2:26 When he said ”He had actually found a room with a shape such as…”, I imagined sir Roger Penrose roaming the world with a lightbulb - barging in, testing the room, grunting and moving on to the next one…
I am SO happy to see this thing built in real life! I always thought it would be utterly amazing to be in a normal sized version of this room, with a fixed light in the center. If you walked into one of the square areas: How does the light disappear? What do you see now? Does the square room on the opposite side appear really close or far away? This would be the coolest museum exhibit ever.
If it were designed properly you might ONLY be able to see the light refracting off dust particles and the like in the air while you are standing in the dark potions. Sort of like seeing a laser beam from the side. That would be amazing
@@justmayhem771 No it would be different. In the shade light is still refracting to your eyes off the grass or whatever. In the dark spots of this room, there would be almost NO light refracting to your eyes You wouldn't see the illuminated parts of the room
Really cool! I was just expecting a room painted with the black 2.0 or other extremely black paints shown on this channel (which would make it's walls close to illuminable, but not entirely). I never taught of the idea that a room with mirrors could get truly illuminable in some areas, by having the right shape to only reflect light in certain angles...
How amazing it is, that one of my favorite science youtuber, Steve Mould, sent me over to watch another of my favorite youtubers. I love the science youtube community. It's so collaborative!!!
Ladle ladle ladle ladle ladle ladle ladle ladle ladle ladle ladle ladle ladle ladle ladle ladle ladle ladle ladle ladle ladle ladle this isn’t as much fun as when i was 8mos old…
Came from Steve Mould's video. Thank you so much for posting this. Any time I try to look into this topic, all the search engine hits just explain what the room is, but nobody has any demonstrations on how this works with real-life light rays.
4:15 Experiment with water is even more intriguing. How can waves travel in one direction like a laser without disturbing adjacent molecules of water, what happens at the interface between still and wavy water, is it progressive or abrupt ? Is the shape of the mirrors acting like a wave guide or a lens or like a filter or are they causing destructive interferences ? As it something to do with caustics maybe? 🤔
Interesting enough light and water are similar I remember a long time ago there was some sort of experiment that showed light behaves in both wavelengths and particles like water. Something like that I suppose
Light is also a wave, so they both have the same properties. The mirrors act like a wave guide, they really don't do anything but to stop/guide the wave.
so, it is not exactly the same, due to the fact that water diffracts much more easily than light, the waves in water will reach every corner of the room. They both diffract, but water is much better at it. Light will also reach every corner of the room because of diffraction, but the amount of light is so small that it is negligible especially compared to the waves
I was honestly hoping to see a demonstration. The idea that you could have a point of darkness in the middle of one of the ends of a room that is otherwise illuminated is fascinating.
@@Ck87JF A point is infinitely small so you wouldn't see it. Also the light source needs to be infinetly small so those solutions can't be observed in the real world.
yeah and now we know he's gonna make this room again but bigger so he would be able to go in. We'll see it sooner or later. He just loves making rooms. Also really curious how would sound work in this room.
sound would be an interesting one, especially if this was actual room sized and you could walk around and hear the different volumes (or not hear it at all). Im guessing it would work exactly like the waves in the water did.
This is a great idea. Also it would be interesting to see how it behaves with mirror floor and ceiling whether other parts would get more light, if that is the case - sound shouldn't be heard there too or silence. Adding reflective surface is definitely going to impact it, since atm it leaks out the top.
wonderful idea. I was wondering what one would see standing in unilluminated part and looking towards the illuminated part. We are used to that light scatters at all directions usually from regular non mirror walls so that even when we are in unilluminated part we still get some light so we can observe the illuminated part. But if all walls are ideal mirrors then it would be like looking into darkness. Just walk one step further and suddenly you see all the illuminated parts of the mirror room. Sounds ridiculous. Or am I missing something?
@@andriusk5044In the scenario you described person standing in an illuminated area wouldnt see dark areas, because by definition light from those places couldn't reach him... I think so
@Kim You may be on to something there! In a light speed engine the desparity between light and darkness ...blah ...blah ...something ... manipulating light. So far we've learned how to bend light and even slow it down but for some reason, we just can't go FTL. Even despite the fact that scientists recently discovered that we ...our entire galaxy and the space it's in is already moving faster than the speed of light. Contrary to Einstein's predictions we are not spaghettified are we? I think the speghettfication part of his prediction is just an optical illusion.
Seeing a real Penrose room model it is very cool to see that it actually works. I gotta ask though, does this mean if you stand at the bottomof one, would you not be able to see the light at all?
Yes. In an idealized scenario with nothing to scatter/bend the light (both the surface of the walls and the medium the light passes through) zero photons would enter your eyes and you would not even see the other parts of the room. I’d be interested in how it looks in the illuminated part assuming perfect 100% reflection. But again, everything would have to be ideal, including your body and eyes and retinas in the illuminated field to truly experience that effect. Wait.. even in that scenario you would not see any of the walls, only yourself.. wait but you would see any photons that scatter off of your body into your eyes, plus photons that scatter off your body and reflect off the walls back into your eyes. Which would eventually be coming from every point of the walls… so what the hell would you see?
You would actually. Nils berglund has the animation that shows that diffraction will lead some of the light towards the unilluminable room. And by some it's very little.
I think this might help. If you stick the light into one of the top corners, it lights up the floor for that top ellipse. If you're standing in the bottom-center, you will be in darkness and (in perfect conditions) won't be able to see yourself, but you could see the floor at the top of the room. I think based on perspective, you wouldn't be able to see the wall, or it would be very faint, since it's mirroring your location. If your friend was standing in the lit portion of the room, you could see them but they couldn't see you. Think of it another way: if you've ever been in a large completely dark room with a door open to another room which is lit up, you could see the other room but not yourself or your room (except toward the door where light leaks in).
Because light waves (observed photons) grow they propagate to the "hidden" spaces. Mathematically it is true, but with real light waves, this doesn't work.
First time you didn't explain why it is like this. Maybe you could add this. This is the best part of your videos. This way around it is just like a "magic show", you know.
What about sound? I know that sound would travel through 3D space instead of a "2D plane" but it should be possible still right? I imagine that maybe you could try making a "penrose ellipsoid" maybe? Although now that I think about it the water example is technically the same thing just with a nearly uncompressible fluid. Yeah, I'm not terribly sure how well that would work. I should look into the physics myself probably, I think I'm hitting a wall with my current understanding of this.
@@louf7178 I guess that works but I was thinking more of a shape that doesn't allow sound waves to go to a certain region of it, rather than cancelling out and dampening sound waves. The way a muffler works is pretty cool though. (Edit: Now that I think about it I don't really know much about the physics of the shape in the video, It could be causing some destructive interference with the waves in the water example.)
Damn this is really too interesting. Just think about music festivals in a giant room like this or a bed shaped in this position. If the other person would turn their night light on (for sure since there is a person it woukd reflect but i think not this much) you could turn the light on without disturbing your partner. Would be so cool to see this room in normal size
Guys it already exists, in various places of italy (and probably the world, its stuff fro roman empire) there is a half elliptic walls that go corner to corner of a place, if 2 guys are on the 2 ends of it, they can clearly hear their voices even with a loud crowd talking (because you need to be in that specific spot only for the waves to get brought on the other side) pretty cool to try
@@SToXC_. Not really the same thing? That shows how a parabolic can be used to focus sound, but doesn't show there are areas it can never reach. FWIW there are various science museums that have this demonstration with parabolic reflectors.
Nils Berglund has some nice simulations on this topic but this is the first time I’ve seen such a well done and ingenious practical demonstration . only James could demo this so cleverly ! Well done !
@@johnnicholson8811 Sound can easily diffract around the corners, so it would spread around the entire room. This is a thought experiment and light is being idealized as simple rays
I really liked your transparent comment about your website... You made a single simple statement that you "sell" experiment kits on your website... It just seemed so blunt and honest; Zero marketing or sales pitching.... It was very refreshing. You're a true UA-cam gem! My wife is a teacher, so im gonna send her over to your website to see if she could use any of your products! Im sure many others feel the same and are following suit! Bravo! ETA: She wanted the Extreme Garage Science for Kids book... Scooped it on Amazon! Her kids are gonna love it!!!
Sir Roger Penrose -- an incredible visual imagination! He invented the Penrose Impossible Triangle, the Never-ending Staircase (with his father), Penrose Non-Repeating Tiles, the Unilluminable Room. PLUS getting the Nobel Prize for Physics in 2020 for proving that Black Holes MUST exist -- another feat that required HIS visual imagination. What a hero!!!
But this is only for 2d. What if the floor and ceiling were mirrored too? Isn't that the point? Just as your fully illuminable room was mirrored on all sides.
That wouldn't make a difference. A flat mirrored floor/ceiling would just bounce it in such a way that if you looked at it from above, it would still appear 2D and have the same effect.
@@protox4 it would create a significant amount of variables that would change the outcome drastically. Currently so much light is escaping for all kinds if angles, its possible a ceiling would reflect them back down to bounces that would reach those previously dark areas.
@@satay71 No, it's not possible if the walls are 90 degrees from the floor and ceiling. Think of pointing a laser between parallel mirrors. Does that make the laser take a left/right turn? No, it doesn't, it just keeps going straight while bouncing up and down.
If you're getting interested in what he does he's more of a physicist than a chemist. He understands the physics of chemistry more than the chemistry of chemistry if that makes any sense.
@@Moonlightglitter his chemistry videos are still mostly about the physical reaction tho is what I'm saying. He doesn't get into chemical formulas which is really what chemistry is. He does like a hybrid of chemistry and physics but focusing on the physical reactions moreso than breaking down the chemistry.
David Castro was in the undergraduate geometry course I taught at Macalester C. when he improved Tokarsky's result. Of course Tokarsky gets major credit for finding a polygonal solution -- but it was very nice to see a young student improve on it, with fewer sides, and nice to see that his discovery is noted.
Next challenge: can you make box with walls made entirely of lenses that perfectly creates “blind spots” or “points of invisibility” such that an object inside is not visible for that specific location inside the box from all angles that you view this “lens box”? This would be a perfect “box of invisibility”.
of course you could, havent you seen the "invisibility" shields that already function in the same manner? But those are meant to be movable, and that ability reduces how well the "invisibility" actually works, if it were made of static lenses that were specifically design to hide a single stationary point then I imagine it would be even easier to make and much more effective
Hey, I wonder what the effect would be if the room was purely elliptical, with mirror walls, and the light source was placed on one of the ellipse's focal points? Would another object in the room be illuminated from only one direction? Similar to the totally black room?
The Penrose Room doesn't always have to be the semi elliptical shape that gets used as a physics model, it can have different orientations, as long as the light from the light source doesn't go past the top or bottom half when turned on in one of these.
Because the floor also isn't. It's a diffused floor, the roof is open and thus all light can get in. But he's in a dark room so theres no light coming in.
So for the purpose of better demonstration, he could cover the roof and floor of that room with mirror and place a camera inside it and see what happens... Because it seems plossible that some extra light reflection might happen...
Technically, there is no need to cover the roof since this room has no change in the height dimension. Every ray that will reflect from the roof is already traced by the existing rays. Since the roof and the floor are parallel, any ray that will reflect off them would not affect the x or y position of the light particle and just the z so we can effectively ignore it.
@@htetmyatanglet's assume the light source to be spherical like the sun. Then, I can totally imagine the rays bouncing-off of the roof at an angle and hitting the walls (sides) of the room.
Yes, I came to make that comment. You beat me to it. Seems like light hitting the roof would be able to go down and illuminate some of the room. Maybe more than once. But when he did the software program, did that do a 2D or 3D simulation?
I see this as a good application for boat in a dock. Usually the motion of the ocean will pull and push the boat so they basically need to tie it. But if the waves get stopped by this shape the boats wouldn’t move much.
i had these thoughts in my head, similar to how light spreads in a room. I was up late one night, something like 3am, and i have a small lamp. I can move this lamp head, to pivot, and angle differently. I wanted to light up my room without lighting up the underneath of my door, and though of a few things, like putting the lamp in a closet, and the doors would stop the light from reaching my door, but then i have a smaller area lit up as well. of course, in the end, i just covered the door with clothes and sheets to keep both air and light inside.
hmm, laser beams don't spread out like light does so you'd need something to diffract it, that would be cool but i think it would be like a light in a big room like he mentioned not that brightly lit
Wait. I'm a bit confused. The experiment was done by having most of the "room" covered in mirrors. But what about the "ceiling"? I thought it was supposed to have the whole room mirrored..
If you project the light rays going in an arbitrary 3D direction onto 2D, they will have the same trajectory as 2D light rays in this model. So you can just put flat mirrors on the floor and ceiling and it will still be unilluminable in 3D.
@@janami-dharmam No, they can be mirrors too, as long as they are flat. As long as the mirrors are flat, light going in a random direction which bounces off the floor will only be redirected in the Z direction, not X and Y, so if you project to the X-Y plane it is as though it didn't bounce at all.
@@janami-dharmam sigh, you have to give me more than that to help. Let's say that a light ray is traveling in the direction of vector v = (x,y,z), and hits the flat mirrored floor (say z = 0). The light will be redirected in the Z direction, resulting in a new direction vector (x,y,-z), making an equal angle with the floor outgoing as incoming in accordance with the second law of reflection. Now consider projecting these vectors into the X-Y plane, which is to say ignoring the Z coordinate. The original vector is (x,y) after projection and the new vector is also (x,y), which is just as though it didn't hit anything at all. (To use an analogy, if you bounce a ball on the floor, the bounce will not be visible from a directly overhead view unless there is something funny on the ground to send the ball careening off in the wrong direction.) You referenced the first law of reflection, which says that the incident ray, reflected ray, and the normal to the surface all lie in the same plane. This is true here: the incident vector (x,y,z), reflected vector (x,y,-z), and the surface normal (0,0,1) all lie in the same plane, the vertical plane spanned by the (x,y,0) and (0,0,1) vectors. The 2D projection of this plane is just the line in the (x,y) direction, i.e. the light cannot leave the line while bouncing off the floor. (It can of course leave this line when it hits the side walls, but that's just the same analysis as for the 2D Penrose room.)
Its just feedback. You have a general direction where you want it to go, then use curvature to redirect it if it strays out of that direction. May I suggest an idea ive had for a long while but never did anything with? What if you can invent a solar cooker/boiler of some sort where there are lenses in there which can keep light inside a ring or something. Like imagine using magnets to confine plasma in a tokamak, but here its just a trap that wont let ambient light that enters to exit the device unless the light fully turns into heat and then maybe heat up water or something. But before it turns to heat, there should be a region with a very high concentration of light that is maintained that way. If boiling temperatures can be achieve this might be interesting. It would be much more harder to achieve full boiling throughout the solar cooker box using the sun. But to get a tiny spot 100Celcius it might ease it a bit. With a normal lens, it needs to be controlled to ensure the point of light doesnt burn something you dont want. With the light confinement, its passive and should work in any orientation
we already have cloaking devices that work because of lenses that bend light in certain directions, plenty of videos of them up here on youtube. They only really work for hiding vertical objects on a background of mostly horizontal scenery though and I dont think theyll ever get much better
with flat mirror floor and ceiling you will most likely get it completely illuminated, making a 2d room with dark spots is relatively easy, you can reach it with trial and error on the simulator he had shown but a 3D mirror room with dark spots is a completely different story, you need much more complex math i guess
@@jimmurphy6095 looks too highly polished for that, i think its likely thin plastic or card with some kind of coating because the convex curves have a perfect mirror finish but the concave curves are a little scrunched in places. if it is ali tape ill be very impressed with action lab lol.
This kind of room design could also make a good reinforced room with the entrances being the two entry points on each side. Tachtically it would make it a nightmare for either side to try and hit an enemy opponent flank you, presuming there is no way around from the other side of each entry way. The round inner protrusions would deflect rounds effectively meaning it would also make it safe if taking cover from the entry ways.
Also another challenge, build this into a room that you can crawl into. Make every wall floor and ceiling ellipse shaped. (Note that this particular object has a flat ceiling and flat floor and that might influence the optics to not be entirely unilluminable.)
Question. If Sodium metal reacts with water which is composed of hydrogen and oxygen, why doesn't it react so violently with air which contains both of those? Does it have something to do with waters adhesive properties?
Just a guess, it might relate to the products. Sodium oxide slows down the diffusion of oxygen but sodium hydroxide dissolves away, allowing for more contact with water.
Hey, Action Lab, I live in Utah, (pretty close to you) I love science, is there anyway at all I can help you make your projects? I'll do anything to help you, I love you're channel. If I can't help you, I will still watch every one of your videos cause I love science and I love your videos.
That's a fascinating idea; could you build a house where a very loud stereo couldn't be heard even in the same room? Imagine the sales pitch to sell a house with rooms like that to families with kids and teenagers.
That's a good trick, but I want you to isolate and invert the type2 spin field that scientists can't find, the one that unifies field theory, and then make a dark room that is lighted by... nothing.
@@lindaedvardsson4218 Thank you too. I was looking at particle physics and noticed that there's no anti photon. There's an anti particle for every other kind of particle, I think. They say that there is a type2 spin particle or a type2 spin field that they can't find, but they are pretty sure it must exist. I think whatever or wherever it is, it has to be there for light to shine. It is essentially darkness, just... dark, ness. If it is a field and it were inverted, then a dark room would be lit up, when there's no light. But would a light make that room dark? Hmmmm...
@@lindaedvardsson4218 if Nassim Haramein and his Resonance Academy are correct, space has super fluid qualities, and the entire universe obeys the conditions of a black hole. The entire universe is Inside a black hole. So you might guess that things are somewhat backwards, maybe. If the normal inside the hole is darkness, the norm outside might be light. Which would be strange, light, everywhere. Can you think of a place they describe like that? Think... up... ^
@@alanmalcheski8882 wow.. Yes.. I have to look that up😅.. da*n there are interesting things.. and We know so little.. It is much bigger than so.. Thank You for all info and so.. Gold👌🏼 👋🏼☺️🇸🇪 (new sub on Your channel😉)
Could be used to build a shorter path corridor to prevent the transmission of a shock wave, such as from an explosion, provided the external material were dense or absorbant enough, reducing cost and construction time, interesting
For future reference, "besides" and "other" don't mix, because the "besides" already _means_ "other..." something. So if you use a "besides," then the thing to be listed should go without an "other."
@@DaP84 if the spiral is big enough, like infinitly big and it continues to loose light on each time it goes round eventually it would have zero light... 🤔
Heard about this before, but it's really cool to see a real life example! I suppose the obvious question is what is the class of apl unilluminable rooms and what mathematical properties they have.
This should work with anything that have wave-like properties. What your seeing is the waves reflecting off the curved wall. The range of angles that allow light to reflect off the wall and toward the other wall are selective enough that it just can't reach into certain places. Sort of like how a parabola will reflect all of a waves towards it's focal point no matter where you place the source.
Given that a point source of light is actually not physically possible, it was nice to see the demonstration. What would be very interesting is to have the point of view of bing in the dark zones. We can see the light reflect off the paper, so if we were stood in the dark zone we would see the paper, meaning it’s not truly dark where we would be standing
2:26 When he said ”He had actually found a room with a shape such as…”, I imagined sir Roger Penrose roaming the world with a lightbulb - barging in, testing the room, grunting and moving on to the next one…
Back when *real* scientists did *real science*, when the only medicine is mercury and zeros are witchcaft
/s
Having a good chuckle at this!
hahah xD
Even better if he didn't say anything or give anyone context to why he was doing what he was doing 🤣
I am SO happy to see this thing built in real life!
I always thought it would be utterly amazing to be in a normal sized version of this room, with a fixed light in the center. If you walked into one of the square areas:
How does the light disappear?
What do you see now?
Does the square room on the opposite side appear really close or far away?
This would be the coolest museum exhibit ever.
If it were designed properly you might ONLY be able to see the light refracting off dust particles and the like in the air while you are standing in the dark potions. Sort of like seeing a laser beam from the side. That would be amazing
isn't light in the other box?
center is visible from everywhere
Wouldn’t it just be like standing in the shade lol
@@justmayhem771 No it would be different. In the shade light is still refracting to your eyes off the grass or whatever. In the dark spots of this room, there would be almost NO light refracting to your eyes
You wouldn't see the illuminated parts of the room
@@coltenh581 my brain is too smooth for this
I never would have thought this was possible, but it does make a lot of sense. So cool!
SCIENCE!!
But what if it had a curved ceiling and floor?
How does he mathematically prove it? It’s easy to see, but I imagine the proof involves calculus…
Yeah lil🐢
@@medohendawy1155 it's mathematic not science
Really cool!
I was just expecting a room painted with the black 2.0 or other extremely black paints shown on this channel (which would make it's walls close to illuminable, but not entirely). I never taught of the idea that a room with mirrors could get truly illuminable in some areas, by having the right shape to only reflect light in certain angles...
not being a gammar nazi, just trying to help out: i believe it's "unilluminable"
what's the ... for
@@Green_Bean_Machine .... .....
Fun fact: you can use the phrase "unilluminable room" as a sobriety test.
Criminal animal
Indubitably
Jokes on you! I only slurred my speech at "subiety test"
Guess I'm never sober. Even my thoughts are stuttering at the mere presence of the phrase "unilluminable room"
FALSE! I am completely sober and I cannot say it, OFFICER!
You always have something totally unique and new to show!
And it's always so simple, he never uses pricey props.
I already knew about this before this video :)
I only needed to see the title and knew whose video it was.
His thumbnails and titles are so clickbaity , however I have never been disappointed once and have always learnt something new
@@erstwhilegrubstake yuuuuuuuuuuuuu7uuyyyyyyuuyyyuu7u7uuuyyyuuuuu
How amazing it is, that one of my favorite science youtuber, Steve Mould, sent me over to watch another of my favorite youtubers. I love the science youtube community. It's so collaborative!!!
Okay that is interesting. Now I want to know if you can make an aluminum unilluminable illuminati room?
So the unilluminable room gets made of solid aluminum, and on the floor is the illuminati symbol
@@BazukinBelyugovich Better on the ceiling, eye in the sky and all that.
Ladle ladle ladle ladle ladle ladle ladle ladle ladle ladle ladle ladle ladle ladle ladle ladle ladle ladle ladle ladle ladle ladle this isn’t as much fun as when i was 8mos old…
Came from Steve Mould's video. Thank you so much for posting this. Any time I try to look into this topic, all the search engine hits just explain what the room is, but nobody has any demonstrations on how this works with real-life light rays.
4:15 Experiment with water is even more intriguing. How can waves travel in one direction like a laser without disturbing adjacent molecules of water, what happens at the interface between still and wavy water, is it progressive or abrupt ? Is the shape of the mirrors acting like a wave guide or a lens or like a filter or are they causing destructive interferences ? As it something to do with caustics maybe? 🤔
Interesting enough light and water are similar I remember a long time ago there was some sort of experiment that showed light behaves in both wavelengths and particles like water. Something like that I suppose
Light is also a wave, so they both have the same properties.
The mirrors act like a wave guide, they really don't do anything but to stop/guide the wave.
so, it is not exactly the same, due to the fact that water diffracts much more easily than light, the waves in water will reach every corner of the room. They both diffract, but water is much better at it. Light will also reach every corner of the room because of diffraction, but the amount of light is so small that it is negligible especially compared to the waves
the wave leaks into the unilluminable region a bit due to energy dissipation, but it decays to nothing.
As C Fandey pointed out the waves will spread, so it is not abrupt. It was more of mathematical question with idealized rays of light
A scaled up version of this would make for an epic theme park attraction
“There are two other solutions…” I like his you resisted in saying “Neither of which work as well or are as elegant an the Penrose solution” 😉👍
I was honestly hoping to see a demonstration. The idea that you could have a point of darkness in the middle of one of the ends of a room that is otherwise illuminated is fascinating.
@@Ck87JF A point is infinitely small so you wouldn't see it. Also the light source needs to be infinetly small so those solutions can't be observed in the real world.
yeah and now we know he's gonna make this room again but bigger so he would be able to go in. We'll see it sooner or later. He just loves making rooms. Also really curious how would sound work in this room.
sound would be an interesting one, especially if this was actual room sized and you could walk around and hear the different volumes (or not hear it at all). Im guessing it would work exactly like the waves in the water did.
Sound would be much more leaky than light, which cannot easily penetrate the wall materials.
This is a great idea. Also it would be interesting to see how it behaves with mirror floor and ceiling whether other parts would get more light, if that is the case - sound shouldn't be heard there too or silence. Adding reflective surface is definitely going to impact it, since atm it leaks out the top.
wonderful idea. I was wondering what one would see standing in unilluminated part and looking towards the illuminated part. We are used to that light scatters at all directions usually from regular non mirror walls so that even when we are in unilluminated part we still get some light so we can observe the illuminated part. But if all walls are ideal mirrors then it would be like looking into darkness. Just walk one step further and suddenly you see all the illuminated parts of the mirror room. Sounds ridiculous. Or am I missing something?
@@andriusk5044In the scenario you described person standing in an illuminated area wouldnt see dark areas, because by definition light from those places couldn't reach him... I think so
I now have the determination to reorganize my house with Mirrors all reflecting off one light to fully illuminate my entire house. STONKS!
Keep in mind that the intensity fades over distance travels.
And then you could have the lights turn on/off in specific rooms simply by moving or blocking a mirror
This was a legit bronze age technic
Welcome back to the bronze age brother.
@@hogandromgool2062 Would save money tho on electric bill
Interesting that this shape looks remarkable like the warp coil in the Star Trek universe.
@Kim You may be on to something there!
In a light speed engine the desparity between light and darkness ...blah ...blah ...something ... manipulating light. So far we've learned how to bend light and even slow it down but for some reason, we just can't go FTL. Even despite the fact that scientists recently discovered that we ...our entire galaxy and the space it's in is already moving faster than the speed of light. Contrary to Einstein's predictions we are not spaghettified are we? I think the speghettfication part of his prediction is just an optical illusion.
I was thinking that exact thing.
*Its crazy how much scientists have worked to get to a point/theory , which is available to us at a click of a mouse button*
We're truly standing on the shoulders of giants.
Seeing a real Penrose room model it is very cool to see that it actually works. I gotta ask though, does this mean if you stand at the bottomof one, would you not be able to see the light at all?
Yes. In an idealized scenario with nothing to scatter/bend the light (both the surface of the walls and the medium the light passes through) zero photons would enter your eyes and you would not even see the other parts of the room. I’d be interested in how it looks in the illuminated part assuming perfect 100% reflection. But again, everything would have to be ideal, including your body and eyes and retinas in the illuminated field to truly experience that effect. Wait.. even in that scenario you would not see any of the walls, only yourself.. wait but you would see any photons that scatter off of your body into your eyes, plus photons that scatter off your body and reflect off the walls back into your eyes. Which would eventually be coming from every point of the walls… so what the hell would you see?
You would actually. Nils berglund has the animation that shows that diffraction will lead some of the light towards the unilluminable room. And by some it's very little.
I think this might help. If you stick the light into one of the top corners, it lights up the floor for that top ellipse. If you're standing in the bottom-center, you will be in darkness and (in perfect conditions) won't be able to see yourself, but you could see the floor at the top of the room. I think based on perspective, you wouldn't be able to see the wall, or it would be very faint, since it's mirroring your location. If your friend was standing in the lit portion of the room, you could see them but they couldn't see you.
Think of it another way: if you've ever been in a large completely dark room with a door open to another room which is lit up, you could see the other room but not yourself or your room (except toward the door where light leaks in).
@@khaphorarex6796 Incorrect.
Because light waves (observed photons) grow they propagate to the "hidden" spaces. Mathematically it is true, but with real light waves, this doesn't work.
First time you didn't explain why it is like this. Maybe you could add this. This is the best part of your videos. This way around it is just like a "magic show", you know.
What about sound? I know that sound would travel through 3D space instead of a "2D plane" but it should be possible still right? I imagine that maybe you could try making a "penrose ellipsoid" maybe? Although now that I think about it the water example is technically the same thing just with a nearly uncompressible fluid. Yeah, I'm not terribly sure how well that would work. I should look into the physics myself probably, I think I'm hitting a wall with my current understanding of this.
Muffler
@@louf7178 I guess that works but I was thinking more of a shape that doesn't allow sound waves to go to a certain region of it, rather than cancelling out and dampening sound waves. The way a muffler works is pretty cool though.
(Edit: Now that I think about it I don't really know much about the physics of the shape in the video, It could be causing some destructive interference with the waves in the water example.)
Damn this is really too interesting. Just think about music festivals in a giant room like this or a bed shaped in this position. If the other person would turn their night light on (for sure since there is a person it woukd reflect but i think not this much) you could turn the light on without disturbing your partner.
Would be so cool to see this room in normal size
Guys it already exists, in various places of italy (and probably the world, its stuff fro roman empire) there is a half elliptic walls that go corner to corner of a place, if 2 guys are on the 2 ends of it, they can clearly hear their voices even with a loud crowd talking (because you need to be in that specific spot only for the waves to get brought on the other side) pretty cool to try
@@SToXC_. Not really the same thing? That shows how a parabolic can be used to focus sound, but doesn't show there are areas it can never reach. FWIW there are various science museums that have this demonstration with parabolic reflectors.
Nils Berglund has some nice simulations on this topic but this is the first time I’ve seen such a well done and ingenious practical demonstration . only James could demo this so cleverly ! Well done !
I would love to see it in action actually, since this is mostly in 2D, I would like tosee it with the floor and ceiling with the mirrors. :)
This was a really fascinating video, both with light and with water. What further intrigues me is wondering if this would also work with sound?
Sure. No reason for it not.
@@johnnicholson8811 Sound can easily diffract around the corners, so it would spread around the entire room. This is a thought experiment and light is being idealized as simple rays
The room of a true gamer
I really liked your transparent comment about your website... You made a single simple statement that you "sell" experiment kits on your website... It just seemed so blunt and honest; Zero marketing or sales pitching.... It was very refreshing. You're a true UA-cam gem! My wife is a teacher, so im gonna send her over to your website to see if she could use any of your products! Im sure many others feel the same and are following suit! Bravo!
ETA: She wanted the Extreme Garage Science for Kids book... Scooped it on Amazon! Her kids are gonna love it!!!
Would this be true if the floor and ceiling were mirrors?
if there is a storm and it cut off the lights, you can use a unilluminable room make the light visible
Sir Roger Penrose -- an incredible visual imagination!
He invented the Penrose Impossible Triangle, the Never-ending Staircase (with his father), Penrose Non-Repeating Tiles, the Unilluminable Room.
PLUS getting the Nobel Prize for Physics in 2020 for proving that Black Holes MUST exist -- another feat that required HIS visual imagination.
What a hero!!!
also Penrose chicken
Now there is always a dark spot for the monsters to hide...
But this is only for 2d. What if the floor and ceiling were mirrored too? Isn't that the point?
Just as your fully illuminable room was mirrored on all sides.
Just what I thought too!
Yeah i need answers
That wouldn't make a difference. A flat mirrored floor/ceiling would just bounce it in such a way that if you looked at it from above, it would still appear 2D and have the same effect.
@@protox4 it would create a significant amount of variables that would change the outcome drastically.
Currently so much light is escaping for all kinds if angles, its possible a ceiling would reflect them back down to bounces that would reach those previously dark areas.
@@satay71 No, it's not possible if the walls are 90 degrees from the floor and ceiling. Think of pointing a laser between parallel mirrors. Does that make the laser take a left/right turn? No, it doesn't, it just keeps going straight while bouncing up and down.
We should use this geometry to help buffer incoming tsunami waves from vulnerable coastlines
Thank you for the amazing videos. Iam getting interested in chemistry more and more because of your videos☺️
If you're getting interested in what he does he's more of a physicist than a chemist. He understands the physics of chemistry more than the chemistry of chemistry if that makes any sense.
Bro this is physics experiment
🙃
I know I wanted to say about his chemistry videos
@@xd2456 Iam not talking about this one video
@@Moonlightglitter his chemistry videos are still mostly about the physical reaction tho is what I'm saying. He doesn't get into chemical formulas which is really what chemistry is. He does like a hybrid of chemistry and physics but focusing on the physical reactions moreso than breaking down the chemistry.
David Castro was in the undergraduate geometry course I taught at Macalester C. when he improved Tokarsky's result. Of course Tokarsky gets major credit for finding a polygonal solution -- but it was very nice to see a young student improve on it, with fewer sides, and nice to see that his discovery is noted.
Next challenge: can you make box with walls made entirely of lenses that perfectly creates “blind spots” or “points of invisibility” such that an object inside is not visible for that specific location inside the box from all angles that you view this “lens box”? This would be a perfect “box of invisibility”.
of course you could, havent you seen the "invisibility" shields that already function in the same manner? But those are meant to be movable, and that ability reduces how well the "invisibility" actually works, if it were made of static lenses that were specifically design to hide a single stationary point then I imagine it would be even easier to make and much more effective
@@SpydersByte So where would the photons that bounce off the item go then? I know of the Lubor lens but for all directions.
How does this relate to sound? I love that you did the test with water as imo when dealing with sound water and air are similar.
I've taught classes in what I considered to be an "unilluminable" room before, but for different reasons. Penrose was a true genius.
Penrose IS (still alive)
Thanks again for all the great and educational videos!
Hey,
I wonder what the effect would be if the room was purely elliptical, with mirror walls, and the light source was placed on one of the ellipse's focal points?
Would another object in the room be illuminated from only one direction? Similar to the totally black room?
nils bergund on youtube
The Penrose Room doesn't always have to be the semi elliptical shape that gets used as a physics model, it can have different orientations, as long as the light from the light source doesn't go past the top or bottom half when turned on in one of these.
Cool! Shout out to Steve Mould!
Ruby Rod Laser was my first childhood science fair project, this brings back memories.
But, why isn't the roof of the room also covered with a mirror? It's amazing by the way, your demonstration...
Because the floor also isn't. It's a diffused floor, the roof is open and thus all light can get in. But he's in a dark room so theres no light coming in.
So for the purpose of better demonstration, he could cover the roof and floor of that room with mirror and place a camera inside it and see what happens... Because it seems plossible that some extra light reflection might happen...
Technically, there is no need to cover the roof since this room has no change in the height dimension. Every ray that will reflect from the roof is already traced by the existing rays. Since the roof and the floor are parallel, any ray that will reflect off them would not affect the x or y position of the light particle and just the z so we can effectively ignore it.
@@htetmyatanglet's assume the light source to be spherical like the sun. Then, I can totally imagine the rays bouncing-off of the roof at an angle and hitting the walls (sides) of the room.
Yes, I came to make that comment. You beat me to it. Seems like light hitting the roof would be able to go down and illuminate some of the room. Maybe more than once. But when he did the software program, did that do a 2D or 3D simulation?
I love to see this room from the inside or even better a big version to go inside.
I would say a Discord mod's cave is pretty unilluminable too.
A room of mirrors that doesn't fill the whole room with light? Okay, that is bonkers!
This is so cool, and that water demonstration was illuminating 😊
I see this as a good application for boat in a dock. Usually the motion of the ocean will pull and push the boat so they basically need to tie it. But if the waves get stopped by this shape the boats wouldn’t move much.
i had these thoughts in my head, similar to how light spreads in a room. I was up late one night, something like 3am, and i have a small lamp. I can move this lamp head, to pivot, and angle differently. I wanted to light up my room without lighting up the underneath of my door, and though of a few things, like putting the lamp in a closet, and the doors would stop the light from reaching my door, but then i have a smaller area lit up as well.
of course, in the end, i just covered the door with clothes and sheets to keep both air and light inside.
air and light? sounds like someone is up late smoking out the window at their parent's house :'D
@@SpydersByte lol That's a classic
Sounds like you need a towel along the bottom of the door to me
This guy is out here unlocking secrets to the time/space illusion.
Hey Action Lab, could you please try putting laser in closed mirror room where light illuminates all part? Will laser illuminate entire room too?
hmm, laser beams don't spread out like light does so you'd need something to diffract it, that would be cool but i think it would be like a light in a big room like he mentioned not that brightly lit
use difraction gratings to modify the light patterns, light transfer patterns
Wait. I'm a bit confused. The experiment was done by having most of the "room" covered in mirrors. But what about the "ceiling"? I thought it was supposed to have the whole room mirrored..
If you project the light rays going in an arbitrary 3D direction onto 2D, they will have the same trajectory as 2D light rays in this model. So you can just put flat mirrors on the floor and ceiling and it will still be unilluminable in 3D.
@@digama0 ceiling and floor must be painted black
@@janami-dharmam No, they can be mirrors too, as long as they are flat. As long as the mirrors are flat, light going in a random direction which bounces off the floor will only be redirected in the Z direction, not X and Y, so if you project to the X-Y plane it is as though it didn't bounce at all.
@@digama0 wrong; study the first law of reflection
@@janami-dharmam sigh, you have to give me more than that to help. Let's say that a light ray is traveling in the direction of vector v = (x,y,z), and hits the flat mirrored floor (say z = 0). The light will be redirected in the Z direction, resulting in a new direction vector (x,y,-z), making an equal angle with the floor outgoing as incoming in accordance with the second law of reflection. Now consider projecting these vectors into the X-Y plane, which is to say ignoring the Z coordinate. The original vector is (x,y) after projection and the new vector is also (x,y), which is just as though it didn't hit anything at all. (To use an analogy, if you bounce a ball on the floor, the bounce will not be visible from a directly overhead view unless there is something funny on the ground to send the ball careening off in the wrong direction.)
You referenced the first law of reflection, which says that the incident ray, reflected ray, and the normal to the surface all lie in the same plane. This is true here: the incident vector (x,y,z), reflected vector (x,y,-z), and the surface normal (0,0,1) all lie in the same plane, the vertical plane spanned by the (x,y,0) and (0,0,1) vectors. The 2D projection of this plane is just the line in the (x,y) direction, i.e. the light cannot leave the line while bouncing off the floor. (It can of course leave this line when it hits the side walls, but that's just the same analysis as for the 2D Penrose room.)
DEPENDING ON THE REFRACTING angles (angle of the mirrors) , thickness , quality of the mirror and the specific angle of the light.
Its just feedback. You have a general direction where you want it to go, then use curvature to redirect it if it strays out of that direction.
May I suggest an idea ive had for a long while but never did anything with? What if you can invent a solar cooker/boiler of some sort where there are lenses in there which can keep light inside a ring or something. Like imagine using magnets to confine plasma in a tokamak, but here its just a trap that wont let ambient light that enters to exit the device unless the light fully turns into heat and then maybe heat up water or something. But before it turns to heat, there should be a region with a very high concentration of light that is maintained that way. If boiling temperatures can be achieve this might be interesting. It would be much more harder to achieve full boiling throughout the solar cooker box using the sun. But to get a tiny spot 100Celcius it might ease it a bit. With a normal lens, it needs to be controlled to ensure the point of light doesnt burn something you dont want. With the light confinement, its passive and should work in any orientation
A life size room like that would be very relaxing
This is a great video! My only comment is that a "control" room, a different shape of mirrors, would be an informative comparison!
And this is EXACTLY why Action Lab is where the party is at.
This guy is FREAKING genius..how easily he explained that thing..just wow😲
luv your videos buddy..😊🙂
To be fair there was no explanation. That was a demonstration.
Comment above is right there's no explanation lol
your water wave demonstration blew my mind!
Interesting. Would be cool to experiment and see if this could be used in some sort of cloaking technology.
we already have cloaking devices that work because of lenses that bend light in certain directions, plenty of videos of them up here on youtube. They only really work for hiding vertical objects on a background of mostly horizontal scenery though and I dont think theyll ever get much better
i need to see this in that simulator software. i can't understand why those spots won't get illuminated.
Is there a way to do the test with mirrored floors and ceilings too? I really want to know if that can effect the results.
with flat mirror floor and ceiling you will most likely get it completely illuminated, making a 2d room with dark spots is relatively easy, you can reach it with trial and error on the simulator he had shown
but a 3D mirror room with dark spots is a completely different story, you need much more complex math i guess
Oh man that 2 point mutually unilluminable room would have been sick to see in person
Great project! Im looking for a source of the high quality stick on mirror that you used. Any help would be appreciated.
It looks like aluminum sheet metal tape used to seal joints in HVAC systems. Just carefully applied.
@@jimmurphy6095 looks too highly polished for that, i think its likely thin plastic or card with some kind of coating because the convex curves have a perfect mirror finish but the concave curves are a little scrunched in places.
if it is ali tape ill be very impressed with action lab lol.
This kind of room design could also make a good reinforced room with the entrances being the two entry points on each side. Tachtically it would make it a nightmare for either side to try and hit an enemy opponent flank you, presuming there is no way around from the other side of each entry way. The round inner protrusions would deflect rounds effectively meaning it would also make it safe if taking cover from the entry ways.
Also another challenge, build this into a room that you can crawl into. Make every wall floor and ceiling ellipse shaped. (Note that this particular object has a flat ceiling and flat floor and that might influence the optics to not be entirely unilluminable.)
"What did you see in the unilluminable room?"
"Flat-earthers."
Question. If Sodium metal reacts with water which is composed of hydrogen and oxygen, why doesn't it react so violently with air which contains both of those? Does it have something to do with waters adhesive properties?
Just a guess, it might relate to the products. Sodium oxide slows down the diffusion of oxygen but sodium hydroxide dissolves away, allowing for more contact with water.
@@henrytang2203 yeah. That’s a good guess. I believe aluminum forms a coat of aluminum oxide on its surface preventing it from further reaction.
Over here from Steve Mould's video on the same subject who suggested your video is worth a watch as well.
Hey, Action Lab, I live in Utah, (pretty close to you)
I love science, is there anyway at all I can help you make your projects?
I'll do anything to help you, I love you're channel.
If I can't help you, I will still watch every one of your videos cause I love science and I love your videos.
I'm so sorry I forgot your name, I have memory problems.
I will even do research for you for free. I just wanna help.
Nice! Brilliant idea to try it with water. Obvious next step, scale up to house size..? The acoustics should be interesting.
That's a fascinating idea; could you build a house where a very loud stereo couldn't be heard even in the same room? Imagine the sales pitch to sell a house with rooms like that to families with kids and teenagers.
That's a good trick, but I want you to isolate and invert the type2 spin field that scientists can't find, the one that unifies field theory, and then make a dark room that is lighted by... nothing.
This sounds very interesting.. Hope He does that.. Thank You❣️ 👋🏼☺️🇸🇪
@@lindaedvardsson4218 Thank you too. I was looking at particle physics and noticed that there's no anti photon. There's an anti particle for every other kind of particle, I think. They say that there is a type2 spin particle or a type2 spin field that they can't find, but they are pretty sure it must exist. I think whatever or wherever it is, it has to be there for light to shine. It is essentially darkness, just... dark, ness. If it is a field and it were inverted, then a dark room would be lit up, when there's no light. But would a light make that room dark? Hmmmm...
@@alanmalcheski8882 wow.. Yes.. valid question and very interesting.. for sure hope He does a vid of Your request..👏🏼☺️
@@lindaedvardsson4218 if Nassim Haramein and his Resonance Academy are correct, space has super fluid qualities, and the entire universe obeys the conditions of a black hole. The entire universe is Inside a black hole. So you might guess that things are somewhat backwards, maybe. If the normal inside the hole is darkness, the norm outside might be light. Which would be strange, light, everywhere. Can you think of a place they describe like that? Think... up... ^
@@alanmalcheski8882 wow.. Yes.. I have to look that up😅.. da*n there are interesting things.. and We know so little.. It is much bigger than so.. Thank You for all info and so.. Gold👌🏼 👋🏼☺️🇸🇪 (new sub on Your channel😉)
That section of the video where you show yourself in the room of mirrors. Is perplexing.
legends say only eminem is capable of saying _aluminum unilluminable_ 10 times in 5 seconds
Bet you'll find ancient ports where the surrounding land follows unilluminable room rules.
Cool, is the shape used to optimize shape of sea ports to reduce the waves getting into the basin?
Could be used to build a shorter path corridor to prevent the transmission of a shock wave, such as from an explosion, provided the external material were dense or absorbant enough, reducing cost and construction time, interesting
I was more impressed that a mirrored room will be lit no matter what shape it is. An unilluminable room, on the other hand, is just a room!
For future reference, "besides" and "other" don't mix, because the "besides" already _means_ "other..." something. So if you use a "besides," then the thing to be listed should go without an "other."
This is some Dr.Strange stuff.
ive always pointed flashlights at the ceilings to light up a room when i have a power outage but this is pretty cool
How would this work with sound waves? Could you get dead spots in a room similarly?
Got the VSauce swag I see
It would look really cool with the water example if you dropped in a drop of food coloring next to the motor!
Well, now I can't sleep before you build a real lifesize replica of such a room.
“It’s amazing this even works with water” he keeps going hehe Great videos!
When I heard Penrose, my first thought was "Ah, yes, of course it was him". His mind must have been working in polygons since his birth.
The text: Unilluminable room
My brain: illuminati room
Makes you want to walk into a room size version of this without mirrors and experience how it messes with the sounds and echos
What about a spiral shape? Maybe that would work where the light is bright and then fades into darkness?
Nah, that would illuminate evenly!
@@DaP84 if the spiral is big enough, like infinitly big and it continues to loose light on each time it goes round eventually it would have zero light... 🤔
didn't know this was a problem that needed a solution ...
A room that can be illuminated is called an illuminable room.
A room that can not be illuminated is called an illuminati room.
Thank God someone spent the time to create a room that can't be lit with just one light. Phew.
Are there applications of this for sound? A soundproof room? Or for ocean wave barriers etc.
My former perfect house design was a collection of circular domes. Now it's a collection of ellipses.
Heard about this before, but it's really cool to see a real life example!
I suppose the obvious question is what is the class of apl unilluminable rooms and what mathematical properties they have.
This should work with anything that have wave-like properties. What your seeing is the waves reflecting off the curved wall. The range of angles that allow light to reflect off the wall and toward the other wall are selective enough that it just can't reach into certain places. Sort of like how a parabola will reflect all of a waves towards it's focal point no matter where you place the source.
The two last examples are not "mirrored" in the way that the first shape is. The elipse shape is impressive because it's all uniform.
The most difficult thing was to say the word 'unilluminable' multiple times and correctly.
Thank your action lab guy for teaching me more about physics than I ever learned at school
Given that a point source of light is actually not physically possible, it was nice to see the demonstration. What would be very interesting is to have the point of view of bing in the dark zones. We can see the light reflect off the paper, so if we were stood in the dark zone we would see the paper, meaning it’s not truly dark where we would be standing