Laser burns underwater!!!

[tomcatguy74]

I am pretty sure this is not something new but I just discovered that my 1.2w 445 can burn the leaves on my plastic plant under the water about 6 inches below the surface in my 5 gallon fish tank. If I shoot the laser through the glass from the side and focus the beam on the leaf you can hear a crackling sound and see bubbles and debris come off the leaf. I don't know about you all but that really amazes me. Just thought I might share!

 

[Newb2Lasers]

Lasers really are amazing!

 

[Misanthrop]

I literally only just thought of doing this a minute before..

I was burning part of a plastic bag under a couple of inches of water..

Smoke was coming from under the water aswell..

Can't believe I've never thought of it before.

 

[lasersbee]

Hmmmm..
How about a video of that under water burning..
Maybe it's just me...but I can't see burning plastic
below 212 Deg F under water...:thinking:


Jerry

 

[Cyparagon]

^The heat created can only be taken away from the point so quickly. Try it yourself if you think it's BS.

Many objects crackle from the rapid expansion/contraction of the tiny steam bubbles

 

[Misanthrop]

Hmmmm..
How about a video of that under water burning..
Maybe it's just me...but I can't see burning plastic
below 212 Deg F under water...:thinking:


Jerry

Of course I didn't mean burning..

i meant what cyparagon said.

 

[Benm]

Its not really burning, but it could be localized boiling. I've seen the same effect myself in soy sauce, and it also works with ink. At the waist of the beam the power density is great enough to locally boil the liquid. Obviously these bubbles of steam collapse and redissolve rapidly, but their formation and collapse creates a very interesting crackling sound.

 

[lasersbee]

^The heat created can only be taken away from the point so quickly. Try it yourself if you think it's BS.

Many objects crackle from the rapid expansion/contraction of the tiny steam bubbles

Whoa....don't eat your socks Cyparagon....

I didn't say it was BS as you so eloquently stated...

I asked to see a video of the "burning of plastic under
water"

I believe what I see.........

I understand that water requires more that 212 Deg F to
evaporate... and hence questioned the statement...

As it is possible to boil water in a paper cup but it
is impossible to burn the paper cup while water remains
in that paper cup.

BTW... there is a difference in Kitty Liter in free air and
Plastic under water...

Its not really burning, but it could be localized boiling. I've seen the same effect myself in soy sauce, and it also works with ink. At the waist of the beam the power density is great enough to locally boil the liquid. Obviously these bubbles of steam collapse and redissolve rapidly, but their formation and collapse creates a very interesting crackling sound.

That seems to make sense... but I would like to see
that effect in a video...
Perhaps I should just try it on my own....:beer:


Jerry

 

[Cyparagon]

BTW... there is a difference in Kitty Liter in free air and
Plastic under water...

Look again: it's submerged in water.

As it is possible to boil water in a paper cup but it
is impossible to burn the paper cup while water remains
in that paper cup.

Well, I've just done the impossible. :thinking: Sharpie, and a cup made out of paper. A 445nm laser at 1.3A makes a hole small enough so that it leaks slowly.
Like I said, try it yourself if you think it's BS.

It works for the same reason you can weld under water or stick your hand briefly into liquid nitrogen. The steam creates a barrier between the surface and the liquid. I believe it's called the leidenfrost effect.

 

[tomcatguy74]

op:

 

[tomcatguy74]

Great, now look whadda done started!!
I figured this was old news!
I tried to get a video up but YouTube is giving me crap. I will have to try again without using my Xoom. Maybe my phone will work. I will try it tomorrow.

 

[Ghostchrome]

You guys blind your fish yet?

 

[tomcatguy74]

No fish were cooked......er uh harmed during this experiment.

 

[GoolGaul]

No fish were cooked......er uh harmed during this experiment.

what did you have for dinner then?

 

[benmwv]

Look again: it's submerged in water.



Well, I've just done the impossible. :thinking: Sharpie, and a cup made out of paper. A 445nm laser at 1.3A makes a hole small enough so that it leaks slowly.
Like I said, try it yourself if you think it's BS.

It works for the same reason you can weld under water or stick your hand briefly into liquid nitrogen. The steam creates a barrier between the surface and the liquid. I believe it's called the leidenfrost effect.

What he meant is that you can put a paper cup full of water into a campfire and it won't burn, not that you can't burn it with a laser

I've boiled an egg like that before.

But I don't doubt that you can "burn" plastics underwater. I've burned (real) plants in the fishtank before.

 

[djayz]

Now thats cool, lasers are AWESOMEEE