The Weirdest Microscope

[00:00] Have you brushed your teeth?

[00:01] >> Yes.

[00:02] >> H Let me see. I made a video about Gel

[00:06] Site about 2 years ago, and they just

[00:07] released this new one that goes even

[00:09] smaller. Its purpose is to take precise

[00:12] 3D measurements of very small things.

[00:15] But here's what I've been using it for.

[00:16] I've been comparing fake things to real

[00:18] things, old things to new things, and

[00:21] natural structures to synthetic

[00:23] structures. We discovered loads of

[00:24] amazing things, and I'm just going to

[00:26] show you all of them. Like this, for

[00:28] example, is the grippy surface on a

[00:30] PlayStation 5 controller. How cool is

[00:32] that? There's a link to the original

[00:34] video in the description, but here's a

[00:35] quick recap of how the thing works. So,

[00:38] what shape do you think a poppy seed is?

[00:41] Under a normal microscope, it's hard to

[00:42] tell because the surface of a poppy seed

[00:44] is black, but you'd probably assume it

[00:46] was roughly spherical. But if you could

[00:48] spray paint it like 50% matte gray, it

[00:52] would be a lot easier to figure out the

[00:54] shape of the thing. And that's the idea

[00:56] behind this weird microscope. It's as if

[00:58] it gives your subject a temporary coat

[01:01] of extremely neutral paint. And look,

[01:04] when an object is the same color all

[01:05] over and you shine a light on it from

[01:07] one direction, your brain can easily

[01:09] figure out the shape based on which bits

[01:12] are dark and which bits are light. This

[01:14] object is the same shape, but it's much

[01:16] harder to get a sense of its dimensions.

[01:18] But how does the Gelite microscope

[01:20] achieve this temporary coat of paint?

[01:22] Well, the camera is behind a gel pad,

[01:25] which confusingly is red, but the camera

[01:27] is black and white, so it comes out

[01:29] looking gray. Here's a large model of

[01:31] it, so I can show you what I mean. If I

[01:33] press my finger in on this side, you can

[01:36] see a gray version of my finger on this

[01:39] side, and that's what the camera sees.

[01:41] And there's lights on the inside, so it

[01:44] can be lit from different angles. And

[01:46] so, you can really get the sense of the

[01:48] structure of a poppy seed, for example.

[01:50] And isn't that amazing? I had no idea

[01:52] poppy seeds were shaped like that. It's

[01:54] kind of alien looking. So this way your

[01:56] eyes can more easily discern the

[01:58] structure of things. But interestingly,

[02:00] the software can actually map out in

[02:02] precise detail the 3D structure of

[02:05] whatever you press into the gel. More on

[02:07] that later. Gel site aren't paying me or

[02:09] anything, by the way. I just wanted to

[02:11] make a video about it and they said I

[02:13] could borrow one for a couple of months.

[02:15] Right, let's have a look at some stuff.

[02:16] This was the real versus fake example I

[02:19] showed you earlier. I don't know if you

[02:20] had any guesses, but this is real frost.

[02:23] And this is frost from a spray can.

[02:26] Frost is amazing. Actually, you can see

[02:28] the six-fold symmetry that arises from

[02:30] the underlying crystal arrangement of

[02:33] the water molecules. It's the same

[02:35] reason snowflakes have six-fold

[02:37] symmetry, but it's surprising to see

[02:39] those little turret looking things here

[02:41] and there. My car gets this spidery

[02:43] looking frost sometimes. That's pretty

[02:45] cool. And this is how the frost on

[02:48] blades of grass look. Actually, crystals

[02:51] in general are really fun. This is salt

[02:53] flakes. The symmetry is different

[02:55] because the underlying crystal structure

[02:57] is different. So, you end up with right

[02:59] angles and squares and cubes instead of

[03:01] hexagons. For comparison, here's fine

[03:04] pouring salt. You can still see lots of

[03:06] right angles. I guess they're all little

[03:08] cubes. I was a bit worried about pushing

[03:10] something so pointy into the gel, but

[03:12] actually it seems to fite well. This is

[03:14] the needle from a record player, for

[03:16] example. And this is what happens when

[03:18] we smeared tuna paste on it. If you're

[03:21] like me and you try to avoid thinking

[03:23] about the fact that cat tongues are

[03:25] spiky, well, I I'm sorry I reminded you,

[03:28] but anyway, this is another spike that I

[03:30] always wanted to take a proper look at.

[03:31] You find these on the back of a leaf.

[03:34] You can hardly see it with the naked

[03:35] eye, but it has the effect of only being

[03:38] able to stroke the leaf in one

[03:40] direction. If you've ever experienced a

[03:42] one-way leaf, this is why it's like

[03:45] that. This is what it looks like to

[03:47] write on gel site with a ballpoint pen.

[03:49] You can see the ball rolling around. I

[03:52] guess this is what it feels like to be

[03:53] paper. And for comparison, here's a

[03:55] pencil tip. You can see where the

[03:57] sharpener stopped sharpening. Coral is

[04:00] surprisingly sharp. Like from a

[04:02] distance, it looks like a smooth surface

[04:04] with little holes in it, but it feels

[04:06] really rough. And you can see why under

[04:08] a microscope. It's basically a load of

[04:10] tightly packed spikes. This is another

[04:12] type of coral and you can see all the

[04:14] tiny tubes. How cool is that? I like

[04:17] this one so much I printed it out. But

[04:19] how was the software able to extract 3D

[04:21] information from this image? Well,

[04:23] because that gray color is so even,

[04:27] there's a direct correlation between the

[04:29] brightness of a pixel and the steepness

[04:32] of the slope in that location. But

[04:34] because the direction of the slope also

[04:36] affects brightness, the software needs

[04:38] to take multiple pictures that are lit

[04:40] from different angles. The 3D

[04:42] information can then be exported in a 3D

[04:44] format, which means you can zoom in even

[04:47] more.

[04:49] Wait,

[04:51] wait.

[04:53] Nature has layer lines. You might have

[04:55] spotted some interesting structures in

[04:57] the background of the spiky leaf. And

[04:59] actually, leaves are really interesting.

[05:02] You can see this sort of branching even

[05:03] at a really small scale. They kind of

[05:05] look like veins. Some leaves don't have

[05:08] a fractal structure because they're

[05:09] actually feathers. Fake feathers look

[05:12] nothing like real feathers, by the way.

[05:13] Not that you need a microscope to

[05:14] discern that. But on the subject of fake

[05:16] and real things, which one of these do

[05:18] you think is real leather, and which is

[05:21] pleather? Well, this is the real

[05:22] leather. You can see those little pits,

[05:25] which I believe is where the fur was

[05:27] plucked from the hide. I've not found

[05:29] any fake leather that tries to replicate

[05:31] that detail, but it's not always that

[05:33] easy to tell the difference between

[05:35] natural and synthetic fibers. Can you

[05:37] tell, for example, which is real hair

[05:39] and which is plastic hair from a wig?

[05:43] This is some wooden furniture and this

[05:46] is fake wood veneer. The difference is

[05:48] quite clear. The veneer is perfectly

[05:50] flat except for the grooves, whereas the

[05:53] real wood has a general roughness to it

[05:56] as well. This is a nylon rope and a

[05:59] cotton rope. The nylon's much smoother.

[06:02] This is horsehair, which is to say it's

[06:04] a cello bow. The gel pads don't like

[06:07] being scraped, but I wanted to see what

[06:09] it would look like to drag the cello bow

[06:11] across it. So, I added a bit of

[06:13] lubricant. That's cool, isn't it? While

[06:16] we've got lube on the thing, here's

[06:17] Lycra or spandex being stretched.

[06:21] And here's Velcro. You can see the hook

[06:23] and loop in action there. And you can

[06:26] see where the hook eventually gives way.

[06:28] Let's have a look at some more synthetic

[06:30] objects. This is a printed circuit

[06:32] board.

[06:34] This is a light bulb filament. You can

[06:36] see that the coiled up wire is itself

[06:39] made of a coiled up wire. This is a

[06:41] pill. This one helps me make videos.

[06:43] Actually, it's got a clever design that

[06:45] lets you split the pill in half and then

[06:47] in half again.

[06:49] Woven fabrics look really cool,

[06:51] especially netting type fabrics like

[06:53] this laundry bag. You can see how all

[06:55] the different strands are all kind of

[06:57] hooked together. Here's some woven

[07:00] metal. And here's a tea strainer.

[07:03] This is sound waves carved into a disc.

[07:06] Not sure what that's about. I'm a big

[07:07] fan of nurling actually. And it looks

[07:10] really nice up close. These are some of

[07:12] my favorite knurled objects. Look at

[07:14] this though. It's like nature's nurling.

[07:17] Looks very different up close though.

[07:19] Let's have a look at some more natural

[07:20] structures. Actually, this is fish

[07:22] scales. I didn't take this one. Mrs.

[07:24] Jessica Arbor specifically, it's an

[07:26] orange throat dart. And the spikes on

[07:29] the edges of the scales actually helps

[07:31] to reduce drag. This is a pepperc corn.

[07:35] And this is some fungus. These are some

[07:38] more interesting seed varieties, though

[07:42] poppy seeds are the best in my opinion.

[07:44] I just want to go on a poppy seed

[07:45] tangent for a second because they're so

[07:47] cool. There's very often two different

[07:48] ways to explain why something is the way

[07:51] it is in biology. There's the mechanical

[07:54] reason and the evolutionary reason. The

[07:57] mechanical reason is that as the seed

[07:59] forms, the outer layer of cells fit

[08:02] together like hexagons and pentagons.

[08:04] The joining walls of the cells are

[08:06] thick, but the top walls are quite thin.

[08:08] So, when the poppy seed dries out, those

[08:11] top walls collapse, and you're just left

[08:13] with those joining walls. But what

[08:16] evolutionary pressures push the poppy

[08:18] seed towards that shape? Well, it's

[08:20] probably a few things. Seeds need

[08:23] protection, but in the case of poppy

[08:25] seeds that are dispersed by the wind,

[08:27] they also need to be really light. So

[08:29] instead of a full heavy outer shell,

[08:32] it's protected by lightweight ridges

[08:34] instead. And a bit like the dimples on a

[08:36] golf ball, the rough surface might help

[08:38] the seeds to be carried further by the

[08:40] wind. And finally, when the seed does

[08:43] land, that pitted surface helps to

[08:46] retain moisture. This is owl poop. Check

[08:49] out what's inside, though. Well, lots of

[08:51] fur for a start, but this is probably a

[08:54] mouse jaw. And there's a bit of spine

[08:56] there and some tail.

[08:59] I bought some dead bees on eBay because

[09:01] I wanted to see the compound eye. That

[09:03] doesn't really show up, unfortunately.

[09:05] But it's interesting to see a gray bee

[09:08] slowly being crushed. And here's a dead

[09:10] spider.

[09:12] These shots kind of remind me of horror

[09:15] movie posters, you know what I mean?

[09:16] It's often like something being pressed

[09:18] into fabric. I don't know why, but

[09:20] anyway, here's a tiny skull that I

[09:22] found.

[09:25] I suppose I should try and use this

[09:26] thing for what it was designed to do.

[09:28] And actually, in my video about bone

[09:30] drills, I cut a groove in the nail of my

[09:33] thumb. There's a nice feature where you

[09:35] can remove the first order slope, so you

[09:37] don't have to worry about getting the

[09:38] angle right when you press it into the

[09:40] gel. And so now, look, when I analyze

[09:42] the depth of the groove, I can see that

[09:44] it's about 300 microns or about.3 mm.

[09:48] The nail itself is only about.5 mm

[09:51] thick. So, a couple more takes and I'd

[09:53] have started to be in trouble. I made a

[09:55] video about atomic trampolines a while

[09:57] back. The reason the amorphous metal is

[09:59] so bouncy is because it doesn't

[10:01] plastically deform on impact. Compare

[10:04] that to steel where impacts create these

[10:07] little divots. You can exaggerate

[10:09] defects in the software to make them

[10:11] easier to see. And look, measuring it,

[10:13] it's only 16 microns deep. And actually,

[10:16] it's interesting in general to look at

[10:19] old things versus new things under the

[10:21] gel site. Here's a fresh razor blade

[10:24] versus a used one, for example. And

[10:27] here's an old key versus a new key. You

[10:30] know, if you bend a wire back and forth,

[10:32] it eventually snaps. That's metal

[10:34] fatigue. And look under the gel site,

[10:36] you can see all these fishes near the

[10:39] brake point. This is a brand new foot

[10:41] scraper. And this is after it's been

[10:43] used.

[10:45] I'm sorry you had to see that. This is a

[10:47] scab and this is a scar. See how the

[10:51] scar tissue is smoother than the skin

[10:53] around it? Actually, cuticles look

[10:55] pretty gross, too.

[10:58] Look at the difference between young

[11:00] teeth and old teeth. And this is brushed

[11:03] teeth versus unbrushed. Actually, on the

[11:06] subject of toothbrushing, this is

[11:08] toothpaste. See how it's full of little

[11:10] hard bits that araid your teeth? And

[11:13] finally, we come full circle. This is an

[11:16] inter dental brush. And I guess this is

[11:18] your gums point of view. Kids, I think

[11:21] you need a new toothbrush. I don't know

[11:23] what it is about this microscope, but I

[11:25] just love seeing all the tiny structures

[11:27] of things with all the glare and

[11:30] transparency and color information

[11:32] stripped away. Maybe it's about

[11:34] understanding the world at a deeper

[11:35] level. Or maybe it's just how my brain

[11:37] works. And actually, if you've watched

[11:39] the video this far, maybe your brain

[11:41] works in a similar way. in which case

[11:43] the sponsor of this video is really

[11:45] interested to hear from you. I'm talking

[11:47] about internships at Jane Street. Jane

[11:50] Street is a quantitative trading firm

[11:51] with offices in some of the most

[11:53] exciting cities in the world. And right

[11:55] now they're looking for the next wave of

[11:57] curious and passionate people to join

[11:59] their internship program in Hong Kong.

[12:01] Don't worry, you don't have to live in

[12:02] Hong Kong or be from Hong Kong to apply.

[12:04] And in fact, all travel and

[12:06] accommodation is paid for and you get a

[12:08] salary on top. J Street uses all sorts

[12:10] of interesting techniques to trade on

[12:12] markets around the world like machine

[12:14] learning, programmable hardware,

[12:16] statistics. So if you're a student and

[12:19] if you're interested in exploring a

[12:20] career in Hong Kong, internship

[12:22] applications are open now for

[12:24] quantitative trading, software

[12:25] engineering, research, and more. The

[12:28] program runs from May to August next

[12:30] year. And really, it's a one-of-a-kind

[12:32] experience. Basically, you get to dive

[12:34] into all the interesting stuff they do

[12:36] around the firm, and you'll be

[12:37] surrounded by brilliant people from

[12:39] diverse backgrounds and cultures that

[12:41] are passionate about what they do and

[12:43] who love sharing their knowledge. And

[12:45] when you're not working, you can explore

[12:46] the beautiful city of Hong Kong with a

[12:48] community of like-minded people. You

[12:51] need to be fluent in English and

[12:52] graduating in 2027 or later, but you

[12:56] don't need to have a background in

[12:57] finance to apply. In fact, many current

[13:00] people at Jane Street were in exactly

[13:02] that position when they first applied.

[13:04] If you have a curious mind and a

[13:05] collaborative spirit, you'll fit right

[13:07] in. So, click the link in the

[13:08] description to find out more and apply

[13:11] to the Jane Street Hong Kong internship

[13:13] program today. I hope you enjoyed this

[13:14] video. If you did, don't forget to hit

[13:16] subscribe and the algorithm thinks

[13:18] you'll enjoy this video next.