The Weirdest Microscope

Have you brushed your teeth? >> Yes. >> H Let me see. I made a video about Gel Site about 2 years ago, and they just released this new one that goes even smaller. Its purpose is to take precise 3D measurements of very small things. But here's what I've been using it for. I've been comparing fake things to real things, old things to new things, and natural structures to synthetic structures. We discovered loads of amazing things, and I'm just going to show you all of them. Like this, for example, is the grippy surface on a PlayStation 5 controller. How cool is that? There's a link to the original video in the description, but here's a quick recap of how the thing works. So, what shape do you think a poppy seed is? Under a normal microscope, it's hard to tell because the surface of a poppy seed is black, but you'd probably assume it was roughly spherical. But if you could spray paint it like 50% matte gray, it would be a lot easier to figure out the shape of the thing. And that's the idea behind this weird microscope. It's as if it gives your subject a temporary coat of extremely neutral paint. And look, when an object is the same color all over and you shine a light on it from one direction, your brain can easily figure out the shape based on which bits are dark and which bits are light. This object is the same shape, but it's much harder to get a sense of its dimensions. But how does the Gelite microscope achieve this temporary coat of paint? Well, the camera is behind a gel pad, which confusingly is red, but the camera is black and white, so it comes out looking gray. Here's a large model of it, so I can show you what I mean. If I press my finger in on this side, you can see a gray version of my finger on this side, and that's what the camera sees. And there's lights on the inside, so it can be lit from different angles. And so, you can really get the sense of the structure of a poppy seed, for example. And isn't that amazing? I had no idea poppy seeds were shaped like that. It's kind of alien looking. So this way your eyes can more easily discern the structure of things. But interestingly, the software can actually map out in precise detail the 3D structure of whatever you press into the gel. More on that later. Gel site aren't paying me or anything, by the way. I just wanted to make a video about it and they said I could borrow one for a couple of months. Right, let's have a look at some stuff. This was the real versus fake example I showed you earlier. I don't know if you had any guesses, but this is real frost. And this is frost from a spray can. Frost is amazing. Actually, you can see the six-fold symmetry that arises from the underlying crystal arrangement of the water molecules. It's the same reason snowflakes have six-fold symmetry, but it's surprising to see those little turret looking things here and there. My car gets this spidery looking frost sometimes. That's pretty cool. And this is how the frost on blades of grass look. Actually, crystals in general are really fun. This is salt flakes. The symmetry is different because the underlying crystal structure is different. So, you end up with right angles and squares and cubes instead of hexagons. For comparison, here's fine pouring salt. You can still see lots of right angles. I guess they're all little cubes. I was a bit worried about pushing something so pointy into the gel, but actually it seems to fite well. This is the needle from a record player, for example. And this is what happens when we smeared tuna paste on it. If you're like me and you try to avoid thinking about the fact that cat tongues are spiky, well, I I'm sorry I reminded you, but anyway, this is another spike that I always wanted to take a proper look at. You find these on the back of a leaf. You can hardly see it with the naked eye, but it has the effect of only being able to stroke the leaf in one direction. If you've ever experienced a one-way leaf, this is why it's like that. This is what it looks like to write on gel site with a ballpoint pen. You can see the ball rolling around. I guess this is what it feels like to be paper. And for comparison, here's a pencil tip. You can see where the sharpener stopped sharpening. Coral is surprisingly sharp. Like from a distance, it looks like a smooth surface with little holes in it, but it feels really rough. And you can see why under a microscope. It's basically a load of tightly packed spikes. This is another type of coral and you can see all the tiny tubes. How cool is that? I like this one so much I printed it out. But how was the software able to extract 3D information from this image? Well, because that gray color is so even, there's a direct correlation between the brightness of a pixel and the steepness of the slope in that location. But because the direction of the slope also affects brightness, the software needs to take multiple pictures that are lit from different angles. The 3D information can then be exported in a 3D format, which means you can zoom in even more. Wait, wait. Nature has layer lines. You might have spotted some interesting structures in the background of the spiky leaf. And actually, leaves are really interesting. You can see this sort of branching even at a really small scale. They kind of look like veins. Some leaves don't have a fractal structure because they're actually feathers. Fake feathers look nothing like real feathers, by the way. Not that you need a microscope to discern that. But on the subject of fake and real things, which one of these do you think is real leather, and which is pleather? Well, this is the real leather. You can see those little pits, which I believe is where the fur was plucked from the hide. I've not found any fake leather that tries to replicate that detail, but it's not always that easy to tell the difference between natural and synthetic fibers. Can you tell, for example, which is real hair and which is plastic hair from a wig? This is some wooden furniture and this is fake wood veneer. The difference is quite clear. The veneer is perfectly flat except for the grooves, whereas the real wood has a general roughness to it as well. This is a nylon rope and a cotton rope. The nylon's much smoother. This is horsehair, which is to say it's a cello bow. The gel pads don't like being scraped, but I wanted to see what it would look like to drag the cello bow across it. So, I added a bit of lubricant. That's cool, isn't it? While we've got lube on the thing, here's Lycra or spandex being stretched. And here's Velcro. You can see the hook and loop in action there. And you can see where the hook eventually gives way. Let's have a look at some more synthetic objects. This is a printed circuit board. This is a light bulb filament. You can see that the coiled up wire is itself made of a coiled up wire. This is a pill. This one helps me make videos. Actually, it's got a clever design that lets you split the pill in half and then in half again. Woven fabrics look really cool, especially netting type fabrics like this laundry bag. You can see how all the different strands are all kind of hooked together. Here's some woven metal. And here's a tea strainer. This is sound waves carved into a disc. Not sure what that's about. I'm a big fan of nurling actually. And it looks really nice up close. These are some of my favorite knurled objects. Look at this though. It's like nature's nurling. Looks very different up close though. Let's have a look at some more natural structures. Actually, this is fish scales. I didn't take this one. Mrs. Jessica Arbor specifically, it's an orange throat dart. And the spikes on the edges of the scales actually helps to reduce drag. This is a pepperc corn. And this is some fungus. These are some more interesting seed varieties, though poppy seeds are the best in my opinion. I just want to go on a poppy seed tangent for a second because they're so cool. There's very often two different ways to explain why something is the way it is in biology. There's the mechanical reason and the evolutionary reason. The mechanical reason is that as the seed forms, the outer layer of cells fit together like hexagons and pentagons. The joining walls of the cells are thick, but the top walls are quite thin. So, when the poppy seed dries out, those top walls collapse, and you're just left with those joining walls. But what evolutionary pressures push the poppy seed towards that shape? Well, it's probably a few things. Seeds need protection, but in the case of poppy seeds that are dispersed by the wind, they also need to be really light. So instead of a full heavy outer shell, it's protected by lightweight ridges instead. And a bit like the dimples on a golf ball, the rough surface might help the seeds to be carried further by the wind. And finally, when the seed does land, that pitted surface helps to retain moisture. This is owl poop. Check out what's inside, though. Well, lots of fur for a start, but this is probably a mouse jaw. And there's a bit of spine there and some tail. I bought some dead bees on eBay because I wanted to see the compound eye. That doesn't really show up, unfortunately. But it's interesting to see a gray bee slowly being crushed. And here's a dead spider. These shots kind of remind me of horror movie posters, you know what I mean? It's often like something being pressed into fabric. I don't know why, but anyway, here's a tiny skull that I found. [sighs] I suppose I should try and use this thing for what it was designed to do. And actually, in my video about bone drills, I cut a groove in the nail of my thumb. There's a nice feature where you can remove the first order slope, so you don't have to worry about getting the angle right when you press it into the gel. And so now, look, when I analyze the depth of the groove, I can see that it's about 300 microns or about.3 mm. The nail itself is only about.5 mm thick. So, a couple more takes and I'd have started to be in trouble. I made a video about atomic trampolines a while back. The reason the amorphous metal is so bouncy is because it doesn't plastically deform on impact. Compare that to steel where [snorts] impacts create these little divots. You can exaggerate defects in the software to make them easier to see. And look, measuring it, it's only 16 microns deep. And actually, it's interesting in general to look at old things versus new things under the gel site. Here's a fresh razor blade versus a used one, for example. And here's an old key versus a new key. You know, if you bend a wire back and forth, it eventually snaps. That's metal fatigue. And look under the gel site, you can see all these fishes near the brake point. This is a brand new foot scraper. And this is after it's been used. I'm sorry you had to see that. This is a scab and this is a scar. See how the scar tissue is smoother than the skin around it? Actually, cuticles look pretty gross, too. Look at the difference between young teeth and old teeth. And this is brushed teeth versus unbrushed. Actually, on the subject of toothbrushing, this is toothpaste. See how it's full of little hard bits that araid your teeth? And finally, we come full circle. This is an inter dental brush. And I guess this is your gums point of view. Kids, I think you need a new toothbrush. I don't know what it is about this microscope, but I just love seeing all the tiny structures of things with all the glare and transparency and color information stripped away. Maybe it's about understanding the world at a deeper level. Or maybe it's just how my brain works. And actually, if you've watched the video this far, maybe your brain works in a similar way. in which case the sponsor of this video is really interested to hear from you. I'm talking about internships at Jane Street. Jane Street is a quantitative trading firm with offices in some of the most exciting cities in the world. And right now they're looking for the next wave of curious and passionate people to join their internship program in Hong Kong. Don't worry, you don't have to live in Hong Kong or be from Hong Kong to apply. And in fact, all travel and accommodation is paid for and you get a salary on top. J Street uses all sorts of interesting techniques to trade on markets around the world like machine learning, programmable hardware, statistics. 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Learn more about Jane Street’s Hong Kong internship opportunities: https://jane-st.co/hkginternship26-SteveMould The GelSight Microscope can map out the exact shape of tiny objects. It's used in metrology. This one can measure even smaller details than the last one. Original GelSight video: https://youtu.be/qtQ4rK66vlE The video in which I drill the nail on my thumb: https://youtu.be/tRDxBwverlI Atomic trampoline video: https://youtu.be/QpuCtzdvix4 You can buy my books here: https://stevemould.com/books You can support me on Patreon and get access to the exclusive Discord: https://www.patreon.com/stevemould Twitter: http://twitter.com/moulds Instagram: https://www.instagram.com/stevemouldscience/ Facebook: https://www.facebook.com/stevemouldscience/ TikTok: https://www.tiktok.com/stevemould Buy nerdy maths things: http://mathsgear.co.uk