Should I just try it? Should I
just swing my arm right through? You didn't think I was actually going to show you
that in the first five seconds of the video... Don't worry, it does happen though. So in case you've been living under a rock, Disney recently announced that they've created the world's first retractable lightsaber which is kind of strange considering I have a certificate right here from last year. Ok ok so ours is still technically a proto
lightsaber since it requires a backpack but we are actually working on a
newer version that might just be fully self-contained in the hilt. But more on that later. So has Disney really made a real
working, fully in the handle gosh darn, laser beaming,
plasma cutting, lightsaber? Well probably not it's actually probably similar
to the toy lightsabers that I grew up with. In fact they actually filed a
patent a few years ago about it, but of course patents are always
a little confusing to read. And if you're looking at
this with an untrained eye you might be like "yeah
this is a lightsaber, cool" but if you look a bit closer it's pretty obvious
it won't be cutting through anything anytime soon. Luckily benriddout on Twitter created an animation that kind of explains the
rough concept of this patent. And it's pretty cool. I just hope the LED's they're using
are super bright because if they are it will be the most realistic and coolest
extendable prop lightsaber on the market. Anyway let's talk about the closest
thing to a real lightsaber on the market. Well I guess it's not really on the market
since we're not willing to sell it... But I'm talking about our current proto saber. In celebration of May the 4th be with you we thought this would be a good time to answer
a few more questions about our lightsaber and maybe try a few new tests
including putting a hand through it. Which we'll do at some point in this video. Our original lightsaber video
is now our fourth most viewed video on the channel with over 31 million views! That's absolutely insane! If you add up all the views of all our lightsaber
videos it's over a hundred million views! You guys must like lightsabers or something. So let's take a deep dive and talk a
bit more about how this actually works, what it can and can't do, and touch on how
we're going to make it better for the future. As we mentioned in the build
video the basic principle of a proto-saber is burning a
mixture of laminar flow gas. In this case propane and oxygen. It's not creating pure plasma but there is a
certain amount of plasma in the burning blade. What makes it possible is the laminar flow nozzle
which is from GTT glass torch technologies. That's right the secret to our proto-saber is
a piece of tech that's been around for decades! And I guarantee anyone who's ever used or seen a glassblowing torch has probably waved
it around humming lightsaber sounds. The cool thing is we're actually
going to be working with GTT to develop a new type of torch more
suitable for our lightsaber-like application which might just be the key in being able
to make one of these fully cordless...maybe. Either way make sure you subscribe. So what are the biggest issues with our design? Well for starters it's a proto-saver
and having a cord is kind of lame. But we've explained in past episodes one of
the biggest issues with a real lightsaber is getting enough energy into such a small hilt. It's just one of those things that you know
is limited by our technology of the time. Maybe someday though. The other big issue that lots of people pointed
out is how the length of the blade kind of varies. Since it is a torch flame it's susceptible
to having its gas flow disrupted like this. When it's pointed straight up we can get a blade length of almost three feet
or around 100 centimeters, but when moved fast the blade can shrink
down to a foot or about 30 centimeters making swinging a lightsaber
around kind of difficult. Now the thing I'm curious about is if
it's air resistance that causes this, what if I use this lightsaber in outer space? I'm probably not going to be able
to try that anytime soon but what if I could test it out in a
large enough vacuum chamber? Hypothetically since this lightsaber provides
its own oxygen it doesn't need air to work, and if it's the surrounding air
that's causing this disruption of gas you might be able to swing this around in a
vacuum chamber without the blade changing at all which would be really cool. The issue is, where do we find a giant vacuum
chamber that we can put this in besides like NASA? Seriously if any of you guys know of a
vacuum chamber that this could be tested in let us know and send us an email
at contact@thehacksmith.com. A lot of people also asked what are lightsaber
sounds like without any added lightsaber sounds... and well this is what it sounds like... it basically sounds like a louder
version of a mini saber blowtorch. Which honestly is probably what a
real lightsaber would sound like if a real lightsaber is in fact plasma. It would make some noises not
unlike that of a real lightsaber is. In fact, a laser well it probably
wouldn't make any sounds at all. Okay now what about cutting power. In the movies lightsabers can swing quickly
through things cutting them instantly. Unfortunately in real life we have to deal
with a branch of physics called thermodynamics. Specifically heat transfer. Have I lost you yet? Let's start with a basic example. Take a tea kettle for instance. Water boils at 100 degrees Celsius. A tea kettle heating element can
heat up to 100 degrees Celsius, but water doesn't just boil instantly when
you turn on the kettle or when you blast fire. You see it takes a few minutes. That's because the heat created from the
element needs to transfer into the water. In order to heat it up or in
the case of a light saber, how long does it take for the heat from the light saber to heat up the
material to its melting point, at which point it would start to cut? So how do we figure out how long that
takes using specific heat capacity? The specific heat capacity of material is
the energy required to raise one kilogram of the material by one degree Celsius. The specific heat capacity of water is
about 4180 joules per kilogram Celsius. A watt is a joule per second so how
long does it take to boil water? Well let's try out the calculation. If we take one kilogram of water which would be one liter since water is a
kilogram per liter in density and it has a specific heat capacity
of 4180 joules per kilogram Celsius. We want to hit 100 degrees Celsius and it
starts at room temperature or about 20 degrees. Therefore the calculation is one kilogram
times 4180 times 80 degrees Celsius which equals 334 400 joules which means in order to have a kettle boil a
liter of water in just one second you would need 334.4 kilowatts of heating power! Remember the average North American home only has
about 48 kilowatts of power for the entire house! Luckily no one needs to boil water instantly. Even our original tungsten titanium proto
lightsaber which was essentially a giant 20 kilowatt heating element well it would take
that 16.7 seconds to boil a liter of water. It's fast but it's definitely not instant so if you want to boil a liter of
water in a minute we can divide this total power by 60 seconds
which will only be 5.56 kilowatts. Quite a bit more reasonable but the
average kettle is only 1.5 kilowatts because of the limitation from an outlet. At 1.5 kilowatts of heating power it
would take the average kettle about 3.71 minutes to boil an entire kilogram of water so yeah it takes a while to heat things up. Luckily water actually has a really really really high specific heat capacity
while water's around 4200. Steel is only 420 or a tenth of water. That's great right, that means you
can slice through a wall of steel 10 times faster than boiling a wall of water. Right? That doesn't even make any sense. Anyway for those that didn't
listen to my physics explanation, is it takes a long time to transfer heat into
an object or cut an object with a lightsaber. The only things we can control to speed it up is the temperature of the lightsaber or
the melting point of the material, or the amount of material. So yeah we can cut through a sheet of thin lead quite quickly since it has a
lower melting point than steel, but there's less material to heat up. And it's not steel, so the real question
is how hot could we get a lightsaber? Well I'm off, I'll be back in a couple days. What? Where are you going? I'm going to Japan. Anime. What those like Japanese cartoons? Have you? I know what anime is. Owen why are you going to Japan? Well because they have stuff on
Netflix that we don't have here. I can't get it here. You kidding me? What? Just install NORDvpn on whatever
device you're using for streaming. Whether it's a computer, your phone, or a laptop. What's a vpn? Is that some type of like
animated streaming service I've never heard of? It's a vpn, a virtual private network. It's super simple. One click that's all. Open the map click on a location
and you'll be connected in seconds. It's that easy! You'll have access to all the Netflix content available in Japan or in over 50
countries without leaving home! Damn. I already got a ticket though, is it
fast because I hate chunky video... It's the fastest vpn out there and it also
offers a cool anti-malware tool called cybersec. You can be in Japan on your phone while
you're on the bus on your way home while even protecting yourself from hackers and bad people trying to read
your sensitive information. I heard the wi-fi on those buses aren't so
safe man and that goes for you guys too! Visit NORDvpn using my link below
or use the coupon code hacksmith during checkout for a huge discount on NORDvpn. Plus one extra month for free. They offer a 30 day money back guarantee and they're doing their final
sale at the moment so get going. And you get back to work! So how hot could we get our lightsaber? Our current saber clocks in at an impressive
2200 Celsius or about 4 000 Fahrenheit. Using the current fuel mixture an acetylene torch
can hit about 6200 Fahrenheit or 3500 Celsius which is hotter than most
materials melting points. Unfortunately there are some challenges in
running oxy acetylene in a torch like this which is why we use propane instead. Anyway the issue is even at
those massive temperatures we still need to take into account heat transfer. A focused oxy acetylene torch can cut
through steel plate fairly quickly, but part of the reason that works is
because a cutting torch is good at cutting. It's because it has a very thin blade which means it only needs to heat up a
small amount of material, which means it can cut things a lot faster. Even though our lightsaber is
hella hot it's got a big blade and that means the heat isn't
very focused when cutting things. It has to heat up a lot of material
before it can start cutting and unfortunately that's just the
reality of lightsaber physics. In fact the only time lightsabers
were portrayed in a reasonable way was when Qui-gon Jinn cut
through the blast shield doors. It actually showed that it took time to heat up
that much dura steel in order to cut through. Even though every other depiction of
a lightsaber shows it either cutting through things instantly or in
the case of vesgar not at all. Our lightsaber could cut through a few inches of steel plate it'd just take a
really really really long time. If we wanted to be able to
slice through things and cut metal just like the movies
I'd guess that our lightsaber would have to be in excess of
twenty thousand degrees Celsius aka four times hotter than the surface of the sun! We could even do some calculations with our
handy dandy specific heat transfer equation but why bother if the blade
is 20 000 degrees Celsius. You wouldn't even be able to hold the lightsaber. Okay back to our other lightsaber questions... Lots of you guys asked if it would be
possible to put some kind of solid blade inside of our lightsaber so it could
actually deflect another lightsaber. Now that could work but the issue is most materials that are capable
of withstanding this heat are also rather brittle which means it
might work but you'd still have to gently hit lightsabers against each
other which is also kind of lame. A lot of people also asked what would happen if you shot a bullet
through the lightsaber, would the bullet melt? Well no, no it wouldn't. And again we can thank heat
transfer for the answer. Since a bullet would be moving super
fast through the blade I would guess that it wouldn't even warm up because it spends
so little time inside of the heat source. But hey let's prove it. I'm going to
use a nerf gun for our demonstration. Though now a nerf dart has a very
very very very low melting point and it travels a lot slower than a bullet. So first off let's see what happens
if we put this into the lightsaber. And it's gone. Now that happened pretty quick, but the
question is what if I shoot the nerf dart? Not even warm. And that's that's heat transfer for you. Because it moved so quickly it didn't actually
take on much heat from the lightsaber. I guess lightsabers aren't actually very good
at deflecting things or even melting things. Alright that was kind of
disappointing, but was to be expected. So let's get to the real meat and potatoes of
this video, the reason you clicked on this video. Would this lightsaber cut off my hand? Should I just try it? Should I
just swing my arm right through? So like we learned as long as I can minimize
my hands time inside the lightsaber blade hypothetically I won't cut my hand off. My skin and body have their
own specific heat capacities. Though the human body's ability to self
regulate temperatures kind of changes that it takes a long time obviously. A dead hand might actually be
a more scientific test...maybe. Yeah it's a box of hands. In all seriousness though these are actually wax hands from Ripley's Believe
It or Not museum in Orlando. A big thank you to Kurtis to sending
these to us for our lightsaber tests which well you get your wish. We're gonna we're gonna see what happens. Alright okay for the first test we're gonna
slowly put this hand through and see what happens. Whoo. That still takes a while but
that would most certainly be a third degree burn or a fourth degree burn. Is there such a thing as a fifth degree burn? It definitely burns the hand but what
if we swung the hand through quickly? And this one...this one has hair on it
so let's see what happens if I swing this through the lightsaber really quickly? Is it going to heat up is it going to melt at all? And depending on the result is that
going to give me the confidence required to swing my own hand through the lightsaber? Here we go karate chopping a lightsaber. Um not even not even warm. Let's uh let's do it upside down see
if we can burn some of these hairs off. Even the hair Alright so this can't be
overstated do not try this at home. I am a trained professional idiot and uh yeah based on my calculations
everything should be fine. You guys ready? uh Alright that was awesome! Did you see how the flame wrapped
around my hand and through my fingers? And I didn't even get burnt! That's because the time my
hand spent in the actual fire wasn't long enough for the
heat to transfer into my skin. Regardless do not try that at home,
don't try sticking your hand in fire just to see if you can. If you end up holding it in for just a bit
too long you could end up with serious burns. This was a risk, it was a calculated risk
on my part and I'm a trained professional. But don't try this at home. I hope you guys enjoyed this video and
maybe learned a thing or two about physics. We're going to keep working on our lightsaber
technology so make sure you subscribe. Because our next version of this,
well maybe not the next version. We're going to try and make it fully
cordless which would be really cool. And also make sure you keep your
eyes peeled at hacksmith.store because we're releasing our very own mini saber. Thanks for watching guys!
