The lens on my welding helmet was gold. It reflected and absorbed enough of the light to prevent eye damage, but allowed just enough light through to see my work without striking an arc. It was especially good for looking at the sun during an eclipse.
How can Action Lab be so consistently fascinating for so long? I love this guy. It's amazing that I get astonished every time I watch a video here, and this, once again, blew my mind so hard. Thank you so much for sharing these superb insights from nature itself. Please continue for good, humanity needs heroes like this.
I know many people are scared of physics classes because of the math. However, if we could get people just take a year of high school physics, you'd be surprised how the world opens up to you. It's not just about learning "how things work," it's also about learning to ask questions and then looking for the answers. I can look at anything in my office right now and find an interesting physics question about it that applies to the real world. I like science fiction, but the real world has so many crazy dynamics to it. Some of the demonstrations he does are classic physics examples, but he does a great job explaining it. And he comes up with demonstrations I've never seen before.
I never seen anyone shine light through gold leaf before! Quite an extra treat to see for sure in addition to the weird properties of germanium in the long-wave infrared!
@@thaphreak not everyone is curious enough to stumble onto things like this. It's a shame and one of the consequences of a standardized education where exploration isn't encouraged over regurgitation of just the info you're given and nothing more.
@@brfisher1123 it may not have been a demonstration. Sometimes kids just hold something up to see how it acts with the light. None of my science classes ever involved gold leaf, but I found this property elsewhere in metallic films, like the ones signs are made from and some parts of toys with metalized clear plastic.
One of the neat things about gold is that it's particularly good at reflecting IR radiation, so for EVA suits and the helmets used in the moon landings, their visors are coated with a very thin layer of gold to more effectively protect them from the unabated IR radiation of direct sunlight without an atmosphere.
@@GeoffryGifari I mean, the reflectivity of all metals differs on the frequencies involved. Gold just on its own is good at reflecting infrared light, which is why the James Webb Space Telecope uses a gold coating for its focusing mirrors since other materials would absorb a higher portion of the deep infrared-shifted light they designed it to observe.
@@Aderon O.K. But is IR dangerious? I thought UV cause of higher frequency? After googling i got that this layer also reflects UV. But which of this 2 sorts more?
@@xylfox UV is more dangerous in general, but they used a polycarbonate which is already good at reflecting and absorbing UV on it's own. The problem is that while it does a fine job at absorbing and protecting from UV, the polycarbonate doesn't handle IR radiation as well, so having a gold coating mitigates concerns of IR damage remarkably. To be perfectly clear, the gold coatings aren't _just_ there to protect from IR radiation, the primary purpose is to protect them from _all_ the light coming from the sun, essentially a full visor of sunglasses, it's just that for the monstrous amounts of IR radiation the sun puts out, a gold metallic coating is one of the best options at protection the visor and astronaut within from said IR exposure. Even if it doesn't cause skin damage like UV radiation does, it can still damage their eyes, and having your pilot who intends to land the space shuttle get flash blinded is generally a bad time for everyone.
This is why germanium is used for the lenses of thermal optics. Thermal optics operate in the far IR spectrum and glass blocks it, so germanium has to be used. It's one of the reasons thermal optics are expensive. Glass will, however allow near IR through, so it's suitable as lenses on night vision optics that operate in that spectrum (i.e. digital IR night vision). Thermal is passive and does not require an active light source (far IR is "heat"). Near IR devices require active emitters (IR lights) to "see" in total darkness.
I'm trying to do the math on how much gold is in a golden apple vs how much he consumed. a golden apple has 17 metric tonnes and one gold leaf is about 18 mg. let's assume he consumed 1/8th of an apple. if he consumed one eighth of a golden apple in minecraft he'd get about 0.63 seconds of regen and 15 seconds of absorption if the effects translated to real life 18 milligrams of gold would give.... idk a couple nanoseconds probably. I tried to do the math but failed.
It would be 212bilionths 231 millionths 870 thousandths the time of a regular golden apple with some room for margin maybe a couple thousandths maybe even a couple millionths of error depending on apple wedge size and gold to apple ratio in potion Power
@@jeanrenaudsagswing I always thought that was because the tiny holes which carry the information. But the metal could also be see through I learned today ;-)
(0:50) *Now, just so you don't think this is normal, to be able to see through something with infrared light* I'm glad you pointed that out. Movies and TV dramas tend to have unrealistic portrayals of using infrared cameras to see through walls or ceilings.
Hi, I really like your channel. However, this time there is a mistake. Germanium is not a metal. It is a semiconductor meaning that its electrons are bound and cannot move freely. Only when the light photon energy exceeds the binding energy (also called the band gap), the electrons become free. The band gap of germanium is in the near-infrared range. Therefore, the visible light gets absorbed/reflected and the thermal mid-infrared light passes through. Although germanium looks like a metal, its mechanical properties are similar to insulators - it is brittle and cannot be forged like metals. The glass in turn is mirror-like in infrared since its ions oscillate in the light field and act similar to free electrons in metals. Germanium and silicon are non-polar - they don't have positive and negative ions. So they are transparent in the whole infrared range. This is a great advantage and the most of infrared optics is made out of germanium or silicon.
@alexejpashkin3562 Once he showed the IR light shining through, I knew he had a semiconductor. However, I don't think *"The glass in turn is mirror-like in infrared since its ions oscillate in the light field and act similar to free electrons in metals."* is a correct explanation. One, glass doesn't act like a mirror in the infrared anymore than visible light does. Glass actually absorbs infrared light. And I could be wrong, but I always assumed this absorption was mediated via phonon modes, not ion oscillations. But now I need to look it up and get back on that.
Many metallic films are mildly transparent. That includes mirrors, which are usually painted on the back for both durability and opaqueness. I used to make signs, and most of our gold or silver-colored adhesive films would let enough light through that you could read a newspaper through them, or use as a rudimentary one-way mirror when the other side was well-lit. (Not requiring a flashlight that rivals the sun...) That includes the "metal-flake" style films, as well as the flat/mirror. I believe most of them were also considerably cheaper than gold leaf.
the gold "filter" looking greenish makes it look perfect as an in-camera nightvision effect! I imagine this would be a cool filter to use in photography or hobby filmmaking
@@DonariaRegia You are thinking of Neutrinos Cosmic Rays are atomic nuclei that move at a high %C and are mostly stopped by the upper atmosphere. They are working on using this decay to take deep scans of things using the produced Muons.
Wouldn't higher frequency light be more inclined to be absorbed, because they have energy for the electrons to be excited? Or is there some new effect at high frequencies?
It's often referencing the emission source of the high energy photon: from a nuclear transition (gamma) or an atomic one. There are actually some nuclear energy transitions in Thorium that result in a 149.7nm gamma ray photon out. Relatively low energy.
Get some scrap silicon wafers . Most are IR-transparent, depending on the doping. But silicon, like germanium, is a non-metal (no mallebility, no electron-sea, and insulating when cold.)
I know many people are scared of physics classes because of the math. However, if we could get people just take a year of high school physics, you'd be surprised how the world opens up to you. It's not just about learning "how things work," it's also about learning to ask questions and then looking for the answers. I can look at anything in my office right now and find an interesting physics question about it that applies to the real world. I like science fiction, but the real world has so many crazy dynamics to it. Some of the demonstrations he does are classic physics examples, but he does a great job explaining it. And he comes up with demonstrations I've never seen before.
The problem is the formal education side requires the math… I was interested in meteorology as a kid, but struggled with advanced math equations so I gave up on that dream. As an adult, I’ve watched many physics based educational videos on all aspects of weather, and physics. Lectures as well. To the point now where I have a solid intuitive understanding of the processes, but couldn’t tell you anything about the equations involved.
Thanks again for a most informative and educational video! It's interesting how materials can be be invisible to certain wavelengths of electromagnetic energy. Your video from about two years ago on making transparent metals was interesting too. And for those who didn't know, astronaut helmets have a gold layer as well which is used to block the sun's intense unfiltered light while in space.
I like to see your thought process. You first made a video about laser metal cutting, and then you wondered if red hot metals can reflect light or not, and now you are working on light penetration in metals. You are personally educating yourself and also make all of these processes available for us, viewers. Keep up with good work. And for the next video, i would like to see if electrical current or static charges would effect the reflection properties or not (because you mentioned that those properties are strongly related to free electrons and their specs).
Another cool thing about germanium is its temperature dependent leakage in transistors and it’s use in the original fuzz (distortion) guitar pedals that Hendrix made famous.
how do you manage to find such fresh yet interesting sciency content? you really win youtube man, germanium being transparent to IR is very interesting.
This reminds me of that Star Trek movie where Scottie gives the guy in the past the molecular structure of clear aluminum. That was a pretty funny scene. “Computer. Computer? Oh, a keyboard. How quaint.” I lost it during that scene.
In the entire Elements table, is there this one and only one metal that does this? Is it maybe the very only (in solid state) element that does this? Blocking visible light, but letting through infrared. What an odd characteristic. First time I ever hear about this. As always, great video! And thanks much for sharing these fascinating oddities!
Free electrons was first discovered by JJ Thompson, in a cathode Ray tube filled with vacuum. Electrons was deemed to be the carrier of electric charge (across vacuum). Electric charge induced on a glass sphere stay at the contact point, not so on a metal sphere. On metal sphere the charge spread evenly across a uniform sphere. So charge spread across a conductor naturally without the need of a carrier I.e. “electrons”. Electrons is however required to move charge across space, the vacuum and not conductor. Charge distribute through electrolyte requires electrons.
@@hunterwyeth a pop tart wrapper is vapor thin, I think I have seen light through that before. Real aluminum foil? No way, even the thinnest cheapest stuff won't have light getting through. That's someone confusing food wrappers for actual aluminum foil.
You don't actually need gold to experiment light across metal. Many candy wrappers are made with glittered PET, it is s thin layer of aluminium on PET. It has the same effect and changes the colours of light.
Loved the explanation for how reflection works, you and 3blue1brown are the only ones I have seen that have explained it in that way, even though its one of the most accurate ways. If you want to see more stuff on light I highly recommend 3blue1browns optics series, its really good. Just realized this looks like a bot comment, I swear its not I just really like 3blue1brown.
Everybody who likes proper explanations even if they hurt their brain a bit and appreciates good educational presentation animations loves 3blue1brown. 😁
The Royal Bank Plaza in Toronto has two towers with gold windows. The gold is only a few atoms thick, so you can see through them a lot like a one-way mirror. Speaking of, one-way mirrors are another example of looking through a metal.
You can shine light through iron as well! For this, the iron film with a thickness around 100 nm or less should be on some transparent substrate. The important thing here is that the metal film thickness should be of the same order or less than the skin depth of the material.
What people dont realize is, that for many lights colors even pass through our thickest stone walls. visible light is about 10THz-800THz and the color is the frequency. if you could see lower than red you would see electromagnetic waves pass walls below 1GHz (Wlan) and lower (Radio) its the same thing as light, but another frequency.
Very cool. I would like to have seen a demonstration that gold is not transparent to IR. This is why space probes near the sun are covered with gold foil.
This is exactly why we use germanium to make filters for JWST! Especially the mid infrared instrument MIRI, which measures wave links from 5 µm to about 28 µm
I want to first echo all the "Oooo, cool!" comments. But not using a tip when handling the gold leaf made me a bit crazy. A tip is a fine hair brush roughly the width of a piece of gold leaf. Lightly brushed over your skin it picks up oils, and then, touched to the edge of the leaf, can pick the leaf up. Even a wide sable paint brush would have done a better job than your fingers--particularly when the gold sticks to your fingerprints. Though the tooth thing was amusing😊
A compact disc has a thin coating of aluminum (and top coating of plastic). You can easily see a bright light source through it (If it's shiny on the top side and doesn't have a print covering it). So you do not need leaf gold to demonstrate this.
![[UNCUT] ขยี้ "อลิส" ปม "คลิปลับแตงโม" เปิดชื่อคนพยายามแฮก "มือถือแตงโม" I คนดังนั่งเคลียร์I 10ก.พ.68](http://i.ytimg.com/vi/_RPLEIi5Sz8/mqdefault.jpg)
![บังเอิญมันได้อ่ะ - แอน อรดี [OFFICIAL MV]](http://i.ytimg.com/vi/9fwjammKY4A/mqdefault.jpg)
The lens on my welding helmet was gold. It reflected and absorbed enough of the light to prevent eye damage, but allowed just enough light through to see my work without striking an arc. It was especially good for looking at the sun during an eclipse.
My gold welding lens has been to three solar eclipses!
I read that first as "wedding helmet" and the thoughts I had were glorious.
Yeah, it's interesting that gold blocks all but green light, but when put on green welding glass you see a more colour accurate weld pool.
Just how expensive is that helmet?
@@EarthPlusPlastic Google will tell you faster than OP.
How can Action Lab be so consistently fascinating for so long? I love this guy. It's amazing that I get astonished every time I watch a video here, and this, once again, blew my mind so hard. Thank you so much for sharing these superb insights from nature itself. Please continue for good, humanity needs heroes like this.
I know many people are scared of physics classes because of the math. However, if we could get people just take a year of high school physics, you'd be surprised how the world opens up to you. It's not just about learning "how things work," it's also about learning to ask questions and then looking for the answers. I can look at anything in my office right now and find an interesting physics question about it that applies to the real world. I like science fiction, but the real world has so many crazy dynamics to it. Some of the demonstrations he does are classic physics examples, but he does a great job explaining it. And he comes up with demonstrations I've never seen before.
Next weeks video will be about 💩 gold bricks 🧱 . LoL 😂
It's cause he has an actual degree and legitimately understands how these things work.
yep, that's my boy
@@mhughes1160 you beat me to it "how to turn sh*t into gold - literally"
I never seen anyone shine light through gold leaf before! Quite an extra treat to see for sure in addition to the weird properties of germanium in the long-wave infrared!
literally the first time I had gold leaf in jr high science we discovered this.. like 30 years ago.
@@thaphreak Unfortunately, none of the science classes I had in school demonstrated that phenomenon, thus I was completely unaware of it.
You mean SOLID gold
@@thaphreak not everyone is curious enough to stumble onto things like this. It's a shame and one of the consequences of a standardized education where exploration isn't encouraged over regurgitation of just the info you're given and nothing more.
@@brfisher1123 it may not have been a demonstration. Sometimes kids just hold something up to see how it acts with the light. None of my science classes ever involved gold leaf, but I found this property elsewhere in metallic films, like the ones signs are made from and some parts of toys with metalized clear plastic.
One of the neat things about gold is that it's particularly good at reflecting IR radiation, so for EVA suits and the helmets used in the moon landings, their visors are coated with a very thin layer of gold to more effectively protect them from the unabated IR radiation of direct sunlight without an atmosphere.
So the reflectivity of very thin gold also depends on frequency, and not just brightness?
@@GeoffryGifari I mean, the reflectivity of all metals differs on the frequencies involved. Gold just on its own is good at reflecting infrared light, which is why the James Webb Space Telecope uses a gold coating for its focusing mirrors since other materials would absorb a higher portion of the deep infrared-shifted light they designed it to observe.
@@Aderon O.K. But is IR dangerious? I thought UV cause of higher frequency? After googling i got that this layer also reflects UV. But which of this 2 sorts more?
@@xylfox UV is more dangerous in general, but they used a polycarbonate which is already good at reflecting and absorbing UV on it's own. The problem is that while it does a fine job at absorbing and protecting from UV, the polycarbonate doesn't handle IR radiation as well, so having a gold coating mitigates concerns of IR damage remarkably.
To be perfectly clear, the gold coatings aren't _just_ there to protect from IR radiation, the primary purpose is to protect them from _all_ the light coming from the sun, essentially a full visor of sunglasses, it's just that for the monstrous amounts of IR radiation the sun puts out, a gold metallic coating is one of the best options at protection the visor and astronaut within from said IR exposure. Even if it doesn't cause skin damage like UV radiation does, it can still damage their eyes, and having your pilot who intends to land the space shuttle get flash blinded is generally a bad time for everyone.
Perfect for jwst
This is why germanium is used for the lenses of thermal optics. Thermal optics operate in the far IR spectrum and glass blocks it, so germanium has to be used. It's one of the reasons thermal optics are expensive. Glass will, however allow near IR through, so it's suitable as lenses on night vision optics that operate in that spectrum (i.e. digital IR night vision). Thermal is passive and does not require an active light source (far IR is "heat"). Near IR devices require active emitters (IR lights) to "see" in total darkness.
6:43 he's gonna get regeneration from that
I'm trying to do the math on how much gold is in a golden apple vs how much he consumed. a golden apple has 17 metric tonnes and one gold leaf is about 18 mg. let's assume he consumed 1/8th of an apple. if he consumed one eighth of a golden apple in minecraft he'd get about 0.63 seconds of regen and 15 seconds of absorption if the effects translated to real life 18 milligrams of gold would give.... idk a couple nanoseconds probably. I tried to do the math but failed.
It would be 212bilionths 231 millionths 870 thousandths the time of a regular golden apple with some room for margin maybe a couple thousandths maybe even a couple millionths of error depending on apple wedge size and gold to apple ratio in potion Power
You know those transparent umbrellas you sometimes see in Japan? They are freakily good camouflage against thermal cameras/ sights.
The greenish-blue teal tint of the light through the gold is really rather pleasant.
and that's why astronauts have gold visors =)
CDs without any printing can also let light pass through. The metallized layer inside is quite thin.
@@jeanrenaudsagswing I always thought that was because the tiny holes which carry the information. But the metal could also be see through I learned today ;-)
I thought it was because they were trying to look like pimps. Damn it dad! Yet another lie!
@@DonariaRegia lol
(0:50) *Now, just so you don't think this is normal, to be able to see through something with infrared light* I'm glad you pointed that out. Movies and TV dramas tend to have unrealistic portrayals of using infrared cameras to see through walls or ceilings.
Hi, I really like your channel. However, this time there is a mistake. Germanium is not a metal. It is a semiconductor meaning that its electrons are bound and cannot move freely. Only when the light photon energy exceeds the binding energy (also called the band gap), the electrons become free. The band gap of germanium is in the near-infrared range. Therefore, the visible light gets absorbed/reflected and the thermal mid-infrared light passes through.
Although germanium looks like a metal, its mechanical properties are similar to insulators - it is brittle and cannot be forged like metals.
The glass in turn is mirror-like in infrared since its ions oscillate in the light field and act similar to free electrons in metals. Germanium and silicon are non-polar - they don't have positive and negative ions. So they are transparent in the whole infrared range. This is a great advantage and the most of infrared optics is made out of germanium or silicon.
whoa
All elements are classified as a metal except Hydrogen and Helium.
@@Vincent67337that is only an astronomy thing. Chemists and physicists do not call germanium metal...
I thought being a semiconductor played a part...
@alexejpashkin3562 Once he showed the IR light shining through, I knew he had a semiconductor. However, I don't think *"The glass in turn is mirror-like in infrared since its ions oscillate in the light field and act similar to free electrons in metals."* is a correct explanation. One, glass doesn't act like a mirror in the infrared anymore than visible light does. Glass actually absorbs infrared light. And I could be wrong, but I always assumed this absorption was mediated via phonon modes, not ion oscillations. But now I need to look it up and get back on that.
I've always wondered what IR windows were made of and now you've clarified my doubts. Thanks for the video!
I didn't know IR windows even existed!
Many metallic films are mildly transparent. That includes mirrors, which are usually painted on the back for both durability and opaqueness. I used to make signs, and most of our gold or silver-colored adhesive films would let enough light through that you could read a newspaper through them, or use as a rudimentary one-way mirror when the other side was well-lit. (Not requiring a flashlight that rivals the sun...) That includes the "metal-flake" style films, as well as the flat/mirror. I believe most of them were also considerably cheaper than gold leaf.
Gold is the classic because it is so damn malleable (in the technical sense of the word meaning it can be hammered very flat)
the gold "filter" looking greenish makes it look perfect as an in-camera nightvision effect! I imagine this would be a cool filter to use in photography or hobby filmmaking
Gamma rays: am I a joke to you
Gamma is just X-rays, just light with a higher energy...
@@DonariaRegia You are thinking of Neutrinos Cosmic Rays are atomic nuclei that move at a high %C and are mostly stopped by the upper atmosphere. They are working on using this decay to take deep scans of things using the produced Muons.
Wouldn't higher frequency light be more inclined to be absorbed, because they have energy for the electrons to be excited? Or is there some new effect at high frequencies?
@@DonariaRegia 😹
It's often referencing the emission source of the high energy photon: from a nuclear transition (gamma) or an atomic one. There are actually some nuclear energy transitions in Thorium that result in a 149.7nm gamma ray photon out. Relatively low energy.
Love your videos, I wish I had had a science teacher like you when I was in school.
THANK YOU FOR DOING GOLD! This is something I've been wondering about for years!!!
When I was little I remember playing with aluminium foil and I liked how u could see trought it if u placed near your eyes
How did I not know this?
Ikrr
did you know you can also do this with mylar
Education system in shambles
coz you can't see infrared
Get some scrap silicon wafers
. Most are IR-transparent, depending on the doping. But silicon, like germanium, is a non-metal (no mallebility, no electron-sea, and insulating when cold.)
I know many people are scared of physics classes because of the math. However, if we could get people just take a year of high school physics, you'd be surprised how the world opens up to you. It's not just about learning "how things work," it's also about learning to ask questions and then looking for the answers. I can look at anything in my office right now and find an interesting physics question about it that applies to the real world. I like science fiction, but the real world has so many crazy dynamics to it. Some of the demonstrations he does are classic physics examples, but he does a great job explaining it. And he comes up with demonstrations I've never seen before.
The problem is the formal education side requires the math… I was interested in meteorology as a kid, but struggled with advanced math equations so I gave up on that dream.
As an adult, I’ve watched many physics based educational videos on all aspects of weather, and physics. Lectures as well. To the point now where I have a solid intuitive understanding of the processes, but couldn’t tell you anything about the equations involved.
Now we have to worry about spy cams with metal lenses. Gee thanks 😂
A spy cam seeing in infrared? Army-related then
@Julzaa I'm more thinking about the gold leaf
@@Autistic_Artist there are already see-through mirrors, the gold leaf as a lens is just a gimmick
You think ultra sonic cameras need lenses? They already have them.
Love this channel. Nothing but learning disguised as fun.
Germanium also has an extremely high refractive index. Its used for lenses in thermal imagers and for focusing CO2 lasers. ❤
6:53 NileRed made himself gold grillz to “avoid crippling embarrassment” (and posted a video) 😂
The infrared camera shots of germanium are absolutely insane. I just cannot reconcile that with my previous knowledge of physics.
This is the coolest thing I have ever seen. I know, I know, I should get out more.
Thanks-Awesome!
Thanks again for a most informative and educational video! It's interesting how materials can be be invisible to certain wavelengths of electromagnetic energy.
Your video from about two years ago on making transparent metals was interesting too.
And for those who didn't know, astronaut helmets have a gold layer as well which is used to block the sun's intense unfiltered light while in space.
Some infrared-vision aliens gotta have extremely strong fish tanks
literally the best science channel on youtube second to codys lab. and trust me i've watched all the science channels on here
That was a pretty cool video. You should make a follow up short about the James Webb telescope, and why they use gold and beryllium on the mirrors.🧐🙂
I never would have guessed that light (or lazer) could make it through metal without damaging the metal. super interesting.
So, can we use germanium glasses to correct a snake's prescription if they suffer from visual distortions?
How about: If you block a snake's eyes with germanium, can it still see you?
@@KarstenJohanssonThat would be interesting, you could also block the prey with germanium and see if it could find the prey.
So cool! Very constant color going through the gold!
To do physics experiments like this everyday would be a dream job for some, like me.
I love how the letters printed on the Ge sample weren’t see thru but the rest of the sample was!!! 😮
My brain cant compute this knowledge lol
Love your videos, thanks for showing us cool stuff! :)
yeah i agree
Love the color cast when you put the gold up to the camera.
I like to see your thought process. You first made a video about laser metal cutting, and then you wondered if red hot metals can reflect light or not, and now you are working on light penetration in metals. You are personally educating yourself and also make all of these processes available for us, viewers. Keep up with good work.
And for the next video, i would like to see if electrical current or static charges would effect the reflection properties or not (because you mentioned that those properties are strongly related to free electrons and their specs).
Plasmachannel made a nice video on electrostatic materials.
" i would like to see if electrical current or static charges would effect the reflection properties or not"
well it does though not on metal but LCD
That's why I subscribed him early, he never let my interest down.👍👍👍
Gotta love things that exhibit characteristics of both a wave and a ray.
Another cool thing about germanium is its temperature dependent leakage in transistors and it’s use in the original fuzz (distortion) guitar pedals that Hendrix made famous.
how do you manage to find such fresh yet interesting sciency content? you really win youtube man, germanium being transparent to IR is very interesting.
This reminds me of that Star Trek movie where Scottie gives the guy in the past the molecular structure of clear aluminum. That was a pretty funny scene. “Computer. Computer? Oh, a keyboard. How quaint.” I lost it during that scene.
Fun fact: Thermal camera lenses are made of solid germanium to block all the "normal" light and only let infrared light go to the sensor
Thanks!
In the entire Elements table, is there this one and only one metal that does this? Is it maybe the very only (in solid state) element that does this? Blocking visible light, but letting through infrared. What an odd characteristic. First time I ever hear about this. As always, great video! And thanks much for sharing these fascinating oddities!
Whenever I hear about like going through metal it always makes sense in my head because I can go through crystals and metal is a crystal.
I am 50, retired and just took up art as a hobby. 8:01 totally changed how i look at colors , only took half a century.
excellent..fascinating demonstration and clear explanation
I already found out about this in high school when I blindfolded myself with coloured aluminium foil and I was still able to see.
Free electrons was first discovered by JJ Thompson, in a cathode Ray tube filled with vacuum. Electrons was deemed to be the carrier of electric charge (across vacuum).
Electric charge induced on a glass sphere stay at the contact point, not so on a metal sphere. On metal sphere the charge spread evenly across a uniform sphere. So charge spread across a conductor naturally without the need of a carrier I.e. “electrons”. Electrons is however required to move charge across space, the vacuum and not conductor.
Charge distribute through electrolyte requires electrons.
Thanks, great explanations!
Would light pass through an iron sheet with the same thickness?
Pretty similar to space suit helmets. Except it’s applied differently. That or Mylar.
Nice video, Transparent Aluminum has similar properties, that too can be covered in future videos.
Excellent, never ceases to amaze
00:04 "today im going to show you how to shine a light through solid metal" processeds to drop a nuke
real
Lmaoo guess it worked
It worked a bit TOO well
I really needed this! Just thinking about how I would get a signal into a faraday cage. Looks like laser + thin metal is the way to go.
Light is ALWAYS a wave:)
except when it's not:)
You can also see through aluminum foil with a bright light
Depends on the quality.
I’ve read about cases where people have made whiteout glasses out of thin foil wrappers like you’d find around a pop tart
@@hunterwyeth a pop tart wrapper is vapor thin, I think I have seen light through that before.
Real aluminum foil? No way, even the thinnest cheapest stuff won't have light getting through.
That's someone confusing food wrappers for actual aluminum foil.
You don't actually need gold to experiment light across metal. Many candy wrappers are made with glittered PET, it is s thin layer of aluminium on PET. It has the same effect and changes the colours of light.
Interesting and you can even buy germanium lenses.
it is so cool this is a thing, I wish I had some of that metal
Germanium is inexpensive. Gold isn't, but some gold leaf from a hobby store is within many budgets.
I loved Germainium for making fun guitar pedals already. Even better now 🔥❤👀
'Look at this light shining through metal'
Next shot: shows a disc of the semi conductor metalloid Germaniun 😅
Like your videos a lot James.
Could germanium be formed into a lens to focus infrared light?
Yes, it is used for that
Amazing presentation so much to learn. Thank you
Light can pass through anything, even lead if you make it thin enough. Thickness only affects attenuation, it never blocks it entirely.
Loved the explanation for how reflection works, you and 3blue1brown are the only ones I have seen that have explained it in that way, even though its one of the most accurate ways. If you want to see more stuff on light I highly recommend 3blue1browns optics series, its really good.
Just realized this looks like a bot comment, I swear its not I just really like 3blue1brown.
Everybody who likes proper explanations even if they hurt their brain a bit and appreciates good educational presentation animations loves 3blue1brown. 😁
The Royal Bank Plaza in Toronto has two towers with gold windows. The gold is only a few atoms thick, so you can see through them a lot like a one-way mirror. Speaking of, one-way mirrors are another example of looking through a metal.
Why didnt he got regeneration after eating the golden apple?
Edit:Mom, i am famous
Or absorption...
Gold apple just grants full health
Didn't he get**
😂😂😂
or get "kicked out"
Thats very interesting! Never thought! Thanks!
It's crazy how important of a role Light plays within our Universe.. 💡 As well as the interconnected Magnetic Fields.. 🧲 and Electricity 🔌 ⚡ 🔋
Silicium is also very intersting because it is both used to make visible detectors and IR lenses
You can shine light through iron as well! For this, the iron film with a thickness around 100 nm or less should be on some transparent substrate. The important thing here is that the metal film thickness should be of the same order or less than the skin depth of the material.
your content is so unique and fascinating. thank you!
What people dont realize is, that for many lights colors even pass through our thickest stone walls. visible light is about 10THz-800THz and the color is the frequency. if you could see lower than red you would see electromagnetic waves pass walls below 1GHz (Wlan) and lower (Radio) its the same thing as light, but another frequency.
Very cool. I would like to have seen a demonstration that gold is not transparent to IR. This is why space probes near the sun are covered with gold foil.
All your videos are amazing, keep it up! 😁
WOW...brings to mind the "Transparent Aluminum Matrix" from Star Trek IV: The Voyage Home"
This is exactly why we use germanium to make filters for JWST! Especially the mid infrared instrument MIRI, which measures wave links from 5 µm to about 28 µm
00:39 wouldn't say " completely. I'd say 60%
ok
Boooooooo 👎👎👎
🤦
Looks like glass bro
Even 1% is good enough for metal
"Transparent Aluminum??"
That's the ticket, Laddie!
Thank you for your video. The are very original and interesting. My life is better because they exist. Keep sharing your gift.
From memory I think space suit helmets have gold on their visors to filter out higher frequency em radiation.
That's why it's possible to make partially silvered mirrors like the ones in gas tube lasers or in interrogation rooms.
If you had a bar of gold, could you have a bright enough light to eventually shine through it?
RIP to the German person that got sacrificed to make this video.
Also the lens in that thermal camera you use is made of germanium. Glass (which is used in visible-light cameras) blocks infrared.
Really cool experiments. Thank you, sir.
Impressive!! Very interesting this Germanium stuff ...
The Action Lab: "Woah, I am literally seeing through solid gold!!!!"
Airline pilot: (Yawns) "Tuesday"
You should try to make lenses for a telescope or magnifying glass with Germanium.
So fascinating! Thanks for sharing this!
Now I know what to tint my car windows with. 🥰
anything is transparent if you make it thin enough
I want to first echo all the "Oooo, cool!" comments. But not using a tip when handling the gold leaf made me a bit crazy. A tip is a fine hair brush roughly the width of a piece of gold leaf. Lightly brushed over your skin it picks up oils, and then, touched to the edge of the leaf, can pick the leaf up. Even a wide sable paint brush would have done a better job than your fingers--particularly when the gold sticks to your fingerprints. Though the tooth thing was amusing😊
I learned three new things in this video!!
Did you recover the gold in your toilet 😂 ?
For $1 of gold?
That’s more of a Cody’s Lab kind of thing
A compact disc has a thin coating of aluminum (and top coating of plastic). You can easily see a bright light source through it (If it's shiny on the top side and doesn't have a print covering it). So you do not need leaf gold to demonstrate this.