If there’s something most of us can agree
on, it’s that lightsabers are awesome. But this is probably the closest I'll get
to holding a real one... or is it? Now, I don’t actually mean mining kyber
crystals or injecting our bloodstreams with midi-chlorians (because everyone knows midi-cholorians
are a cop out) — but instead using real technology we have today to create something
that looks, acts, and feels like the most famous movie weapon ever. So, how close are we to creating a lightsaber? Now, we realize there are no actual scientific
endeavors focused on specifically creating a lightsaber at this point in time. Sadly. But if we were going to build our own, the
first thing we need to do is look at how the lightsaber works in the films. If you're trapped in a cell, you might be
able to use your lightsaber to cut through the walls to be able to get your way out. If somebody is giving you trouble in a cantina,
you can chop off their arm and let them know that you mean business. So our lightsaber needs to be a handheld device
hot enough to slice through what looks like steel or cut off a limb. What else? Lightsabers are powered by a Diatium power
cell. It's essentially the battery for the lightsaber. The beam of a lightsaber is contained by the
Force powers of the user being channeled through the kyber crystals. Definitely don’t have any of those, so we’ll
need to find an alternate power source. Probably the characteristics of a lightsaber
that make it the most dramatic and exciting to watch are one, the glowing beam, but two,
the sounds that it makes as you swing it back and forth.That is very iconic. Or the crashing sound of two beams coming
together. Those are some of the most iconic aspects
of a lightsaber. Ok, so in total, there are five key functions
our lightsaber has to fulfill. A natural starting place for using real life
technology might be with light itself, given the name. Even George Lucas has previously, and confusingly,
referred to the lightsaber as a laser sword. And although it’s true that lasers can be
powerful enough to cut through metal or cauterize a wound, like current gamma knife technology
we use in hospitals, they do present some other challenges in terms of our five criteria. So a laser lightsaber essentially is a very
high-powered flashlight or a very high-powered laser pointer. Your standard laser pointers obviously are
not going to be able to cut through metal or anything like that. That would be quite dangerous for all your
screens and PowerPoint slides. But if you’ve ever held a laser pointer,
you know it doesn’t look anything like a lightsaber for two big reasons — one, you
can’t really see the beam from the side. And two, the beams go on infinitely, rather
than the roughly 1 meter long lightsaber. If you want to contain the beam in a finite
length, the best or easiest way to do that with light would be to just have a mirror
that can retract or be extended from the hilt of the lightsaber and then that is able to
reflect the light back and forth to create a contained beam of light. And it's just not going to have the look of
a lightsaber. It's going to have the look of a flashlight
with a mirror on the end, even if that flashlight is really powerful. Also, if you were to have a lightsaber battle
using this method, it would be the metal contraptions holding your mirrors clunking into each other
rather than the actual beams of light, because the beams of light, spoiler alert, would not
actually collide with one another. One light beam will just pass through another
light beam. But what if that could be changed? Some researchers at Harvard and MIT found
that it would be possible to have photons work together as they move through ultra-cold
rubidium atoms and behave much like a molecule in the traditional sense. This study was able to show that they could
do this for two, three photons, but in principle if we could do this for millions upon billions
of photons we could create a unified beam of light that would be very much like a lightsaber. Photonic molecules are very difficult to make. They can only be generated in very precise
experimental conditions. Ah, I thought there might be a catch. Turning light into molecules really just opens
up a whole new can of space slugs, since it would need to happen in a supercooled vacuum
and a beam wouldn’t actually cut through anything. It again kind of takes away from the excitement
and the awesomeness of a lightsaber. I think the best method for generating a lightsaber
in the real world would be to create a highly contained plasma. A plasma is one of the four states of nature. You know about solid, liquid, and gas. Plasma is, perhaps, like more gas than gas. What it is, is when you heat up gas so much
that you're actually breaking apart the atoms so that the electrons and the center of the
atoms are no longer connected together, and they kind of move around next to one another. If you want to see a plasma, go outside and
don't look directly at the sun, but know that if you were to look at the sun, that is a
big ball of plasma. Plasma has a lot of uses. They can cut through metal very impressively. Some surgeons will use plasma scalpels. And these plasma scalpels actually make a
more precise cut than an ordinary scalpel. Now, this is definitely starting to sound
more like a lightsaber — plasma checks the box for being hot enough, but I sense another
catch. It's incredibly difficult to hold a plasma
in, and so if you don't have strong magnetic fields, it doesn't work. This is exactly the problem that tokamaks
face, the donut shaped devices that produce controlled thermonuclear fusion power. The trouble has to do with the fact that plasma
is made up of charged particles. Charged particles moving around make their
own magnetic field. And so, you have the magnetic field of the
containment, but then you have the magnetic field the plasma makes, and the two of them
interact, and it's very hard to keep a stable field with that very, very complicated process. Right now if we tried to create a plasma lightsaber,
it would look nothing like what we'd imagine, and it would in fact be so large that we would
be unable to hold it. The smallest containers that can contain plasma
are still large enough that a human can walk through them. Right. Ok, so until we can downsize that to a handheld
hilt to clip on our belt, do we have other options in the meantime? One possibility is that inside a lightsaber,
there's like a telescopic rod. So, like an old car antennae, the telescope
would come out of a lightsaber, perhaps, made of ceramic so it wouldn't melt and that would
be the thing that would set the magnetic field that would then control the plasma. So, we would press the button on the hilt
and the ceramic rod would begin to come out of the handle, producing the crucial buzzing
sound and the shape. Refractory ceramics and alloys also have melting
points as high as 4215 degrees celsius, so they would be able to withstand plasma as
hot as 1370 degrees celsius — that is hot enough to melt through a steel door. Essentially, the plasma would cut through
and the rod would follow through the hole. Ok, let’s acknowledge the bantha in the
room — that kind of heat is going to be dangerous to be around. Essentially imagine having a cylindrical piece
of the sun three inches away from your hand. It's not going to go well for you unless you
have some kind of really, really insulating gloves, probably got to be made out of tungsten. Done. What about the color? The color is very important. Luckily, generating the different colors of
a lightsaber is actually easy. All that matters is the gas that's in the
plasma. Change the gas, get a different color. Exactly like neon lights. So that would mean using neon for a reddish
lightsaber, krypton for a green, helium or sodium for a yellow, and xenon or argon for
a blue. And just for you Samuel L. Jackson: mercury
for purple. Problem with that is it gives off ultraviolet
light, too, which if you look at it too long will make you blind. Ok so maybe we skip roleplaying Mace Windu. Got it. What about dueling with this prototype? If the idea of the telescoping center of the
lightsaber is real, then it actually could be those two telescoping central rods are
touching one another. But, even if somehow we were able to make
magnetic fields that didn't have the telescoping rod, what I was thinking is perhaps it would
be the interaction of the magnetic field of one lightsaber with the plasma of the other
one. After all, if the magnetic fields can contain
the plasma of our saber, it will also repel and interact with the plasma of the other
saber. So, it's a bit of a stretch, but that's maybe
some way that could happen. In order to power this lightsaber design,
we’re likely going to need millions of amps of current to generate a magnetic field powerful
enough to contain this plasma. Unless...we use antimatter? Antimatter is something that sounds like science
fiction, but it's fact. If you mix antimatter and matter together,
you get a crazy amount of energy. How crazy is crazy? A single gram of antimatter could produce
an explosion equal to an atomic bomb. So maybe, just maybe inside the hilt of a
lightsaber, is a tiny few micrograms of antimatter, and if there is, you got all the power you
need. In 2006, NASA actually funded research to
explore the possibility of designing an antimatter-powered spaceship. Antimatter has the highest energy density
of any known substance. We have been able to create a nanogram of
antimatter in the Large Hadron Collider, but it wasn’t cheap. current estimates put the cost of producing
just 1 gram of antimatter at about 25 billion US dollars. Which is a shame, because a super teeny amount
would fit perfectly in our handheld lightsaber hilt, and wouldn’t come with the drawbacks
of say, radiation from a nuclear powered lightsaber. Ok, I think I already know the answer, but
how close are we to creating a lightsaber? Although a number of advances are required
for this, individually all of these advances are currently being researched to try to generate
better batteries, to try to generate smaller contained plasmas, and to generate high temperature
superconductors. I would probably estimate that we're still
a century or two away from having a lightsaber as we know and love them. We can generate variations on a lightsaber
today with current technology. It's just a matter of which aspects of your
childhood dreams you want to give up. I'm not sure that we'll ever be able to make
a lightsaber, and that certainly is a shame, because it is an elegant weapon for a more
civilized age. You know? Lightsabers might not be real, but I want
them to be. For more episodes of How Close Are We, check out this playlist right here. Don't forget to subscribe, and come back to Seeker for more episodes. Thanks for watching.
