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How I got my laser eye injury

funraniumlabs.com

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Re: How I got my laser eye injury

#251
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.

2.5 billion microwatts.

Sure but how many millijoules per day is that?

Re: How I got my laser eye injury

#252
post #180

Earlier quoted context omitted.

Hypothetically, someone could have left a guest (like say an engineer from the shipyard doing sea acceptance testing) fire a rifle and an unlucky wave reflection might have bounced a round back towards the bow.

Wow what an incredibly unfortunate hypothetical situation. 1 in a million ricochet that one.

Draw a ship. Draw some waves. Note the angle from Crayon Eater those waves.

Also note how wide an angle "ship hull" represents both vertically and horizontally.

Not so 1 in a million.

Re: How I got my laser eye injury

#253

Earlier quoted context omitted.

They are actual lasers and they're fine. Assuming you're talking about the light shows and not just random people.

I mean the light shows. Why do you say they are fine? It'd depend on who sets it up, right? If it's professionals I'd be a bit less worried, but in my country and many others def-not-professionals handle things that they shouldn't be handling, including setting up official shows.

Are they building homemade laser rigs or something?

Re: How I got my laser eye injury

#254

Earlier quoted context omitted.

> So some of them in the lowest price range don't even require you touch the gun to metal before letting you fire, etc. Are you able to attach them to the heads of sharks?

If you can get them to stay still long enough, maybe.

PSA: Sharks die quickly if you get them still. Their heartbeat is connected to the swimming motion.

Re: How I got my laser eye injury

#255
post #179

I worked in a laser lab for a few months early in my career. After the safety training I fear lasers getting near my eyes in situations most people don't care about. I even look away from barcode scanners at grocery stores. Sometimes I wonder about lidar being shot in all directions from those self-driving cars around SF.

Wait, are barcode scanners lasers? I've always thought of them as red lamps because their cone spreads out so widely quickly.

Some of them are, some of them aren't. There are obviously laser based ones that are easily recognizable as they produce a pattern of lines instead of a relatively evenly lit field. It's surprisingly difficult to find a picture of that, but I found a video that shows it well[1]. The ones that produce even illumination are probably LED based.

[1] https://www.youtube.com/watch?v=PIn00-qW5WI&t=1m34s

Re: How I got my laser eye injury

#256

Earlier quoted context omitted.

I tig. wear a helmet and have to buy argon every year. this seems like a huge hassle in comparison. is there that big a difference in quality and or range of processes that make it worth it?

I know one of the reasons we wanted pico-second and shorter pulsed lasers is that they can cut material with little to no damage of the neighboring material. There was a demo that I read about when this was all brand spanking new research, where they claimed that a laser scalpel causes no heat damage to tissue outside of a cell’s breadth from the contact point.

Is it this?

https://en.wikipedia.org/wiki/Coulomb_explosion

Re: How I got my laser eye injury

#257
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.

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

Re: How I got my laser eye injury

#258

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.

Brits don’t mess around with tea I guess. I believe they’re mostly on 240v even for residential there. Correct me if I’m wrong but I don’t think it would even be possible to heat water that fast in the US on 120v.

Correct, it takes about twice as long to boil a kettle in the US. But the US is the anomaly here. Most countries use 220-240V mains like Britain [1].

[1] https://en.wikipedia.org/wiki/Mains_electricity_by_country#T...

Re: How I got my laser eye injury

#259

One of my favorite sites, was the US Navy Safety Picture Of The Day site. It was crazy, how bad we can get. I think the site has long been retired.

You are probably thinking of this -- long gone, but still archived thanks to the Wayback Machine: http://web.archive.org/web/20081019180813/http://safetycente...

Re: How I got my laser eye injury

#260

Earlier quoted context omitted.

I'm dying of curiosity how cheap a cheap laser welder can be.

So, to clarify - what i have is a very nice IPG lightweld 1500 XR. They are normally not cheap (30k), and are very nice and well thought out safety wise. One of the fun parts when i lived in the bay area was that as companies got acquired, they didn't know what to do with the stuff they had before acquisition that isn't needed anymore, and it either sits in a warehouse, or gets auctioned off (or both!) So for example…

I see a bunch of them for about 1k on aliexpress. Any thoughts on those? I realize getting the cheapest possible unit is probably not the safest idea with laser welding.
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