See-through Metals Actually Exist! 

In 1986 Scotty gave the formula and process for transparent aluminum to an engineering and manufacturing company that was capable of transparency at 4" thick and many times stronger than steel just to get home.

I love this channel. Some days it's like "here's a cool silly thing you can do with physics," then other days it's like "here's an explanation of fundamental concepts of matter and energy that you never really thought about and should probably be over your head but I'll explain it in a way that'll give you a solid layperson understanding that will make mundane things suddenly cooler."

Most music compact disc (CDs) , despite their silver color, are also transparent enough to allow some light to pass through- which is evident in sunlight and with other bright light sources like lasers

Strange that we usually don't see the alkali metals like sodium do that cool effect despite how commonly we see people adding the metals (especially sodium) into water.

If I recall correctly, there are actually many more "transparent" metals. It's just that they are transparent in radiation ranges close to visible, but not in it. For example, Germanium is used to make lenses for thermal vision optic due to its infrared range transparency. Also, germania (germanium dioxide) is used in visible range photography optics and as optical fibre cores.

I was surprised that you did not mention that these semi transparent mirror have plenty of technical applications like interferometry, simultaneous projection and measurement, etc.

The fire brigade's fire protection clothing sometimes has a small window to look through. This is vapour-deposited with a few layers of gold atoms.

As a dumb high school senior back in 1970 I was in charge of our chemistry lab stockroom along with another friend. We were bored one day and starting playing with sodium. We rapidly moved on to seeing what would happen with a really BIG piece of sodium when thrown into water. Fortunately for us as it started to sizzle we moved back. The explosion threw hot molten sodium into the ceiling but didn’t explode the beaker. We could have been seriously injured. If we had done that today the FBI would have arrested us for domestic terrorism and our lives would have taken a very different path.

This is how those mirrored windows in interrogation rooms work. As it's dark in the observation room the light that pass through is easily seen while no light leak through to the bright side. 😁

Fascinating, but Scotty already gave us the formula for transparent aluminum on Star Trek decades ago.

I believe the correct term to use for the plastic film coated with the aluminum Oxide is translucent, not transparent. On the whole this was a very interesting video and educational. Thanks for sharing.

This property is what allows 'one-way' mirrors to work. So, however, the amount of transmission is relative to how much light is present, which is why it's important for the room behind such a mirror to be dimly lit, or lit entirely by light transmitted through the mirror. One quirk of this is that if you cast a shadow on a one-way mirror, you can darken one part of it to the point where the transmission across both sides is about equal, and then actually peer past the mirror to see what's behind it.

The easiest way to see a "transparent" metal is a good old CD: it's exactly the same kind of deposited aluminium or even gold in older/premium CD-Rs. All it matters is that it's reflective enough to infrared light.

Wait a minute, I was sure that Mr. Scott shared the secrets of transparent aluminum with us when the Enterprise came back to get some whales.

Wow! The Action Lab always thinks up of properties of materials that we never thought about!

Fun fact that I learned recently: metals would be different colors if we could see UV. Basically, metals have electric field resonances...how quickly forces tend to be passed through the electron cloud. EM radiation of the resonant frequency will be absorbed. For most metals, the resonant frequency is somewhere in the UV range. Gold and copper are two of very few metals with a resonant frequency in the visible range (blue), hence they have color to us, instead of just looking grey / silver.

i remember looking through the reflecting side of a 1 way mirror. they used them for security to watch people , at least they used to. looks like a regular mirror but someone on the other side can see through. if you get up really close you can also see through the shiny side to see the people behind it. did that once and heard the guy behind say yah i know you can see through.

I noticed this phenomenon when I looked at the sun through a CD. I always wondered how that worked. Thank you for explaining it.

Thanks for the consistent good content and for answering all the questions that I never thought of.

I had alot of lead, maybe 40-50 lb., from alot of things and desided to melt together and put into forms to be able to stack and store it better. In a lg. Iron kettle, I melted it and remove all the junk that floated on top, poured into the forms, but they ended up all with a curved bottom, so remelted it all again, and skimmed the top many times. It seemed to become clear but dark and was sure I could see the bottom of the kettle through it, but then a skin would form over the top, but reskimming, it would again appear clear. I'm sure there were some other metals in with it, tin and maybe silver or other low melt temp. metals. I tried sticking things like a wire into it and it looked like I could see them though it, but it was hard to say as the top was also a good mirror and putting to much light on it would increase that.

That was amazing man! Thanks for teaching us cool stuff man! Keep up the awesome work dude!

@TheActionLab : Legend has it that Newton started studying spectroscopy by looking at the sun through a thin gold foil. Could @TheActionLab do a video looking through gold foil at the sun? Apollo moon suit have gold plated visors. Was this foil or vacuum-dep? My understanding is that in a foil the gold atoms are so close together they only allow blue wavelengths of light through.

We would love the reaction mechanism written and explained too !! Thank you for sharing your experiments with us!

Finally! I've been asking for this experiment many times before. I even gave up. Can't wait to watch it.

That painting idea is so creative wtf!! It looks great too, I love the colors on the accretion disc.

If memory serves, infrared cameras will sometimes use metal lenses - lenses that block visible light, but focus infrared light.

This video is talking about Drude Model which is the topic i just learned in college few weeks ago. This clears lot of my confusion especially about the plasma frequencies and extinction coefficient. Thank you so much 🙏

We had transparent aluminum windows in our MRAPs in Iraq. They were thinner and lighter than regular glass windows and still strong enough to take direct hits from most heavy weapons.

Interesting video, well presented with great props/demos.

I swear to god i thought it said meals and got ready to say this. Holographic Meatloaf: am I a joke to you?

This is really cool! It all sounds so straightforward, but there’s really a lot to absorb.

00:04 "I have done a lot of experiments with sodium in the past, but we usually focused on it exploding.." Yes, we have done a lot of explosions and i'm all in for it😂 But this is nice content too

Before watching this, I am going to guess thin films. Because of metals' conductivity, by maxwell's equations you find that when a light wave enters a metal that the electric and magnetic field end up being shifted out of phase which causes a damping effect on the wave causing it to decay exponentially. This also means though that if the metal is thin enough you will still see light make its way through since it was not inside metal for long enough to complete damp out the wave.

gold leaf is also transparent , even the fake copper/nickel based ones

I watch a lot of scienc chanels but most of the time i have some ide of whats going on but every time i come to your chanel i always seam to get amazed by some new concept and learn something new, absolutly amazing content!!

i have seen this experiment a few years ago discovered independently by one russian chemistry channel and he could not find the answer why it happened, he discovered it by completely by accident. and now ofc its actionlab that gave the explanation😊

0:40 That little "woah" there contains an emotion that's hard to put into words.

Nice to see a good explanation of this. You get the same type of reaction with table salt when its heated up until its red hot. It will explode in a similar fashion, probably because there's not much there holding it together since its ionic and the water can intrude and make it unstable. And the term "columbic explosion" is maybe a bit over-exaggerated, at least for me. Its a reaction just like anything else. If you capture it before it explodes and stop the reaction, nothing interesting happens since its not molten anymore. Conversely, you can probably heat sodium oxide and sodium hydroxide in their pure states and make them explode in water the same way once they are molten.

That painting looks absolutely awesome

Thanks bud! Love your content!❤

Transparent aluminum is my favourite one of these, as it's applicable everywhere

4:12 Scotty is upset he didn't get his cameo

These clips are fascinating and definitely teach me what I did not learn in high school science classes. I wish I could understand them better!

Great job as always, thank you.

awesome lesson, thank you.

When I tried to explain this method to someone about how you can marginal expand metal with slight integrity to be transparent parallel for light exposer to clear-metal. They were like, "its not some kind of essence!"🙄.

Nuance is so important. Thank you!!

That 3d animation of how electrons flow through metal was really helpful

Wow! I always wondered why sodium burns for a time, sits, and then pops/explodes, instead of explode right after they touch

Brilliant video - I’m sure many other people are now looking at that Star Trek film with the transparent aluminium holding tanks in a whole new light.

As always incredibly informative

Wow! Amazing! First time I saw this was in Thunderfoot's video years back! Now it's much more clear here! Amazing!

The "molten transparent sodium" myth is something Thunderf00t started, at my huge annoyance and unpleasant surprise. It's clearly sodium hydroxide being stable for a couple of seconds due to Leidenfrost effect. It can also be decanted into another dry container where it will solidify into a translucent, white mass that behaves identically to NaOH, so there is really no mystery about it. As far as I know, Thunderf00t issued a retraction of his claims, which is something I would not expect from a person of his caliber. As for transparent metal films, we've all seen mylar foils passing light through when we'd examine and play with candy wrappers. Gold leafs transmit blue-green light. Some thin metal films transmit ultraviolet radiation, as well, so they're used to make UV pass filters.

You can see light trough some compact discs that don't have a image printed on the back, if you hold them against a strong source of light. As a unsupervised kid it was a way for me to look at the sun without getting blinded immediately.

Those paintings are fire mate!!

Thank you for teaching me chemistry in a safe and fun way!

In one of Thunderf00t's videos, he was showing a very small piece of sodium (could be potassium or NaK) becoming transparent. It's very unusual and baffling to see this effect on a big chunk.

It’s nice to finally get some visuals and a more clear explanation. So.. does this mean electrons have metallic luster? I mean… they are metallic luster. Like that anhydrous ammonia thing where the liquid becomes copper colored.

This is so amazing! 👌🏼

This is clearly amazing!

James: "Let's see what happens when it doesn't explode" Sodium: *explodes*

I have seen this with plastic potato chip bags where if you hold it up against direct sunlight you can see through it ! They also use a similar metal depositing process and as a surprise to anyone if you remove the outer plastic they become cheap and kind of useful wires

I cracked to your “Ouhh” after every ball exploding 😂😂🙏🙏

Bro looks happy and worried at the same time💀

Thanks! Through your experiments, we’re able to witness phenomena we’d never be able to perform in our homes. Cheers to science and your dedication!

In Star Trek 4, Mr Scott asks the computer to make transparent aluminum. Turns out that naturally occurring aluminum oxide is corundum, aka sapphire and ruby. Yet they aren’t metals in the material sense, even though we think of aluminum as always being one. Similarly, while tungsten is a metal, as tungsten carbide, it’s a ceramic. The differentiator is what we define as a metal vs another kind of atomic structure with different properties.

you are one of my best teachers. Thank you☺

I always appreciate your videos, very cool

I believe the 1st take where that drop burned through the paper and exploded in the water below in the beaker is what happened to my father who as a kid got those (in)famous chemistry kits where he did the same test. Only in his case all the windows of the kitchen blew out . That was 75 years ago.

Oh man. I am using the Drude formula in my thesis and this was really on my mind. Are there any transparent metals? Yes! (but...)

You are amazing dude, an educator, a scientist.

I’m more concerned about shining a laser near the camera, I’m scared af for the sensor, I was just dodging the beam for him 🤣🤣🤣 interesting video! Every time is a good time to watch TAL!!!

Imagine if this was used in buildings

Thunderf00t has some AMAZING slow speed footage of this stuff. Edit, this is also why it will turn your skin into soap.

Three common metal film objects you can see through are mirrored sunglasses, which have been around a LONG time, DVD and CD discs, and metal film gift wrap, which can make easy and cheap solar filters for projects.

I understood all of this while not understanding most of it. Well done!

I’d like you to do a video on bendable glass , apparently back during the Roman or Greek times someone invented this and he was killed by the king who he had presented it to .Not clear why but I have heard they know how to do this today.

At 5:15, isn't that what half silvered mirrors are? Like the ones used in beam splitters? Great video as always! 👍👍

That's CRAZY fascinating!!!

loved the painting

Makes me wonder if something along this line might be done with a thin layer of metal in the presence of a strong magnetic field, or by passing a current through it, maybe a pulsed or variable current with the proper resonance, to influence the free electrons to assume a state that would allow visible light to pass through.

I thought you could do that with just a regular mirror. Does it have to be this ultra-thin aluminum?

Great video!

OMG, that blow-up in the beaker startled me evern more!

After the first two caught fire they turned yellow and then transparent, but the last one you showed first turned blue and then caught fire, I'm curious whether it would still turn yellow and transparent afterwards but unfortunately we will never know as it fell through the paper and exploded :/ The most interesting experiments are those that produce results you did not expect.

Bro you uploaded exactly on December 1 on my time

In costume-making we often need to make helmet visors to have a "one-way mirror" effect. We airbrush the inside of a plastic visor with a special laquer called "Alclad II Chrome" - It's just tiny metal particles suspended in a solvent. When applied the solvent evaporates and you are left with an extremely thin metal coating, very similar to your aluminium plate, and for some reason it is still transparent when viewed from the darker side, but from the well-lit side it is a perfect chrome mirror. It's a really cool effect and I don't understand the science behind it at all, your video reminded me of it.

Sodium in water be like: Burns Burns Burns - Let me be clear. Explodes

I've seen that light passes through CDs. I think the metal foil is one whole peace especially on the writable ones, although I'm not entirely sure.

Is this the same as a "half silvered mirror" often used in optics?

Nice keep up the good work.

Very cool episode.

"Usually we put the sodium in water to see it explode" *puts sodium in water "look it's perfectly clear" *sodium explodes

Be careful with that laser pointer. A lot of green/blue/purple laser pointers are significantly higher power than the 5mW it probably says it is.

Reminds me of the Star Trek ‘The Voyage Home’ When Scotty said what about this material for the Whale Tank - Transparent Aluminum- . In 2009, Oxford scientists made headlines when they created the sci-fi material in the real world using a special laser - High Energy Pulse Laser

molton drop of NaOH that spontaneously explodes, throwing a base strong enough to eat glass in all directions! Love it, make sure you have good PPE.

You could have included an explanation regarding complex indexes of reflection. Also fascinating.

Could one quickly harvest and store the clear resulting hydroxide before it pops?

It's a beam splitter! I always wondered how they worked. Great to have an explanation!

Cool! I wouldn't think it's possible! Thanks!