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Hank talks about how warp drives could potentially work.

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Warp drives and their nacelles and plasma conduits and dilithium crystals and subspace processor cores, those things are just storytelling devices. Ways for fiction writers to create a realistic-seeming world in which humans explore broad swathes of the galaxy. Ways to go where no one has gone before, on a TV show, not in real life. Right?

(0:26) Now I'm not going to lie, the physics and math involved here are kind of mind-boggling, and it's all theoretical anyway, so consider this the most basic of primers regarding a device that will probably not ever exist.

But if it does... oh, if it does.

(0:41) It's all about exploiting a kind of a loophole in Einstein's theory of relativity, which handily proves that nothing can move faster than light. But what if instead of moving the object, we moved the space around it?

(0:52) The idea is to manipulate space-time. For the purposes of theoretical physics space and time are two parts of the same thing. While it is impossible for any object to move faster than light, scientists do not believe that there is any speed limit when it comes to the ability of space-time itself to expand and contract.
 
(1:09) So the idea of a warp drive, as first seriously suggested in 1994 by Mexican physicist Miguel Alcubierre, is that an object remains still inside something called a warp bubble, and then space moves around it.

(1:22) The warp in warp drive refers to the theory that such a device would use gravity to compress space-time ahead of it and expand space-time behind it. As the empty space behind the vehicle expands rapidly, it would push the craft forward. Anyone on the vehicle would perceive this as crazy-fast movement.

(1:39) But yeah, about that warp bubble. Space-time, it turns out to be pretty sturdy stuff, expanding and contracting it requires an enormous amount of negative energy. In Alcubierre's model, initiating such a device meant coming up with the energy equivalent of the mass of Jupiter, and that right there explains why we didn't hear much about this idea for the next 18 years.
 
(1:59) Jump ahead to last September, where at the 100-year Starship Symposium, NASA scientist Harold White, seen here holding a fancy sciencey-looking thing, said that his team may have discovered a more practical method to build a warp drive by changing the geometry of the bubble. 

(2:14) In an interview with i09, White said, "I suddenly realized that if you made the thickness of the negative vacuum energy ring larger - like shifting from a belt shape to a donut shape - and oscillate the warp bubble, you can greatly reduce the energy required - perhaps making the idea plausible."

(2:31) Recent models have suggested that a craft pushed along by such a system could reach 10 times the speed of light - fast enough to get to Alpha Centauri in 6 months - using only 65 exajoules of energy! 

(2:43) Yeah, that's... that's a lot of energy, isn't it. It's like roughly the amount of energy that's consumed by all of America every year, so, yeah. But at least it's an amount of energy that we're capable of creating!

(2:53) At the Eagleworks lab, where NASA investigates advanced propulsion systems, White and his colleagues are using laser interferometry to try and measure whether or not they can create minuscule, but detectable warp bubbles. And if they prove that it can work, even on a small scale, practical applications might not be far away. Though 65 exajoules is not an easy amount of energy to come by. And it's not just normal energy either, it's theoretical weird wibbly negative energy. 

(3:20) On the other hand everybody knows that Zefram Cochrane didn't pilot the first warp drive until 2063, so we shouldn't be surprised that there's still quite a lot of work to do. But NASA's stated goal is to build interstellar space craft before 2100, so if you're lucky, and maybe a little younger than me, you may indeed be around to see it.

(3:38) Thank you for watching this episode of SciShow. If you have any questions or comments or ideas for us please, down in the comments below or on Facebook or Twitter. And if you want to keep getting smarter with us here at SciShow you can go to youtube.com/scishow and subscribe.