.

ferferferfrr• 14 years ago

Agreed

Musk's Hyperloop

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