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How I got my laser eye injury

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Re: How I got my laser eye injury

#331

Post by subpub47 »

pflenker wrote: post #188
madjam002 wrote: post #175

Earlier quoted context omitted.

One of the things I hate most in tourist hotspots these days are the people selling high powered laser pointers, normally selling them to kids, and they are shining it at their faces, in the faces of others, and at the neighbours. I swear they never used to be so commonplace. Having worked nightclub lighting a long time ago I have a deep appreciation for laser safety haha

When I was ~12 years old one boy pinned me down and another one shone a laser pointer in my eye just for fun. Needless to say, this has been my „bad eye“ ever since (I’m 39 now)

[flagged]

Re: How I got my laser eye injury

#332

Post by subpub47 »

NathanielBaking wrote: post #61

Safety guys always ruin the fun. I was in the Marine Corps and every time we got to test some new piece of gear the safety officer was like "No, you can't live fire it off the flight deck of the ship" or "No, not here, that village is down wind of the dust you will kick up when it goes off." No, that has a kill distance of 6 miles, you have to fire it into a hill." Blah, blah, blah. So after I got out I joined the Na…

[flagged]

Re: How I got my laser eye injury

#333

Post by viernullvier »

grundrausch3n wrote: post #282
donw wrote: post #261

Earlier quoted context omitted.

Technically, the US does as well. You have 240 V at the panel, but you only run half for each common circuit.

Technically basically all buildings in Germany (residential and commercial) run on 400V 3 phase power. But access to it via sockets is only common in residential homes via sockets in a garage. It gets more common with car charging although they rather use 3 x 230V as far as I am aware of.

Fun fact: 400V 3-phase and 3x 230V are the very same thing. You'll get 230V AC between Neutral and each of the three phases, but the AC voltage between two of the phases will actually be 400V.

Re: How I got my laser eye injury

#334

Post by maldie »

sebastiennight wrote: post #249
cwillu wrote: post #247

Earlier quoted context omitted.

‹twitches in metric prefix› 2.5 kilowatts. It's called 2.5 kilowatts. ‹calms down› 2.5 kilowatts is how much power a tea kettle in the UK draws. It's an insane amount of power to pump into a 60 micron point.

This seemed like a wild claim (2500 watts for a tea kettle!? As much as a microwave oven in full blast?) so I looked it up. Wow.

Interesting what power do microwaves in US deliver. In EU the regular micros are about 900W range give or take 200W (that is 1500W from wall because microwaves are not efficient machines) but kettles have usually range 2200..3000. So it is obvious why everyone uses kettles. I myselft have 3kW one and it heats 0.35 litres to boiling in 51 seconds. To have similar microwave it would have to be 3000W micro that is 4500W from wall and have not seen that kind of monsters, also regular 1 phase EU socket delivers max 3600W so that limits it also.

Re: How I got my laser eye injury

#335

Post by latexr »

subpub47 wrote: post #331
pflenker wrote: post #188

Earlier quoted context omitted.

When I was ~12 years old one boy pinned me down and another one shone a laser pointer in my eye just for fun. Needless to say, this has been my „bad eye“ ever since (I’m 39 now)

[flagged]

Out of your ten comments, half are flagged. I propose that the lesson to take from that is to reread the guidelines¹ and adapt, not triple down on the same thing and complain.

¹ https://news.ycombinator.com/newsguidelines.html

Re: How I got my laser eye injury

#336

Post by harshreality »

lupusreal wrote: post #321
gcanyon wrote: post #309

Earlier quoted context omitted.

Technology Connections did an excellent video on this: https://www.youtube.com/watch?v=_yMMTVVJI4c tl;dw -- kettles in the U.S. only take about 4+ minutes to boil a liter of water. So when you say "now" you really mean it.

I just nuke a mug of water for a minute or two when I'm making instant coffee. I never understood the big deal about electric kettles.

A water kettle lets you consistently heat water to the same temperature (not just boiling, high-end kettles have additional temperature options), regardless of:

- Amount of water

- Initial temperature of water

- Position of water container

They also prevent superheated water accidents.

Re: How I got my laser eye injury

#337

Post by gambiting »

ruined wrote: post #257
sebastiennight wrote: post #249

Earlier quoted context omitted.

This seemed like a wild claim (2500 watts for a tea kettle!? As much as a microwave oven in full blast?) so I looked it up. Wow.

british household AC is wild, it's like they've got a full-power american range plug for every outlet

And because nearly every single house in UK is wired for single phase only, your connection to the grid is usually rated at 80-100amps(so a regular British home can draw around ~20kW on a single phase).

Re: How I got my laser eye injury

#338

Post by geysersam »

ziofill wrote: post #234
DannyBee wrote: post #17

So I laser weld, and beyond my own PPE, interlocks (gun won't fire if it's not touching metal, etc), the most important part of the whole setup is laser safety curtains. Because it's a 2500 watt laser, if i didn't have laser safety curtains , the relections/etc could very easily blind someone at a fairly long distance. The NOHD (nominal ocular hazard distance) is something like 10km (2500 watt laser, 0.06mm spot size…

What are the curtains made of? I’m surprised 2500W on 0.06mm don’t just go through like there’s no curtains

Maybe it just diffuses the beam?

Re: How I got my laser eye injury

#339

Post by codr7 »

subpub47 wrote: post #331
pflenker wrote: post #188

Earlier quoted context omitted.

When I was ~12 years old one boy pinned me down and another one shone a laser pointer in my eye just for fun. Needless to say, this has been my „bad eye“ ever since (I’m 39 now)

[flagged]

And it would be a wasted life, just ask Jesus.

Re: How I got my laser eye injury

#340

Post by queuebert »

eru wrote: post #303
queuebert wrote: post #216

Earlier quoted context omitted.

Whatever refracts the light will have to stand up to the beam for long periods of time. Maybe it's a materials science problem.

As long as it doesn't absorb the light, it's fine. Just like the electric cables for your water kettle typically don't get hot.

Your kettle's power cable is sized to handle the relatively tiny current put into it, but even then it does warm up slightly. Try to run a million amps through it, and it will vaporize.

This type of laser carries so much energy that even a tiny fraction of a percent absorption will add up quickly, hence the propensity for injury.

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