Is a warp drive possible?
Space ships with warp drive can travel to just about any alien planet in the galaxy, as easily as we travel by plane to anywhere on earth, in hours. This makes for a lot less boring science fiction.
At maximum warp, the Enterprise from Star Trek the Next generation can go 9000 times the speed of light. And if you think that’s fast, the Mellenium Falcon from Star Wars can go 9,000,000 times the speed of light.
By comparison, the fastest manmade object, the Juno probe around Jupiter goes a whopping 0.0002 times the speed of light. This is superfast by earthly standards, 46 miles or 74 kilometers per second. But at this rate, it would take 20,000 years to reach the nearest alien planet Proxima Centauri. If we had warp drive like The Enterprise, we could make it a day trip – there and back in only 9 hours.
But isn’t warp drive all a bunch of science fiction fantasy? Isn’t faster than light travel forbidden by Einstein’s special theory of relativity? Well, it turns out there is a loop hole.
And to be honest, before I started researching this subject, I thought this video was going to be all tongue in cheek. But I was shocked at the volume of real science that has been done on this subject. Turns out there are a lot of scientists who have been inspired by Stark Trek.
And I think you are going to be shocked that although the warp drive is highly theoretical, it is based on some real physics. How would such a warp engine work? And is it really plausible?
The unorthodox, crazy physics of the warp drive is coming up right now…!
In 1994, Mexican physicist, and Star Trek fan, Miguel Alcubierre published a paper on “The warp drive” while still a phD student, and became instantly famous.
How did he figure this out? He did this by manipulating Einstein’s equations of general relativity. This was a purely geometric manipulation. What you have to understand is that General Relativity at its core is about the geometry of space-time. Einstein showed that Gravity is a geometric warping of space time.
By manipulating this geometry to look the way a warp field would look for a space ship, Alcubierre made the equations find an answer to the idea of a warp drive, regardless of whether it was feasible or whether other laws of physics would allow it. It was more of a thought experiment.
But his equations are mathematically consistent solutions to Einstein’s equations. And this is how Alcubierre’s warp drive would work:
Take a space ship and put a bubble of space around it. If you can compress space in front of the bubble, and expand space behind the bubble, then you can make the bubble of space along with the space ship, move. This would be like riding a wave on a surfboard. You are not moving on the surfboard, but the surfboard is moving because it is being pushed by the wave.
This is where the loophole is in Einstein’s speed limit, that nothing can move faster than the speed of light. This speed limit only applies to objects travelling within space, not the movement of space itself. Space can move at any speed.
So that bubble of space in Alcubierre’s geometric solution can move at any arbitrary speed, theoretically, even 9000 times the speed of light.
Alcubierre figured out a geometry that would fold space in such a way that a ship would not move in its frame of reference, but the space that it was resting on would travel.
But Can space really move at faster than light speed? Yes, for example, our observations appear to show that space very far away from us, at the edge of the universe is moving faster than the speed of light. Any light from galaxies or stars in this space is light that we will never see. In addition, as I showed in the previous video, that space inside a black hole’s event horizon moves faster than the speed of light. So this is a real phenomenon.
Let’s look at Alcubierre’s warp drive more carefully and what it is doing to the space-time around the space ship.
Space is being expanded in the back of our spaceship, and being contracted in front of it. Can space expand and contract like this? Yes, Space is allowed to do both.
Space is malleable according to general relativity, it can bend, stretch, and create waves.
Space is contracting around you and earth right now. That’s what gravity is. Similarly, Space can expand too. It is expanding right now on a cosmological scale, because when you look through a telescope, you can see that far away galaxies are red-shifted. The galaxies are not moving locally. It just means that space between those galaxies and us is expanding.
Alcubeirre’s warp drive, creates a kind of bubble around the ship, which is like the surfboard. The ship sits within this bubble, analogous to you standing on the surfboard. Your ship does not move within the bubble itself, so Einstein’s laws are not violated. But the bubble of space is moving or carried by a kind of wave that is being created in space.
So how would the warp engine make space contract in front and expand in the back?
This is not easy. Space is a fairly stiff fabric on the order of: c4/8G – ‘c’ is the speed of light to the 4th power – that is a very large number.
And to make space warp locally around a spaceship like this requires a lot of mass or it’s Energy equivalent via E=MC^2 – densely concentrated around the space ship. (Show equation from PDF)
And this is not just regular mass or regular energy. This is negative mass and negative energy, because in order to create expansion of space, you need some kind of anti-gravity.
How do you get anti-gravity? You need negative matter – or exotic matter. This is something that would have negative gravity.
The problem is Negative matter is not known to exist.
Note that negative matter is not anti-matter. Antimatter does not have negative gravity. It has positive gravity. It is just like matter except it has the opposite charge. So an antimatter proton would have a negative charge, and an antimatter electron would have a positive charge.
Antimatter does exist. But this anti gravity, negative matter is something completely different. it has never been detected.
I’m not sure what it would be. Imagine something that weighs negative 1 kilogram. What does this even mean? It may not even exist.
You could substitute the energy equivalent of negative matter, and that is negative Energy. This comes from E= – MC^2. But again, what the heck is negative energy?
This is not the same as an absence of energy. It is energy with a value less than 0 energy that would theoretically create anti gravity, and allow you to expand space-time.
But Antigravity has never been seen in a lab. And there is not a known distribution of energy that can produce antigravity or negative mass. It has never been found in any accelerator or observed in nature.
Even Alcubierre called his results “nonsensical.”
However, anti gravity, negative mass, and negative energy are not forbidden in Einstein’s equations. Could this mean that if we are clever enough, could we create it?
Let’s presume that we could. There is group at NASA called the Advanced Propulsion Team, also known as Eagleworks, who is working with this assumption, and they have even created an artist’s rendering of what a warp drive space ship would look like. They even call it the Enterprise.
Alcubierre’s original warp bubble around a space ship would have required a lot of negative energy – the energy equivalent in fact of all the mass in the universe. So it was obviously not feasible.
But further reworkings of Alcubierre’s orginal concept by NASA physicist Harold White reduced the negative energy requirement to the equivalent to about 700 Kilograms, or 1500 lbs. This is still a lot of energy, about 1000 hydrogen bombs, but may not be out of the question, and makes the concept somewhat plausible, if negative energy can be created.
How did Dr. White make Alcubierre’s engine go from nonsensical to plausible. He did this by changing the shape of the warp bubble around the ship to a torus shaped somewhat like a donut, and by oscillating the negative energy field. These changes he says not only make the warp field more efficient, but also make the space around the ship more pliable for expansion and contraction.
Dr. White’s calculations show that a 10 meter diameter ship could go at 10 times the speed of light using 700 kg. of negative mass or energy.
Why is there a torus needed around the ship. People think that since the space is expanding in the back, you need the negative energy directed at the back, but if you do the math, what you find is that the negative energy is all needed around the ship. That’s why the ring in the concept renderings is around the space ship.
White’s team has even tested the feasibility of warping space by doing a very small scale table top test. They have attempted to slightly warp the trajectory of a photon, changing the distance it travels over a fixed length, and then observing the change with a device called an interferometer. This is warping space on the tiniest scale possible. The first test was done in 2013 and was inconclusive.
Tests by other teams have shown that if such a drive could be built, it could hypothetically work but perhaps not past the speed of light which presents a host of other problems.
Travelling faster than light for example, may create hawking radiation that could burn everything within the bubble, or may make the bubble so unstable that the ship is destroyed, and other issues as well.
But I think these are minor issues compared to the idea of creating negative matter or negative energy – let’s address that elephant in the room, then we can work on the other problems. And nearly all these problems go away if we stay below the speed of light. But even achieving a speed of say 10% the speed of light would be a huge breakthrough because it would still be 50 thousand times faster than the fastest speeds we have today.
Is negative energy even realistic? Some scientists have pointed to the Casimir effect as displaying a kind of negative energy. This is a quantum mechanical phenomenon that occurs when two conducting plates are brought very close together. Something like 10 nanometers apart. When this is done, a certain proportion of the virtual particle frequencies between the plates are excluded, because not all frequencies will fit between the 10 nm space.
Frequencies with wavelengths higher than 10 nanometers will be excluded, whereas, all frequencies will fit outside the plates. The pressure outside the plates is greater than the pressure inside the plates. And this can be seen in a physical attraction of the plates that brings them together. This creates is a real mechanical energy that can be measured.
So the thought is that if the total vacuum energy is 0, than this would mean that the energy between the plates must be negative.
Some scientists have proposed harnessing this negative energy of the vacuum on a large scale. But this is flawed, because while the energy between the plates is less than the vacuum energy, it is not negative. It is positive. Vacuum energy is positive, it is just higher than the energy between the plates which is also positive. And so it produces positive space-time curvature, not negative curvature. There is not really any negative energy that can be harnessed to make a warp drive using the Casimir effect?
So given the problems I talked about, is all hope lost for the warp drive? Not quite.
There is one observational phenomenon that should give us hope that negative energy or anti gravity may exist.
The observable universe is expanding at an accelerating rate. This is called Dark Energy. See my video on that. We have no idea what it is, why it exists, or where it comes from. But 70% of our universe is made of this dark energy. And this energy behaves like anti gravity. Essentially it is some kind of energy or force that is pulling space apart. It is expanding space.
Well, expansion of space is precisely what we need to create the Warp drive. It is possible that sometime in the future, if we can develop a better understanding of dark energy, we can learn to harness it, and use it to power the warp engine. Our universe if full of this stuff. So we could potentially have a near endless supply of it. If we knew what the heck it was and how to manipulate it, we could build not only warp drives, but possibly worm holes too.
Sometimes technologies are inspired by mathematical equations. It took about 40 years to go from E=MC^2 to the first atomic bomb. In the past 20 years, the warp drive concept has gone from impossible to plausible. Maybe in the next 20 it can go from plausible to possible.
Maybe it can become reality given enough time, and given more thought-provoking episodes of Star Trek to inspire the next generation of physicists?
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Needs negative energy.
How warp drive would be different than Star Trek:
Will this be like star trek. Not likely. For one thing there is no theoretical way to communicate faster than the speed of light. So captain Pickard talking to Admiral McCoy on a subspace frequency to earth, would no be impossible. If you travelled 10 light years away, you might reach there in 10 hours year at 9000 times the speed of light, but your communication back and forth to earth would still take 20 years.
If you go into hyperspace, you would stop interacting with all electromagnetic radiation. Would you go into a different dimension? Maybe.
If you were travelling faster than light, and you could point a telescope to your alien planet destination, you could see the history of that planet play out in fast forward. 0You could for example, use a warp drive to go out into space 80 light years, point a telescope towards earth, and view it as it was in 1940, 80 year ago, around the time of the 2nd World war, and on your way back you would see all of earths history from 1940 to today play out in fast forward as you went past all the light from those years.
You could plan history trips around this.
We could go anywhere in the universe and they would never see you coming, because you would get there faster than the light would reach them.
You would be immune to any weapon
How do you actually build a warp drive? According to White, if a normal positive energy field is spread out over a large enough volume, the energy of the field can become negative, producing a negative gravitational field as a consequence. White also showed that if there are more than 3 spatial dimensions, oscillating the energy field would produce a hyperspace oscillation which will give rise to a stronger distortion of space. An oscillating electromagnetic field inside a Taurus that is superconductive could achieve this.
Even though general relativity prohibits traveling faster than the speed of light, there are two loopholes in its math that that would allow you get to other places apparently faster than light speed – wormholes and space warp. Space warp is the idea that you can expand and contract space around a stationary bubble of space, so that locally, you might be standing still, but relatively, you are travelling faster than light.
Warp metric requires exotic matter. Dr. Harold White is testing the possibility of negative energy effect called the Casimir effect, on a very small scale using positive energy. There is no way currently to get this same effect on a very large scale. Negative energy density in Casimir effect.
– Casimir effect is shown here in a sonic analog of the Casimir effect is shown here. More sonic waves are outside the two poles than in between, causing them to move towards each other.
Richard Obousy, a physicist who is president of Icarus Interstellar, a nonprofit group composed of volunteers collaborating on starship design, said “it is not airy-fairy, pie in the sky. We tend to overestimate what we can do on short time scales, but I think we massively underestimate what we can do on longer time scales.”
