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Michael Aranda explains the nuts and bolts of Hyperloop, the new magnet-driven, solar-powered transit system proposed by Spacex genius Elon Musk. Learn how Musk answered three vexing questions to create the transportation of the future -- or maybe the transportation of Futurama.

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Hello and welcome to SciShow News. I'm Michael Aranda, in for Hank Green who is currently faffing about in England.


Ambitious Billionaire and big dreamer Elon Musk has hatched a new model of transportation that could soon transport us, futuristically. 

On Monday, Musk unveiled his plans for the 'Hyperloop' - a proposal to use the principals of fluid dynamics, thermodynamics and electromagnetism to send a pod full of people from Los Angeles to San Francisco, a trip of about 560km, in 30 minutes. Carry the one... That's 1120km per hour and its about time right? I mean we've been seeing two base transportation in science-fiction since, like, forever.

Musk's vision is based on a simple magnet driven motor and a whole bunch of fans to send people tubing down the California coast. But it turns out that the Physics of blowing someone at subsonic speed, if you know what I mean, is a lot harder than it sounds. Of course, in Science, as in business, Musk has proven himself to be no dummy and he think's he's found answers to everybody's questions.

 Breaking The Kantrowitz Limit

Our first question is how do you get around the "Kantrowitz Limit"? The Kantrowitz Limit, oddly enough named after Arthur Kantrowitz, is basically the speed limit for an object passing through a tube - at which point the air in front of the object, kind of bunches up and can longer flow around the object. Sort of like compressing a syringe, the object starts pushing the air down the tube which means no superfast travel.

Musk's proposal for breaking through this barrier is to mount compression fans on the front of the Hyperloop's passenger pod to keep pushing all that air out of its way.

 Eliminating Friction

Our second question is how doe we eliminate friction? Friction, of course, is the resistance caused by two things moving against each other. Sort of like your socks on the carpet.

Musk's answer to this problem is air bearings. These air bearings are essentially meter-and-a-half long paddles that use the air around them to create pressurized cushions of air on which the pod can ride and the current design for the Hyperloop calls for each passenger pod to be equipped with 28 of these bearings.

This won't eliminate friction entirely of course because there's still air rushing around the pod. But while Musk says the total vacuum might be more efficient in terms of the physics, its not really feasible to create and maintain a vacuum in a tube several hundred kilometers long. So his Hyperloop calls for transport tubes to be filled with very low pressure air.

Now all of this stuff takes energy, especially the propulsion. The Hyperloop would be propelled by a pretty straightforward 'Linear Induction Motor' in which a thin metal fin on the passenger pod would slide between magnetic elements inside the tube. Now magnetism requires electricity, they're actually the same thing, so how do you power it?

 Powering The Future

Well, if you guessed 9-volt batteries, you guessed wrong. It's actually solar power. Musk's model calls for solar panels to be mounted on the whole length of the Hyperloop tube. With those panels generating 120 watts per square meter, he thinks they'll generate an average of 57 megawatts of energy per year ,which is actually more than the Hyperloop would use.

So easy-peasy right? Well Musk's plan is elegant in its simplicity but Physics can often be more complex than it sounds so we're linking to his whole proposal below.

What makes things really difficult is all the red-tape and here Musk faces probably the toughest question - how can he get others, namely the State of California, on board with this idea? At a total cost of $6 billion it might not be easy but that's a lot less expensive than the state would probably spend on its planned high-speed-rail project. So far, a number of scientists and planners have voiced support for the Hyperloop and so do we. But I'd like to make my own suggestion, Mr Musk. 560 kilometer long slip and slide.


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