But what if we tried MORE power?

[@NarlepoaxIII]

"If a beam of light gets too bright, space itself stops being transparent." That's a hell of a thing to drop so casually.

[@davidharshman7645]

Definitely my learned fact of the day...

[@thomasjetzer2823]

Well, that's basically the problem with superluminal travel, isn't it? If you speed up an object with mass to a fast enough velocity, the enormous accelleration from your spaceship bends space-time to such a degree that you essentially start getting space-drag. This provides resistance to further accelleration like air drag in atmosphere.

[@maxek46]

I think I want that on a t-shirt.

[@NOT_A_ROBOT]

​@@thomasjetzer2823That isn't really due to spacetime curvature. You're thinking of the increased perceived mass due to relativistic effects.

[@Jason9637]

​@@thomasjetzer2823That is not at all how special relativity works. From your perspective you can always keep accelerating, but to an outside observer you will approach the speed of light.

[@notme222]

My brain was already struggling with the idea of photons creating a gravitational field. "Space itself stops being transparent" just broke it.

[@Grauenwolf]

It's something they think about when doing Big Bang calculations. If you look up the timeline there's actually an entry for when the universe stopped being opaque.

[@SimonClarkstone]

The universe bechming transparent was a different phenomenon. It was mundane high-temperature gas cooling down, no more extreme than the glowing gas in some sorts of lighting (e.g. flourescent tubes or candles).

[@MrSottho]

My guess is that it works like air pressure, there's a limit to how much stuff you can pack together before it starts interacting with itself.

[@Grauenwolf]

@SimonClarkstone 380,000 years is when the universe became transparent. Before that particles and light were "coupled". I'll leave it to you to figure out what than means. I, unfortunately, have chores to run.

[@thedoom523]

E= mc^2. Anything with energy has apparent mass and mass generates gravity. This isn't real mass, which is referred to as rest mass, but instead due to having energy.

[@ripp_]

So like how we have "welcome to high voltage where everything is a conductor" we now have "welcome to high laser power where SPACE IS OPAQUE"

[@EEEEEEEE]

E‎

[@Llortnerof]

Isn't that basically the same as "everything is a pipe when the pressure is high enough"?

[@Tyron-sd9hg]

@@Llortnerofyes, and the pipe ended in a wall

[@alansmithee419]

@@Llortnerof I don't know why but that just sounds like a threat lol.

[@lXlDarKSuoLlXl]

More like "welcome to high laser power, where the tip is always a black hole" 😂

[@mjsvitek]

3:48 my sadness is immeasurable and my day is ruined.

[@hrishikeshaggrawal]

I went "literally 1984"

[@AstonKwok]

Sorry that your day is ruined. But surely sadness can be measured?

[@Bluhbear]

@@AstonKwok I've never seen it done.

[@alexyz9430]

I never expected the answer to "what could possibly stop you from making a stronger laser?" to be "at some point the laser would be so powerful that it'd spontaneously generate a wall to stop itself." 😨

[@notenoughmice]

it's got restraint

[@lordgrub12345]

​@@notenoughmice good for the laser!

[@captainufo4587]

Certain things are so stupid that the universe itself has to do an intervention to make people stop.

[@jackuval9362]

game devs putting in absurdly high hard limits thinking players would never encounter them, but just in case they do

[@fiskehandler]

So, it becomes a lightsaber!

[@unflexian]

Also it might be good to mention that 2*10^44 Watts is 2*10^44 Joules per second, which due to E=mc^2 is equivalent to 2.2*10^27 kg/s of pure mass being converted to energy, or about *ONE EARTH PER MILLISECOND*

[@tanveer_badar_]

Yikes

[@djinn666]

So you're saying we could run it for one millisecond?

[@tanveer_badar_]

@@djinn666 Less than that. Energy conversion is almost never 100% efficient.

[@feuby8480]

wow that's some kind of sick explanation. I wondered how powerfull it was, but like vaporizing the earth into energy for running it 1 milisecond is just...

[@foogod4237]

I'm going to start thinking of all energy consumption / power numbers in terms of "earths per (milli)second" now.. ("This is a 1.858e-39 earths-per-second space heater.")

[@jasonnorman-hodges3471]

"Why did the laser stop?" "Oh that, It spontaneously" "turned into physical matter"

[@tonyth9240]

E=mc^2 works both ways. So if you have too much energy, it becomes matter. So yeah, that literally is what happens, and it slightly breaks my brain too.

[@devoof]

​@@tonyth9240we just broke physics

[@pauldeddens5349]

@@tonyth9240 The math checks out, you just gotta move around the variables. M = EC^2 Mass does also equal the speed of light squared times energy. And well, since light doesnt have too much energy, you need _alot_ of it.

[@penguinflames707]

@@tonyth9240what kind of matter would pure energy be though?

[@tonyth9240]

@@penguinflames707 From my understanding, any matter is just solidified energy, so it could be anything. I think this goes beyond my understanding and imagination.

[@dovahgamer9689]

i love the idea of the universe basically going "oh no you don't - STOP IT NOW" when you go to far on the fuck around and find out scale

[@LimeyLassen]

It reminds me of the water hammer effect in pipes.

[@sashaboydcom]

it's fine with us destroying ourselves, but not other planets

[@Bozothcow]

"A telescope is a death-ray running in reverse." I'm gonna remember that one.

[@ErrorTH]

flashlight instead of an eyepiece transforms your telescope into a projector, pretty fun

[@captainshelf7]

This is why you DONT want to use it to look at the sun

[@Bozothcow]

Yes true hahaha

[@Monkaehbutgameromg]

i just put my telescope that can look hundreds of billions of light years away, and i accidentally blew up 40 galaxys, was that supposed to happen?

[@glenm99]

Suddenly my nerd degree seems way more hardcore.

[@socalminstrel]

"If a beam of light gets too bright, space itself stops being transparent." Also, if you pack too much light into an area, it'll collapse into a black hole. A black hole created this way is called a kugelblitz. But of course, the effect mentioned in the video would happen way earlier.

[@darkmatter21_xx]

Pretty sure a Kugelblitz can't exist in nature. There are quantum effects that prevent light itself from achieving the concentration necessary to form an event horizon. As far as transparency goes, if one area becomes too dense with energy gravity takes over forming a black hole so no light would pass through that area

[@EEEEEEEE]

E‎ ‎

[@GardenData61371]

A​@@EEEEEEEE

[@maythesciencebewithyou]

You should also mention that there are different things called Kugelblitz and this is not what is usually referred to as a Kugelblitz. What you are talking about is better called a Geon.

[@socalminstrel]

​@@maythesciencebewithyou I'm not talking about a geon. A geon is still a wave, just held in a localized area by its own gravitation. The classic concept of a kugelblitz is so much energy (it doesn't have to be light, specifically) in an area that it collapses into a black hole. It's analogous to a normal black hole, except with "too much" energy in a space to prevent gravitational collapse, rather than mass. Since there's equivalence between mass and energy, either one can cause gravitational collapse.

[@lucianoardanazsgalla8630]

3:25 i hate when devs put absurd limitacion like that and then just says "quantum physics" and hope nobody notice

[@ensiehsafary7633]

Please tell me you didn't mean limitation with limitacion because that's just another level of typo

[@BeaglzRok1]

Dev notes straight up saying that such damage output has to be nerfed to shorter range and putting in a check to spawn force fields when DPS exceeds a threshold. No wonder people think this is a simulation.

[@M___X_]

​@@ensiehsafary7633 English isn't everyone's first language.

[@Sean_735]

@@ensiehsafary7633 It is spelled limitacion in Spanish

[@XplosivDS]

​@@ensiehsafary7633 Most likely they speak Spanish or any other similar language

[@happyvirus6590]

3:44 "A mathematician may say anything he pleases, but a physicist must be at least partially sane." -J.Williard Gibbs

[@K-o-R]

_"[..]space stops being transparent."_ That combination of words just blew my mind.

[@ImSquiggs]

It's unreal that I can spend half a lifetime watching videos on how physics and space works, but there's always some brand-new concept out there that keeps blowing me away. It's so cool to live in the future where all this information about the world around us is just free for the taking.

[@krystina662]

i dunno why but it just makes sense to me, like if you put too much stuff in the same place things will go wrong eventually, and light is stuff in one way or another, right?

[@jamesmeppler6375]

Apparently people who like science really know nothing about it.....what happens if you turn on a light in a pitch black room...you guys surprised its no longer dark? That is essentially what youre surprised about, if youre 5, then sorry. But as someone whose last grade competed was 8th grade, this is so obvious that we shouldn't need to be told..flip a light on and the darkness goes away...wow so challenging lol

[@syrslava705]

Well, now you *do* know that in high enough concentration photons actually interact.

[@shortposeidon]

@@jamesmeppler6375 that's not the point of what he's saying. you're saying, "if you put light somewhere, it gets bright." He's saying "if you put enough light/energy somewhere, you can see space itself." If you turn on your lights and show me where in your room space suddenly gets visible, I'll be very surprised.

[@guymitchell9234]

“You can find a bigger number, But you can’t make a bigger laser :(“ Most relatable :( I’ve seen

[@trollster7133]

Honestly the fact that we only found out about gamma ray bursts from a satellite tracking nuclear explosions is just really funny to think about. Like imagine reading the data and immediately thinking “holy shit aliens exist and all of them have nukes 100x stronger than ours!”

[@Tathanic]

and they are nuking each other right now

[@mightypirat9875]

Conclusion: We need bigger nukes!

[@officiallyaninja]

100x is way way way too small

[@RichWoods23]

@@mightypirat9875 Bigger nukes would be no good without ISBMs to carry them, so you could join in the fun. (Inter-Stellar Ballistic Missiles. But probably not so ballistic.)

[@davidharshman7645]

​@@RichWoods23Luckily, the propulsion issue can be solved by the same research: More efficient, powerful nukes!!! 😂

[@joshuasims5421]

2:37, so what you're saying is, the interstellar planet-destroying laser beam in Star Wars 7 is strangely plausible, given fantasy power generation capabilities.

[@justharmless2319]

The fact that there's a size a which a laser begins to collapse in on itself as it progresses due to gravity implies that there size somewhere between this an regular lasers where the collapse is just barely enough to counteract the diffraction, allowing you to focus on targets way further than optics would otherwise permit

[@r.connor9280]

New sci fi weapon found, and as far as scaling goes, we could built thousands of them firing at dozens of targets at a time Musket Lines of exploding stars erasing worlds from galaxies away, with self correcting laser optics built into the very laws of physics

[@zeux5583]

if the laser is strong enough, it could form a black hole once fired/impacting on target.

[@darkmatter21_xx]

​@@zeux5583highly unlikely. If you had a laser capable of producing Planck frequency / Planck energy beams, the area around the source of the laser would become a black hole. Maybe two separate lasers from opposing angles colliding with each other on a distant target could form a black hole on impact, maybe.

[@AubreyLavigne]

​@@zeux5583This is called a Kugelblitz

[@liorramati265]

I feel like there's a limit on this too. Like, the diffraction is effectively photons emitted at extremely subtly wrong angles, right? And then the idea is that gravity would tilt them back towards the center. Presumably they'd eventually fall into the center, continue past it, and then gravity would start pulling it in the opposite direction. It seems to me like this should somehow sap energy from the photon, even if it's just due to increased probability of colliding with a second photon. Although all of that reasoning is from a very classical perspective and almost certainly doesn't apply

[@sebbes333]

3:36 AHA! So *THAT* is how the Star Wars light-sabers just stops in mid-air ;D

[@Selsato]

Meanwhile the Jedi holding it has become very interesting to theoretical physicists as well

[@sebbes333]

@@Selsato :D

[@pauldeddens5349]

It is hilarious to imagine light sabers as not some form of intense plasma. But rather a _very_ slow laser pointer with such intense energy it literally falls off about 3 feet away from the source.

[@anson7064]

So.. A lightsaber would have to have ~10^27 watts of energy. Enough to ignite the atmosphere on fire and start a nuclear reaction :D

[@mnxs]

​@@SelsatoI wonder what would kill them faster; the gamma-rays from the electron-positron annihilations happening at the tip, or the thermals from firing a nuke-level laser in atmosphere? Either way, it's on the order of milliseconds or shorter, I'd presume.

[@dextonhowell-davis5127]

Absolutely love the professional quality laser sound effects.

[@dziban303]

need that SimCity 2000 power lines bzzz sound effect

[@snjert8406]

​@@dziban303I love how highly specific this is hahaha

[@stephanecloutier181]

I heard the exact sound in my head while reading your comment 😂

[@DracheLehre]

The fact that, at one point, the universe will essentially go, “Okay, just… Just STOP!” Is astounding to me.

[@bridgecross]

"Space itself stops being transparent" Video is worth it for that sentence alone.

[@Phyrre56]

I'm still struggling to visualize what exactly this means. It's like trying to picture something in 5 or 6 dimensions, it just doesn't compute.

[@tylerboothman4496]

@@Phyrre56 I suppose you’d end up recreating the conditions of the very early universe

[@stevegredell1123]

almost as good as "oops we've accidentally made a particle accelerator"

[@88porpoise]

​@@Phyrre56I think you are overthinking it. Those photons contain a ton of energy. Concentrate enough of that energy into a small enough space and it will be converted into matter. That matter will block more of the photons photons causing further concentration and the creation of more matter blocking more photons. There is probably a lot more to it at the detailed level, but I think that covers the basic idea of what is happening.

[@KBRoller]

@@88porpoise Kind of like the doppler effect leading to a sonic boom, but for mass-energy equivalence 😂

[@phlosen7854]

2:25 If NASA would call their Telescopes "inverse Deathrays" they'd get all the funding

[@Ihsnetad]

"If a beam of light gets too bright, space itself stops being transparent" Why does it sound like ancient wisdom?

[@Genny207]

3:47 "You can always make a bigger number..." Yes, but were not gonna talk about just how ridiculously, how unfathomably, how inconceivably large 3↑↑↑↑↑7 is.

[@JHe-f9t]

Psh. It's not as big as 3↑↑↑↑↑8

[@TheConstellationofOnewhostares]

@@JHe-f9t Pathetic, its nothing compared to 3↑↑↑↑↑9

[@Trafficallity]

what does the ↑ mean it might be a tiny fraction of the sh#ts i dont give

[@FriedrichHerschel]

@@Trafficallity Arrow notation. You use it if normal potentiation isn't doing it for you anymore.

[@Yonkage-ik5qb]

Okay but what if I'm just like TREE(99)

[@Muonium1]

For the part described at the end, as the explanation of why infinite power is not possible, this is called the "Schwinger limit" after Julian Schwinger who first derived the e-/e+ creation rates theoretically in the '50s. It's exactly what we've been trying to do at various petawatt (10^15 watts) lasers like the one I work at for some years now, and is called "sparking the vacuum" when done experimentally in the laboratory. We haven't quite been able to reach the e fields necessary to do it yet, but next generation exawatt and zetawatt lasers will very likely be able to achieve it.

[@RichWoods23]

Have any journalists already asked you if that will open a portal to a nightmare world of unholy monsters eager to feast on human souls?

[@RHCole]

"Sparking the Vacuum" is terrifying sounding

[@mcmuinorac5848]

I can now say I know of someone who is actively working to turn space itself non-transparent. This is one of the coolest comments I’ve ever read.

[@whiteeye3453]

So why infinite power is not possible?

[@theaikidoka]

@@RHCole Sparking The Vacuum sounds like an indie band name.

[@kingchamp5923]

The MOST funny thing is I did a college presentation on the first part JUST YESTERDAY, getting a part 2 today is INSANE

[@nascosta1965]

You know, my day would have been a lot better if I didn't know that book sitting on my shelf has been out for 10 years.

[@JHe-f9t]

Depends on if you're over 40 or not...

[@tncorgi92]

I was so happy when my local library picked it up. We need more eye-opening stuff at our library rather than the threadbare romance novels and mysteries.

[@XiaolinDraconis]

@@JHe-f9t GET DOWN THIS MAN IS TAKING SHOTS!

[@SimonClarkstone]

I encounter people 20 years younger than myself at D&D, and I appreciate being able to say "oh actually you're way too young to remember that" occasionally. :-)

[@playgroundchooser]

Right? My knee hurts for no apparent reason now. 😢

[@Sonic-ic4yc]

Laser - "Im so powerful nothing in the universe can stop me!" Fabric of Space - "Fine, i'll do it myself"

[@deseosuho]

I have an undergraduate degree in physics that I don't use in any aspect of my life. I find the the observation that a sufficiently powerful laser makes space opaque to itself to be in the same category of phenomenon as virtual particles and Hawking radiation. It's approximately true to say that in quantum field theory, reality is constantly cheating everywhere in small ways. Entire interactions of exotic particles can come into being and disappear almost instantaneously without anyone noticing. Occasionally along the boundaries of high energy phenomena, that cheating indeterminacy has actual observable consequences.

[@KSignalEingang]

It is a constant source of amazement to me that Heisenberg uncertainty is a basic fact of the universe. When I was first introduced to the idea it was presented as sort of a quirk of measurement - since you have to bounce some amount of energy off the subject to observe it, you're going to wind up altering its trajectory in some small way. That's fine, whatever, makes sense. But, no, it's such a fundamental principle that the universe conspires to make sure that there can never be a perfect vacuum anywhere, just so that we can't even be 100% certain about the presence of *nothing*.

[@macslash5833]

@@KSignalEingang ^ for anyone who doesn't know where heisenbergs uncertainty principle exactly comes from, basically quantum mechanics says that momentum and displacement can be treat as waves, where this comes from is that if you take the fourier transform (in contexts like sound this means finding the frequencies that make up a sound, it kind of works here just don't think too hard about it) of the wave describing position you get the wave describing momentum, the heisenberg uncertainty principle comes from using the fourier transform and is inherent to it! it's literally inherent to the maths that make up quantum mechanics which is an absolutely beautiful fact

[@Rudxain]

@@KSignalEingang And also why "absolute 0 temperature" is impossible, because the position of a "coldest" particle can be determined with infinite certainty

[@Rudxain]

BTW, Darragh Rooney wrote a thesis about the relationship between the Casimir Effect and Hawking Radiation. Allegedly, it's somehow related to quantum-gravity too

[@mnxs]

My tired ADHD brain read this as "underground degree in physics", and in a moment I'd cooked up a vision of a combined Fight Club and Lord of War, but with giant lasers. 😂

[@EPATZ]

1:53 "keep deer out of garden" The deer can't be in the garden if there are no deer left... Or garden for that matter...

[@justineberlein5916]

0:22 Are you sure about that? Because I tried counting all the real numbers from 0 to infinity and ran out before I even reached 1

[@lichh64]

"Actually 👆🤓"

[@Me-0063]

@@lichh64shhhh. Its a good comment

[@aldar8240]

@@lichh64 okay grandpa let's get you to bed

[@Idran]

What was the second number you counted? I want to settle a bet

[@justineberlein5916]

@@Idran I was actually using binary to make things easier, but I decided to start by counting all the decimals with a single 1. So 0.1, 0.01, 0.001, etc. But I ran out of numbers before I got to all the decimals with 2 1s.

[@igiveupfine]

this was honestly, very impressive. i am a little disappointed i never saw something like this on star trek. torres: if we tuned the shield array, to the harmonic frequency of the erupting super nova, we could channel the excess energy to the phaser array tuvok: *eyebrow janeway: torres..... torres: *continues, .....if you have enough concentrated light energy, space ceases to be transparent tuvok: that is, correct torres: we route the excess energy to the phasers and the deflector array, and converge them to........there. it will spontaneously start creating particles and anti particles. we'll close the space time fissure and stop getting all these alternate dimension neelix's janeway and tuvok: *eyebrows tuvok: fascinating

[@ikschrijflangenamen]

This made me smile, thank you

[@DashSpiderJumpscares]

Randall’s catchphrase for what if seems to be “but what if we tried MORE power?”

[@csn583]

I believe it all started with a hairdryer in a cardboard box...

[@acidhelm]

It's a running joke that Hat Guy repeatedly shows up and asks "What if we tried more power?"

[@DryPaperHammerBro]

@@acidhelm *Black Hat

[@Y0gurt123]

When I was learning set theory, my professor demonstrated how quickly things get out of hand when you take the power set of a power set of a power set... comparing math to physics, he said "we have more stuff."

[@KSignalEingang]

Once you check into the Hilbert Hotel, you never check out.

[@zacharyfeely7068]

When he said "no one can stop you" I passively laughed and thought "physics might." Oh how right I was.

[@EEEEEEEE]

E‎

[@Commander_Appo]

(Sets your laser’s power to negative) (Accidentally makes you a bad telescope)

[@longerthanyouthink]

I love how the answer to every question just amounts to "please don't do that"

[@veervishalmishra4526]

"Help, I am trapped in a book cover printing facility"💀 0:03

[@FragFrog01]

Fun fact: that's pretty much what happened right after the big bang. There was SO MUCH energy that some of it spontaneously converted itself into matter (e = mc^2, and all that).

[@chrism3784]

which leads us to a huge mystery when energy is converted back to matter it creates a particle and antiparticle, in equal amounts. Where did all the antimatter go, why we only see matter.

[@theaikidoka]

@@chrism3784 It hasn't necessarily gone, but maybe we aren't looking in the right way. If we weren't, then it would seem as if there were no dark matter.

[@jackirerioa4971]

Do you have a paper on this? Genuinely curious

[@CerealExperimentsMizuki]

​@@chrism3784 its not gone, its just matter that we cannot see as its on a wavelength that our current technology cannot detect, its exotic and the oppoaite of ehat we are made up of. We estimate that almost 95% of the entire Universe is made up of Dark Matter and Eenrgy and everything else is just what we can see. We know that theres Hundreds of Partifles that ee cannot see and can only detect eith specific machines and Dark Matter works the same way. We have such an insanely limited view of the Universe that its amazing that we've even been able to discover what we have.

[@felixroux]

@@theaikidoka Just fyi, dark matter and antimatter are not the same thing. Antimatter is basically identical to regular matter but with opposite charges (so anti-protons are negative and anti-electrons are positive.) Dark matter is a theoretical concept (albeit one that is considered very likely by most physicists) that would account for certain astronomical objects behaving as if they are experiencing a stronger gravitational force than we predict.

[@yeetyeet7070]

wow! this has been insanely educational, even more than the usual videos, probably by an order of magnitude

[@danielhale1]

Tech: Universe says no. Customer: Wait, I thought there were infinite numbers? Does it have an error message? Tech: Nope. It just stops, right there. Universe says no. Customer: ...I'd like to speak to your manager?

[@ItsMrBozToYou]

Manager: "yeah we tried more power once, anyway long story short that's where your universe came from. You're welcome, I guess?"

[@tompw3141]

I understand that a number people over the years have tried to speak to the universe's manager. The results have been mixed.

[@AndreasPeters-r3e]

Threaten your life´s manager with combustible lemons!

[@davidwells5611]

+++ Divide By Cucumber Error. Please Reinstall Universe And Reboot +++

[@danielhale1]

@@tompw3141 The Universe: "I AM THE MANAGER!"

[@core3gamegd587]

0:23 I love how most of the numbers feel big but 3↑↑↑↑7 is just so much bigger that it shouldnt even be grouped with the others xd

[@triacontahedron]

Also has 2^2^2^2^2^2 and (10^1000)!, which both exceed googolplex

[@johonn]

"A telescope is really just a death ray in reverse" is not a sentence I expected to hear today.

[@johnchessant3012]

"space itself stops being transparent" woah

[@theOtherNism]

1:53 Vaporize raindrops to stay dry

[@_fishy]

More like vaporize the atmosphere to stay dry forever

[@sullivan108]

A lower power laser that tracks raindrops and evaporates them before they hit you, like a point-defense umbrella, is a cool idea.

[@philipwilson46]

Nice call back.

[@smugbowkid9919]

More What If is always a treat. Wish the site had been updated with more questions too.

[@h1_Im_Sevak]

"What if? "suggestion: What if the moon was made out of cheese like in those random depictions

[@Sally4th_]

And how big a laser would you need to toast it?

[@emm6064]

John Scalzi has a book out in a few months with exactly that absurd premise. "When the Moon Hits Your Eye"

[@pairofrooks]

surely it would curdle or something, being left out in the sun that long

[@arynica]

Wensleydale

[@Kwyjor]

Probably something similar to the "mole of moles". (Cheese wouldn't be so different from mole meat on that scale, I reckon.)

[@JustinMcBride21x]

"But don't rush out to buy a 10^44 laser just yet." Aw phooey. There go my weekend plans.

[@steemlenn8797]

It's too late anyway. Black Friday is over, you have to wait a year for the sale.

[@jimsvideos7201]

You can’t make a bigger _single_ laser, but that’s why good solar systems have more than one planet 😅

[@krabkit]

yes but you can focus them all at the same spot, at a certain point the universe stops you again by forming a kugelblitz

[@callhimtim3188]

"Parry this you filthy casual"

[@mr.cauliflower3536]

@@krabkit That's the spot you aim at.

[@WaldoHandFord]

“A telescope is just a death ray running in reverse” is actually a beautiful quote about peaceful exploration and curiosity.

[@lekrashar]

Could totally picture Jean-Luc Picard saying this quote out of nowhere lol

[@TehNoobiness]

On the one hand, the laser getting so powerful that it makes a wall of electrons and positrons that blocks the laser is kinda wild, and obviously makes it hard to use the laser part. On the other hand...Would you be able to use the generated particles for anything? I'd imagine that a sudden burst of electrons and positrons appearing on your doorstep would kinda suck. Or be a great way to boil water. Or both!

[@resurgam_b7]

Once you get into physics bending power levels, "use" isn't really on the table anymore. The largest supernovas only sometimes produce energy levels approaching that so if you had a technology capable of creating those conditions on demand, it would quite literally be the most powerful thing in the universe. Turning it on for even just one second would release enough energy to destroy a solar system several times over. It would act less like a death ray and more like a bomb though so you probably wouldn't want to hang around to watch the fireworks. On the other hand though, assuming wormholes can actually exist, whatever power source you plugged your superlaser into would also be powerful enough to let you create them. So if you did want to use this device as a weapon, you could just portal into the core of your enemy's sun (the stellar plasma would be millions if not billions of times less energetic than whatever magic is on the inside of your superlaser so it wouldn't mind being inside a star). Turn it on for a second or two, and then, after 6 hours or so (the time it takes light to travel to the outer solar system) you would have converted all the planets into plasma themselves and sent them blasting out into the interstellar void, so your enemy probably wouldn't be in the mood to fight back anymore 😂

[@TheFalrinn]

The electrons and positrons would immediately collide with each other, annihilating and turning into photons traveling in random directions. Which basically means the amount of light will stay the same, it's just that it will now be traveling in random directions instead of as a focused laser beam.

[@Kualinar]

It would boil everything, including space.

[@aidenaune7008]

they would collide and turn back into light, scattering in all directions.

[@foogod4237]

@@TheFalrinn And there is actually a word for when a large amount of energy (such as photons) moves outward from one place rapidly in all directions. That's called an "explosion". This is basically exactly the same result you would get from a nuclear bomb explosion, but of course in this case it would be several million times bigger (depending on how much energy you could pump into it in the minute fractions of a second before it annihilated the laser itself (and everything else)).

[@busimagen]

1:35 "We need to give each person [... a] laser." See, that's where you messed up. You would not have passed out a 100 of them before people start randomly shooting it at others, themselves, the Earth, a cat, etc.

[@danielklinkner]

The phrase "10th anniversary edition of 'What If?'" chilled me to the bone.

[@ElectricalInsanity]

The years start coming and they really do not stop coming.

[@EEEEEEEE]

E‎

[@brianm4393]

"If a beam of light gets too bright, space itself stops being transparent." I'm a game dev and that really seems like a hack I would put in a game engine to prevent a weird corner case exploit.

[@jamesmeppler6375]

Seems like you dont know much about science. He basically said if you turn on a light in a pitch black room, its no longer dark....that is what you guys are amazed about....seems like all you know is code and not much else? No offense, but if youre amazed by a room no longer being dark because a light.... This stuff is for 5 year olds. Sounds like most people here need to go back to school if they are amazed by such simple elementary things

[@lantami1199]

Ignore the troll. He's been spewing that bs all over this video

[@renakunisaki]

You set the transmissiveness of space to some absurdly large number, but some player still managed to exceed it.

[@ፔ̇̈]

My totally very wise and logical take away from this video: We can make the Death Star if we really wanted to.

[@theaikidoka]

Seems like the Death Star had a relatively puny laser. It had to be in the same solar system as it's target, and only blew up a single panet. Some of the lasers Randall was theorising would make the Death Star totally irrelevant - it would be vaporised before it ever left it's home system.

[@CerealExperimentsMizuki]

This ain't a Death Star laser, this is something that the Xeelee would conjure up just to cause chaos around the Universe. This is on a whole other scale beyond just destroying planets. This is an Intergalactic ray of doom that not rven the most powerful forces of Nature can hold a candle too.

[@Crowned_Hearts]

Humans used: giant ass lazer. Universe used: Empty space. Its super effective

[@guyincognito1406]

So the laser gets so intense it becomes its own wall.

[@dl1thy]

I'm so glad, that he answered my question in the comments under the last video. Thank you, xkcd!

[@sterlingparkway]

Dang! Glad I watched this, as I was contemplating making one tonight, whew. Dodged a Laser there, didn't I.

[@differentone_p]

BRO CONTINUED COOKING🗣️🗣️🔥🔥

[@ScottOshawott]

Finally, Randall gets to ask the questions.

[@studiosraufncingr6965]

Today I learned that space itself can in fact stop being transparent. Its been a while since a fact actually blew my mind!

[@typenullgaming5741]

casually mentioning numbers orders of magnitude larger than the output of stars, then being surprised when space simply refuses

[@defcynodont5110]

I had just watched a documentary on the cosmic microwave background, so when he said "space is opaque" I was like "oh sh*t!"

[@SaxophoneChihuahua]

so there is a workable theory behind energy shields

[@RichWoods23]

Yes. You irradiate your own starship before the aliens can do it for you.

[@nosackbeating]

lol

[@alveolate]

just need a way to coat your spaceship with a >10^26 laser!

[@Fred-rv2tu]

“Workable”

[@brll5733]

There is also that reported static electricity field in a foil factory that not even humans could cross. Irrc, a section of foil ran over a corridor during processing and during exceptional dry weather so much static was produced people couldn't walk through it. No idea how true that is, though. Actually, might be a good quesiton for Randall...

[@crimsondragon2677]

Add this to the list of reasons why a physically accurate magic system will never be simulatable.

[@Comalv]

but what if we tried MORE power?

[@superchinmayplays]

BREAK THROUGH THE WALL

[@christopherrogers532]

@@superchinmayplays If you think about it all natural limits are able to be overcome with enough energy. If you don't mind the side effects of doing so of course. :)

[@identity__thief]

I'm so glad you made this channel. I was introduced to you and XKCD when your book released. XKCD is still regularly referenced in my life as a programmer, but What If? fell into the background. Each of these videos is either a trip down memory lane or a new lesson

[@umikaliprivate]

2:22 And then there is a beam splitter, and a hidden solar panel 😂

[@SallyRodrigues-i4p]

The fact nobody notices is that the last part creates electron positron pairs, essentially a huge antimatter bomb

[@Gauldame]

E.E Smith from the Lensmen series has a tear of pride in spirit.

[@evernewb2073]

it's people like you that turn "y' know what? you do you" into a compliment. here's hopein' you keep being awesome for a long time to come.

[@havcola6983]

"How big do you want your laser?" "Yes"

[@TheHuangShan]

Just remember that if you are offered a laser more powerful than 10^26W/cm2, it is a scam.

[@dogarucos]

Awesome content with great animations and unbelievable sound effects 😁 Love it! ♥

[@AnoopKhetani]

2:27 Imagine dropping that

[@KillianTwew]

The difference between ^22 and ^44 is unfathomably unfathomable

[@dominikbeitat4450]

This is like theoretical Mythbusters. Or maybe like "What if... Mythbusters, but with unlimited resources?"

[@05digit]

so youre saying if a beam of light gets too powerful it stops itself... So we CAN make realistic lightsabers

[@legoworks-cg5hk]

0:56 if Microsoft made stars:

[@daoletto2]

Stupid quantum mechanics preventing me from having my own Starkiller Base

[@MahaCodes]

True KZbin success is apparently when people comment before watching a video in full.

[@kicorse]

That's true. I mean, if people actually go on to watch a KZbin video in full after commenting, that's definitely a success.

[@MahaCodes]

@@kicorse I more so meant that they trust the video would be good without watching it fully but that's also a valid interpretation 😊

[@Commander_Appo]

3:14 woah woah woah you can’t just drop that out of nowhere. I need a new what if that revolves around this now

[@darklordofsword]

I have a copy of What If, hard to believe it's been 10 years!

[@superchinmayplays]

same, this is probably the first new (for me) vid ive seen, already read the previous ones lmao

[@AlmightyEnel]

You can always have a bigger math, but you can’t have a bigger physic :(

[@ponypapa6785]

omg that is why lightsabers just stop ^^

[@Heroo01]

no, they're not lasers and this wasn't even a conceivable idea back when they were thought up

[@gamechip06]

​@@Heroo01"erm ackshually" 🤓🤓🤓🤓🤓

[@csn583]

​@@Heroo01 You're just a lot of fun aren't you?

[@Heroo01]

@@csn583 yup, physics is a blast

[@Heroo01]

@@gamechip06 it isn't even explained like that in-universe. why do you children always think this tiktok comeback is a slam dunk

[@thewafflegamer6152]

Even if such reactions didn’t exist, it would still be stopped eventually due to the light kugelblitzing into a black hole

[@thefoxoverlord]

0:20 busy beavers mentioned

[@extramedium3163]

I love the atmosphere that the casually drawn animations + mouth sound effects + calming music + the calm voice create

[@squishybrick]

I think what he's trying to say when he says "Space itself stops being transparent" is this: Space isn't a perfect vacuum, there IS stuff in space, and like when traveling through air, if you're going fast and hard enough, the air provides more and more resistance until at some point, either YOU explode, or the AIR explodes.. (Or both) In space, things can go stupidly fast and far because there isn't much IN space, but there IS a few dots and specks of matter hanging around regardless. Sending something through space big, fast, and hard enough, and you will eventually "hit" a resistance. What that resistance is may vary, for example, he said it'd come from the energy of the lasers themselves creating some blips and blops of matter/anti-matter, and 'that' colliding with the laser, and creating a cascade effect. - Sincerely, your friendly neighborhood "That Guy"

[@SG-sc2ur]

So basically... Since the beam stops itself, it becomes a lightsaber...!

[@steemlenn8797]

One for stopping Death Star beams.

[@JonFawkes]

"A telescope is just a death ray running in reverse" so, given enough power, we could turn Hubble into a death ray?

[@Heroo01]

did you miss the word "reverse"?

[@tylershannon9319]

No, given enough Hubble's we could neutralize a death ray. (And turn it into scientific data! :D )

[@nordithen]

Sure, just put a light source in place of the cameras lol

[@DragoniteSpam]

A time-reversed death ray

[@csn583]

​@@Heroo01 No ...did you? You swap the receiver for a transmitter, same as a satellite dish.

[@orwor3923]

I just love your voice, it is so calm at explaining weird but very interesting and also often very deadly stuff to me

[@RonaldMcDonald-o5z]

So that's why light sabers stop. Who knew Georgieboy was a physician

[@Crawsome_Crustacean]

I got your book at the bath tour, it was amazing!

[@smileyp4535]

Wait so then what IS the most powerful laser you can conceive of? The gamma ray burst focused to the defraction limit?? And then after enough of those it starts getting less and less effective because of the whole spontaneous particle generation??🤔

[@TheAdvertisement]

AND THIS... IS TO GO EVEN FURTHER BEYOND

[@simonplayer3406]

What if..... You used a laser level to make a perfectly flat bridge. How far could you walk along the "flat" bridge before you felt like you were walking up hill or down hill?

[@qwertyuiop-l1c8m]

2:55 Cursed Feynman diagrams

[@tzfsr]

When they start explaining how powers work in Jujutsu Kaisen:

[@LAJ-47FC9]

This is a real damper on my plans to build a Nicoll-Dyson beam, you know. Guess I'll go tell the Gigastructural Engineering folks...

[@triacontahedron]

Huh, so that's what it's called. My idea was to direct _all_ the energy from a Dyson _sphere_ (preferably around the sun, for Bill Wurtz-related reasons) into a laser, but that's much less feasible.

[@LAJ-47FC9]

@@triacontahedron Yep! Isaac Arthur talks about the theoretical capabilities of one. He should be one of the top hits if you look up the phrase "Nicoll-Dyson beam".

[@triacontahedron]

@@LAJ-47FC9 He was. Looking it up is how I found out what it was.