Thursday, June 1, 2017

Michio Kaku Says: Alcubierre’s Warp Drive is “A Passport to the Universe!”

Well, your kids won’t be traveling by the speed of light—probably not their kids either—but new theoretical advances may mean that warp drive will someday become a reality. Light travels at 186,000 mi/sec—if we could move that fast today, we could circle the Earth along the equator 7.5 times per second. Or travel to Mars in 3 minutes. We’re nowhere near the ability to travel at or close to the speed of light today, making warp drive—or faster-than-light (FTL)—travel seem like an insurmountable feat best left for the fictional realm. But, back in 1994, the idea of faster-than-light (FTL) travel became a possibility when physicist Miguel Alcubierre hypothesized a way to travel FTL on a “magic carpet” that doesn’t actually move at all. Because no object can move faster than the speed of light, we would instead travel by remaining still on a piece of space-time (i.e., the carpet) that sits inside a warp bubble capable of moving at FTL speed.

This all rests on the idea that there is no limit to the speed at which space-time can expand and contract. During the Big Bang, for example, we know that space-time expanded at 30 million billion times the speed of light—at least. So how does this warp bubble idea work? It uses gravity to compress the space-time fabric in front of an object, then expand that fabric behind it. The actual space-time that we (or a spacecraft) would sit on would float along at theoretically 10 times the speed of light or more, wrapped comfortably in a warp bubble much like a surfer is carried along on a wave.

Sounds great in theory, but the negative literally outweighs the positive in this model. Alcubierre’s original model would require more negative energy than the total mass of the Universe to allow even a small aircraft to travel at FTL speeds. Although refinements in the 20+ years since he developed the idea have brought the amount of negative energy needed down to a few hundred kilograms, we’re still traveling in the land of science fiction here, because this so-called “exotic matter” with the negative energy and negative pressure to make this happen doesn’t exist in the realm of classical physics. Quantum mechanics holds some possibilities for negative energy, but not the right kind to generate the warp bubble we need for FTL travel.

Luckily, there’s a dark side to all of this. We know that dark energy is the stuff that causes the universe to expand. If we can harness and manipulate dark energy—which makes up almost 75% of the universe—perhaps we could use it to expand space-time and create the warp bubble. This model still comes with problems—dark energy is spread thin across the universe, and we have yet to figure out how to amass enough of it to put it to use. But theoretically, doing so is possible. Scientists at NASA are experimenting as we speak to see if warp drive can someday become a reality. Since 2012, NASA’s Advanced Propulsion Physics Laboratory (aka. Eagleworks) has had a team of scientists working on warp field mechanics. “We’ve initiated an interferometer test bed in this lab, where we’re going to go through and try and generate a microscopic instance of a little warp bubble,” said team lead Dr. Harold Sonny White. “And although this is just a microscopic instance of the phenomena, we’re perturbing space time, one part in 10 million, a very tiny amount… The math would allow you to go to Alpha Centauri in two weeks as measured by clocks here on Earth.”

Source: http://sciencevibe.com/2017/06/01/michio-kaku-says-alcubierres-warp-drive-is-a-passport-to-the-universe/