I'm gonna reveal some of the greatest science gadgets ever invented, starting with gadgets like this perpetual motion machine, then leveling up to a saw that's supposed to cut through anything except for human skin. The first gadget is a potato battery. To make it, we need zinc, copper, and wires. Let's stick the zinc into one side, the copper into the other, then connect the potato to an electronically powered alarm clock. It works. Let's try connecting more potatoes and see if we can power this light. We just repeat the same process as before. Now we have a lot more potatoes connected. It's lighting up. Look at that. The next gadget can pick up any spill without altering its shape. This is a pizza peeler. Let me show you. Look at that. And then, no spill at all. This is made of a nonstick surface. When it slides under the spill, it gently lifts it without changing its shape. You gotta keep a consistent, smooth motion, otherwise, it will mess up the shape. But if you're able to do everything correctly, kind of looks like magic. Onto the next invention. This is a stirling engine. If we put it above a cup of boiling water, let it generate energy from the steam, and give it a small nudge, and the gadget should spin on its own. This machine repeatedly converts heat energy into mechanical work by compressing and expanding gas. But the moment we take it off, it will start to cool down and eventually lose its power. What can we actually use it for? This is a sterling engine car. This engine converts heat into mechanical energy to make the wheel spin. Boom. Damn, bro. This is a working turbine. It has its own fuel source. We gotta fill it up with butane over here. All we gotta do is press the ignition. Whoa. We just give it a little nudge, and it should spin. Oh, my God. This is so fast. We can heat it up even more. Let's see. Yo, this is so fast right now. All right, here's a piece of paper. Let's see. It tore right through that page, and we're just getting started. There are gadgets crazier than this coming up later. This is a perpetual motion machine. If we take a metal ball and then we place it on top, the ball will slide down the track and loop back up. Science says this machine should eventually lose energy from the friction. But why is it infinitely going up and down, up and down? Well, there's actually a hidden power button on this machine. Now the ball can't go up anymore. So what's happening here? Through the magic of money, I bought you a see-through one, and as we can see, there's actually hidden electronics inside of the machine. In this case, it's an electromagnet right there. So once the ball reaches the bottom, it will reach a sensor, which then activates the electromagnet. And the electromagnet gives the ball a push upwards. As soon as we turn it off, the ball doesn't have enough energy to make the full loop. So to this day, perpetual motion still remains a myth. Onto the next gadget. This is a levitation device. Your eyes aren't deceiving you. The top is really floating. So how does this work? As you can see, if I just place the spin top on the base, it will automatically flip around because the base of this gadget has a giant ring magnet inside here with its north oriented upwards. And this spin top has a magnet inside with its north facing downwards. So when I spin it in the center here, since two north magnets repel, they create an invisible magnetic force that keeps the spin top afloat. But this gadget is impossible to get working. If you read the Amazon reviews, there's a lot of people giving it one star because they just kind of "rage quit." 3 hours later. If you buy this, you will be frustrated and hate your life. Let's give it a good spin... and then wait for it to stabilize and then lift it slowly and let itself float. It's pretty cool. This next gadget is a globe that spins forever. It's called the Mova globe. It's trippy to look at, but the science behind it is even more fascinating. There are two main features. The first is the fact that it spins forever without any batteries or power cords. How does it work? Inside, there are tiny solar panels that harness light, producing just enough microcurrents to power a motor. But for the motor to generate torque, it needs something to attach to. And there are no visible anchor points anywhere on this globe. So how's it spinning? Well, the motor is actually anchored by magnets to the earth's magnetic field, similar to how a compass works, allowing this globe to spin freely. The other cool feature about the Mova globe is how it rolls. It looks like it's floating across the surface. This is because there are actually two layers to the globe. The inner sphere is neutrally buoyant, meaning it floats perfectly in the center of the outer sphere surrounded by a liquid, which eliminates friction. So when the outside layer is rolling, the inside layer is actually not moving at all. That's why it looks like it's floating. The Mova globe is an amazing blend of science and engineering that just looks so mesmerizing. By the way, if you want any of these products, I'll link them down in the description below. This next gadget is able to defy gravity. It's called a super precision gyroscope. I have a string tied to it here. What do you think will happen if I let go? It drops. Boring. Why? Because gravity. But, if I start spinning it with this motor and now I let it hang, what do you think will happen? It defies gravity. This is because the spinning gyroscope is generating torque horizontally outwards. That outward angular momentum is what's keeping the gyroscope up, thus defying gravity. Now, if you take the gyroscope, rotate it upwards. Now you're able to balance it on your finger because the angular momentum is going upwards. Now, taking it to the extreme, we can even balance the gyroscope on a tightrope. Let's see if it works. That should not be possible. But somehow it is. Science rocks, man! This is one of my favorite gadgets because it perfectly showcases the laws of physics. And if you want to buy one for yourself, normally it costs $120, but I'm going to show you how you can get one for $0.01. So over the weekend, I use this free drag and drop website builder to make a E-commerce website where I'm listing some of the gadgets I used in this video for $0.01 each. Yeah, you heard me right. It's only gonna cost one penny. There's a limited quantity so it's first come, first served. I'll be revealing the website at the end of the segment and all this is only possible thanks to our sponsor Odoo that used to build a website with. So Odoo is an all in one tool for business professionals. So they have a bunch of applications like website builder and E commerce, and your first application is free for life. So I chose their website builder to build a site where you can buy these gadgets. It was quick and easy. All I had to do is answer some prompts about the type of website I wanted to build and it generated me a website. Then I customized it by simply dragging and dropping design elements. The best part is, Odoo even offers you a free custom domain for the first year. So here's the website: Go to Hafu Go dot odoo.com and you can buy some of the science gadgets featured in this video for $0.01 each while supplies last. While you're on the site, check out some of the features that Odoo has to offer. If you want to build your own website for free, click the link in the description or at the bottom of my website to get started. Hafu Go dot odoo.com. Now let's go on to the next gadget. This next gadget is like stepping into the future. Say hello to my new virtual girlfriend. So, this is a holographic fan. It works because on the fan, there's a bunch of tiny LEDs, which are programmed to display lights at different speeds and colors. And when the lights spin really fast, they blend together to form an image. And that's what you see here. This is different than a projector display because you can see right through the image. So there are a lot of different approaches for creating holograms, but it's one of the more cost effective ways of doing it, because it's just a fan with a bunch of LEDs. And you can link a bunch of these fans together to create life size images! But the limitation is you can't touch your waifu because she will cut you. Maybe that's the case in real life, too. Who knows? And my favorite part is that you can load up anything onto this thing. This is a Tesla coil. It's one of the greatest inventions by Nikola Tesla. This Tesla coil has a power dial and a frequency dial. So, let's just turn the power dial on. Oh, yeah, baby. The sound you hear is produced by the spark, because when the spark hits the air, it heats it up and creates a rapid expansion of air, which produces a vibration in your eardrums. So if we turn up the frequency... That's hot! A Tesla coil works by converting low voltage, high current electricity to high voltage, low current electricity. A Tesla coil is not just for show. It actually wirelessly conducts electricity. Let me show you. These are tiny little light bulbs. The light bulbs will blink at the same frequency as the sparks. And the closer we get to the coil itself, the brighter the light bulb will be. And there are a lot of cool things that can happen when you place objects on top of the Tesla coil. Try a singular leaf. That's crazy. Oh, I think it's burning. The leaf is hot. As we saw in the science experiment video, steel wool, under the right conditions, can light, so. Oh, yeah. Oh, cool. Ah, hot! There's one more thing that this Tesla coil can do. I haven't told you about that. It can play music with electricity. We can flick it to music mode. It's synced up to my phone. Right now, let's press play. Because we're able to control the frequency and the power of the electric discharge, that means we're also able to control the sound that it makes. We got some Super Mario. Let's see. This is the electricity making the music. It's not a speaker. That's hot. Alright, this song you might recognize. Are you ready for the drop? We are done. Onto the next gadget. The next gadget was supposed to be this laser. I saw it in a viral YouTube video a while back, but after some research, I found out it was fake. It's actually just a digital render from this Instagram page. So I found another laser gadget that's even cooler. There's so many cool features here, but let me show you this. This is a laser. And with the laser, I can magically draw on this wooden board. Look, I can draw a smiley face, draw a heart. What we've done here is we made the backboard light sensitive. The entire backboard is coated with glow-in-the-dark paint, which is activated by uv light, and you're able to see a light trail in real time. When I saw this on YouTube for the first time, I didn't believe it was real because I thought this light trail effect was edited in, but it's actually just happening in real life. So you might be asking, yeah, that's cool, but what's the purpose of this? So this part of the gadget is a double pendulum. And double pendulums are like my ex: completely chaotic. They swing around in a non repeating pattern. Combine that with the uv light we have at the bottom, now we're able to make a light painting that never repeats itself. I'll turn off the lights and let you enjoy the show. For our final gadget right here. This is a saw that will cut through everything but me. Let me show you. It can saw through a piece of wood, no problem. This is a cast saw. The first time I saw it was when I broke my ankle two years ago. I was so scared when the doctor pulled this out and just started sawing my leg. But surprisingly, he didn't cut me. And at the time, I thought it was because the doctor had such steady hands that he never touched my skin. But I was wrong. The doctor doesn't have sniper hands. I was just protected by science. To demonstrate the cast saw, I got this right here. It's called fiberglass cast tape. It dries really fast. And what we gotta do is put a little gauze around my arm. I don't really have any, so I'm just gonna use paper towel. Then we just dip this in water to activate it. If this doesn't work, I might actually have to go to the hospital to get it off. All right, now we just wait. Whoa. Why is it bubbling? I feel it heating up. Now that my cast has hardened, I actually feel like I have a broken arm now. Let's pray to God this saw doesn't actually saw my skin, because otherwise I would actually go to the hospital. Okay, let's turn it on. Alright, here we go! It's getting awfully close to my skin. Well, the saw worked because there's no blood here. So a regular saw uses rapidly spinning circular blades with teeth to cut through things. As the blade spins, the teeth bite into the material that's being cut, and the teeth remove material with each spin, creating a clean and precise cut. But unlike traditional saws, this cast saw uses a blade that vibrates instead of rotating fully. This oscillating or jiggling action won't hurt you because your skin is actually kind of stretchy. So when the saw jiggles, your skin jiggles along with the saw instead of being cut by it. Keep in mind, if the saw is spinning fast enough or it's sharp enough, it will still cut you just because of friction. Oh, I am free. And the saw was able to cut through so many layers. No cuts, no scratches. Did burn me a little bit right there because the saw got a little hot. This gadget is proof that science is not lame. It's everywhere. And understanding how and why things work around us will unlock a world of possibilities for you. You can literally build anything once you grasp the secrets of science. So click here to watch level one to 100 science experiments. And click here to watch another video that YouTube thinks you'll love.