When i was a kid i got my hands on a 100mw green laser decided to take it outside during winter i thought its batterys were dead and pointed it at my left eye. i lost about half off my eyes accuracy and now i see very badly with my left eye and depend on the right eye.
Treat every laser as if it were on. Never point a laser at anything you do not intend to blind. Keep laser safety goggles on while laser is in use. Keep power disconnected from laser until you intend to use.
This is actually really scary stuff. Random people buy those green laser lights for Christmas all the time and completely and unknowingly carry an extremely dangerous weapon. And they don't even know it's on.
@Akhenaton yes, but do your own research. I find it easier that way cause once you're on one side, it kind of sticks. If you do, you'll be surprised how misleading media can be
I burnt my retina in the 70’s looking at eclipse of sun with no eye protection. I can’t tell how much hassle it is only having 1.5 eyes. Play safe kids!
@@yummyliciosable is not a joke, a fire ember while drinking beers on the beach burned a hole in my cornea... I can't describe the feeling. It's like a never ending and outrageously frustrating to have 'empty white dot' about 10% to the right, from the center of my left eye. I can't track lines when, let alone speed, reading anymore... I feel like I have something in my eye that won't go away even years later, almost like a small flake of skin will never fall out... Optometrist says it's likely a disfugred piece of 'eye meat' lol, from searing from hot ash. Know how it is supposed to go away? Years of blinking... Every minute, every day, hour, etc... Until the feeling of a sliver in your eye goes away
Blue DPSS 473 nm lasers have the same issue - maybe even worse since they are less efficient and need a stronger infrared pump diode. But 445-450 nm direct diodes have no issues in the cold. Thanks for watching!
@@brainiac75 what about UV purple lasers I own a UV purple laser that was marketed at a purple laser I know it is UV because if I shine it at stuff that glows under UV it glows very bright
@@bluethefoxyt I could be wrong so do your research but I think UV lasers are if not even more powerful because the UV spectrum is way above the visible range and requires more energy to produce Again, i could be totally wrong since i don't know exactly.
“Remember... if it comes with a warning label, somebody did it.” - Stephen Colbert My first slot-load DVD-ROM drive came with this label: “Do not use the accompanying tool to manually eject any disc from this drive while the disc is still spinning. Doing so may cause a variety of serious injuries including decapitation.”
The, “tool” was just a glorified push-pin that went in your standard manual eject hole. Difference being, there was no tray or front-flap to stop the disc from firing out when you shoved the pin in when it was spinning away at 32x while doing say, a large file transfer. If you pointed it away from yourself, it became a formidable weapon at medium range. Kinda like my tower was a cannon.
That’s kinda like Rocket Launchers having “Point at enemy” printed on them. Also I saw a label on a saw that said “do not put penis in front of saw” really want to know what happened to that guy.
I've learned a lot about "harmless consumer grade" lasers from your channel. I honestly don't even want to play with my cat using the laster pointer anymore because I'm afraid it's improperly constructed or rated and it'll harm his eyes if it hits them directly while he chases the dot. :( I have lost all trust in cheap laser manufacturers and I don't assume that wavelength or power rating labels are anywhere close to being correct anymore.
bdf2718 “And then they went to tailspin and crashed into a hillside, and the plane exploded in giant fireball, and everybody died! Except for me. You know why? Cause this story is fake, and my seat was back in the full up right position, cause this story is fake, and my seat was back in the full upright position! Cause this story is fake, and my seat was back in the full upright position! Hahaha, haha, oh!" Maybe listen to Albuquerque?
Obviously the answer is using proper quality industrial grade megawatt lasers for playing around with like you would a those "harmless consumer grade" stuff.
You showed me a very interesting thing indeed: I tried using the camera on my phone to view the IR LED in my television remote, and the camera showed the IR as red. I cannot see the LED with my own eyes, but my phone camera picks it up clearly! Now, I've got a good way, to tell if a remote control is working or not. Thanks for showing this.
I saw a post a while back about doing this in hotels. If you look around the room with your phone camera you can catch the IR from hidden cameras. Same with changing rooms
For anyone else trying this: the back camera of a smartphone often has a filter to remove infrared light, but the front "selfie" camera usually doesn't. If you test this out and it doesn't work, try the front camera instead!
@@sbalogh53 exactly. thats the reason it didnt even show up when he did the warm test. because that thing was over the laser just as you would use it in your yard.
IT seems to me that as this is a safety issue, that laser pointers should possibly be banned altogether, along with these "star" generators for Christmas and other uses. I can see no real purpose in every day use beyond some "convenience uses. There is not even a good cause for use as sighting devices for pistol and rifle. There are other devices that give just as accurate or more accurate firearm alignment. Regardless of "splitting" the beam into hundreds, that relies on a diffraction plate which can be damaged or come loose or fail.
Invisible light is terrifying but so cool. Also my uncle had one of those laser displays inside his house and one of the green beams hit me directly in the eye and I was dazzled for a full day. I feel immensely lucky to still have my vision. My uncle is so stubborn he still refused to turn the thing off.
@@liamhartrey9014. Technically yes, but it's a blanket statement for anything over a few milliwatts. Spartan certainly falls into that category. Spartan would be, do not aim at face while lighting cigarette.
Intersting. I've got two of the green 5mW pointers like you show here. One functions correctly. With the other, it appears that the green lasing went out on it; not sure if it is due to a misalignment or whatever, but you can see inside the bezel that there still is some activity going on. Not sure I would have guessed it could still be lasing in the infrared spectrum, but I've seen enough here that I think I am going to permanently disable it.
The following only applies to DPSS Laser pointers... Direct green diode lasers work fine...I use a Nichia 9mm direct green equipped pointer pushing 1250mW and never had an issue in subzero temperatures. Keep the optics from fogging up as the pointer thaws and you're good to shine.
Wow, I didn’t know green lasers could make infrared when cold. I took a laser safety training course in college, we were very careful about locking the door, taking off all jewelry, putting a filter in front of the laser till we had it aligned, etc. lasers are scary!
I wish i knew this when I was a younger. The amount of times I have looked directly into a laser beam is unbelievable. When my green laser was dead flat I would see a red light so id look directly into it. But now I am a lot safer with lasers. Especially knowing just how powerful and dangerous they are
Yep, me too and probably explains the inexplicable blind spots in my right eye many years after ever touching a laser. Back then it was a very very early red pointers, when they first started to appear on the market back in the late 90s. I've had retina scans done when I noticed this and again a few years later but my eyes show up very healthy. So it might not be visible physical damage but probably biologically my photo receptors are buggered. I first noticed these blind spots some 10+ years after stuffing around with the pointer, but I also welded lots without a mask and guilty of the magnifying lens on a hot summers day lol.
@@3800S1it was the welder dude it's gotta be. I got a blind dot from a worker building a bank in traffic. I looked and now that spot shows up when I look at white web pages. West a freaking mask when u weld man seriously. Think
@@nuguns3766 Tell that to a 14 year old that acquired a dodgy welder with a even more dodgy mask that would couldn't see though so ended up flashing his eyes to see where the rod was before striking up and accidentally arcing. Young and dumb!
The first diode laser I used was cooled by liquid helium and the experiment software I wrote for it drove a heater underneath and read the resulting spectrum after it passed through a CO2 sample. Thus, this isn't much of a surprised to me. As to the heater, in the yard decoration, I'm surprised they didn't spend an extra fifty cents and keep the laser off until it was up to temp. Oh, the grand profits they must have reaped.
I’ve always been told to never, under any circumstances, bring an active laser near my eyes or anyone else’s. My grandmother has cats and she would only let us use the laser pointer when we were younger if she was watching us and that we were careful with where my brother and I pointed it. If the button was being pressed, then you could no longer look at it directly.
I had noticed on my own that my green laser pointer would produce a much weaker beam when cold. I just assumed it was the batteries struggling. This was really enlightening. Thank you
This winter my electric fireplace kept kicking on randomly. I figured there was an IR leak but I had no idea it was in the front lawn. Awesome explanation.
Just point it at a mirror, away from your eyes, you should be able to see if its shining a light. Or just point it at a wall in a really dark room, no damaged eyes there
It's legal to kill people in war, but not to maim/blind them on purpose. There are also no rounds for small arms that use depleted uranium. Armour piercing rounds for rifles and machine guns use either hardened steel or tungsten. Some tank rounds are DU however.
This is pretty spooky to see. I had a friend with one that we were messing around with one late on a cold night. I don’t recall looking at it directly ever but it was only working when it was warm. Worrying to think I could’ve damaged my eyesight
if someone could get 1MW of laser output from what I am guessing is two AAA or AAAA batteries, They would not only probably violate a laundry list of laws of physics but also would have every military on the phone with fat cost plus contracts for hand held laser rifles.
@@Imdor Ah ok, maybe we do here as well, but I only ever see top freezer, or left side freezer. The very bottom is the 'crisper' for fruit and veg. I think it's supposed to have a different humidity down there or something.
In the USA I see all configurations. In older refrigerators the freezer is usually at the top. In more modern ones I tend to see the freezer at the bottom or on the side.
That means you’d need a very level floor or need to use shims, since the adjustable feet will be on the top. Heck, the condenser drip tray would be up there too. Seems impractical to me. Why don’t they just flip them over?
Those green lasers are as dangerous as they are fun... I definitely didn't play safe enough with the 150mw green laser I used to have... I never looked directly into the laser and was careful of reflections... but I was obsessed with seeing that green beam in the dark, it looked so cool on a dark night, and I'd also point it at the walls in my room sometimes, and occasionally pop balloons... I even used it to etch my name into black plastic once or twice. the beam was always defused, but still dazzlingly bright... Im convinced all that playing with the laser was what caused vision in my right eye to go blurry later down the line anyway with the current rate of technology I figure I'll be in line for a bionic eye in like 20 years... I wonder if I can get one that shoots lasers
There’s a dude who really lost an eye and he did infact construct a reasonably bright and useful flashlight eyeball… I’m pretty sure he made a red laser as well. I need to rewatch that
Oh… yea… I meant to say, so long as you want a bionic eye that emits then you’re good. One that receives and receives and displays is probably more than 20 years away… but I don’t know… maybe they’re find a way to grow a new eyeball from like slug and salamander genes… in fact I bet we’re closer to that tech being reality than a real functional bionic eye… I’m now intrigued but it’s 4am
@@swayback7375 honestly between things like nuralink and the constant improvement and shrinking of technology… I wouldn’t be surprised if we’re only 20 years away from a useful bionic eye Heck I’d say the technology is there to fit the components of a smart phone into something the size of an eyeball, when you consider most of a smartphone is screen and battery… so making the eye isn’t a problem… it just comes down to how we plug it in and make it compatible with the human brain… but I think scientists working with AI could help solve some of these problems in the coming decades 🙂
Very well done. I was not aware of the IR hazzard at low temperatures. All of this danger simply because manufacturers are too cheap to add a low cost filter. They also fail to adequately warn against the hazzard.
Yes, I bought one of those "5mw" lasers at a gift show when I was younger. Was v bright, and could even see the beam quite well. Dont know how many mw it really was. Quite scary in hindsight.
When an old fart (like me) tells you about something stupid they did which didn't turn out ok... That's the sort of advice you should probably pay attention to. ;)
@@memejeff No. Condescending would be pointing out that you have apparently low reading comprehension skills and an immature habit of interpretating statements in the worst possible way (even when other interpretations are more obvious). :p Seriously though... What I wrote was clearly self deprecating ("old fart") and basically amounts to "don't be as dumb as we were" along with an implicit but obvious dig against the common "in my day we did X and I turned out OK" BS. So, yeah, *woosh*
When the button on those green lasers doesn't seem to respond often times the entire unit inside the casing is twisted and doesn't allow the button press to be correctly recognised. Just remove the foamy ring and turn it around with a pair of tweezers so the button lines up. Don't know if that is the case with your unit but worth a try.
I used a yard light one year. I turned it on but it wasn’t doing anything! Now I know why... good thing I never looked into it! Never look directly into any laser.
Really interesting and a little worrisome! It would be cool to see a followup that goes into the physics of why laser diodes are affected this way by cold?
I own a green laser that works just like the broken one in the video, I live where it (thankfully) gets down to -30°, and I don't even know why I'm here.
Agreed with your conclusions. But keep an eye on the Ir laser diode datasheets: the shift of the emitted wavelength according to the temperature is well known and fully characterized. As well, pumping the Nd:YVO4 crystal can only happen at a precise wavelength (808nm). Mirror coatings of the cavity Nd:YVO4 + KTP are also tailored for this frequency. Any strong wavelength deviation will render them inefficient allowing an increased proportion of Ir to go through as the Ir power is by design quite strong (several 100mW, up to 1W or more). Simple Ir blocking filter, even the best will let some going out... (e.g. a 1% filter will let 10mW output if excited by 1W) This is a "by design" limitation of a cheap DPSS configuration. Also, things can go worst with some cheap APC laser that monitor the green power output instead of the Ir level for the regulation: as the green output decreases with decreasing temperature. The loop control increases the current in the Ir diode, increasing the unwanted invisible Ir...
Ahh, so the cold temperature is affecting the optical doubler (which doubles the frequency and cuts the wavelength in half). When it warms up, then the optical doubler starts working again.
omar rios Nope. I’m a pilot. The laser flashing is getting more and more common. It’s a felony and dangerous. And we report it. Just aware that some folks don’t know any better and the potential harm it can cause is huge.
@@tigerbhoy1996 you know how you can't see out of your car on a cool morning when the sun glare glances across your dirty/dusty/frost covered windshield? Yeah that x10 on an airplane. Then factor in color vision distortion, meaning you lose the ability to discern certain wavelengths of color. Imagine having to look at instruments and you can't properly read them because they're displayed in a specific color in which you are now blinded. Source: Am Naval Aeromedical Research engineer and we've done a lot of study and looking for solutions to this problem.
I had a little red laser pointer and I was at a cousins party and the laser stopped working then I swear I pointed it at my eye but nothing bad happened and I’m so thankful
Ooh! New blue warning sign to mark the freezing temperatures, that's great! Overall, another interesting video, showing how cheap, green lasers can be really bad if misused.
Interesting, I assumed green diode lasers just used a ~2eV bandgap semiconductor for their gain medium like LEDs, instead of using a silicon gain medium and a frequency doubler. I’d only heard of frequency doublers being used in 1064 Nd:YAGs. But I guess those doubling crystals are pretty cheap compared to the YAG crystals. So if I understand correctly, it’s more the temperature drift of the laser diode’s peak wavelength out of the tuned wavelength of the doubling crystal, as opposed to the doubling crystal’s tuned wavelength changing. I studied how those doubling crystals work, among other nonlinear optical phenomenon, really fascinating stuff.
It is possible to protect against any wavelength of coherent laser light while letting regular light through. This is done using special materials that react to the laser wavelength by forming its own diffraction grating and deflecting the beam. However, because this only deflects and doesn't block, it's only really useful for cameras and not for glasses.
man same, i rememebr when i was 8-10 yrs old. used to looks into Red Laser lights, they're cheap like 20 cents. i look in them in my pupil like I can't see anything but the laser, i feel like I'm in space , it's cool. now the consequences i got was blurry left eye.. I'm saving my right for now...
When I was 7 I pointed a 5mw laser in my eye messing about, a couple months later I had to get glasses. No idea if it was from the laser but now I'm blind as a bat, my eyes have gotten worse every year
@@fandyus4125 No, they never used lasers. The IR LEDs they use are much less harmless than a laser as the light is much less focused (if it was focused, you'd have to aim it precisely at the receiver). Before IR LEDs they used (mainly ultrasonic) sounds to transmit the signal, or in rare cases radio waves. Some modern remotes use bluetooth. All those technologies are completely harmless.
TV remote IR LED's are diffused, so they will not concentrate their IR energy in a highly focused beam. Unless you all but touch your cornea with the center of the LED capsule, no worries. Looking at the emission end of a TV remote is harmless.
Glad you made this video. This danger is well know in the laser hobbyist community but most people don't realize how dangerous those cheap "5mw" green pens can be. I have one that puts put about 40mw total power but when I filtered out the green 30+ of that was IR. Also I really need a spectrometer like that for my collection.
@@lemau8458 yes I have watched the video more than once. Out of curiosity, are you saying that condensation is not a thing? I assure you condensation is real. Slow methods of freezing such as in a common freezer can allow condensation to occur and then turn into ice crystals which conduct electricity and can cause problems on circuit boards. This is what I'm referring to. If he were to use a method of flash freezing such as exposure to liquid nitrogen, there would not be a chance for condensation to occur and he could test it immediately afterwards before condensation could occur and see if it still has the same problem.
@@lemau8458 Actually, I simply took the opportunity to make the more detailed comment I originally intended. I took your comment to mean that I had made the mistake of presuming that my brief comment would be understood.
"NEVER LOOK DIRECTLY AT THE SUN!!" *How many times did you have to tell people that before they understand that they will suffer permanent eye damage?!
Weird, the "200" mw laser I got has a mini TEC cooling the diode, and despite being small it does get sorta cold, mine seems to keep the laser around 10°C, but glad I didn't upgrade it to be colder
Standard batteries should work fine, recharge batteries will probably be less efficient and have a lower life expectancy. This problem seems to be caused by the filter itself which is seen very well with the christmas light (main power) as a comparison. It also makes a lot of sense physically.
It's true. Once I was at this football game in freezing weather and tried to use a green laser. The enemy quarterback wasn't dazzled at all and threw a touchdown pass. We lost the game and then he went blind. So humiliating. :(
Thank god Sponsor Block has a feature that takes you to the highlight of the video, so I only had to watch this for about 5 seconds instead of wasting 9 minutes on it.
Just sounds like a Dane. A lot of Danish people sounds funny when they venture into the English language. I'm Danish myself, but I'm all in on a cockney accent. I don't really know why 🤔
Oddly enough I remember being able to see the little diodes blinking on remotes and other things that emit IR when I was a child. I also remember my parents telling me to stop lying and there isn't a light on the front of the remote. I played with IR emitters just because they blink. You can probably guess why a child would play with a blinking light.
It would be of interest to understand how much (if any) of this is due to substantially reduced battery voltage and/or current performance at freezing temperatures. In some battery chemistries these can be extremely degraded. Also whether due to self-heating while powered on, the diode eventually warms up enough (in the same external temperature conditions) given enough time to perform properly
Oh right, lithium cells are drastically going down in the cold. Little life hack: If your phone turns off during winter, put it in the inside pocket and let your body warm up the battery.
This is very interesting, thanks! I love videos like this and some from Action Lab and others, that show me interesting things that I didn't even know I was curious about but which simultaneously create and answer my curiousity!
Thank you very much, SalmonParadise. It is not intuitive that a laser supposed to emit green will only emit invisible light when cold. Hope all who use a green laser outside at a frost-clear night to point at stars realizes it...
I know that green and blue lasers initially produce infrared, the frequency of which is doubled in crystal resonators, but I didn't think that they don't work properly in the cold and spread IR. Thanks for the portion of knowledge.
@@TAIR736 Fun Fact... What powers the internet is, people getting offended at the slightest hint of derision from total strangers, combined with condecending attitudes.
When i was a kid i got my hands on a 100mw green laser decided to take it outside during winter i thought its batterys were dead and pointed it at my left eye. i lost about half off my eyes accuracy and now i see very badly with my left eye and depend on the right eye.
Damn
Ouch.
Yikes
Jeepers
krikey
Yes I will!
Yes I will!
@Sixhawk yes, for science!
Yee
Don’t do iiiit
*For science!*
"Do not look at laser again with remaining good eye" was the warning sign on a laser equipped device in one of my workplaces.😉
lol
And on my Spectra Physics is written : "This device will not only kill you, it will hurt until you're dead ..."
It’s a winking face because the laser hit one
... @@TomKappeln ...and keep hurting youre corpse
Looking at a laser is a mistake that you will only make twice :D
Treat every laser as if it were on.
Never point a laser at anything you do not intend to blind.
Keep laser safety goggles on while laser is in use.
Keep power disconnected from laser until you intend to use.
Underrated comment
So basically treat it like a firearm
Rah
SMH why haven't we banned assault lasers yet? 🙄
@@Majima_Nowhere lasers don't blind people, people blind people, I have never seen a laser sitting on a desk decide to get up and hurt someone /s
"Lazer beams are always an eye hazard, especially the invisible ones in this video..."
*puts on safety goggles and carefully peeks at the screen*
I always feel like that when watching TV or video where they are welding!
Hill's Workbench Hahahaha sameee
@Dr. W.D Lefty {yandere 0wU} is a joke
@Dr. W.D Lefty {yandere 0wU} Yeah, no shit Sherlock.
@Dr. W.D Lefty {yandere 0wU} you don't have full spectrum 64k tv?
"Never eat yellow snow"
Or red snow
@@joelchristensen9744 oh no
Never pet a burning dog!
BarryTGash Why? Its so tasty!
Joel Christensen What flavour is that?
Had a 'legal' limit blue laser and a slight reflection off shiny metal gave me a spot in my vision that didn't go away for years..😐❤️🇬🇧
Damn, that sucks.
Hope you are better off now
Cheers mate
Laser goggles?
Legal doesn't always mean that the product is safe.
I bought a legal blue laser off of eBay. Tested it. It was 5x the legal limit. Smh. I love it tho
Edit:I just broke it... Fucking water logged it.
Cold sensitivity is part of the reason I used a 520nm direct diode when building my astronomy laser. VERY expensive, but it was absolutely worth it!
Can just wrap in heater wire
@@pokemoncrusher1246 Still could take a bit to heat up, meaning it still releases dangerous light that we can't see!
@@alexandermcclure6185 I guess you could add a temperature interlock.
@@DKNguyen3.1415 yeah itd be like a 7$ diy solution using esp32 chips even
This is actually really scary stuff. Random people buy those green laser lights for Christmas all the time and completely and unknowingly carry an extremely dangerous weapon. And they don't even know it's on.
Not to mention all the terrorist Antifa scum taking them to riots to intentionally blind people for life
Most products sold in the US seem to have a high lvl of danger. This doesn't seem to be an accident.
@Akhenaton yes, but do your own research. I find it easier that way cause once you're on one side, it kind of sticks. If you do, you'll be surprised how misleading media can be
@@Superabound2 when has that happened?
@@Superabound2 this comment didn’t age well
I burnt my retina in the 70’s looking at eclipse of sun with no eye protection.
I can’t tell how much hassle it is only having 1.5 eyes.
Play safe kids!
@Akhenaton its ussually a sudden procces. At furst you only feel a bit warmth but that turns into burn in matter of milliseconds.
first question, i'm sorry, but did you begin with 2.5 eyes?
I once looked into sun eclipse without eye protection, glad i didnt burn my eyes.
@@gabriella2902 i'm pretty sure i was only fine when did it because the clouds dulled the light.
@@yummyliciosable is not a joke, a fire ember while drinking beers on the beach burned a hole in my cornea... I can't describe the feeling. It's like a never ending and outrageously frustrating to have 'empty white dot' about 10% to the right, from the center of my left eye. I can't track lines when, let alone speed, reading anymore... I feel like I have something in my eye that won't go away even years later, almost like a small flake of skin will never fall out... Optometrist says it's likely a disfugred piece of 'eye meat' lol, from searing from hot ash. Know how it is supposed to go away? Years of blinking... Every minute, every day, hour, etc... Until the feeling of a sliver in your eye goes away
Don't use a green laser in the cold!
-Blue laser
Blue DPSS 473 nm lasers have the same issue - maybe even worse since they are less efficient and need a stronger infrared pump diode.
But 445-450 nm direct diodes have no issues in the cold. Thanks for watching!
@@brainiac75 what about UV purple lasers I own a UV purple laser that was marketed at a purple laser I know it is UV because if I shine it at stuff that glows under UV it glows very bright
@@bluethefoxyt
I could be wrong so do your research but
I think UV lasers are if not even more powerful because the UV spectrum is way above the visible range and requires more energy to produce
Again, i could be totally wrong since i don't know exactly.
@@bluethefoxyt that would most definitely be worse
@@Dogetuberyt yeah but I follow standard safety procedures of lasers so the risk is small but its still there so eh
“Remember... if it comes with a warning label, somebody did it.” - Stephen Colbert
My first slot-load DVD-ROM drive came with this label:
“Do not use the accompanying tool to manually eject any disc from this drive while the disc is still spinning. Doing so may cause a variety of serious injuries including decapitation.”
Damn poor guy "decapitated by putting stick in dvd slot"
The, “tool” was just a glorified push-pin that went in your standard manual eject hole.
Difference being, there was no tray or front-flap to stop the disc from firing out when you shoved the pin in when it was spinning away at 32x while doing say, a large file transfer.
If you pointed it away from yourself, it became a formidable weapon at medium range. Kinda like my tower was a cannon.
That’s kinda like Rocket Launchers having “Point at enemy” printed on them. Also I saw a label on a saw that said “do not put penis in front of saw” really want to know what happened to that guy.
Ahh...negative entropy [aka natural selection]
@@londonuntergunther252 what a reply
I've learned a lot about "harmless consumer grade" lasers from your channel. I honestly don't even want to play with my cat using the laster pointer anymore because I'm afraid it's improperly constructed or rated and it'll harm his eyes if it hits them directly while he chases the dot. :( I have lost all trust in cheap laser manufacturers and I don't assume that wavelength or power rating labels are anywhere close to being correct anymore.
bdf2718 Lol no I’m not buying that :P
@@fireemperorzuko8756 Damn, the joke flew higher over your heads than the plane in their story.
Well hitting eyes for not long enough is not that dangerous
bdf2718 “And then they went to tailspin and crashed into a hillside, and the plane exploded in giant fireball, and everybody died! Except for me. You know why? Cause this story is fake, and my seat was back in the full up right position, cause this story is fake, and my seat was back in the full upright position! Cause this story is fake, and my seat was back in the full upright position! Hahaha, haha, oh!" Maybe listen to Albuquerque?
Obviously the answer is using proper quality industrial grade megawatt lasers for playing around with like you would a those "harmless consumer grade" stuff.
You showed me a very interesting thing indeed: I tried using the camera on my phone to view the IR LED in my television remote, and the camera showed the IR as red. I cannot see the LED with my own eyes, but my phone camera picks it up clearly! Now, I've got a good way, to tell if a remote control is working or not. Thanks for showing this.
Makes me wonder why some remotes do emit visible light.
I saw a post a while back about doing this in hotels. If you look around the room with your phone camera you can catch the IR from hidden cameras. Same with changing rooms
For anyone else trying this: the back camera of a smartphone often has a filter to remove infrared light, but the front "selfie" camera usually doesn't. If you test this out and it doesn't work, try the front camera instead!
if your in a dark room you can see light form a remote control with your naked eye
@@sleetskate only if it also has a red visible light led in it as well, infrared is invisible to humans
I would say you have prevented a few eye damage cases with this information. Thanks for presenting it.
the worst part about those lights are: it typically points at your front of the house where you walk past it (and potentially directly at it)
I think they might be "safe" because the beam is split into hundreds of smaller spots so the power reaching your eye would be very low.
@@sbalogh53 exactly. thats the reason it didnt even show up when he did the warm test. because that thing was over the laser just as you would use it in your yard.
IT seems to me that as this is a safety issue, that laser pointers should possibly be banned altogether, along with these "star" generators for Christmas and other uses. I can see no real purpose in every day use beyond some "convenience uses. There is not even a good cause for use as sighting devices for pistol and rifle. There are other devices that give just as accurate or more accurate firearm alignment.
Regardless of "splitting" the beam into hundreds, that relies on a diffraction plate which can be damaged or come loose or fail.
@@djea3589ban everything!!
and in windows reflecting who knows where
Invisible light is terrifying but so cool.
Also my uncle had one of those laser displays inside his house and one of the green beams hit me directly in the eye and I was dazzled for a full day. I feel immensely lucky to still have my vision. My uncle is so stubborn he still refused to turn the thing off.
Maybe he can't see the off switch but doesn't want to admit it... ;)
I think they're horrible and ugly anyway. Just arrange an accident for it.
INSIDE his house? Wow, that's got to be blinding even on a good day.
Don't you have something smarter to do???
@@Loverboy6027 ?
Well, there goes my Monday plans.
First reply
First second reply.
God help us, even normal comments aren’t safe from retards saying if they are “first”, even tho no one ever gives a shit.
@@ikillfurries dude i'm joking sorry
Yugo Deandra Wirayudha You have no idea how bad it is, I just really hate people who think people care that they are first
Or never stare into one with remaining eye.
Reminds me of AvE's sign for "caution: laser radiation" written in braille
😐
Yet they do surgery with a computer controlled laser to reshape your eye so you don’t need glasses.
Spartan laser reference?
@@liamhartrey9014. Technically yes, but it's a blanket statement for anything over a few milliwatts. Spartan certainly falls into that category. Spartan would be, do not aim at face while lighting cigarette.
Intersting. I've got two of the green 5mW pointers like you show here. One functions correctly. With the other, it appears that the green lasing went out on it; not sure if it is due to a misalignment or whatever, but you can see inside the bezel that there still is some activity going on. Not sure I would have guessed it could still be lasing in the infrared spectrum, but I've seen enough here that I think I am going to permanently disable it.
"Don't look at directly at the laser"
Proceeds to look directly at his laser
Is that how you lost your eye, Grimmes?
@@oxymoron296 😂
Lemme guess. You licked the frost too...
I thought he looked at the laser with his camera, not directly with his eyes.
The following only applies to DPSS Laser pointers...
Direct green diode lasers work fine...I use a Nichia 9mm direct green equipped pointer pushing 1250mW and never had an issue in subzero temperatures.
Keep the optics from fogging up as the pointer thaws and you're good to shine.
Wow, I didn’t know green lasers could make infrared when cold. I took a laser safety training course in college, we were very careful about locking the door, taking off all jewelry, putting a filter in front of the laser till we had it aligned, etc. lasers are scary!
I wish i knew this when I was a younger. The amount of times I have looked directly into a laser beam is unbelievable. When my green laser was dead flat I would see a red light so id look directly into it. But now I am a lot safer with lasers. Especially knowing just how powerful and dangerous they are
Me too
Yep, me too and probably explains the inexplicable blind spots in my right eye many years after ever touching a laser. Back then it was a very very early red pointers, when they first started to appear on the market back in the late 90s.
I've had retina scans done when I noticed this and again a few years later but my eyes show up very healthy. So it might not be visible physical damage but probably biologically my photo receptors are buggered.
I first noticed these blind spots some 10+ years after stuffing around with the pointer, but I also welded lots without a mask and guilty of the magnifying lens on a hot summers day lol.
@@3800S1Yeah I'd say the welding without a mask is probably what did it lmao
@@3800S1it was the welder dude it's gotta be. I got a blind dot from a worker building a bank in traffic. I looked and now that spot shows up when I look at white web pages. West a freaking mask when u weld man seriously. Think
@@nuguns3766 Tell that to a 14 year old that acquired a dodgy welder with a even more dodgy mask that would couldn't see though so ended up flashing his eyes to see where the rod was before striking up and accidentally arcing. Young and dumb!
The first diode laser I used was cooled by liquid helium and the experiment software I wrote for it drove a heater underneath and read the resulting spectrum after it passed through a CO2 sample. Thus, this isn't much of a surprised to me. As to the heater, in the yard decoration, I'm surprised they didn't spend an extra fifty cents and keep the laser off until it was up to temp. Oh, the grand profits they must have reaped.
This is interesting
Hey
Ray mak
You have 100 k subs
Nice
{Captian Titan} nice bro
0:55 "...and don't lick the frost."
But, more importantly, watch out where the huskies go, and don't you eat the yellow snow.
People always want to break rules.
zappa chad
Honestly, I don't trust those lawn laser shows because I'm scared they're gonna make me blind if they shine through my window.
Don't look at them then
I thought they just use prisms
Just close the curtains/blinds lmao
Bro don't smoke rubbing alcohol it'll make you say things this stupid
But not all types of lasers
I’ve always been told to never, under any circumstances, bring an active laser near my eyes or anyone else’s. My grandmother has cats and she would only let us use the laser pointer when we were younger if she was watching us and that we were careful with where my brother and I pointed it. If the button was being pressed, then you could no longer look at it directly.
This Video most likely saves a lot of eyesights. Thank you.
I had noticed on my own that my green laser pointer would produce a much weaker beam when cold. I just assumed it was the batteries struggling. This was really enlightening. Thank you
enLIGHTening huh...
This winter my electric fireplace kept kicking on randomly. I figured there was an IR leak but I had no idea it was in the front lawn. Awesome explanation.
"Do not point lasers In your eyes"
Me who does it thinking the battery died: 👁️👄👁️
❌👄👁️
@@Pablovru lol
Kristina Petrov Haha xD
Just point it at a mirror, away from your eyes, you should be able to see if its shining a light. Or just point it at a wall in a really dark room, no damaged eyes there
@@Pablovru i laughed too hard
DON'T USE GREEN LASER IN THE COLD
Military Special forces: about that...
well, when you're shooting people with depleted uranium slugs, blinding them becomes a lesser concern.
It's legal to kill people in war, but not to maim/blind them on purpose. There are also no rounds for small arms that use depleted uranium. Armour piercing rounds for rifles and machine guns use either hardened steel or tungsten. Some tank rounds are DU however.
@@blackirish781 Don't forget the A-10 Vulcan cannon!
they use red
@@cutiebunnyamber3447 No we don't.
I appreciate your sincerity of the severity regarding Laser safety. Thank you for the ever present and important education.
This is pretty spooky to see. I had a friend with one that we were messing around with one late on a cold night. I don’t recall looking at it directly ever but it was only working when it was warm. Worrying to think I could’ve damaged my eyesight
7:38 Pet peeve: incorrect units. "DIODE LASER MAX OUTPUT
We all have dreams. Some of them just happen to include ionizing the air or lighting things on fire from a few kilometers away.
Styropyro should show you a mere 100w can burn through metal. I could only imagine what a megawatt could do
if someone could get 1MW of laser output from what I am guessing is two AAA or AAAA batteries, They would not only probably violate a laundry list of laws of physics but also would have every military on the phone with fat cost plus contracts for hand held laser rifles.
@@filanfyretracker oh you could definitely get a megawatt or two with the right capacitors. For a fairly brief time obviously.
How about 1.21 GW
Today I learned Europeans have upside down refrigerators.
We use both, small freezer and it goes at the top, big it goes to the bottom.
@@Imdor Ah ok, maybe we do here as well, but I only ever see top freezer, or left side freezer.
The very bottom is the 'crisper' for fruit and veg. I think it's supposed to have a different humidity down there or something.
In the USA I see all configurations. In older refrigerators the freezer is usually at the top. In more modern ones I tend to see the freezer at the bottom or on the side.
@@rich1051414 to the left?
That means you’d need a very level floor or need to use shims, since the adjustable feet will be on the top. Heck, the condenser drip tray would be up there too. Seems impractical to me. Why don’t they just flip them over?
"and don't lick the frost" jokes on you I'm eating icecream while watching this
me too
don't eat yellow snow
Those green lasers are as dangerous as they are fun... I definitely didn't play safe enough with the 150mw green laser I used to have... I never looked directly into the laser and was careful of reflections... but I was obsessed with seeing that green beam in the dark, it looked so cool on a dark night, and I'd also point it at the walls in my room sometimes, and occasionally pop balloons... I even used it to etch my name into black plastic once or twice. the beam was always defused, but still dazzlingly bright... Im convinced all that playing with the laser was what caused vision in my right eye to go blurry later down the line
anyway with the current rate of technology I figure I'll be in line for a bionic eye in like 20 years... I wonder if I can get one that shoots lasers
There’s a dude who really lost an eye and he did infact construct a reasonably bright and useful flashlight eyeball… I’m pretty sure he made a red laser as well. I need to rewatch that
Oh… yea… I meant to say, so long as you want a bionic eye that emits then you’re good. One that receives and receives and displays is probably more than 20 years away… but I don’t know… maybe they’re find a way to grow a new eyeball from like slug and salamander genes… in fact I bet we’re closer to that tech being reality than a real functional bionic eye… I’m now intrigued but it’s 4am
@@swayback7375 honestly between things like nuralink and the constant improvement and shrinking of technology… I wouldn’t be surprised if we’re only 20 years away from a useful bionic eye
Heck I’d say the technology is there to fit the components of a smart phone into something the size of an eyeball, when you consider most of a smartphone is screen and battery… so making the eye isn’t a problem… it just comes down to how we plug it in and make it compatible with the human brain… but I think scientists working with AI could help solve some of these problems in the coming decades 🙂
Remind me not to make eye contact with you in 20 years time
Very well done. I was not aware of the IR hazzard at low temperatures. All of this danger simply because manufacturers are too cheap to add a low cost filter. They also fail to adequately warn against the hazzard.
This is an important video, spread it wide. Super easy to damage your eyes when messing with lasers.
And the answer is simple: Don't mess with lasers :)
I'm starting to realize that my chances of becoming (at least partially) blind are a lot higher than I thought.
Yes, I bought one of those "5mw" lasers at a gift show when I was younger. Was v bright, and could even see the beam quite well. Dont know how many mw it really was. Quite scary in hindsight.
@@alecwhatshisname5170 same
When an old fart (like me) tells you about something stupid they did which didn't turn out ok... That's the sort of advice you should probably pay attention to. ;)
@@travcollier condescending as hell
@@memejeff No. Condescending would be pointing out that you have apparently low reading comprehension skills and an immature habit of interpretating statements in the worst possible way (even when other interpretations are more obvious). :p
Seriously though... What I wrote was clearly self deprecating ("old fart") and basically amounts to "don't be as dumb as we were" along with an implicit but obvious dig against the common "in my day we did X and I turned out OK" BS. So, yeah, *woosh*
When the button on those green lasers doesn't seem to respond often times the entire unit inside the casing is twisted and doesn't allow the button press to be correctly recognised. Just remove the foamy ring and turn it around with a pair of tweezers so the button lines up.
Don't know if that is the case with your unit but worth a try.
I frickin love your triangle hazard icons bro, it's so interactive in every video
I used a yard light one year. I turned it on but it wasn’t doing anything! Now I know why... good thing I never looked into it!
Never look directly into any laser.
7:30 I mean they're not lying with the
You literally wrote 'Less than' symbol, so they lied.
@@RedLine_Renesis Technically no. One megawatt (MW) is not one milliwatt (mW).
@@RedLine_Renesis they literally wrote megawatts soo
lol
When you really can't be bothered to measure...
Really interesting and a little worrisome! It would be cool to see a followup that goes into the physics of why laser diodes are affected this way by cold?
This sounds like a phrase to reawaken a sleeper agent
I've never owned a green laser and live somewhere where temperatures never drop below 26°C, yet here i am
Where are you live?
Za waradu
I own a green laser that works just like the broken one in the video, I live where it (thankfully) gets down to -30°, and I don't even know why I'm here.
@@alexdashwood4976 wild guess, Singapore, it's about the same temp all year around from what I ve heard.
Sukeri Monstah
Watching this while I'm from a tropical country where it's never colder than 27 degrees celcius.
Thank you very, very much for this. I had NO idea this was happening with cold lasers.
Agreed with your conclusions.
But keep an eye on the Ir laser diode datasheets: the shift of the emitted wavelength according to the temperature is well known and fully characterized. As well, pumping the Nd:YVO4 crystal can only happen at a precise wavelength (808nm). Mirror coatings of the cavity Nd:YVO4 + KTP are also tailored for this frequency. Any strong wavelength deviation will render them inefficient allowing an increased proportion of Ir to go through as the Ir power is by design quite strong (several 100mW, up to 1W or more). Simple Ir blocking filter, even the best will let some going out... (e.g. a 1% filter will let 10mW output if excited by 1W) This is a "by design" limitation of a cheap DPSS configuration.
Also, things can go worst with some cheap APC laser that monitor the green power output instead of the Ir level for the regulation: as the green output decreases with decreasing temperature. The loop control increases the current in the Ir diode, increasing the unwanted invisible Ir...
Ahh, so the cold temperature is affecting the optical doubler (which doubles the frequency and cuts the wavelength in half). When it warms up, then the optical doubler starts working again.
Yep yep.
Please don’t use those to “point out stars”, that’s how you end up shining them on airplanes.
Sounds like you've done this before hmm 🤔😂
omar rios Nope. I’m a pilot. The laser flashing is getting more and more common. It’s a felony and dangerous. And we report it. Just aware that some folks don’t know any better and the potential harm it can cause is huge.
@@richntampa what are the dangers?
tigerbhoy1996 Just google lasers and airplanes. Tons of articles and examples. abcnews.go.com/US/lasers-dangerous-airplane-pilots/story?id=32499432
@@tigerbhoy1996 you know how you can't see out of your car on a cool morning when the sun glare glances across your dirty/dusty/frost covered windshield? Yeah that x10 on an airplane. Then factor in color vision distortion, meaning you lose the ability to discern certain wavelengths of color. Imagine having to look at instruments and you can't properly read them because they're displayed in a specific color in which you are now blinded. Source: Am Naval Aeromedical Research engineer and we've done a lot of study and looking for solutions to this problem.
I had a little red laser pointer and I was at a cousins party and the laser stopped working then I swear I pointed it at my eye but nothing bad happened and I’m so thankful
probably didn’t hit your retina and only got really close
Ooh! New blue warning sign to mark the freezing temperatures, that's great! Overall, another interesting video, showing how cheap, green lasers can be really bad if misused.
Interesting, I assumed green diode lasers just used a ~2eV bandgap semiconductor for their gain medium like LEDs, instead of using a silicon gain medium and a frequency doubler. I’d only heard of frequency doublers being used in 1064 Nd:YAGs. But I guess those doubling crystals are pretty cheap compared to the YAG crystals.
So if I understand correctly, it’s more the temperature drift of the laser diode’s peak wavelength out of the tuned wavelength of the doubling crystal, as opposed to the doubling crystal’s tuned wavelength changing. I studied how those doubling crystals work, among other nonlinear optical phenomenon, really fascinating stuff.
A brilliant video about a danger too few people know regarding green lasers. Thanks!
Only when you said "In Denmark", I realised how danish your accent was. Great video man!
7:38 "DIODE LASER MAX OUTPUT
Braniac: "Wear laser safety goggles that protect your eyes against all emitted wavelengths"
Me: *Picks up blindfold* "Done!"
note: EMITTED wavelengths - ergo the wavelengths that the laser may be emitting.
Sebastian Nielsen
Me: *makes a joke*
You: ”Nothing goes over my head, my brain is too big, it will catch it!”
You cant blind me twice!
@@sebastiannielsen all light is emitted
@@alf3071 My pillow is light. Is it emitted? /obvious_idiot_joke
0:50 You can't have glasses that protect at "all emitted wavelengths" unless they're impossible to see through.
It is possible to protect against any wavelength of coherent laser light while letting regular light through. This is done using special materials that react to the laser wavelength by forming its own diffraction grating and deflecting the beam. However, because this only deflects and doesn't block, it's only really useful for cameras and not for glasses.
This is great work - Hardly anyone knows about lasers (cold) this needs to be past on
* *has flashbacks to childhood looking into lasers* *
man same, i rememebr when i was 8-10 yrs old. used to looks into Red Laser lights, they're cheap like 20 cents. i look in them in my pupil like I can't see anything but the laser, i feel like I'm in space , it's cool. now the consequences i got was blurry left eye.. I'm saving my right for now...
@@cutiebunnyamber3447 lol for now XD
This is an excellent video on laser safety! Thank you so much.
Still got a bucket of blood in your freezer?
Don't ask, don't tell.
This guy answers the real questions... holy cow
When I was 7 I pointed a 5mw laser in my eye messing about, a couple months later I had to get glasses. No idea if it was from the laser but now I'm blind as a bat, my eyes have gotten worse every year
As soon as I started watching, I paused to google how dangerous old tv remotes were...
Are they?
@@fandyus4125 No, they never used lasers. The IR LEDs they use are much less harmless than a laser as the light is much less focused (if it was focused, you'd have to aim it precisely at the receiver). Before IR LEDs they used (mainly ultrasonic) sounds to transmit the signal, or in rare cases radio waves. Some modern remotes use bluetooth.
All those technologies are completely harmless.
man same, i knew they emitted IR but never even thought that they could potentially be dangerous (which they apparently aren't).
TV INFRARED REMOTES ,
THEY ARE VERY DANGEROUS WHEN THROWN AT THE TV .
TV remote IR LED's are diffused, so they will not concentrate their IR energy in a highly focused beam. Unless you all but touch your cornea with the center of the LED capsule, no worries. Looking at the emission end of a TV remote is harmless.
Bruh this man made the least scariest thing, scary 😂I’m trying to go to bed here 😂
You should look up StyroPyro
I'm very glad this got recommended to me right before the holidays
I literally couldn’t understand anything in this video but I still watched to the end idk why it was just interesting
Thank you UA-cam, for putting this on my recommendations
Glad you made this video. This danger is well know in the laser hobbyist community but most people don't realize how dangerous those cheap "5mw" green pens can be. I have one that puts put about 40mw total power but when I filtered out the green 30+ of that was IR. Also I really need a spectrometer like that for my collection.
Now this is a good halloween gradw video
You should freeze them in a manner that prevents condensation. The issue might be related to ice crystals.
Did you not watch the video? And that's really not a thing.
@@lemau8458 yes I have watched the video more than once. Out of curiosity, are you saying that condensation is not a thing? I assure you condensation is real. Slow methods of freezing such as in a common freezer can allow condensation to occur and then turn into ice crystals which conduct electricity and can cause problems on circuit boards. This is what I'm referring to. If he were to use a method of flash freezing such as exposure to liquid nitrogen, there would not be a chance for condensation to occur and he could test it immediately afterwards before condensation could occur and see if it still has the same problem.
@@equesdeventusoccasus My guy. You waaay overthought what I said because that's not what I meant at all.
@@lemau8458 Actually, I simply took the opportunity to make the more detailed comment I originally intended.
I took your comment to mean that I had made the mistake of presuming that my brief comment would be understood.
@@equesdeventusoccasus K
"NEVER LOOK DIRECTLY AT THE SUN!!"
*How many times did you have to tell people that before they understand that they will suffer permanent eye damage?!
By tellimg them "IT WILL CAUSE PERMANENT DAMAGE" instead of just yelling "Never look at the sun" and not telling them the consequence.
Weird, the "200" mw laser I got has a mini TEC cooling the diode, and despite being small it does get sorta cold, mine seems to keep the laser around 10°C, but glad I didn't upgrade it to be colder
I thought the title was clickbaity going into the video but surprisingly it's not at all. Thanks for warning people about this
Batteries are also affected by cold. How much of the cold is affecting the laser itself, and how much is affecting the batteries?
Standard batteries should work fine, recharge batteries will probably be less efficient and have a lower life expectancy. This problem seems to be caused by the filter itself which is seen very well with the christmas light (main power) as a comparison. It also makes a lot of sense physically.
youtube wouldn't stop recommending this to me so i watched it and i still have no idea why youtube recommended it to me
It's true. Once I was at this football game in freezing weather and tried to use a green laser. The enemy quarterback wasn't dazzled at all and threw a touchdown pass. We lost the game and then he went blind. So humiliating. :(
Thank god Sponsor Block has a feature that takes you to the highlight of the video, so I only had to watch this for about 5 seconds instead of wasting 9 minutes on it.
Don’t tell me i’m the only one who heard goofy’s voice. I love this channel 😂
Dude! Sounds so much like Eckhart Tolle. If I'm lyin' I'm dyin'!
Just sounds like a Dane. A lot of Danish people sounds funny when they venture into the English language.
I'm Danish myself, but I'm all in on a cockney accent. I don't really know why 🤔
you know it's gonna be good when there's THREE hazards
LOL every time I play the sound of the opening scene with the freezer drawer my kitty gets startled and looks around for a minute.
Woah! I never would have thought of this as a risk!
Oddly enough I remember being able to see the little diodes blinking on remotes and other things that emit IR when I was a child. I also remember my parents telling me to stop lying and there isn't a light on the front of the remote. I played with IR emitters just because they blink. You can probably guess why a child would play with a blinking light.
I did this too. Maybe thats why my eyesight is garbag
@@kathy2659 so it turns out i can still somewhat see the infrared but it has to be almost pitch black
@@ethandoessomestuff...8949 me too. I can see when my phone uses the facedetection
It would be of interest to understand how much (if any) of this is due to substantially reduced battery voltage and/or current performance at freezing temperatures. In some battery chemistries these can be extremely degraded.
Also whether due to self-heating while powered on, the diode eventually warms up enough (in the same external temperature conditions) given enough time to perform properly
Oh right, lithium cells are drastically going down in the cold.
Little life hack: If your phone turns off during winter, put it in the inside pocket and let your body warm up the battery.
You really explain the importance of laser safely well, and how dangerous lasers can actually be
Thanks for the heads up, and also educating others on this as well.
This is gonna be recommended to a lot of random people soon, were you one of them ?
I was, just now!
yessir
yep
I have no idea why I’m watching this but I can’t turn it off..
youtube did it's stuff
This is very interesting, thanks! I love videos like this and some from Action Lab and others, that show me interesting things that I didn't even know I was curious about but which simultaneously create and answer my curiousity!
damn thanks! didnt know that.
also this video was damn entertaining!
you always make good content braniac!
Thank you very much, SalmonParadise. It is not intuitive that a laser supposed to emit green will only emit invisible light when cold. Hope all who use a green laser outside at a frost-clear night to point at stars realizes it...
I know that green and blue lasers initially produce infrared, the frequency of which is doubled in crystal resonators, but I didn't think that they don't work properly in the cold and spread IR. Thanks for the portion of knowledge.
I bet UA-cam Will Stop This Video's Reach For The Next 6 years and then Recommend to every UA-cam User😐
6 years later.....
Such a copied and overused comment.
I love how he talks to us like we're masters at lasers too
Yeah especially whe he shows graphs 😂😂
Paraphrasing but Bart Simpson once said, you don't catch up by going slower than others
@@TAIR736 Fun Fact... What powers the internet is, people getting offended at the slightest hint of derision from total strangers, combined with condecending attitudes.
Brainiac75 : Milliwatts
UA-cam auto subtitles : MILLIWATERS !
(Thank you for your work :) )
This is one excellent safety video. This should be shown at any profession where lasers are present at workstations