Spaceships with warp drive can travel to
just about any alien planet as easily as we travel to anywhere in the world in a
matter of hours. At maximum warp the Enterprise from Star Trek, The Next
Generation, can go nine thousand times the speed of light. And if you think
that's fast, the Millennium Falcon from Star Wars can go nine million times the
speed of light. By comparison, the fastest man-made object, the Juno probe around
Jupiter, goes a whopping 0.0002 times the speed of light. this is still super fast
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 Cenauri.
If we had warp drive like the Enterprise, we could make it a day trip - there and
back in only nine hours. But isn't warp drive all a bunch of science fiction
fantasy? Isn't faster than light travel forbidden by Einstein's Relativity. Well,
it turns out there's a loophole. 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's been done in this subject.
Turns out there are a lot of scientists who've been inspired by Star Trek. And I
think you're going to be shocked that although warp drive is highly
theoretical, it is based on some real physics. How would such a warp drive work?
And is it really plausible? The unorthodox, crazy physics of the warp
drive is coming up right now! In 1994, Mexican physicists 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 spaceship, 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 spaceship 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
spaceship move. This would be like riding a wave on a surfboard.
You're not moving on the surfboard, but the surfboard is moving because it is
being pushed by the wave. This is where the loophole is an Einstein speed limit,
that nothing can move faster than the speed of light. This speed limit only
applies to objects traveling within space, not the movement of space itself.
Space can move at any speed. So that bubble of space, and Alcubierre geometric
solution can move at any arbitrary speed, theoretically even 9,000 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?
Our observations seem to indeed confirm this. For example, the 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, space inside the
black hole's event horizon moves faster than the speed of light. So this is a
real phenomena and should not be discounted. Let's look at out Alcubierre's
warp drive more carefully, and what it is doing to the space-time around the
spaceship. Space is being expanded at the back of the 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. Space is contracting around you and Earth right
now. That's what gravity is. Similarly space can expand too. It's
expanding right now on a cosmological scale, because when you look through a
telescope, you can see that faraway galaxies are red shifted. The galaxies
are not moving locally. It means that the space between those
galaxies and us is expanding. Alcubierre's warp-drive creates a kind of bubble
around the ship which is like the surfboard. The ship's sits within the
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 a 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 this equation. C is the speed of light to the fourth power, so this is a
very large number. And to make space warp locally, around a spaceship like this,
requires a lot of mass, or its energy equivalent via E=MC^2,
densely concentrated around the spaceship. And more importantly, 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 theoretically 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's 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. Imagine something that weighs negative 1 kilogram. What
does this mean? it may not even exist? Now you could substitute the energy
equivalent of negative matter, which 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 zero, that would theoretically create anti-gravity and
allow you to expand space time. But anti-gravity has never been seen in a
lab. There's not a known distribution of energy that can produce anti-gravity 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, we could create it? Let's presume
that we could. There is a group at NASA called the "Advanced Propulsion Team," also
known as "Eagleworks" who is working with on this assumption, and they have even
created an artist's rendering of what a warp drive spaceship would look like.
They even call it the "Enterprise." Alcubierre's original warp bubble around
a spaceship 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 reworking of Alcubierre's original concept by NASA physicist
Harold White reduced the negative energy requirement to the equivalent of about
700 kilograms, or 1500 pounds. This is still a lot of energy - about a thousand
hydrogen bombs worth, 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 doughnut, and by oscillating the negative energy field.
These changes, he said, not only makes the warp field more efficient, but also makes
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. Now you might say, "why is there torus around the ship?" the torus is
what would create the negative energy field around the ship. You would think
that since space is expanding in the back, you need the negative energy
directed at the back of the ship. But if you do the math what you find is that
the negative energy is needed all around the ship. That's why the ring in the
concept renderings is around the spaceship itself. White's team has even
tested the feasibility of warping space by doing a very small-scale tabletop
test. They've attempted to slightly warp the trajectory of a photon, changing the
distance it travels over a fixed length. The first test was done in 2013 and was
"inconclusive." Tests by other teams have shown that if such a device could be
built, it could hypothetically work, but perhaps not past 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 50,000 times faster than the fastest
speeds that we can achieve 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 on the order of 10
nanometers. 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 nanometer space. Whereas all frequencies will fit outside
the plates. The pressure outside the plates, thus, is greater than the pressure
inside the plates. And this can be seen in a physical attraction of the plates that
brings them together. The sonic analog of this is shown in this video. So the
thought is that if the total vacuum energy is 0, then 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 still positive. There is no negative curvature.
This is not negative energy, and cannot be harnessed to power our warp drive. 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 antigravity 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, or negative
energy. Essentially it is some kind of energy or force that's pulling space
apart. It's expanding space. Well, expansion of space is precisely what we
need to create a warp drive. Is it possible that sometime in the future, if
we can develop a better theoretical understanding of dark energy, we can
learn to harness its power, and use it for the warp engine? Our universe is full
of 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.
Some technologies are inspired by mathematical equations. It took 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 years 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? Yes, please! Arvind Asha here. If you like our videos, then consider subscribing. And ring the bell
so that you can be informed when we upload more fascinating videos. We make
one to two videos a week. We'll see you in the next video!
now stop me if im wrong here, but isnt that a computer sim and not real life?
One day we will be able to do this