A laser powered by tiny molecular springs (2^16)

[@AlphaPhoenixChannel]

Side note before the FAQs: THANK YOU to everyone that chipped in to help the students of FRC Team 435! They’re headed to states! bit.ly/435fundraiser FAQs and corrections: 1) Extra shoutout to reddit user u/Mezmorizor for helping me understand some of the finer details of these transitions from a spectroscopy perspective! I hope I haven't butchered it… 2) yes I plan to release the files I cleaned up but I’m out of town at an FRC competition. If I haven’t updated the description with a link to GitHub or something by Tuesday heckle me more! 3) I’ve seen a few questions about how the laser STARTS. Before the stimulated emission, there are random photons spit out by spontaneous emission, and as soon as one of those just happens to line up with both mirrors, the chain reaction keeps going! 4) I’ve had a few people suggest erode/dilate filters to do the binary cleaning. I did try this, but the number of iterations necessary to fix most issues also totally garbled the text and fine detail. I was able to successfully clean some noise with a median filter! 5) …

[@_general_error]

Isn't 2^16 = 65536? But you've got 310K atm...

[@bloodalchemy]

​@@_general_error he said he is behind because subscribers are coming faster then him coming up with unique ways to make buttons. That's why he has pieces of paper in the 2^17 and 2^18 spots.

[@AlphaPhoenixChannel]

@@jhoughjr1 couldn’t think of another way to show spinning water in a cross section view 😅

[@rocketman475]

Electron::hole pairs are like a golf ball falling into the hole and emitting a sound as it hits the bottom, but in the case of electrons they emit light ratherthan a sound?

[@rocketman475]

Does changing the isotope of oxygen in the co² produce any observable difference in the energy dynamics of the co² laser?

[@OfficiallySnek]

Seems like you have been doing a lot more than "some woodworking and laser cutter projects" over your 6 month hiatus

[@AlphaPhoenixChannel]

The garage has gotten substantially nicer to work in lol 😁

[@emmanotsostrong]

Damn, has it been *six months* already?

[@Crazyclay78YT]

@@emmanotsostrong dude i know, i feel like the school year didnt start super long ago, even though it ends in 2 and a half ish months. could also be the weed now that i think about it

[@stefankrainer8961]

It's insane how you can explain such a complicated thing in a way everybody understands it, you'd be an amazing teacher!!

[@Timo_Adventures]

He IS a good teacher, this is his classroom)

[@stuffstuff2846]

Idk about everybody

[@DavidVerch]

Great watching to learn how to be a better instructor!!

[@jeremey2072]

I've been following this guy a while, such an under-rated channel. It's going to explode one day.

[@oopsiesh]

@yourt00bz this dude has by far the worst analogy of how stimulated emission works

[@fodonogue3]

Including Wind Walker’s intro has been the biggest positive to my week and brought back the happy parts of my childhood. Thank you.

[@minerharry]

I love the gradual building to the windwaker project - glimpses of the print; then more and more obvious music; then the reveal. Great stuff

[@cberge8]

That is a genius way to test laser power output. May not be 100% accurate, but it's a darn good way to ballpark the power level without extremely expensive test gear.

[@General12th]

As Alec from Technology Connections says, energy is energy and water is water. It just works!

[@liveabovethecrowd]

FYI you don't need to laser power getting out the other end ~10µm laser is like 99%+ absorbed in the first 100s of microns. That being said reflections would be a consideration. Stirring is defiantly a good idea to avoid stratification. Actual laser power meters are basically ~1 emissivity black blocks that measure temp rise over a ~10 sec period and back calculate how much energy was needed to do that. Remember to defocus to avoid ablating, cutting, phase changing your water, etc!

[@General12th]

@@liveabovethecrowd I'll keep all this in mind next time I'm doing a laser test. Common Saturday fun times. :)

[@amarissimus29]

Finger test always gets me within a few cal.

[@miszcz310]

This technique is really basic and used a lot in this kind of measurements. If you have watched crankcity i think even myself I've suggested exactly this.

[@Muratesh]

As an artist who makes woodcutting, all this video put a smile to my face to see the convergences between lasers and engraving (by the way, most methods in manual printing are made with these principles) thank you! PS: most of the imprinting method is right, just the tools really didn't help very much: the ink quantity was indeed very high at some point, it should look like you're rolling in an ink mixed with sand; we normally use a spoon ( generally wood ) doing tiny circular moves, not pressing the paper to much; and use papers with lower gramatures! ( rice papers are the best! ) Keep the good work! cheers from Brazil!

[@DaveEtchells]

Ah, interesting! I figured a brayer made with hard rubber would be good, but light pressure with a hard, gently-convex object makes more sense. It also makes sense that lower gramature would be better, but that wouldn't have occurred to me either. I don't know if I'll ever make a woodcut (wood-laser?), but thanks for sharing the info; now I'm better-equipped :-)

[@rbesfe]

The battery analogy was super helpful, and the walkthrough at the end was great! I'll show this to anyone who asks me how lasers work now!

[@camd3673]

I love how you can see the laser refraction in the wood grain edge @4:00, such an interesting detail I was not at all expecting!

[@AlphaPhoenixChannel]

A surprise for me too!

[@JayTheYggdrasil]

So interesting as always, I love how you try to point out where you're simplifying things and still manage to keep a good flow with your explanations. It's both impressive and appreciated.

[@AlphaPhoenixChannel]

I think approximations are the only way to understand weird physics intuitively, but you’ve got to know the limits! I’m glad I can try to walk that edge!

[@JessieTrinket]

I appreciate the Windwaker battle music during the kinetic energy demo, especially after seeing the finished product!

[@jacobbreitinger6789]

Wow, I have been watching you for years and to see this channel grow from 20k to 311k subs, just wow the pride you must have to have that many people who love to hear you, a scientist tell us about your extremely interesting studies and experiments. You truly make the field better in my opinion, I may be largely uninformed but involving the common man in most studies I think is a good thing because it builds extreme intrigue and practicality for how a complex field affect us. Years ago I didn't even know the importance of material science. Science KZbin really rewards people like you luckily. You work hard, have awesome style(clothing and presentation wise), and break down complex topics. I am deciding my college career and have been watching you from a young age and this content has helped shape my world view when it comes to basic mechanics whether a system of machinery or just a river. More importantly my passion for what I want to do, to understand the world around me. Thank you very much Alpha Phoenix for what you do to make the world better. I apologize if I took anything you said out of context as well.

[@ybab-j]

the understanding of physics is what you’re known for but as a designer and printer i really appreciate the respect you gave the printing process, removing their defects so you could add your own organically. lovely

[@Pants4096]

The early Macintosh operating systems had you choose the color depth of the display by the actual number of colors: 2, 16, 256, 32678, 16777216. (Later versions changed to "thousands" and "millions") I have always had a fondness for 2^24 because of that beautiful number. Here's to many many more play buttons to come!

[@barongerhardt]

Windows did the same thing. For a bit they even had an option for billion of colours.

[@kurtclark8560]

@@barongerhardt of course, the have have been copying the mac since the beginning (and doing a pretty bad job at that)

[@barongerhardt]

@@kurtclark8560 LOL, I will never understand the fangirling for an anti-competitive, anti-consumer, child slave labor producer of goods. Yup, so much better than those copycats.

[@RealCadde]

The early everything started using 8 bits for everything data. Sure, there were some systems that used 6 or 7 bits for data. But processors became 8 bits, those became popular processors, so using 8 bits made the most sense. And so, more and more stuff was packed into 8 bits. And to represent any color, you needed three main ones. Which were red, green and blue. And they were given 8 bits each. There were still file formats that used other bit dephts, including 6-5-6. But the CPU, RAM and everything else ran om an 8 bit wide data bus. Or later 16, 32 and 64 bit ofc. And so, pixel representations used 0-255 or 8 bits of data per channel. And yes, there's image formats that use 16 bits per channel too! Mostly for normal mapping. But there's even a monitor that can handle 16 bits per channel so a grand total of 281 trillion colors and change. As opposed to the normal 24 million and change you get on regular monitors.

[@barongerhardt]

@@RealCadde I think you got 6-5-6 off. 5-6-5 was one of the common 16-bit RGB layouts. The extra bit or two would go to green because green is more important for human eyesight and carries more luma for us. The other major option for the extra bit was alpha. Like 5-5-5-1 RGBA. All sorts of others exist like, indexed colour, HSV, black/white, gray scale, YUV. The even earlier stuff (70s-80s) and consoles like NES had even crazier colour modes. I believe the current standard of 24-bit (8.8.8) RGB is mostly an artifact of digital cameras and screens (LCDs). For cameras it is a decent balance between good image quality, compressed size for digital cameras, and 1 byte each RGB feels nice. (Most cameras use YCbCr420 (8-bit color, total per pixel, not per channel) For the LCD screens, I think they have to operate in distinct quanta. Where earlier CRTs intensity of a single color was a voltage.

[@justrotate]

the Wind Waker reference and music just makes me like this channel more.

[@Sinnicide]

I genuinely love how you present information, Everything from laughing at your own quirks like not having props, to explaining everything in fine detail but in an understandable way! Thank you for helping me learn new things all the time Alpha!!!

[@Michaelonyoutub]

The windwaker intro is one of by most favourite intros of all time and that wood print looks amazing

[@Muonium1]

I'm an optics engineer on the world's second highest power laser (neodymium glass) driven nuclear fusion device and I endorse this message, haha 😄 I'd known about CO2 lasers for a long time of course, and even that they contained N2 and He to make the light production more efficient, but I've honestly never seen anyone go into the detail of why each non-lasing gas was included and which exact vibrational modes of the CO2 molecule were energized (or de-excited) by collisional excitation transfer in the gas mix! Very interesting to learn. Something very similar is going on between helium and neon in a HeNe laser too, just the serendipitous coincidence of and exited energy level in He atoms almost exactly matching that of one in Ne atoms...

[@nohbudinose]

I am but a lowly undergrad physics major, but I was super thrilled with this production. It was astonishingly accurate, and super salifying to see all the analogies resolved even without the math to shore it up. Super cool.

[@AlphaPhoenixChannel]

So I was surprised to learn that one of the stretching modes for N2 and the first asymmetric stretch mode for CO2 have almost the same energy, which is how this pumping works! (I understood the energetics of the “batteries” and whatnot, but all of the specifics of the CO2 laser were new to me when I was working on this video, but way cool!) I wonder if there is a similar coupling between convenient modes in He and Ne?

[@danmartinrc]

I wish I had you as a science teacher when I was in school. Your explanations make so much sense. Great to see you back on KZbin! 👍

[@johnrobholmes]

Another awesome vid! I like how you spent weeks learning and applying new skills to avoid carving the block by hand. Undoubtedly spending more time avoiding the task, but learning a completely different skill set in the processes!

[@skyrailmaxima]

I love the Zelda Windwaker subtle additions in this vid

[@mattfojtik7130]

I was just thinking earlier today "I wonder if I'm still subscribed to AlphaPhoenix" since I realized I hadn't seen one of your videos in a while. And here you are! Welcome back!

[@skivvy3565]

Your channel and content are some of the best top tier on KZbin. I started with *Ben of Applied Science* and *Cody of Codyslab* (ok even Medhi and AvE) while at school. And all this time later I’m still passionate and interested because of you, how well your videos are made, how great of a presenter and teacher you are, and how fun and intriguing your projects are. I cannot thank you enough for all the joy you’ve given me over the years

[@SamanBahrampoor]

This was such an awesome video! Even though I have a master's degree in electronics engineering, and I have studied lasers at the University and I've designed laser based medical systems for work in the past, I found this video refreshingly informative. I enjoyed every second of this video. Keep up the amazing work 😊

[@grendelum]

worked at a planetarium with a laser show and never considered why it was a mix of gases in the tube beyond the 6W of white light color, thanks for clearing that up… wish i remembered the mix, but i do know it was $18,000 to re-gas the tube every 1000 hours (less than a year of shows), 20th century dollars at that.

[@matthewellisor5835]

You had a 7 and a 5 year old enthralled. Clearly, LASERs are awesome! Thank you for the best presentation of "introduction to LASER" that I've ever seen.

[@synergy021]

Your passion really adds to the fun and excitement of science education. This is good stuff, keep sharing... Thanks.

[@meltingzero3853]

7:58 "Where are you putting your energy before you transform it all into light?" This fits weirdly well into a New Age self help channel.

[@theyoutubeguy1545]

Thank you. I finally understand CO2 lasers. You don’t make the mistake so many other KZbinrs make when attempting to teach or inform us about different concepts in sciences, methods or processes, they forget that we’re not scientists and get highly technical. Maybe it’s proof of the extent of their knowledge or to sound professional, but to sit and explain something using terminologies you would have to of learned by studying to be a scientist. That doesn’t help people who have not.

[@literallykey3298]

Man, this is a really good video. Made me excited about physics again since it was done in a really good way (been fighting brain fog/long covid so its often just frustrating when I try to learn things), although now I also need to fight the urge to get or make a cnc laser. The only things I think might have been missing are covering how the light is collected so it can be focused to a point and a link to buy or files to make that art (which looks absolutely awesome).

[@mumblbeebee6546]

What a great description and depiction of the operating principles of a laser, and of life itself - followed by some clever craft and moments of success and pretty printing. Loved it!

[@krinklesofmadness]

your explanations of physics are always capable of bringing even this layman up to speed on what’s happening and this video is no exception

[@whiterabbit47]

Your explanation of lasers was a lot easier to understand than the one I got in on of my quantum physics classes, theirs consisted of some very confusing math that I no longer remember

[@zilog1]

All the math is doing is helping you describe what's going on in a provable and manipulatable way you can share with others. you don't have to use it if you wont want to, its just a useful tool if you want to manipulate these kinds of problems.

[@whiterabbit47]

@@zilog1 It's also mandatory learning for people who take the course. If you don't learn the math, then you don't get the degree. I just don't remember because I don't often find myself using probability functions in everyday life (since I didn't go into a career that requires a strong understanding of quantum math)

[@zilog1]

@@whiterabbit47 It just has to be one of those things you are into and find cool. You can see the world of "ill never use X" which may be true yes absolutly. but you have to enjoy it and thing its cool. there are lots of things in life like that. Its just cool. You cant be overly pragmatic and overly practical about things sometimes or else you might miss out on the cool stuff. Have fun with stuff.

[@whiterabbit47]

@@zilog1 I'm not trying to sound pragmatic, I'm trying to say that I learned the math but have since forgotten it because I haven't used it in years. Unfortunately, use it or lose it doesn't just apply to muscles

[@zilog1]

@@whiterabbit47 gotcha

[@the_grand_blooms]

Love the in-depth description of the laser tube dynamics! I've worked with them for years and have always been trying to find explanations of how they work and this is the first time I feel like it's been made intuitive.

[@jtcustomknives]

This is one of the best explanations of how lasers work. I have seen a lot of “how lasers work” videos but yours is by far the best.

[@reptilianbrother5618]

17:50 Would that mean, that the tube would not work if it was in a pitch black room, where there are no photons? As I understood it, there is kind of a kickstarting process, where a photon that exists outside the tube collides with a vibrating CO2 molecule after it was charged by a N2 molecule.

[@reptilianbrother5618]

@leonskum6864 thank you for the explanation! Didn't think of that

[@gameeverything816]

That was fascinating! Loved the bender figure bending the roller straight lol

[@andiralosh2173]

I love how you model and explain scientific understanding of processes. Keep up the good work!

[@FiltyIncognito]

Awesome! Both the explanation and the art. Must have been so fun for the OG laser researchers, not just working out how to most efficiently fit together all the puzzle pieces into a functional assembly, but looking for and working on the puzzle pieces themselves.

[@TheMaxqb]

I've been watching your videos for what feels like forever now and they never disappoint. The genuine joy all of these things brings you is so nice to see. The science is fun, too.

[@Ramboforever]

"Unreasonably complicated shenanigans" 0:29 Made my day 😂 I had watched a few of your videos, but in only this I recognised how much different skills you obtain or at least in how much different fields you try yourself. You've got my deepest respect.

[@s1ugh34d]

This was the "How a CO2 laser actually works" video I have been looking for. Love the metaphors, "Mass on a spring" sounds like a good bungee jumping company name.

[@Anna-ff2hn]

Your methodology of explanation is a treat. I was pleasantly surprised how easily I understood this as someone with zero prior knowledge of this other than the fact that laser cutting & wood-burning exist.

[@jakebrooks6269]

I really appreciate how you explain this stuff so well without making me feel like an idiot. I understand it way more now

[@Blocka025]

Exactly the content I love to see on KZbin. Your channel is excellent!

[@gh0stwulf863]

Amazing video! As The Wind Waker is my favorite Zelda game, I very much enjoyed this video. The explanation of lasers and your art were both incredible. Loved the usage of the Forsaken Fortress music!

[@Holagrimola]

Thank you soooo much for that explaination! It was so well and well explained, far better than basically any other youtuber at least of what I have seen. You have definitely earned another sub, one from me!

[@Joda-l6o]

You have a phenomenal understanding of physics in a super intuitive way. Thank you for sharing it!

[@minerharry]

I don’t know why but this has wonderful bill nye energy and I love it

[@palpytine]

Okay, the bender gag is worth an automatic upvote even if you weren't going to get one anyway

[@felipecaetano15]

When you think you night couldn't be better and then you get a notification of an Alpha Phoenix video right before going to sleep.

[@massamasmas]

Srrysly tho, just laid down and put on an audiobook

[@lewismassie]

I learnt a little about bending modes when learning about FTIR machines in uni. So once you brought up the bending modes it all snapped together in my head at once.

[@ianmercer1291]

Great video as always, Brian! The end reminds me of when I was trying to screen print at home, I'm still working towards that perfect print. Im an undergrad in MSE at NCSU and work with Kaveh Ahadi in RB1, if you're ever interested and have the time we'd love to show you around our lab and our MBE! It's a telluride system and last summer we had time with the high mag lab's new magnets (same as the recent veritasium video) and had some pretty cool things to show at APS. Anyways, look forward to 10^17!

[@AlphaPhoenixChannel]

Tell Kaveh I said hi! I do need to stop by sometime. Work cuts into my day 😂

[@northhamptonshire]

Thanks!

[@dominicestebanrice7460]

The analogy and the graphics are break-through level. BRILLIANT content.

[@ranenelemson8547]

This is an impressive vid, it's obvious lasers are something you put lots of thought and effort into. It was educational and intuitive. Me and my other 9 accounts really liked it.

[@gytisatmanavicius689]

You are definitely talented in explaining complex topics in a simple way, and also being entertaining whilst doing so. Good style good knowledge good skill. Cool laser, it's almost infinite possibilities that you could do with that thing. And these legends of zelda scriptures look like someone would pay a good buck for. :)

[@gamingclipz7309]

Omg!! I didn’t get a notification about a new video! I’m so excited I truly love your videos. You have got me interested in science a lot now. I have really bad depression and anxiety I was so bad I never even left my home. But your videos have gotten me into science! Ty I truly mean it! Today I’m going out to catalog the insects we have in our city. The city asked our group to catalog because they are worried certain species have taken over. Sorry if this is everywhere just truly ty

[@Arrowed_Sparrow]

Dude... This is easily the best explanation of how a laser works I've ever seen. *Also, the key concepts thing that KZbin is doing is frickin awesome.

[@Cketzalcoatl]

Ah, good old FIJI. AKA, the Engineer's version of Paint. Love your channel man, good to have you back!

[@McZambie1]

Glad you're back, and this is a really good explanation on this subject

[@MrHichammohsen1]

The over simplification in explaining the laser is awesome! Its like having a gravity model that explains 99% of what we see, which is extremely powerful and enough to go to the moon.

[@nepdisc3722]

It almost feels like I'm stealing your incredibly expensive education watching these videos. You're a fantastic educator and the fact that you make these very educational and useful videos publicly available for free is amazing. I'm personally of the opinion that information (education) SHOULD be free, and things like this give me hope we're moving towards a utopian future where university level education is no longer locked behind money or nepotism. Honestly genuinely thank you for these videos. I actually understand a lot more about the world around me thanks to them, it's amazing.

[@Ezio-Auditore94]

Dude I admire the dedication you put on your videos. I wish I had half of that, I'll do much better in my engineering career

[@nonsequitor]

Thank you so much man! Your videos are amongst the best on planet earth. You're up there with the few internationally acclaimed scientists we're lucky enough to be able to learn from on YT. Can't underline it enough. And that's why the channel is growing.

[@General12th]

This was an INCREDIBLE way of explaining population inversions! I am SO HAPPY I clicked on this video! :D:D:D

[@officialfanofrichiebricker8324]

Great video, except for the Zelda part, lol. Ive read so much about lasers and never quite understood the CO2 laser fully. You have explained it very well and now I think that CO2 lasers are a crazy way to do it

[@soniclab-cnc]

Actually not a bad explanation lol. I built myself a big 130 watt laser and had to learn the whole process. I watched every video on laser emission and laser cutters I could find and still learned something from yours.

[@AlaskaSkidood]

13:25 Just casually blowing my mind with an easy to understand definition and explanation for the reason or quantum physics. Great video, keep up the good work!

[@mmhmnms]

the "MASS ON A SPRING" makes me unreasonably happy

[@themightyripples6582]

8:40 in this situation I wonder what the likelihood is of a random emission from a "battery" lining up the right way to amplify the laser - in phase and everything Feels like the type of thing that would be insanely unlikely but the emissions like that might be super frequent to the point that it happens somewhat frequently

[@AlphaPhoenixChannel]

That’s pretty much how the laser starts! You get one random emission that happens to line up with the mirrors and then it goes to town!

[@Muonium1]

This is the magic of stimulated emission at the heart of a laser's operation that Einstein discovered in 1916 (and would live just barely long enough to see realized in the first *m*aser built by Townes in '53). When an excited atom randomly relaxes on its own back to the ground state, this is spontaneous emission, and the photon is emitted randomly. When another photon hits an excited atom whose excitation state matches the energy of the incoming photon, the atom is 'stimulated' to de-excite and release its energy in the form of an identical photon with exactly the same energy as the incoming one going in exactly the same direction and with exactly the same phase.

[@lexihaley2887]

I'm pretty sure each of your videos is a stimulated emission! You are so much fun to watch and learn from, Thank you!

[@omartechnologies]

My kids are in love with link and legend of Zelda in general. Gonna trick them to see this video so they learn about lasers... Thanks for the great content. And congratulations on the 16th power.

[@jasonpatterson8091]

Excellent video! I've been watching since your 2^12 video! Best of luck hitting 2^20 this year!!!

[@liseguy]

That was amazing! By far the most brilliant explanation of Lasers I've head in my 50 years.

[@kq_stol]

Knew what a laser was but never understood the how. The analogy was perfect. Thanks for making it make so much more sense.

[@jonastjepkema]

Little heckle about the files ;) i really love your content, your are one of the youtubers fromwhich I most anticipate releases!

[@bowieinc]

This video is at the perfect level. It’s above my head but with a stretch, I can just grasp.

[@harrisonmeeres7780]

Great video and great explanation of spectroscopy. It reminded me of my favorite quantum chem lab where we used an FTIR to collect rotational spectra of 4 HCl isotopomers to get a handle on transfer of angular momentum, quantization, and several other QM properties of the system. Might be a cool topic if you're interested in spec and some material effects quantum mechanics.

[@ExonerativeKoala]

Yay, I've been looking for something new from you! So fun and informative!

[@kaosz7777]

Wow this was a SICK video. Amazing!! also love that WindWaker reference

[@Sir_Uncle_Ned]

I think that explanation actually made me understand the process of making laser light. Thanks!

[@insanospaz]

Been around since something with thermite(?) and it has been absolutely wild to see you progress with this channel and your knowledge on stuff to do random experiments/proofs on. Congrats on passing the 300k mark and hope to see that half mil

[@andynz7]

That's the most amazing explanation of gas lasers! And love the woodcuts :)

[@party4lifedude]

The way the amplifier tube works is genius. Lasers are already fascinating enough, but this is amazing.

[@realityChemist]

Apropos of nothing, but since I'm early to a video for once: I'm a materials scientist and most of my research is done in a TEM. I just wanted to thank you for the TEM videos you made a while ago, they've been incredibly valuable for making it possible for me to actually show friends and family what it is I'm doing day to day in my PhD! Love all of your videos, but those ones in particular are such a resource. (Also if you ever want to talk shop re: electron microscopy hit me up! I don't have many folks to talk to about it except my advisor and my other group members!) Okay that's all! Now I'm going to watch *this* video! Cheers! 🍻

[@AlphaPhoenixChannel]

I’m glad those videos are getting bonus use! I wish I had done one about diffraction contrast tem/stem while I was still in grad school, but I was never sure how to go from “electrons can bounce off of atomic grids” to “stem image formation” in 20 minutes 😬

[@realityChemist]

@@AlphaPhoenixChannel Yeah sounds like it would be tricky! I'm TAing for the TEM class at my university and a whole semester seems barely enough!

[@john91051]

You're an absolute genius. And the way you explain is incredible.

[@viniciusnoyoutube]

The best explanation about laser I have ever heard.

[@thatravendude]

Top notch video. Best description of laser physics I've seen.

[@FakeMichau]

I was a little worried after that series on uninteresting videos. Glad to see you back

[@SkyhawkSteve]

as an electronics engineer, I'm used to the idea of moving electrons between different shells, gaining and losing energy. Very easy! :) While a CO2 laser is old tech, the complexity of getting energy into the CO2 molecules surprised me! Thanks for the explanation.

[@incorrigible7]

Thanks!

[@nobody2.076]

This is one of zhe best videos I've seen in a while! Thanks

[@tomkajiku]

I don´t want write same things allready mentioned - you got my likes! I also like the "not too fancy cutting", "not too mindblowing animations" ... it leaves me with focus on education! As long as I know, what L.A.S.E.R.´s were and how they work - with your video I feel like picking up information from the zero point, up to reaching to the stars - without being a scientist :) Please go on educating - your community is standing straight behind you! thanks!!

[@malcolmhodge4579]

Love The Wind Waker. One of my favourite games of all time. Also love the science stuff. The Zelda music was the best!

[@Allibabo]

Thank you for making these videos about different topics. They are really interesting and comprehensible!

[@arseniix]

One of the best youtubers out there, hats off

[@MrW3iss]

Wow you've managed to explain an advanced concept very effectively without being annoying at all. Keep it up 😄 Also the spring with kinetic/potential energy metaphor is pretty simple but also fairly eye-blowing when thinking about it in terms of the relationship between positive and negative electrons. Thanks 🙌Subscribed.

[@multicoloredwiz]

Damn brother! That was beautiful! Loved the use of the reveal music.. too bad you're 2 log2s away from complete.. and by then you'll be over 500k, no doubt. Every time you drop a video it's a lovely experience:)

[@unvergebeneid]

Given that in modern physics, pretty much everything is on some level a mass on a spring, I'd like to postulate that modern physics was only made possible by the invention of the spring.