After my original post on Warp Drive problems, I found an article in Popular Science dated April 4, 2013 that discussed a Warp Drive proposed by Miguel Alcubierre (http://www.popsci.com/technology/article/2013-03/faster-light-drive?src=SOC&dom=tw). Since his version of Warp Drive is slightly different than the one I discussed in my last blog, I thought I would look at what his version offers and if it could be built would it work.
Figure 1: Spaceship with Warp Drive as envisioned by Miguel Alcubierre (Popular Science Magazine, April 4, 2013)
What Alcubierre proposes is a Warp Drive that would create a bubble in space-time by using negative energy. I imagine this would be like what happens when you take a cup of water, for example and blow onto the surface causing the surface to bend in the opposite direction. If you kept blowing, you would get the surface to look like a semi-circle. Once this semi-circle in space-time is created by a spaceship with Warp Drive, it would then keep pushing into space-time behind the bending and space-time would then envelop the ship like a sphere entering a body of water. The negative energy produced by the Warp Drive would keep pushing against space-time and would warp it so that a bubble keeps the spaceship out of space-time.
Now I see two potential problems with this part of Alcubierre’s proposal.
First, what is this “negative energy” that is discussed? If there was something in the universe that repelled space-time, wouldn’t it be outside of the universe and out of our reach?
Second, I don’t believe that you can peel back space like it was a physical object. I think it exists like the space in the eye of a needle exists; it only exists as an absence of matter. I also don’t think you could treat it like some sort of liquid that you can blow a bubble in. If it was, it would take an enormous amount of energy to create this bubble and if something like a supernova can’t rip a bubble or hole in the universe, then I doubt you could find the energy to do something like that with a spaceship.
Alcubierre then proposes that his Warp Drive would move the bubble with the spaceship in it by space-time closing in on one end as the bubble moves forward. It’s the force of the universe ‘pinching down’ on the one end of the bubble that has the force. If you have trouble imagining this, think of a marble stuck midway in a garden hose. If you take your fingers and squeeze the hose directly behind the marble, it forces the marble to move away from your fingers in the hose.
With this part of Alcubierre’s model, I see more problems.
How would you navigate? If space is warped around your spaceship then getting an accurate reading from looking at surrounding stars would be impossible. Even if you could calculate this ahead of time, how could your spaceship figure out that it was continuing to move in the right direction? There would be things out in space that float around that would cause you to need a change of direction because, although you have warped space around your spaceship, this won’t matter if your ‘bubble’ runs into a planet or a star. If warping space-time means you could go through these solid objects, what happens when your spaceship drops its bubble at the end of the journey while in the middle of an object like an asteroid? What about changes in gravity that pulls you off course, how would you know to correct for it if you can’t tell where you are?
Alcubierre believes that with this Warp Drive, a spaceship could go faster than the speed of light. Apparently this is because of the theory that when the Big Bang occurred, space-time expanded faster than the speed of light (which, by the way if true, means the Theory of Relativity isn’t correct), so distorting or warping space-time would also relax the rules of relativity as it did during the Big Bang. This might be correct if the spaceship went back in time to the time of the Big Bang but you are only warping a small section of the universe with this spaceship, not riding the expansion of a young universe! Also, if you warp space around your spaceship you are still subject to the laws of physics as you are still in the universe. If the Theory of Relativity really does exist the way Albert Einstein thought it did, then you can’t go faster than the speed of light! In this case, the warping of space is only used as a way to propel you through the universe and wouldn’t cut you off from the universe. Even if it did cut you off from the rest of the universe, the ‘bubble’ of energy surrounding the spaceship is still buffeting against space-time and would be subject to Relativity, just like an air bubble in water is subject to the physics involved in liquids. However, even if you could cut yourself off from the rest of the universe, what would keep your molecules together if the physics of our universe no longer applied?
With all of these questions, I do not believe that anyone will be able to build a Warp Drive like the one envisioned by Miguel Alcubierre. All of this trickery to get around the Theory of Relativity’s rules does not make any logical sense and, as I have shown, is easily picked apart on closer inspection.
I do believe that it is possible to go faster than the speed of light and I know we will achieve that one day. The Theory of Relativity is flawed and the speed of light is not the speed limit of the universe. I think Miguel Alcubierre and others like him have great imaginations and someone one day will build a spaceship that will speed through the stars at speeds people today can’t imagine but it won’t be with a Warp Drive based on Alcubierre’s vision.
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