SciShow Tangents - Light

Episode Date: December 31, 2019

SciShow Tangents’ exploration of the electromagnetic spectrum continues with good old, dependable light! What is it? Where does it come from? Only Ceri knows (sort of)!Also, happy New Year to all of our amazing listeners! Thank you for your support over the last year, and here's to another year of laughing and learning with all of you!Follow us on Twitter @SciShowTangents, where we’ll tweet out topics for upcoming episodes and you can ask the science couch questions! If you want to learn more about any of our main topics, check out this episode's page at SciShowTangents.org![Truth or Fail]E. colihttps://arxiv.org/abs/1104.3113https://phys.org/news/2014-04-bacterial-fm-radio.htmlCactus Radiohttps://www.youtube.com/watch?v=I1shcxHWQasFrequency Combhttps://www.pnas.org/content/116/19/9181https://www.laserfocusworld.com/lasers-sources/article/14035201/frequency-combs-trick-a-laser-into-producingreceiving-an-rf-signal[Fact Off]Battle of the Beamshttps://www.bbc.co.uk/history/ww2peopleswar/stories/63/a3714563.shtmlhttps://www.nytimes.com/1997/12/19/us/r-v-jones-science-trickster-who-foiled-nazis-dies-at-86.htmlhttp://vc.airvectors.net/ttwiz_07.htmlRV Jones ObituaryW5LFLhttps://amsat-uk.org/2013/01/19/amateur-radio-on-bbc-between-the-ears-space-ham/#more-12135https://www.amsat.org/owen-k-garriott-w5lfl/[Ask the Science Couch]Analog radiohttps://public.wsu.edu/~bryan.mclaughlin/Radio/Who_Invented_Radio.htmlhttps://www.pbs.org/wgbh/aso/tryit/radio/radiorelayer.htmlhttps://www.reddit.com/r/explainlikeimfive/comments/4suas5/eli5_why_is_the_sound_quality_of_am_radio_so_much/Digital/HD radiohttps://www.fcc.gov/consumers/guides/digital-radiohttps://electronics.howstuffworks.com/hd-radio.htmhttps://hdradio.com/trademark/https://www.cnet.com/news/digital-radio-all-you-need-to-know/[Butt One More Thing]Pigeon poop / cosmic microwave backgroundhttps://www.smithsonianmag.com/smithsonian-institution/how-scientists-confirmed-big-bang-theory-owe-it-all-to-a-pigeon-trap-180949741/

Hello and welcome to SciShow Tangents, the lightly competitive knowledge showcase starring some of the geniuses that make the YouTube series SciShow happen. This week, as always, I'm joined by Stephan Chayden. Hello. Stefan, what's your favorite kind of hot dog? Ooh, just a normal one. You just, like, actually, well, okay. The Costco hot dog.

Yes! The Costco hot dog. And you put a little onion on there and some extra. And you bring your own cayenne pepper and just dust, do a light dusting. Yeah, we just lost a bunch of listeners. What's your tagline? What's the point of firm tofu? Sam Schultz is here too.

What's up? Sam. Yep. What's your tagline? I need a blankie. That's my tagline. You got one right behind you. Oh shit. Sari Reilly is here as well. What's your tagline? Hot dog gremlin. He eats all the hot dogs? Yeah I guess. He's made of hot dogs. Or that's your tagline? Hot dog gremlin. He eats all the hot dogs? Yeah, I guess.

Or he's made of hot dogs. Or that's who you send to fetch your hot dogs. I think he's the off-brand Hamburglar. And I'm in green. My tagline is pink tomatoes. Every week we get together here on SciShow Tangents to try to one-up a maze and delight each other with science facts. We're playing for glory, but we're also keeping score and awarding Sam bucks from week to week. We do everything we can to stay on topic, but we probably won't be great at it.

So if the rest of the team deems your tangent unworthy, we will force you to give up one of your Sam bucks. So tangent with care. And now, as always, we introduce this week's topic with a traditional science poem this week from Stefan. And now, as always, we introduce this week's topic with a traditional science poem this week from Stefan. Photons hurling through space at speed, giving me life, warmth, and vitamin D. Everything that we know just couldn't be without the sparkle that the sun continuously sets free. Oh, yeah. Light is the only way that darkness can be cured, even if the physics can be quite absurd. Is it oscillating particles or waves? I'm not sure.

I mean, two slits tells us it's both. At least that's what I heard. But the vastness of space is no challenge to transcend at a uniform speed that's hard to comprehend. But then to a prism it concedes and must bend. A rainbow just reminds us that light is our friend. A lamp for my plants, a bright white to mesmerize. And I couldn't see France without light hitting my eyes.

Helping us study microbes and those little points in the sky. Touching everything always. Light was quite a pleasant surprise. Oh, yes. I was very surprised the first time I saw. You come out. I guess, yeah. You open your eyes for the first time.

Whoa, it's bright. What a surprise. But it's a good one. Yeah. That was a good poem thank you that's all i got on that one yeah it was long you worked on it yeah we don't have any time to talk about it oh shoot sari what is light i don't know visible light is generally defined as having wavelengths from 400 to 700 nanometers.

And then there's infrared, which is longer than that. And ultraviolet, which is shorter than that, which is just outside the realm of human vision. So is it defined by what we can see or what any animal could see? It's defined by what we could see, by what humans could see. So other animals can see. So when we see outside of that range when we see when we say light we mean visible light generally okay generally yeah yeah like the the thing that we can perceive okay so it is definitely like it doesn't come down to a scientific thing so much as it comes down to like human perception which is you know certainly affected by science but that range is just what we can see and it

turns out like there's reasons why we can see that range and largely it's because that's the sort of most of the wavelengths that are around on earth the rest of them get either not emitted by the sun at all or they get absorbed by one thing or another on their way to us so that's the sort of like the window where the best range of stuff. But there's other reasons why too. And I don't know what they are. There's like biochemical reasons why these are better wavelengths to see

than some other broader ones. I would just imagine that it's like, those are the ones that help you navigate the space that you're in. They're more plentiful and there's a lot of variety. So there are things within that range that absorb or emit in that range. And so you get this variety that we can see and that's like better differentiate the visible plane.

But bees are like, I don't need to see all that. I just need to see flowers really good. So light seems pretty simple then. No. I mean, what the visible spectrum is, is not super complicated in terms of just like this is just the window once you start getting into like the mathy stuff what is a photon why why like different frequencies different wavelengths different intensities of light yeah polarization of light refraction of light i'm just gonna say more sciencey words that i

don't really know how to define because that is where light gets confusing. And we also need light for biology things. So like photosynthesis is a light-dependent reaction where...

Sure, of course. Put in sun on your butt. Correct. That helps with things, right? What? Putting sun on your butt. No. People put sun in their butts

on Instagram. Because it helps align some stuff. No, Because it helps It lines some stuff No it doesn't help It lines some stuff They say that it's like It gives you like A full day's dose

Of vitamin D Just to put your butt Up to the sun For five minutes I feel like That has an assumption That your butt Is like more absorbent

Of light Than the rest of your body And that we're doing A crime by hiding it In pants We are doing it A crime Yeah That's the natural bent of light than the rest of your body and that we're doing a crime by hiding it in pants? We are doing a crime. That's the powerhouse of the body.

This is so transparent to me that that person was like, oh, I'm going to get a bunch of people paying attention to me if I shine my butthole. Is it butt or butthole? It's butthole. Well, that makes sense. Perineum. Perineum? Perineum something?

Perineum, yeah. Is that what it's called? Anyway, why? Yeah, Caribbean, Caribbean, Perineum, Perineum. Both is correct. Really? I think Perineum and Perineum are both correct, yes. Oh.

Same with Caribbean, Caribbean. Yeah. Pirates of the Perineum. I didn't want to say it, but you kept saying it over and over. Lights etymology is kind of boring. Okay. I didn't want to say it, but you kept saying it over and over again. Light's etymology is kind of boring. Okay. Is it like bone? It just means the thing?

Yeah. My guess is that light existed. We had to have something to describe why it was bright half the day and not so like light as a word. So it comes from the Latin lux. For light? For light. For light. Greek, lukos, for white. Okay. It is strange to me that we think of light as white. Because it's usually yellowish or transparent, sort of.

Sun's white. Right? Yeah, the sun's... Well, if you're outside of our atmosphere, the sun is totally white. From our view, it's a little bit yellow. Because some wavelengths are getting scattered around. The blue ones, that's why the sky is blue.

Right. Makes the sun yellow. I haven't taken a good look at the sun in a while. Don't. Don't. Don't do it. Okay.

And now it's time for Truth or Fail. Where one of our panelists has prepared three science facts for your education and enjoyment. But only one of those facts is real. The other two are lies. And the other panelists have to decide which is the truth and the lie. And if you get it right,

you get a sandbox. I am the purveyor of today's lies. My name is Hank, and I want to tell you about optogenetics. Basically, genetically modifying cells to do specific things when exposed to light or different wavelengths of light, even. And it's a super powerful tool that's opened up a lot of doors in the last five years specifically. And it's a really exciting new thing. So which of the following is a real-life application for optogenetics that has been tested in laboratories? Fact number one, a system called EROS, which stands for erectile optogenetic stimulator which uses light to stimulate erections in rats or a system called mose which stands for mouse zone exploration which uses implanted fiber optic lights that scientists could use to affect a mouse's decision as it moved through a

maze. Mice guided by the mose implants, controlled by scientists, solve the maze 30% faster than those who are not guided. Or, fact number three, a system called FRESH, which stands for Fly Red Stimulated Hunger, that uses red light to drive fruit flies away from rotting fruit that they like to eat, and weirdly had the side effect of making males apparently disinterested in sex. I feel like if it involves

a boner, it's real. It's true. People are very interested in boners. People want that boner technology. Yeah. I don't. People want that boner technology. Yeah. I don't think you'd want boner technology to shine light on your head, would you? Look, whatever it takes.

Yeah. I didn't say that it was in your head. Interesting hint. How else? Light on the dick. Daylight bulbs right on the inside of your pants nestled up against the perineum that sounds warm that's way easier than filming yourself

in the backyard oh actually we could totally sell that just like LEDs in your underwear blue daylights yeah great new vitamin D

creation what is a sunlight carrying with it that light from a light bulb is not carrying with it

that gives you cancer and stuff uv radiation okay that just comes from the sun and that's what i should have known that probably and now i do we learn here yeah we do not helpful for your ability to tell which one is true that's because i have no idea which one is true all of these sound like acronyms that scientists would come up with because they like fun words. I do feel like the fruit fly one, that one feels the fakest to me, which only narrows it down a little bit. Because I feel like over the course of doing these podcasts and being on site, I've heard about mice getting light shined into their brains to do different things. But I've never heard about flies.

But I think the flies are just getting exposed to light and not just their brain. Genetically, they modify the entire fly. Oh my God. So that they shine red light on it and it changes like how their hormones are expressing. That one is realistic to me just because it's so like relatively easy

to modify a fruit fly gene. But if they're not in the light, do they still want that fruit? If they're not in the light, they want the fruit again. Yeah, so you turn the red light on and they're like, I don't want to eat,

but I'm very hungry. And suddenly I also don't want sex. This one's really hard. This is really hard. Yeah, good job. They're all believable, I guess. Okay, two of them are sex. One of them is not.

One of them's towards sex and one is away from sex. Yeah, that's true. So I'll go with the boners. Stephen's gonna go for the boners. Stephen's going to go for the boners. What do you think about the mice zone one? That one seems, I'm like torn between that and the fruit flies. I don't think I can go with that one.

Oh. I think I'm going to go with the mouse zone. Mouse zone for Sam. Okay, I'm going to do mouse zone two. I'm going to trust you about the fruit flies, Sam. Oh my God. Well, don't blame it on me. Fruit flies is fake.

Okay. Mouse zone is fake. It's boners, everybody. Oh no. It's boners, everybody. Fruit flies is fake. Okay. Mouth zone is fake. It's boners, everybody. Oh, no. It's boners, everybody. Boners never let me down. You should have gone with your heart. You should have gone with your heart.

Yeah. Scientists used optogenetics to create a blue light responsive control over cyclic guanosine monophosphate in the corpora cavernosa, which is the erectile tissue. That's one of the main messengers involved in erections. And when they shined blue light on the rats, so not on their brains, but like through their skin. Turn on a mood light. They could wear the underwear. It worked.

Yeah. So one of the reasons is like, yes, there's a lot of money in boners. But the second is that this is a really clear signal. Like, you know when it's working. Because, like, you can see. It's like an on-off switch. You can see when the boner is happening and not happening. Yeah, a literal on-off switch.

You're turned on now. Do they have to be seeing the light? No, I think it's through the skin. Whoa. And number two, the maze thing. There is a thing where basically scientists have been able to like have one mouse go through a thing while wearing that thing on its head. And then they can like program that knowledge into another mouse. I don't like that.

So that's what this was based on. But that's not a thing. They couldn't like tell it to go left or right, which I feel like they should. They could. They could. They just haven't done that yeah and then the red stimulated hunger thing um that was made up but there is a cool thing where male fruit flies their their brain circuits are first activated by smelling fruit before they begin to detect female pheromones so they kind of have to like smell rotting fruit before they can get it on, which is interesting.

For a fruit fly, that makes sense. And optogenetics has been used to control drosophila courtship and sleep cycles. So there is optogenetic research on drosophila, but not this. Is it because they got to lay their eggs somewhere where their babies are going to have rotten fruit to eat? Maybe, yeah. They do like, yeah, that's a good point.

Interesting. They just like literally can't detect female hormones until they smell rotting fruit first. That's really cool and gross. This is not how it works for us. So I guess that means I get two points. That one was too science-y. All right.

Next up, we're going to take a short break and then it'll be time for the Fact Off. Welcome back, everybody. Sam Buck totals. Sari and Sam are tied with zero, and Stefan and I are in the lead with two. Feels good, huh? It's going to be hard to catch us. Impossible, even.

We have infinite percent more points than you. Now get ready for the Fact Off, where two panelists have brought science facts to present to the rest of us in an attempt to blow our minds. And we each have a Sam Buck to award to the fact we like the most who's gonna go first well whoever is closest wins deep sea creatures live below the photic zone or sunlit zone but it's not totally dark down there thanks to bioluminescence about what percentage of the main taxa of deep sea animals produce light 80 we. We got 80. Oh, goodness. 75. Okay, 75.

75! I helped you go high! I was gonna say, like, 0.3%. You know, ultimately, nobody got a point for that, and you don't get to go first, which isn't so bad. That's true.

Oh, well, okay. I thought you got to pick now. Oh, yeah, you can pick. Yeah, you want to pick? Oh, I get to pick. Yeah. I'll go first. During the Apollo program, there were, if you think of the image of the Apollo program,

it's a bunch of people sitting in a room. It's the 60s. They're looking up at a big screen that has a live image of the astronauts floating around in space projected onto it. But how the heck did they get that big picture up there?

Because CRT projectors, which are the old type of projectors with the red, green, and blue lenses, couldn't project that big. Like tube TVs couldn't get that big. There were film projectors, but they weren't like printing this live footage onto film and playing it out really big. They were film projectors, but they weren't like printing this live footage onto film

and playing it out really big. So how did they do it? The answer is the EDA-4, which is a high quality live image projector invented in the early 40s by Fritz Fischer, who is a Swedish physicist. And like basically everything invented before things went digital, it was super complicated, super weird, and used physics in wild ways to solve problems that we just make computers do now. So how it worked was a live video feed was fed into an electron gun, which translated the image into an electron beam. And then they would shoot the beam onto a mirror that had a one micron thick coating of oil.

So the electrons would hit the oil and they would deform the oil so like let's say it's a black and white image each little gradient between black and white would hit and deform it a little bit differently so the more white it was the more it would deform the oil then a light was shined onto the mirror and wherever the electrons hit the oil the light would bend it just enough to get past this barrier inside of it between the light and the lens. Every bit of light that hit a part of the oil that was deformed bounced just barely enough

that it could get between the cracks in this barrier. There were like little cracks in the barrier and everything that just bounced straight off hit the barrier so that became like the black in the image. And while this was all happening, the mirror was rotating because once the oil got hit by the electrons, it couldn't be hit again because it was already bent up.

So there was a squeegee that it would rotate under that would smooth the oil back out so that the electron beam could shoot it. How often? I think somebody said it rotated once every 24 hours. The squeegee? The mirror would do one full rotation. So it was like

really big. So really slow? Really big and really slow because I guess the electrons were making really tiny dents. Electrons are tiny. They're very small. We got into one thing.

Checks out. So all this was happening in a climate control vacuum chamber because the oil had to be just exactly the right temperature

and the electrons had to be in a vacuum too. And to do color, you'd have to have three of these all lined up perfectly shooting at the same time. Each one cost $2 million about. And they broke if anything went wrong with the oil. You had to take the whole thing apart and re-oil it and do all kinds of stuff to it.

And they weighed literally one ton. But they could do huge live projections that were like 40 by 50 feet. And they were super bright, way brighter than anything else at the time. So they were used in sports stadiums, concert venues, and theaters everywhere from the forties until the nineties when digital projectors were invented. And there are lots of people talking about them on forums and stuff, but as far as anybody knows, there aren't any of them left that are operational. And they're redoing right now the control room

for the Apollo program, but they're not redoing those. They're just using digital projections now. So it's like a totally dead technology. How hard is it to do something one micron thick? Should I be impressed that they were able to do that in the 40s? Well, especially that they could squeegee

it on at one micron thick. Once the little divot was made, did it just stay there? It stayed there until it got squeegeed off. Okay. So yes. Was the squeegee wiping off the oil, or is it like a sandbox where you smooth it over? A sandbox. Okay. So a human

hair is about 75 microns across. Whoa. Very small. Yeah. You're not cooking on this disc. No. Not enough sandbox okay so human hair is about 75 microns across whoa very small yeah you're not cooking on this disc no not enough oil

for that probably a mineral oil would be my guess not not a yeah I think it was like proprietary

I couldn't figure out what it was I think only this dude's company was making them so I'm pretty sure only he knew that's awesome

just from his like face he's just from his like face he's just wiping his face yeah he had the perfect face oil no one else can make it were there other projection systems being used or was this like in every single sport this was the only thing that could do big projections until the 90s there were like crt projections which just had like a tube TV inside basically from what I could tell that then shot out the three colors

but they couldn't get any bigger than some certain size before the scan lines or whatever were too big. So if you saw like a big live projection before the 90s, that's probably what it was as far as I can tell. I think that they had some LED stuff

that they were doing before the 90s. Oh, okay. I'm old enough now that when I went to sports games when I was a kid, if they used that stuff now still, we'd be like, what is this trash? And we were like, this is amazing! You can look at the replays up on the Jumbotron!

Uh-huh, all old TV stuff. How could you watch sports on just a regular TV? Oh, my God. Yeah. So much better now. Thanks, technology. Now we can enjoy sports better. Sari, can you beat the Edifor?

The Shelby Electric Company in Shelby, Ohio, was a manufacturing company that was established in 1896 and went out of business in 1912. So they didn't last very long. But when they were still operational, they made light bulbs out of business in 1912. So they didn't last very long. But when they were still operational, they made light bulbs out of hand-blown glass. And specifically, they made incandescent bulbs, which run an electric current through a metal filament so that it glows and it produces heat and light. And then the glass keeps oxygen from reaching the wire so it doesn't oxidize and break down. And the Shelby Electric Company made a variety of bulbs, including a 60-watt model with a carbon-containing filament made by a secret process. Nowadays, bulbs have tungsten filaments, which is a conductor, but this mysterious carbon

filament was a semiconductor and also eight times thicker than modern light bulbs. The reason why this company is important is because there's something called the centennial light, which is a light bulb that has been basically continuously lit up since June 1901, over 118 years. It is located in Livermore, California and maintained by the fire department. And you can watch it on a live stream. There's like a light, you can see it lit up. It had a million hours party in 2001 because it's been lit up for so long besides like weird power outages or like one time when someone was watching

the stream and they were like the light bulb went out they thought it was broken but it was actually like a generator that messed up right just not getting power yeah so they're not flipping that switch on and off when they leave okay no so it's still on and it's instead of 60 watts which is like the estimated start

output of it it's at about 4 watts, which is like the estimated start output of it, it's at about 4 watts now. So like very dim nightlight. Why is it decreasing in brightness? I have no idea. Something to do with like the decay of the universe maybe in the metal. Physicists have like studied this to be like, why is this light bulb on for so long? Studied similar models and I couldn't understand why. So there might be some ideas like the

semiconductor material but that's where my understanding of physics gets wibbly and some people are just like it could be a manufacturing fluke because these light bulbs are all hand blown like something about the combination of the metal and the glass like just made this super bulb but also another contributing factor is something called planned planned obsolescence, which is the sort of stuff conspiracy theories are made of. Big light bulb. So companies like GE, Philips, Tokyo Electric, Germany's Osram, France's Comming de Lamps or something. I can't remember. Beautiful.

Yeah, France's lamp company. Lamp company. Lamp Company. Lamp Company formed the Phoebus Cartel and met in December 1924 to increase light bulb sales by bringing down the lifespan of light bulbs. They used to last over 2,500 hours. And then all these big light bulb people met and said, we only want our light bulbs to last 1,000 hours. And they really regulated factories so that they did that and then they like divided up the world into market zones and set sales quotas yeah that's exactly the kind of thing that is definitely illegal it is what they disbanded in the 1930s

but like planned obsolescence still affects light bulbs and is now like the basis for a lot of other tech speculation of like bad smartphone batteries like is planned obsolescence a thing to make us buy new phones? There's also the conspiracy theory that they all know how to cure cancer but won't tell us because if they cure it, there's no money to be made. Anyway, I hate it. I want like a really old light bulb in my house. I don't care if it's a dim, but I want to be like, this light bulb was passed down for generations.

I'm sure it's extremely inefficient. Yeah, probably. Does turning a light bulb on and off damage the light bulb in an appreciable way? Well, yeah, I don't know. There is some speculation about that. I couldn't find anything for certain. I think it's going to expand and contract, and the glass is going to expand and contract when it gets hot and cold.

And it's probably not producing a ton of heat at this point either because it's so dim. Alright, it's time to choose, everybody. Are you ready to choose, Stefan? Yeah, I think so. One, two, three, Sam. Oh, thank you. I can't resist a cartel.

No, literally, that's what they're for. Easily pressured. Now it's time to ask the science couch where we got some listener questions for our couch of finely honed scientific minds. This is from at Hattinkjorian. I've heard of the darkest artificial dark, but what is the brightest artificial light and what is it used for? Is it used for probably research right yeah yeah uh but also like for a practical use would it be for like exploration of some sort or for like shining it onto something to make something yeah lighthouses happen lighthouses must be pretty

bright what's the darkest artificial dark i've never never heard of that. Yeah, what is that? So there's a material. Vantablack? A Vantablack that the artist Anish Kapoor developed. It's like carbon nanotubes that bounce around light. Does that qualify as the darkest artificial dark? Yeah. If you're in a cube made out of it.

Yeah, you got to get in a cube made out of it. It sucks up all the photons. But also, if you just look at it, it looks very apparently unsettlingly black. But then it's very bright if I turn to the right. If I'm looking at Vantablack. That's why you've got to be in the cube. That's why I need a whole cube. And then the space that I occupy is as dark as your artificial space.

And you've got to cover yourself in Vantablack spray paint. Yes. So what's the brightest bright we've ever brighted? And is it on a submarine? No, not on a submarine. The brightest bright is at the University of Nebraska-Lincoln. There's the Extreme Light Laboratory where physicists do weird stuff. And they created a laser called Diocles in 2017.

Diocles? Diocles. Named after? Named after the inventor from 200 BC of the parabolic reflector, which is the best focusing element for light. And so they created the super bright laser because they wanted to see what super bright light could do. Research. They're like, we're going to make a bright light. Why?

Because we want to see what it will do. Its peak power is 10 to the 14 watts. That's way more than that light bulb in Wacom. Which is, according to their website, greater than all of the world's power plants combined. And it's delivered in short bursts of light, each lasting only 10 to the negative 14 seconds. So like very short bursts, very powerful.

I have found multiple sources on this, and I did not talk to the scientists, but it's somewhere between 10 million times brighter than the sun and 1 billion times brighter than the sun. Okay. At that point. It's like, I can't really picture either of those things accurately, but pro tip, don't look at it.

Don't look at it. Yeah, so the scientists have to wear eye protection like with all lasers. But they also have to wear a lot of like body protection when you work with lasers like hair nets, breathing masks and other things. So to protect the lasers from you because you don't want to like drop particles. If that light hits my hair, my hair is on fire. But it's such short exposure. What are they doing with it? Would you go blind?

Would you or was it just so short that like you'd be fine? Would you go blind? Or was it just so short that you'd be fine? Would you be able to see through me? Oh yeah! Let's do it! That is what they're looking into. Apparently Diocles produces x-rays that can see through 10 inch

thick steel. And so they think that they might be able to use super high powered artificial lights to make x-rays with lower radiation dose or to produce images with really high resolution. Nice.

Is it such a short amount of time so it doesn't actually burn through the thing like a laser? Or like, could it do that even? I don't understand.

Will I vaporize? I think it would carry enough energy that if it's going through 10 inches of steel, it's going through all six inches of you. Okay.

Not a dick joke. And I'm not only six inches tall. Right. No, you're six inches thick. Yeah. But you see it. Dang it. It's not getting better.

Yeah. We just got to shine a lot of blue light on Sam. And then shoot it with a laser? No. You shine it on your perineum, then you're energized for life. You never have to eat again. Become Dr. Manhattan. Is there a saturation point for brightness?

Like, the air around us can only transmit so much sound. Can the sort of universally permeating photon field only create so many photons per square centimeter is the question. What's the max brightness? Probably something to do with Planck limits and string theory. Yeah, I just read the sentence

for maximum light, photons are bosons and I'm like, no! I'm gone! If you want to ask the Science Couch your question, follow us on Twitter at SciShowTangents where we will tweet out topics for upcoming episodes every week. Thank you to at VanillaGodzilla at that's what it says,

at Joseph J. Nathan and everybody else who tweeted as your questions this episode. Ah! Final Sandbox scores. Sari's got one, Sam's got one, and Stefan and I come out tied. A very symmetrical episode. All right, before we get to our butt fact,

if you like this show and you want to help us out, it's very easy to do that. You can leave us a review wherever you listen. That helps us know what you like about the show. Also, we look to iTunes reviews for topic ideas, so if you have any, you can leave those in the reviews. Second, tweet out your favorite moment from the show, and finally, if you want to show your love

for SciShow Tangents, just tell people about us! Thank you for joining. I've been Hank Green. I've been Sari Reilly. I've been Stefan Chin. And I've been Sam Schultz. SciShow Tangents is a co-production of Complexly and the wonderful team at WNYC Studios. It's created by all of us and produced by Caitlin Hoffmeister and Sam Schultz,

who also edits a lot of these episodes along with Hiroko Matsushima. Our editorial assistant is Deboki Chakravarti. Our sound design is by Joseph Tuna-Medish. Our social media organizer is Victoria Bongiorno, and we couldn't make any of this without our patrons on Patreon. Thank you, and remember,

the mind is not a vessel to be filled, but a fire to be lighted. But, one more thing. Fireflies. Their butts light up. Uh-huh. They are, in fact, very good at lighting their butts up as they put out nearly 100% of the light that they produce in the chemical reaction that makes the light. LED lights, on the other hand, usually are somewhere around 50% efficiency. Both fireflies and LED lights have microscopic pyramidal projections

in the part of them that emit light, and these projections help scatter the light outward. But fireflies have asymmetrical projections and LED lights have symmetrical ones. So scientists noticed this and they did a computer model of a LED light design with asymmetrical projections that puts out 90% efficiency light. But they haven't gotten to there with actual 3D printed. They have to actually make it as hard.

Yeah, they've tried and they've gotten better. The prototypes have made it better, but they're not quite to 90%. Fireflies never have to worry about sunning

their perineum