I made a comment above correcting his math and errors. I'm one of the biggest fans of Wren's videos because he answers simple mechanical problems and does it on such an interesting way that one can show it to students and colleagues. I'm a mechanical engineer myself but I think there are too many comments by now for him to find mine that corrects the math.
I love his energy in these. So happy, full of enthusiasm, and it shows in his facial expressions and hand movements. It's a joy to watch his joy I guess
loved the Sims inspired reaction to the fire: 1) sees fire; 2) has an external reaction (oh no ! lifts hands); 3) approaches the fire without extinguisher or safety equipment and just are stressed in front of it
As someone who has been working in optometry and ophthalmology for 18 years, when Wren started talking about refraction, material index, focal point, etc, I got a little excited because I understood everything he was saying for once.
I feel like this is a Wren Mythbusters moment. "Aw, I didn't get the result I wanted. Let me invent a scenario where I DO get the result I want." Seriously, though, good stuff, man. Felt like I was watching a very well-produced science show.
This is the great video with so many scientific detail. But I think you forget "the penetration depth effect". Transparent object does absorb light too. For example, 10 meters of seawater will absorb about 75% of sunlight. Glass absorb light better than water because it is denser. So, moon-size glass ball's thickness will literally absorb all light before the light can penetrate the moon-size glass. I can't find and data about hydrogen gas but don't think light can penetrate 100,000+ km of hydrogen. There are so many hydrogen atom there. It is very likely that the photon will hit hydrogen atom there multiple times, again and again, until the photon get totally absorb.
Understanding the science behind all of this is one thing, but being able to explain it so concisely and easy to understand like Wren does is a huge talent in itself
Steal like an author, my friend. Your words are unique and your story will show your ideas in a unique way. There really aren’t any new ideas. All great authors took inspiration from other places. Don’t be afraid to write something just because someone else has a similar thought! If that were the case I would’ve given up writing immediately!
In the Troy Rising series a guy uses a series of space mirrors to cheaply mine asteroids before using that same network to melt the ships of an invading fleet because at that point, the difference between "mining laser" and "anti-ship laser" is what you call your laser. And for any pedants out there, the whole "it's not really a laser" thing is brought up and dismissed because the guy who named the network of mirrors is explicitly using the colloquial definition of "laser", a "focused beam of light".
@@DaSuDanesi yeah, a fusion drive like in the Expanse would act like a massive cutting torch; there were several times in the books where they are careful to keep their drives pointed away from other ships so as not to melt them.
Is the point of the series to use old Greek/Roman stuff but in a sci fi setting? The title mentions Troy, and you've just described what's essentially an Archimedes ray
Schlock Mercenary did it too, using Earth's ring of controllable mirrors to burn Dom Atlantis (which then forced Dom Atlantis to put up shields which trapped everyone inside which was the actual goal...) This similarity isn't too surprising given the history of how Troy Rising came to be, though, is it?
@@erichurst7897 The Kzinti incident is specifically a failure of intelligence: The Kzinti did have access to an advanced means of gathering intelligence on a ship before attacking, but the only question they thought to ask is "Does this ship have any weaponry?" The answer came back as a firm no, so they attacked. They never thought to ask if the ship had any non-weapon systems which would be easy to repurpose as a weapon.
8:50 that's actually a reused clip from another video of his. Reusing clips helps with production cost, production speed, and most of the time nobody even notices. Keep up the great work!
Yes, even if glass was something like 99.999% transparent, as the glass becomes thicker it absorbs more light, and if the glass was thick enough it would end up absorbing all the light.
This was a fun video to watch. Using some of the stuff I learned in my college physics classes. Nice to see the applications outside of the textbook. Love this.
So I can confirm. I experienced a full eclipse of the sun and one of the things that struck me the most and was not ready for, was just how quick it turned cold. The eclipse happened on a sunny day too... but that made no difference at all. Was freaky.
I experienced that too. The temperature just plummeted from late summer-ish 80s to what felt like mid-fall 60s. And the crickets started freaking out, which doesn't happen when it's ACTUALLY mid-fall. I didn't even particularly care about the diamond ring in the sky anymore; the world just stopped making sense for a couple minutes, and it was fascinating.
That's because the ground is very good at absorbing heat radiation but not very good at retaining it. So once the source of heat radiation was removed, the ground quickly cooled down, thus cooling the surrounding air
@@user-rl4tg2mr9n Roads retain heat rather well however. At my old house there were about 10 cats within a very small area. If you went out at like 2am when there were no cars on the road it wasn't uncommon to see groups of cats lying on the still warm tarmac.
@@bigsmall246 True, that will absolutely make a difference. But it's even more pronounced. In fact, I failed to mention, that coldness creeps in before the eclipse is even full. It's like the cold is an entity (as hippy as that may sound). And regardless, it's not only _very_ cold, but the speed at which it switches is something that just doesn't happen "naturally". Or maybe better said: doesn't happen in nature, outside of an eclipse. In seconds it turns *really* cold (regardless of weather it was hot before). (and I live in a country with heavy winters) You'd imagine that maybe some heat would be stored, or something similar... at least I did.
Even more disappointing is that glass isn't perfectly transparent, even low iron glass has an absorption coefficient of ~0.015 cm-1 (every centimeter of glass will absorb 1.5% of the light's intensity, more or less). By the time you get to more than a few meters of glass you've basically got a completely opaque material, even if it's glass. You'd get a normal eclipse because the moon would simply be opaque like normal. EDIT: @AgentX2006 did the math and it turns out that you'd no longer be able to see the Sun at around 20 meters thickness.
This can't be correct as I'm almost certain sea water with all it's suspended particulate matter blocks more light than glass, and it allows sunlight to be visible to almost 900m down. Per NOAA: Under water (where light decreases 10 fold with every 75 m of descent), the human eye theoretically can detect light down to almost 900 m.
@@AgentX2006the moon diameter is about 3500km, that's many times 900m. So, still possible that a glass moon is fairly opaque, compared to 900m of sea water.
After you asked the first question of what would happen, I figured it would focus the light before the earth. But that glass eclipse is quite the revelation and frankly AMAZING! Like a giant window into the 180 lens at the location of the moon. Incredible!
Not a lot of "sciencey" stuff gets me worked up but this video and all the questions and answers genuinely got me super excited from how awesome it was. And no I don't know a better way to word it lol
An interesting companion video is "Magnifying The World's Brightest Flashlight" by The Action Lab. No matter how hard you focus the light, you'll never get hotter than the origin. Great work again Wren on mixing CGI and real world questions.
Well, that makes perfect sense. You only have as much energy as you started with. All magnification does is focus energy that'd normally be spread out onto a much smaller point. It shows just how much energy the sun is constantly pouring down on earth when you can melt metal with a lens no bigger a person's wingspan.
@@AirLancer It's not about energy it's about thermal equilibrium, the reason it can't get hotter is because if it did then the Earth would be heating the sun. Magnification is a two way street.
@@MOSMASTERINGit would violate the second law of thermodynamics. If you had a situation where you could make heat flow from the Sun to an area that’s hotter than the Sun then you‘d be getting heat to flow from cold to hot without expending energy which violates that rule. The smallest point that you can focus down to if you use all the light from the source is the same size as the source. If you want to focus to a smaller point than that then you have to lose some light and therefore energy. It’s called the conservation of entendu.
@@MOSMASTERING let's think of a magnifying glass and a solar panel together. The solar panel can only catch the light that hits it, and will convert that into its equivalent power (with loss as the panel heats up, but let's ignore that for now) The magnifying glass just squeezes that light like a funnel. It can still only put out as much energy as it's put in, so while it might be "hotter" since it's more focused, but it still only has as much power as the surface area can catch.
Wren, you're my favorite on this channel. Love your passion and ability to break down complex topics into these easy to digest and fun to learn episodes.
I remember in my 8th-grade science class we watched a video about carbon, and at one point they used one of those magnifying glasses at 1:36 to make a diamond pop into a puff of smoke.
What about heat losses? The light has to travel through over 3 thousand kilometers of glass. With each meter, the power falls exponentially... If anything, a glass moon would appear as a black sphere, not as a shiny crystal ball.
Not even a little bit. Crematoria is impossible. Any planet close enough to its star that it reaches 700 degrees during the day would not even cool to a survivable temperature with a ~26 hour night cycle at the equator, never mind fluctuating so wildly that it has has an instant freezing effect within minutes of the sun setting. Even if there was no atmosphere at all (which there is on Crematoria) it would take more than a few minutes for a 700 degree surface to reach the absolute zero of space.
This is such an awesome video produced with so much love and creativity. I feel so personally invested in this video doing well for some odd unexplainable reason
You have a calculating mistake in the very beginning! I'm trying to explain with an example. What you are really doing is increasing the power density (that is the the amount of energy deposited in a unit area over a unit time). This generally causes a rapid increase in local temperature since energy is deposited faster than it can diffuse into the surrounding material and ultimately the air. Normal, unmagnified sunlight has a power density of about 1.4kW/m^2. What the lens does is collect the energy from a larger area and shrink it to a much smaller point. Let's say we have 3" handheld magnifying glass, and it focuses light down to a circle about 1/16" across. The total energy collected by the lens is 7.069in^2 x 1.4kW/m^2 = 6.385 W. This power is concentrated into a region of area of 0.0031 in^2, so the density is 3,226 kW/m^2 in that small region. In general, the total power delivered to the focal point scales with the area of the magnifying glass. That means you only need ~41% larger glass (by diameter) to get double the heat transfer. The power density depends on how well focused the lens can get, and is equal to 1.4kW/m^2 x (rlens/rpoint)^2 . So if the focal point is 100x smaller (by diameter) than the actual lens, the energy density is 100^2 =10,000x higher than it is in normal sunlight. Furthermore, an often overlooked fact. If the moon would be a perfect set magnifying glass, the moon itself would melt immediteltly at the tip. Even if glass absorbs very little energy/temperature when light passes through, in the end it does and will be enough to melt the focal point of the moon, therefore destroying the magnifying glass in an instant. German mechanical engineer here. If found part of this answer on reddit and copied it, after I did the math. I came to a different solution but in the end both solutions speak the same language. The magnifying glass comparison in the beginning is wrong. The moon melting point I did on my own. I will write it down in a later edit.
i was wondering what would happen if moon wasnt glass sphere but flat surface glass (like giant magnifying glass). so if i understand you correctly, the moon glass would melt, because glass cant hold such high temperature? but lets say that it wouldnt melt, would then earth get vaporized?
@@nagolici3206 I think that even if such light burst hit earth for a moment, the point of focused light would firstly heat earth atmosphere so much that the pressure of gas would increase instantly cousing pressure wave to destroy everything on its way. It woud also melt earth crust and cause upper mantle to magma flood the continent. The light from the sun also contains infrared light (more than 50%) which have lower dispersion angle but (BUT!) everything depends on glass compound. Some types of glass are more transparent to IR than others.
Wouldn't the enormous thickness of the glass Moon also affect the result? When the Sun's radiation travels through the 3 475 km of glass, it would suffer quite a bit of losses.
doesnt conservation of etendue limit the heat at each point inside the glass moon to the surface temperature of the sun? (it should actually be way below that) And the focal point should also be limited by that. The focal point shouldn't exceed the surface temps of the sun either
@@thatrandomspaceguy to be fair Corridors react videos are the only ones I watch. As much informative as entertaining. But that is not the standard for those styles at all.
So I am pursing grad degree in physics with focus on photonics and there is cool effect/s you forgot that limit how much light can actually be focused. As you focus light more and more, more energy is contained in smaller space and eventually this can destroy or heat up material until it can not focus light. Secondly, that focused energy can exert pressure and/or interfere with itself on itself that causes it to de-focus or expand outwards again. Thirdly, there is strange quantum uncertainty that goes up when you super-focus light that makes exact positions lesser known. All these effects, esp. first two are important in systems that use really high energy or focused light we make on earth, often these systems either blow up, can only work for nano-seconds or less, and/or are limited do to this. No material I believe known could really focus light at that scale
Xkcd covered this in his what if book. Long story short- you cannot take all of the light from a source and focus it into a smaller area to make that area hotter than the source. This defies the second law of thermodynamics.
The video also ignores the fact that glass has an absorption coefficient. I would think that after a kilometer or so, any light would be be completely absorbed and the glass sphere would be effectively as opaque as rock.
Two things: above about 200atm pressure the ideal gas law generates errors, so you have to modify the equation. (Real gas eq) Also: a heated thing can only get as hot as the heating Element, for the sun about 5k Celsius. See „What if…“, but i Love the Video 👍😊
John Ringo's Troy Rising trilogy uses huge arrays of mirrors in space, focused to make mining lasers (which also double up as weapons against alien invaders)
Nitpick but at 2:26, the temperature wouldn't increase by 4000 °C every second. You cannot direct sunlight with a lens to heat something up to a higher temperature than the surface of the Sun. You'd be violating the second law of thermodynamics otherwise because you'd be transferring heat from a colder object to a hotter one without spending energy, as the lens is passive. So the temperature would be capped at 5600 °C.
Using hydrogen to light up the planet has got to be the biggest form of gaslighting.
Take my vote and skedaddle.😊
💀💀
Or helium
I see what you did there!
Haha
I love how Wren´s show makes me feel like a kid again. Really captures that Bill Nye type of show
I made a comment above correcting his math and errors.
I'm one of the biggest fans of Wren's videos because he answers simple mechanical problems and does it on such an interesting way that one can show it to students and colleagues. I'm a mechanical engineer myself but I think there are too many comments by now for him to find mine that corrects the math.
I feel like it shows what a little kid HE still is, which has its own charm!
@@BlueFlash215we found it! interesting stuff!
I love his energy in these. So happy, full of enthusiasm, and it shows in his facial expressions and hand movements. It's a joy to watch his joy I guess
I said something similar, always love these kinds of videos he makes
loved the Sims inspired reaction to the fire: 1) sees fire; 2) has an external reaction (oh no ! lifts hands); 3) approaches the fire without extinguisher or safety equipment and just are stressed in front of it
Is in the middle of the fire and STAY inside the fire until told to get out of the fire or until they die.
And there was a fire extinguisher on the wall right next to him!
As someone who has been working in optometry and ophthalmology for 18 years, when Wren started talking about refraction, material index, focal point, etc, I got a little excited because I understood everything he was saying for once.
"Angle of incidence."
"Ooh, yeah, baby, talk dirty to me."
I felt exactly the same way 😂
I learned that in high school physics.
AS SOMEONE WHO IS A 18 YEAR OLD 12 STANDARD INDIAN STUDENT , I UNDERSTOOD EVERYTHING HE WAS SAYING FOR ONCE..
Medical physicist here, and loved seeing him come to the conclusion about the shadow cause
I can honestly say I have never ever wondered what would happen if the Moon was made of glass.
Clearly
I wondered about moon being made of steel
Pun intended?@@titheproven954
You don't need to be super smart to know what would happen...... Like have any of you ever burned ants with magnifying glass.
@@Barrett_Jesus finish the video mate
That visualization of the glass moon shrinking the sun to a dot is SO COOL! That definitely wasn't what I expected
I like how wren is slowly turning into photoreal kurzgesagt, it's a good evolution
Hopefully without the globalist propaganda
Hopefully without the globalist propaganda though
But hopefully without the globalist propaganda
too late he's already the entirety of the kurzgesagt team
I’d love to see a channel dedicated to that
I feel like this is a Wren Mythbusters moment. "Aw, I didn't get the result I wanted. Let me invent a scenario where I DO get the result I want." Seriously, though, good stuff, man. Felt like I was watching a very well-produced science show.
This is the great video with so many scientific detail. But I think you forget "the penetration depth effect". Transparent object does absorb light too. For example, 10 meters of seawater will absorb about 75% of sunlight. Glass absorb light better than water because it is denser. So, moon-size glass ball's thickness will literally absorb all light before the light can penetrate the moon-size glass. I can't find and data about hydrogen gas but don't think light can penetrate 100,000+ km of hydrogen. There are so many hydrogen atom there. It is very likely that the photon will hit hydrogen atom there multiple times, again and again, until the photon get totally absorb.
Understanding the science behind all of this is one thing, but being able to explain it so concisely and easy to understand like Wren does is a huge talent in itself
I appreciate your use of Moonlight Sonata.
Me too.
Was looking for this comment
yeah but what version exactly and by what artist? I wanna know!!
@@frankleblanc8730 It's in the description of the video
Now I know why I have that song in my head after watching lol
This is probably the coolest science video Wren has done yet. This one is just mind melting, no pun intended
This really gives new meaning to "glassing" a planet
HALO
HALO
R.I.P Mandalore
Wasn't Reach glassed and Africa nuked in the Halo Universe?
@@theradlad5615 Yeah. Except if i remember correctly, It wasn't a nuke in Africa. A ship jumped to slipspace close to the ground
Love when Wren does his stand-alone videos.
Especially loved the "Wrender" joke when his computer was rendering.
It's an open secret at this point that Wren himself is responsible for all the rendering, the computer is merely along for the ride.
I smell an unhealthy amount of dad jokes around this video
@@Pale_Kingg You can NEVER have too many "Dad Jokes", signed A Dad.
I only wanna come here to say that the shot of Wren's eyes inside the zeros at 2:00 did not go unnoticed. Made me chuckle.
I was just writting a short story about aliens having nightmares about eclipses at their home planet. Screw that now.
Sounds a little like Nightfall by Asimov.
@@yugytomm -_- Well, screw me then.
@@skivernatnjilten493 Back to the writing board! lol. Nah, write it anyway brotha.
Steal like an author, my friend. Your words are unique and your story will show your ideas in a unique way. There really aren’t any new ideas. All great authors took inspiration from other places. Don’t be afraid to write something just because someone else has a similar thought! If that were the case I would’ve given up writing immediately!
@@yugytommyou beat me to it.
In the Troy Rising series a guy uses a series of space mirrors to cheaply mine asteroids before using that same network to melt the ships of an invading fleet because at that point, the difference between "mining laser" and "anti-ship laser" is what you call your laser. And for any pedants out there, the whole "it's not really a laser" thing is brought up and dismissed because the guy who named the network of mirrors is explicitly using the colloquial definition of "laser", a "focused beam of light".
Reminds me of the Kzinti Lesson: If your spacecraft's reaction drive is efficient enough, your vessel is never disarmed unless totally disabled.
@@DaSuDanesi yeah, a fusion drive like in the Expanse would act like a massive cutting torch; there were several times in the books where they are careful to keep their drives pointed away from other ships so as not to melt them.
Is the point of the series to use old Greek/Roman stuff but in a sci fi setting? The title mentions Troy, and you've just described what's essentially an Archimedes ray
Schlock Mercenary did it too, using Earth's ring of controllable mirrors to burn Dom Atlantis (which then forced Dom Atlantis to put up shields which trapped everyone inside which was the actual goal...)
This similarity isn't too surprising given the history of how Troy Rising came to be, though, is it?
@@erichurst7897 The Kzinti incident is specifically a failure of intelligence: The Kzinti did have access to an advanced means of gathering intelligence on a ship before attacking, but the only question they thought to ask is "Does this ship have any weaponry?" The answer came back as a firm no, so they attacked. They never thought to ask if the ship had any non-weapon systems which would be easy to repurpose as a weapon.
8:50 that's actually a reused clip from another video of his. Reusing clips helps with production cost, production speed, and most of the time nobody even notices. Keep up the great work!
When the glass moon casted a regular shadow, I was expecting the awnser to be "no material can stay translucent at such a large scale."
Yes, even if glass was something like 99.999% transparent, as the glass becomes thicker it absorbs more light, and if the glass was thick enough it would end up absorbing all the light.
@@userjames2009 I wonder if the edge would be interesting. It would be thin enough to still transmit light.
I guess you could then see a bright ring that fades towards the center. Like in inside out event horizon observed from the outside.
@@marcusrauch4223 Perhaps it's similar to what a White Hole could look like
technically refraction is only considered when entering and leaving the material, so if the moon was 100% glass it would still work
Near the end:
Aliens: WRITE THAT DOWN WRITE THAT DOWN
Who's the more advanced civilization now?
Humans - 1, Aliens - 0
Solar focus weapon is actually common in Scifi
Guess we know the plot of Independence Day 3 now, lol 😂
This was a fun video to watch. Using some of the stuff I learned in my college physics classes. Nice to see the applications outside of the textbook. Love this.
So I can confirm. I experienced a full eclipse of the sun and one of the things that struck me the most and was not ready for, was just how quick it turned cold. The eclipse happened on a sunny day too... but that made no difference at all. Was freaky.
I experienced that too. The temperature just plummeted from late summer-ish 80s to what felt like mid-fall 60s. And the crickets started freaking out, which doesn't happen when it's ACTUALLY mid-fall. I didn't even particularly care about the diamond ring in the sky anymore; the world just stopped making sense for a couple minutes, and it was fascinating.
That's because the ground is very good at absorbing heat radiation but not very good at retaining it.
So once the source of heat radiation was removed, the ground quickly cooled down, thus cooling the surrounding air
@@user-rl4tg2mr9n Roads retain heat rather well however. At my old house there were about 10 cats within a very small area. If you went out at like 2am when there were no cars on the road it wasn't uncommon to see groups of cats lying on the still warm tarmac.
A sunny day would make the temperature effect more extreme compared to e.g. a cloudy day where you're not getting much sun in the first place
@@bigsmall246 True, that will absolutely make a difference. But it's even more pronounced. In fact, I failed to mention, that coldness creeps in before the eclipse is even full. It's like the cold is an entity (as hippy as that may sound). And regardless, it's not only _very_ cold, but the speed at which it switches is something that just doesn't happen "naturally". Or maybe better said: doesn't happen in nature, outside of an eclipse. In seconds it turns *really* cold (regardless of weather it was hot before). (and I live in a country with heavy winters)
You'd imagine that maybe some heat would be stored, or something similar... at least I did.
You already KNOW the video is going to be amazing when Wren has a weird idea
09:57 love that crashing lens y'all added.
Even more disappointing is that glass isn't perfectly transparent, even low iron glass has an absorption coefficient of ~0.015 cm-1 (every centimeter of glass will absorb 1.5% of the light's intensity, more or less). By the time you get to more than a few meters of glass you've basically got a completely opaque material, even if it's glass. You'd get a normal eclipse because the moon would simply be opaque like normal.
EDIT: @AgentX2006 did the math and it turns out that you'd no longer be able to see the Sun at around 20 meters thickness.
Yeah I was expecting that to be the first "disappointment", and then ignore the absorption for the rest of the video, still cool tho
This can't be correct as I'm almost certain sea water with all it's suspended particulate matter blocks more light than glass, and it allows sunlight to be visible to almost 900m down.
Per NOAA: Under water (where light decreases 10 fold with every 75 m of descent), the human eye theoretically can detect light down to almost 900 m.
@@AgentX2006the moon diameter is about 3500km, that's many times 900m. So, still possible that a glass moon is fairly opaque, compared to 900m of sea water.
@@bastienK That's true. That is definitely enough to do it. I just focused on the few meters of glass being opaque as being incorrect.
I would guess the compressed hydrogen would look like dense upholstery foam.
the editing in this was fantastic, super compelling :D i love when wren has ideas like this and gets into the physics of everything!
What is the moon made of?
Apollo: “GLASC”
Thanks for shining a light on this
your profile only makes it better
@@ZigCade Shine on you crazy death ray
With the dark side of the moon. What a guy.
After you asked the first question of what would happen, I figured it would focus the light before the earth. But that glass eclipse is quite the revelation and frankly AMAZING! Like a giant window into the 180 lens at the location of the moon. Incredible!
Not a lot of "sciencey" stuff gets me worked up but this video and all the questions and answers genuinely got me super excited from how awesome it was. And no I don't know a better way to word it lol
"That's no moon, its a giant magnifying glass!"
"It's too big to be a giant magnifying glass!"
basically what the death star was lmao
@@Elloliott they DID use Kyber crystals after all, like many magnifying glasses...
"Now witness the power of this armed and FULLY OPERATIONAL hydrogen focusing sphere!"
I would of went with glass station, but I'm glad someone said it 👍
Collapsing Gas Giant Death Ray is one of the coolest sci fi weapons I've heard of, nice work!
The mighty C2GDR, it even sounds properly sci-fi 😂
This episode was shot fantastically... *Claps* Thank you for your hard work making it look so good!
That was Enlightening.
Under a Glass Moon. One of my favorite Dream Theater's song.
Wren could have just played the song and saved so much work. 😂
oh there you are
Thanks, I was looking for this comment
was looking for a comment about this lol
It’s not too late for Wren to make a visualizer for the Images and Words tour.
I like the usage of the "Moonlight Sonata" at 12:00
Another brilliant video. I completely enjoyed every second that did not have background music in it.
lmfao
Yeah, this guy is one lab accident away from becoming a super villain.
Please don't stop making these videos, it's like the modern more intense Bill Nye The Science Guy
2:36 The Statue of Skeleton was a nice touch. 😂
Haha yeah I love sneaky gimmicks like that
Liberty and Freedom gone ☹︎
This sounds like an idea that came up during a tabletop campaign.
Like an idea Liu Cixin would come up with
3:48 Debby there: *yay I’m in the simulation!!!!*
In the words of former Corridor intern Mark, "SPACE IS SO COOOOOOOL!"
*Um, ACKTSHYUALLY*
An interesting companion video is "Magnifying The World's Brightest Flashlight" by The Action Lab. No matter how hard you focus the light, you'll never get hotter than the origin.
Great work again Wren on mixing CGI and real world questions.
Well, that makes perfect sense. You only have as much energy as you started with. All magnification does is focus energy that'd normally be spread out onto a much smaller point.
It shows just how much energy the sun is constantly pouring down on earth when you can melt metal with a lens no bigger a person's wingspan.
@@AirLancer It's not about energy it's about thermal equilibrium, the reason it can't get hotter is because if it did then the Earth would be heating the sun. Magnification is a two way street.
Really? Even if the source is not super bright, but VERY large and you focus that into a small point? That would be hotter than the origin, no?
@@MOSMASTERINGit would violate the second law of thermodynamics. If you had a situation where you could make heat flow from the Sun to an area that’s hotter than the Sun then you‘d be getting heat to flow from cold to hot without expending energy which violates that rule. The smallest point that you can focus down to if you use all the light from the source is the same size as the source. If you want to focus to a smaller point than that then you have to lose some light and therefore energy. It’s called the conservation of entendu.
@@MOSMASTERING let's think of a magnifying glass and a solar panel together. The solar panel can only catch the light that hits it, and will convert that into its equivalent power (with loss as the panel heats up, but let's ignore that for now)
The magnifying glass just squeezes that light like a funnel. It can still only put out as much energy as it's put in, so while it might be "hotter" since it's more focused, but it still only has as much power as the surface area can catch.
These are my favorite Corridor videos. Keep up the awesome work!
Wren, you're my favorite on this channel. Love your passion and ability to break down complex topics into these easy to digest and fun to learn episodes.
Feels wren had a lot of fun making this vid in particular
I remember in my 8th-grade science class we watched a video about carbon, and at one point they used one of those magnifying glasses at 1:36 to make a diamond pop into a puff of smoke.
I love these! Never stop making them, Wren!
What about heat losses?
The light has to travel through over 3 thousand kilometers of glass. With each meter, the power falls exponentially...
If anything, a glass moon would appear as a black sphere, not as a shiny crystal ball.
Keeping the temperature in the studio at a very nice 69°F 👌
So basically Crematoria from the Riddick movies.
Not even a little bit. Crematoria is impossible. Any planet close enough to its star that it reaches 700 degrees during the day would not even cool to a survivable temperature with a ~26 hour night cycle at the equator, never mind fluctuating so wildly that it has has an instant freezing effect within minutes of the sun setting. Even if there was no atmosphere at all (which there is on Crematoria) it would take more than a few minutes for a 700 degree surface to reach the absolute zero of space.
@@Hugh_Jas it's possible in the Riddick universe though
This is such an awesome video produced with so much love and creativity. I feel so personally invested in this video doing well for some odd unexplainable reason
"literally throwing shade" is hilarious
You have a calculating mistake in the very beginning! I'm trying to explain with an example.
What you are really doing is increasing the power density (that is the the amount of energy deposited in a unit area over a unit time). This generally causes a rapid increase in local temperature since energy is deposited faster than it can diffuse into the surrounding material and ultimately the air. Normal, unmagnified sunlight has a power density of about 1.4kW/m^2. What the lens does is collect the energy from a larger area and shrink it to a much smaller point. Let's say we have 3" handheld magnifying glass, and it focuses light down to a circle about 1/16" across. The total energy collected by the lens is 7.069in^2 x 1.4kW/m^2 = 6.385 W. This power is concentrated into a region of area of 0.0031 in^2, so the density is 3,226 kW/m^2 in that small region.
In general, the total power delivered to the focal point scales with the area of the magnifying glass. That means you only need ~41% larger glass (by diameter) to get double the heat transfer. The power density depends on how well focused the lens can get, and is equal to 1.4kW/m^2 x (rlens/rpoint)^2 . So if the focal point is 100x smaller (by diameter) than the actual lens, the energy density is 100^2 =10,000x higher than it is in normal sunlight.
Furthermore, an often overlooked fact. If the moon would be a perfect set magnifying glass, the moon itself would melt immediteltly at the tip. Even if glass absorbs very little energy/temperature when light passes through, in the end it does and will be enough to melt the focal point of the moon, therefore destroying the magnifying glass in an instant.
German mechanical engineer here. If found part of this answer on reddit and copied it, after I did the math. I came to a different solution but in the end both solutions speak the same language. The magnifying glass comparison in the beginning is wrong.
The moon melting point I did on my own. I will write it down in a later edit.
ohh interesting! thanks for the correction!
i was wondering what would happen if moon wasnt glass sphere but flat surface glass (like giant magnifying glass). so if i understand you correctly, the moon glass would melt, because glass cant hold such high temperature? but lets say that it wouldnt melt, would then earth get vaporized?
@@nagolici3206 I think that even if such light burst hit earth for a moment, the point of focused light would firstly heat earth atmosphere so much that the pressure of gas would increase instantly cousing pressure wave to destroy everything on its way. It woud also melt earth crust and cause upper mantle to magma flood the continent.
The light from the sun also contains infrared light (more than 50%) which have lower dispersion angle but (BUT!) everything depends on glass compound. Some types of glass are more transparent to IR than others.
Wouldn't the enormous thickness of the glass Moon also affect the result? When the Sun's radiation travels through the 3 475 km of glass, it would suffer quite a bit of losses.
doesnt conservation of etendue limit the heat at each point inside the glass moon to the surface temperature of the sun? (it should actually be way below that) And the focal point should also be limited by that. The focal point shouldn't exceed the surface temps of the sun either
Wren (& Crew), I love how much passion you put into these projects. Keep up the great work and stay curious!
That was the smooth transition into an advertisement i've EVER seen
I miss old vids like this, cuz nowadays there's only reacts and recreation videos, which are boring. These are masterpieces
@@thatrandomspaceguy to be fair Corridors react videos are the only ones I watch. As much informative as entertaining. But that is not the standard for those styles at all.
Why miss them, they are still on here, right?
8:56 this part made me laught real hard 😂😂😂lol
"It's so beautiful!"
[DEATH SOUND]
1:55 modern car headlights belike
I think you made a mistake at 2:30. The temperature wouldn't go higher than 5600 K because that is the temperature of the light source (the sun).
It took way too much scrolling, to get to this comment.
So what you're telling me is that we 𝘴𝘩𝘰𝘶𝘭𝘥𝘯'𝘵 turn the entire moon into glass?
Well dammit there go my weekend plans.
"Ferb, I know what we're doing today!"
Bro is answering a question we never even asked but I'm glad he did
So I am pursing grad degree in physics with focus on photonics and there is cool effect/s you forgot that limit how much light can actually be focused. As you focus light more and more, more energy is contained in smaller space and eventually this can destroy or heat up material until it can not focus light. Secondly, that focused energy can exert pressure and/or interfere with itself on itself that causes it to de-focus or expand outwards again. Thirdly, there is strange quantum uncertainty that goes up when you super-focus light that makes exact positions lesser known. All these effects, esp. first two are important in systems that use really high energy or focused light we make on earth, often these systems either blow up, can only work for nano-seconds or less, and/or are limited do to this. No material I believe known could really focus light at that scale
What about gravity? Could an alien species with a gravity based warp tech use said warp tech to focus light?
Xkcd covered this in his what if book. Long story short- you cannot take all of the light from a source and focus it into a smaller area to make that area hotter than the source. This defies the second law of thermodynamics.
The video also ignores the fact that glass has an absorption coefficient. I would think that after a kilometer or so, any light would be be completely absorbed and the glass sphere would be effectively as opaque as rock.
Given the transmittance of glass, would a 3500km glass moon even let any appreciable amount of sunlight through?
@@eccles99 this VFX video also says the moon is made of glass.
11:44 the mondscheinsonate (moonlight sonata) in the background was subtle, but noticed 🌙 😁👍 (oh, it gets louder later, cool 😁)
gonna call magnifying glasses "photonic funnels" from here on to confuse everyone around me
Wren's curiosity videos are amazing, he needs his own series for sure!
ohoho wren blocks out the light on the moon nice detail
The glass, smoke and laser demos were so cool!!! Wren is like the best science teacher we never had in high school
brilliant video, my favourite kind of Corridor uploads. thank you Wren
The gass thing really sounds like a neat idea for planetary defense. Just make it a mirror
Please do more of these; the informative subject matter mixed with CGI visuals is a fresh change to the channel.
Two things: above about 200atm pressure the ideal gas law generates errors, so you have to modify the equation. (Real gas eq)
Also: a heated thing can only get as hot as the heating Element, for the sun about 5k Celsius. See „What if…“, but i Love the Video 👍😊
Your best presented explainer yet, Wren- thank you!
This has officially become my favorite series on this channel. Thanks Wren!
3:34 Casually makes the coolest thing I've ever seen and wipes it back away for science
Underrated comment
Very good explanations of refraction in this video!
When I was in middle school, I made a death ray using the exact process you guys did. To see that I was correct on how it would work is CRAZY to me.
Another banger from Wren! This sorta gives me Vsauce "What if the Moon was a Disco Ball?" vibes, but on steroids lol
John Ringo's Troy Rising trilogy uses huge arrays of mirrors in space, focused to make mining lasers (which also double up as weapons against alien invaders)
It’s actually spectacular how Wren manages to keep my attention. His speaking is for these types of videos is sooo good
2:51 a villian has born
10:39 is spoken like a true physicist
I love that I learn both about how VFX is done, but also get a physics lesson. Lots of humor too. Keep up the good work guys.
Love love love these Wren videos! They are so much fun :D
0:32 poor computer 😭
"its so beautiful" *disappears*
2:34 this scene is from the show "star trek enterprise" if anyone was wondering when the xindis attack earth in late season 2 or early 3
YES I'M NOT THE ONLY ONE
@@LinusSegueRatings hot take star trek enterprise season 3 was the best *season* of any star trek ever
@@electricminecrafter not even a hot take, it was amazing.
For me it's a toss up between ENT and DS9
5:34 skip sponsor with this
I always love Wren's enthusiasm.
8:03 Nobody talking bout the portal gun?
Underrated comment
The question I’ve never thought of but actually needed to be answered 😅
I wish my teachers were this enthusiastic about science… great job wren
Well now we know what it will feel like when the covenant finally attacks
0:47 This is what happens to Wren when he inhales too much helium.
He thinks helium is cocaine
Nitpick but at 2:26, the temperature wouldn't increase by 4000 °C every second. You cannot direct sunlight with a lens to heat something up to a higher temperature than the surface of the Sun. You'd be violating the second law of thermodynamics otherwise because you'd be transferring heat from a colder object to a hotter one without spending energy, as the lens is passive. So the temperature would be capped at 5600 °C.
Due to a thing I learned about yesterday, the Conservation of Etendue might get in the way.
covenant glassing beam ahh moon
Just noticed CC started this ... This honestly brings me back.. i sense Bill Nye vibes and this helps my brain ...
0:23 - it's fine!