How hot is a 5W Laser?

[@oldstoffire]

I love how most channels will use overproduced graphics to explain science stuff, but you just have the equations written out on a crumply sheet of paper

[@revenevan11]

That's how you know he's really a hands on real scientist and engineer lol. Although some channels with fancy graphics do have real science of course, but they also have a team of editors or aren't building the equipment and science experiments themselves. I love the aesthetic of this channel so much!

[@em3rdud347]

I like that part of his channel

[@jackodonnell3463]

And that’s how we like it

[@MrGlass-ke4rz]

And then lights it on fire to explain the danger

[@abbybonilla4511]

This dude went to school for chemistry but most likely picked up electronics and lasers along the way

[@luckmyst3r986]

the real question is is he good at laser tag

[@NeonBeeCat]

So I made a 100W laser gun...

[@yuxinlittlemagic]

@@nugget8606 the real question is, is he good at laser tag

[@fingleberry9641]

@@nugget8606 ill do you one better, it it.

[@JJM2222]

Hell burn your eyes out yes hes good

[@3am511]

blindingly good

[@FullyAdamatic]

I knew I had a use for all those saved jars of piss - laser show!

[@jimmysyar889]

Adam I think it’s diesel

[@alenavish5592]

Lol, it’s fluorescent dye

[@ScarfFoxxy]

@@alenavish5592 Isn't it Phosphorous? I've heard him state this in some videos.

[@revshobbyshop3989]

nah that's fluorescein

[@777-h6d]

Are we just gonna ignore that this guy jars his piss??

[@Ryanhelpmeunderstand]

3:28 “ya try to ignore the massive storm outside” 🤣🤣🤣

[@ThemTownYT]

the god's are angry

[@SpartanGuy]

two videos within a day of each other? I must be dreaming!

[@jalapenolemonade]

Spartan8907 I must be in the same dream as you.

[@SpilIik]

I think we will never wee him again.

[@cobrajet3412]

wee

[@HikaruCrystal8]

wee

[@LucasGarrow]

Do a collaboration with Cody's Lab and get that prize!

[@ion_propulsion7779]

Yes! They would be the best collab.

[@ChaBawbe]

Guess why the prize is so high ?

[@chasebrower7816]

Yep, this guy is probably a genius with the things he is capable of doing, but there are probably many, many people who are even smarter than him working on problems like this, and said problems have gone unsolved for a long time.

[@TheSpongbob27]

cody's lab isn't nearly smart enough to solve any of those problems. I hardly doubt that he can fully understand the proposal.

[@ChaBawbe]

+ it would be a waste of time for him, he has a working channel, a job, why would he waste what he manages to do for something he might not accomplish

[@LOUDFARTNOISES]

You're spoiling us now

[@Egotiztik]

I am just blown away by your knowledge and expertise. You videos are legit top 3 of everything I watch on the ole' Tube!!

[@HaloBalla]

Hey styropyro. I'm so glad to see you posting videos again. I have been a subscriber for only about 6 months maybe a year. I have gone back and watched almost all of your videos. I love them. Thanks for your hard work and posting videos. I wanted to also comment that in this video you didn't show the damage done to that pvc pipe (at least, not very well). It's not a matter of distrust I just wanted to see the damage (before/after). Anyways, thanks again, please keep the videos coming when you can!

[@_2hu4u]

Should be pretty easy to get an estimate of the upper limit using Stefan-Boltzmann law (P = AσT^4). Assume the laser is illuminating an ideal black body, circular with the same diameter as the laser beam, and infinitely flat. Assume the beam diameter is focused to 1mm, and the power is 5W Beam cross-sectional area = 7.85398163e-7 m^2 σ =5.670367e-8 solving for T we get T = (5/(5.670367e-8*7.85398163e-7))^(1/4) = 3255 K So the absolute maximum temperature of an object illuminated by the laser would be about 3000 degrees C for a 1mm beam.

[@kailiranta9441]

Hey!, this is actually a pretty sound answer. I would include the fact that this would be the average "temperature" of black body in the beam cross section and further clarify that, by definition, the beam and the blackbody are in thermal equilibrium when the power absorbed is equal to the black body radiation emitted. I think the main problem with this answer is that while, as you pointed out, the black body would be a good upper limit for absorbing, it is also the upper limit for the rate of heat lost. If you had a material that showed a black body cross section to the laser and then protected the heat with a low emissivity insulator, then you could get it a lot hotter than 3000 C, right?

[@j.d.2703]

what about air currents, is that an included varible?

[@watsisname]

@@j.d.2703 At these high of temperatures, blackbody radiation will be the most significant cooling mechanism. This is because of that T^4 (temperature to the 4th power) dependence in the Stefan-Boltzmann Law, so the radiated power grows very rapidly with increasing temperature.

[@douglasparkinson4123]

this is coming from a guy with a rastafarian snoop dog jesus pfp

[@texasfossilguy]

thank you

[@yuusssuufff]

Hot.

[@gudgum8479]

Hot.

[@edwardtheodore2840]

SUPAAA HOOOTT.

[@MrRperez10]

Hot.

[@iateanentireleprechaun7294]

Kawhi Leonard (no homo)

[@iateanentireleprechaun7294]

Hot

[@MrBlahblam]

Where have you been laser bro?

[@styropyro]

I've had a low key past year. I took a break from academia and the videos, and did some life re-evaluation. During that time I did a TON of martial arts training (might even do an MMA fight before long...) while working part time construction and landscaping. I did some electrical projects on my own for educational purposes, as well as a good deal of reading. But now I'm ready for more lazors! More vids to come.

[@tannerlucas4351]

styropyro well welcome back we missed you! please have mercy on you subscribers when you take over the world 🌎 👌

[@lordmeme8432]

styropyro wait so you were training to fight? Bro i'm telling you your like spiderman with lasers

[@LayerByLayer3dPrints]

Lord Meme u mean iron man..

[@alexchinowsky3567]

styropyro We missed you!

[@potatojz38]

I absolutely love your videos! Your interest in laser is awesome and it's great that you can share some cool things you do with all of us to enjoy. Lasers are definitely super interesting! What do you study for or is this just a hobby?

[@seegsonroboticsworkingjoe]

There’s an ad for a 5w Odin burning laser on all his vids

[@exoyt7575]

I still was looking at a KZbin commercial but already gave this video a thumbs up!

[@larryal9]

Very good explanation of power density. Also good to see an appreciation for math.

[@joefiegel9537]

I'm super curious how do you know so much about all the stuff you put on your Channel, especially lasers? If somebody could tell me that would be awesome. I've watched a lot of your videos now and I find them insanely interesting! The science and coolness behind it all makes it that much better!

[@CaliforniaCapitalRefuse]

ebay if you are still interested lol prob not

[@michaelmitchell8218]

I like it. Covered a good question there. It’s great to see people your age doing stuff like this. I try to show people how fun electronics,lasers,etc are. Most just don’t want to know and just don’t want to do nothing with there life. So great to see you reaching out to people in Science.

[@ilarious5729]

"Most don't want to do anything with their life" I think that's quite harsh judgement just because they're not interested about the same stuff as you. This stupid war between generations should honestly stop, there's good and bad in every generation and since the beginning of time the previous generation has always said the next one is wrong and can't do anything right.yet somehow the world goes on and technology gets better and better, as do liking conditions etc.

[@Anndrei02]

At last I can see a bit of the practical use of physics!Thanks for sparking my interest in this domain:D I have a question though, how can you know how strong a laser beam is,do you measure it s wave length?

[@tootsitroll9785]

Everything I know is from him. But wavelength is given to specify color. Millie watt is the number you look at. 5mw for a 5 jewel beam. Jewels are the beam has after spending 5mw of power. 300 mw can course instant blindness. So for a beginner I’m going under 300 mw. Even though you need protection after class 3A. Look on google for “ laser classification chart” it will tell you strength and a brief but not complete safety guid. Anything over 5 mw key chain it gets dangerous there is a meter you shine the laser and it converts it to Millie watts.

[@tootsitroll9785]

Oh yea stay safe and happy laseing

[@booth5578]

Pretty hot I think

[@router_BasedUser]

You are

[@eggboi4517]

The Duke of Nowhere It’s definitely at least 70 degrees Celsius

[@jamesgardener7099]

1 million dollar reward for this man

[@justinchavez9835]

Dude I learned more from you than I learned for my science professor😂 Anyways great videos dude. Keep it up !!👍

[@cadeschumacher4598]

YAY for styropyro! KEEP ER GOIN MAN

[@260830107]

some laser power probes out there are just a block of metal with a thermometer embedded inside. the way it works is that you fire the laser at the probe for a few seconds then use the thermometer reading to calculate power.

[@lemagicalpotato8318]

Doesn't melting PVC produce highly toxic fumes? Please don't die

[@Jeffrey_Wong]

Yes, burning PVC releases dioxins and chlorine gas. So, ideally PVC should not be burned, or at the very least in the presence of good ventilation and only in small quantities. Styro's demo was very brief so it shouldn't cause any long-lasting health issues.

[@Schizophenic_catboy]

Yeah BURNING pvc will produce some nasty Chemicals it usually melts and no burning happens

[@darkracer1252]

@@Schizophenic_catboy what do you think that smoke is?

[@pieterpennings9532]

@@darkracer1252 vape

[@override7486]

@@pieterpennings9532 vaping... sure lol. Black smoke is a good indicator of not complete/full burn.

[@25RossT]

You are my hero. So glad to see you have new videos.

[@KahnSkins]

Glad you are back man keep up the science! can you do a video on some of things you are MOST interested in in todays world? What are your thoughts on what SpaceX is doing or Tesla? What are your thoughts on the batterys being produced today, and what you expect for the future?

[@michaelphoscar7509]

Good to have you back

[@kailiranta9441]

Yay!! Thanks Styropyro!

[@styropyro]

Did you see your postcards on the wall? :D

[@RedwoodSupport]

I like the small explanations in this one. Would appreciate this as a tradition. Also would like a demo on thermoluminescence, if that is practical for your channel.

[@kanseidorito6335]

2 video streak

[@id104335409]

You are lucky. I get asked almost every day ''How far does this laser goes?'' This is so not funny when it happens like a thousand times. And explaining people that light doesn't just STOP at a certain distance doesn't help one bit because you know there are hundreds of people with the same idea in their head just lined up to ask you that same question over and over. But at least I get people that ask me ''Does that run on batteries?'' every now and then. That makes my day better

[@thomashardin911]

3:26 you’re messing with LASERS in a storm?! 😳🤣📡

[@coledavidson5630]

I think you should build a really powerful maser. I'd love to see one and you're the only person I know of who's probably smart enough to do it

[@FIRSTLAST-1776]

Just found you and started following you. Very smart and very entertaining!!! Congratulations

[@2ACountryCouple]

so glad you are putting out videos more frequently

[@oyunburosu3259]

Teacher: Exam won't be hard The Exam: 1:50

[@xbfalcon83]

sigh, wish we could have lasers like that downunder. Police searched my car and found two 1mW lasers, resulted in me having them confiscated and also having my firearms license revoked as well as having my firearms destroyed :( Fuck Australia sux sometimes

[@le892]

So glad u are back

[@lucifersamaelmorningstar718]

Great experiment with a very understandable explanation. right to the point sir.

[@tannerlucas4351]

New video within 24 hours ? Hell ya!

[@coffechipmunk2108]

Hey Styro, really glad you're alive! Is there anyway we can get some more moth videos? I love them so much.

[@atdit]

Dude you need to make more videos, they're great.

[@Momsemann]

I love the new uploading scheduele :)

[@davidecapra8845]

What I would personally do is calculating the temperature for which the total blackbody power emission per unit area is equal to the power density per unit area of the laser beam... In this way you should calculate the maximum temperature at which a very small (Biot almost 0) blackbody in vacuum can be heated by the laser beam.

[@MrMyRecon]

hey styropyro, do u still do the thing with the moths? an update on that would be cool :D oh and welcome back man, keep it up

[@rickysimmons4220]

Brilliant man.. stumbled upon your vids in the recommended feed, glad I subbed this stuff is super cool.

[@colbybrown867]

One of the best content channels on KZbin

[@_Junkers]

+styropyro Nice video. Always wondered about the maths behind this. By the way, don't you need to consider the reflectance of the material being heated?

[@1495978707]

The basic definition of temperature is how much energy of a system changes due to entropy change (not volume or particle number change). While you can technically calculate these things, it doesn’t make a lot of sense. Energy density of a photon beam is straightforward, but it only depends on particle density and wavelength. It’s not very sensible to talk about entropy density of a beam of photons like this because once produced, the beam effectively stays in one state. What would be meaningful is the interaction of the beam with the cavity generating it. We can talk about entropy with black body radiation because the system has many micro states to explore, and it is interacting with a thermal reservoir, so the system can explore microstates to find the most likely macrostate given the constraints. Entropy of a macro state in this case is given by how many microstates there are, and ergodicity is usually assumed too so we can assume no preference of microstates. But a laser beam after leaving the cavity just is in a particular microstate and stays in it. In short, it doesn’t even make sense for a laser beam to have a temperature. That’s one of the reasons it’s nice to use light to heat things, it will continue adding heat no matter how hot it is, unlike a hot object touching it, where heat is only added as long as the object has a higher temperature

[@aaronrunkle]

You sir blow me away. Might I recommend a little more dramatization for added suspense. An evil-genius like lab coat could go a long way here too. It all depends if you want to be a crazy (awesome) Bill Nye TV personality or a regular scientist. Either way, your talent is through the roof.

[@alllove1754]

Now u need like 10 of those all focused on the same spot.. also, that millenium prize u mentioned, if u could explain, sometime, what that equation means, id be able to understand. You could easily teach that in videos bc you are easy to listen to

[@revenevan11]

It's more of a mathematical question than an experimental one for that millennium prize question. The Navier-Stokes equations are a series of differential equations (equations involving derivatives) which model fluid dynamics. Differential equations can get pretty wild to solve, only a small subset of all the possible types are solvable at all, let alone easily solvable by hand. Then there are tricks and methods for solving each type that we do know how to solve. For a lot of them though we just plug in numbers on a computer and basically see what happens for a lot of points, which is why we need supercomputers for forecasting with different models or doing virtual aerodynamics simulations with computational fluid dynamics (CFD). The millennium prize involving this equation is to prove that a solution always exists (or disprove it, as far as we know at the moment it's possible that sometimes the equation just isn't mathematically solvable). The million dollars will go to anyone who can mathematically prove that it does always have a solution, or that a case where it's unsolvable (has no solution) exists. I'd also like to see StyroPyro explain it though! It would be a different sort of video than his usual stuff, but I think he could do it really well!

[@Ioarseri]

So if these lasers can heat surfaces up so much, what do you have yours shining on so as not to burn a hole through the wall of your workshop?

[@Vonkunken]

I got an advertisement below the video for a supposedly 5w laser.

[@noahfin5919]

Great to see a new video, I have been missing out for too long. Are you going to start working on your chemical flashlight again?

[@0pen22]

your the coolest & intresting youtuber about lasers there is like the bazoka laser(cool vid. btw) 👍

[@Putrycz]

This is the best channel on youtube.

[@NNNILabs]

So basically we say that the energy put into an object by the laser raises its temperature enough to burn it? So the greater the rate of energy transferred (power) causes faster temperature increase and faster burning... MIND BLOWN

[@Tjita1]

Although the heat losses play a big role in the peak temperature an object can reach, a very big factor when it comes to heating something with light is going to be the surfaces emissivity. The emissivity of a perfect matt black object is 1, while that of a perfect mirror is 0. Heating a perfect mirror that reflects the wavelength of the laser, with a laser, is impossible (in reality there will be losses in any real mirror, and also glass absorbs light more in some spectrums, so it's no problem to cut a mirror with a laser, but we're talking theory here).

[@954DYLN]

That light hurt my eyes at the end

[@taitrunkl7086]

I think the best way you could show us that the beam doesn't have a temperature is to try to measure the temperature of the beam with a laser termometer, it won't recognise it.

[@RAYTHEONGAMING]

Those equations had my brain hurting.... Goddamn Alabama education system

[@maulwurf9414]

ToxicityGaming the education system is the most normal thing there (this is a meme don’t get offended pls)

[@cadelong6636]

Dude brought out some Egyptian hieroglyphics

[@not.enoughto.go.around6176]

enjoy it while it last boys, enjoy it while it last. love your vids man!!!

[@Samien]

Exceptional content from an exceptional human being.

[@Aaron-zu3xn]

could you bounce a laser inside a chamber to make a forge? would it put enough energy into metal to melt it without just completely vaporizing it?

[@hocusproductsltd3557]

We use 30w green lasers for outdoor laser displays and I can hold my hands in the beam to warm them up when it's cold. The beam is 10mm diameter, and the galvo scanners in the projector are moving the beam around so it's not concentrated on one spot. Have to be careful to direct the reflected light from my hands away caus its bloody bright. I don't warm my hands in the laser beam that often but it's a fun party trick haha

[@MakotoKS]

I don't know nothing about Maths or Electricity but I Love Your Videos

[@Nongdamba500]

Keep up the good work bro. God bless you.

[@JacksMemes]

You've hooked me on your videos. Make more pls!

[@cretium805]

1:50 This is even just assuming the object is a black body that absorbs all light. Albedo is a big factor you seem to have forgotten to add. Also, at 3:47 I'd argue it's red hot, but the red goggles really make it impossible to see the difference between red and white light. It's definitely quite hot though.

[@madfury3179]

Another question is distance. How far away can you light up a match or burn a paper with a 5W laser? Does it end up burning but just takes longer if you move it further away?

[@mateuszkowalczyk3254]

1:12 thousand degrees Kelvin?

[@Belta-kw2bm]

I love this guy. I don’t understand much but I love it.

[@humblesoldier5474]

Now if you can build an institute laser rifle. You might be on to something.

[@MiguelAbd]

Hey, man, we missed the hell out of you. Good to have you back!

[@adalet127]

Finally you are uploading again. I missed you mate :D

[@qwartz47]

Not to mention the color of the object opposed to the wavelength of the laser. A laser hitting an object its same color or white wouldn't absorb as much heat as something on the opposite side of the color spectrum or black

[@Adrian-ns8cr]

Finally a Video from you?

[@philliprporter]

Styro. Your country needs you, you would be a big boost to our laser weapons programs, plus you'd be able to blow stuff up.

[@user-dk7eq9fc8e]

p. porter Laser combat weapons are forbiden and thus illegal internationally

[@philliprporter]

Krosmo we are putting them on our ships right now. I'm not talking about hand held devices that will blind people, I'm talking about the big boys.

[@user-dk7eq9fc8e]

Ok so like the ones that destroy missiles in mid air. Then np !

[@philliprporter]

Krosmo yes the ones that stop drones, maybe one day incoming missiles, that kind of laser system. This young man would love it. (I think).

[@pen1102]

Styro isn't up there in the laser science game the complicated math to you is common math to laser defense engineers

[@04mach1speed]

Holy crap!!! I asked this question on Laserpointerforums a while back and my theory was the same as you just explained about laser beams not actually carrying thermal energy or heat. Minus the math since I’m not that good, so I’m glad you made this video so I can prove to people I was right because you basically explained it. Thanks for this video STY :)

[@mistergrieves]

I lost it after the first cutaway to those hand-written equations

[@AidenSalts]

Ya i would say so 0:45

[@joshuahunt3032]

This makes sense. I mean, lasers require an input of power, all that electrical power has to go somewhere, and it’s added to whatever the laser is heating up, right?

[@DukeOAngels]

ΔT = (P x τ) / (A x κ) ΔT is the change in temperature of the material being irradiated by the laser beam P is the laser power τ is the duration of the laser pulse A is the cross-sectional area of the laser beam κ is the thermal conductivity of the material Another way to calculate is ΔT = (α x P x τ) / (ρ x c) ΔT is the change in temperature of the material being irradiated by the laser beam α is the absorption coefficient of the material P is the laser power τ is the duration of the laser pulse ρ is the density of the material c is the specific heat of the material

[@Abo_Humeed]

i love the rain sound i would pay to get some rain here

[@ion_propulsion7779]

He's back hallelujah!

[@galaxygamers760]

He’s back!

[@BranFlakesR1337]

Temperature is a state function and lasers are rated by power, a path function. The question is asking for a state function value from a power function value, so you would have to derive the power function with respect to time, but you would need to rephrase the question based on the type of laser and type of material you are aiming the laser at. The proper way to ask this question would be, "What is the maximum temperature a 5 W 445 nm laser can make my skin?" The answer to this question depends on a few variables, how small is the laser focused, what is the absorbance spectrum of my skin, and exactly what is the chemical structure of my skin. The smaller the laser is focused the hotter it will get, the more absorbance my skin has for a 445 nm laser the hotter it will get (less is reflected), and the less thermally conductive my skin is the hotter it will get. The true answer to this question is that the temperature depends on the color and power of the laser and the material you are aiming it at.

[@shiroandsomaaregoats8101]

BranFlakesR1337 jeez my brain hurts from reading that but i see the logic

[@BranFlakesR1337]

I tried to explain it simply but the question itself is not simple as it may seem. Often the simplest sounding questions are actually the most profound and complex like why is the grass green and what are dreams.

[@ARCSTREAMS]

but what about that 200w hand held laser you claim to have?btw never saw mercury shoot so fast lol,,i think the temp depends on what its interacting with or used as a target,the beam itself is not hot until it absorbs into something

[@williamgrissom1995]

Here is the answer to if a laser is hot, or if it only creates heat in other things. Put your hand next to the laser's beam and see if you feel any heat. My theory is the Lazer beam isn't hot at all. It only induces heat into other mediums rather solid, liquid and maybe some dark gasses. Like an induction stove using magnets spinning to heat the metals of the pan. Or microwaves that heat the food inside the microwave oven. Now I'm not the brightest guy being just a high school graduate back in 1985 an obviously you are brighter than your lasers, aren't they all beams of energy? I mean they aren't all in a visual spectrum our eyes can see, but aren't they all related because they are in waveforms like the signals from all our wireless devices all the way back to shortwaves and CBs and am radios? PS. I love your videos.

[@TheJoU50]

and hes back

[@luongmaihunggia]

Laser can burn, melt, vaporize and ironize anything as long as you give it enough time and hopefully the object won't cool down as fast as you heat it up

[@korudero]

2 videos in a week? Holy cow!

[@Rimzler]

Guess i should stop using my 2.5W laser to zap people! It's just too funny!

[@risebug3]

well here's a suggestion, point the laser at some kind of metal that has a high melting point and then measure the maximum temperature that you can read off the surface of the metal. yes there will be some heat lost but it would still be cool to know how hot this thing can heat stuff.

[@perkofsky]

Most metals are conductive therefore they reflect light quite well but it would be fun to see him trying that 😁

[@ophiuchus992]

Good video dude

[@adude7944]

U also have to calculate with the material you're pointing the laser at right? A black piece of paper would absorb more energy than a white one..

[@logansutton4464]

when its so late your eyes heart from the light.

[@Longcowgaming]

3:27 there is a storm outside my house too

[@DAKODA65]

Holy moly you're alive?