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Don't Cross the LHC Stream! (Maybe)
jamie points out this piece from always-entertaining Bad Astronomer Phil Plait, who asks this week the simple question "What happens if you put your hand in the beam of the Large Hadron Collider?" The thrill of discovery to me doesn't sound worth the worst-case scenario.
You get a built-in tool that makes it easier to masturbate.
They'd just stick a pig foot in there.
"So it was in 1978 that when the proton beam entered Anatoli Bugorski's skull it measured about 200,000 rads, and when it exited, having collided with the inside of his head, it weighed in at about 300,000 rads. Bugorski, a 36-year-old researcher at the Institute for High Energy Physics in Protvino, was checking a piece of accelerator equipment that had malfunctioned - as had, apparently, the several safety mechanisms. Leaning over the piece of equipment, Bugorski stuck his head in the space through which the beam passes on its way from one part of the accelerator tube to the next and saw a flash brighter than a thousand suns. He felt no pain.
http://www.wired.com/wired/archive/5.12/science.html
This is a man who looked into a proton beam accelerator that he thought was non-operational. It's already happened once before.
Someone I know had the small child of a neighbor flash him in the eye with a cheap Chinese red laser pointer some time ago, and got a permanent scar on his retina and a second "blind spot" in one of his eyes. Apparently, the pointer was a little bit too powerful in the IR region than it should have been.
Moral of the story - avoid high energy beams regardless of the wavelength or the particle kind because you never know what will slip by even in a supposedly "safe" circumstances.
An artist makes unusual "sculptures" by putting acrylic blocks into the beam path of a relatively small electron accelerator:
http://www.dailymail.co.uk/sciencetech/article-1232908/Captured-lightning-The-artist-traps-fossilised-bolts-electricity-inside-acrylic-blocks.html
I don't know of any red lasers that have IR components. Lasers are, by definition, monochromatic. That's the idea after all. The reason some have IR as well is they are DPSS. They produce IR radiation directly, a frequency doubler then takes it up to the visual range. That's a lossy process, so the IR is much higher than the final output, hence an IR filter is needed. Green lasers work this way, at least all the ones I've seen. However red laser pointers are all direct drive, the diode outputs the frequency you want. That's why they are used for CDs and so on, keeps the cost down.
That is also the big deal with Blu-ray lasers (actually quite violet, not blue). Again, direct diode lasers. Means they cost less, use less space and so on, and of course being violet have a higher wavelength.
I've never heard of a red DPSS laser pointer.
Someone calculated that about 4 joules of energy would be deposited. I assume that is in a single pass of the beam. However, if the beam recirculates (does it?), then the hypothetical hand will get hit by the beam many times. Then a huge amount of energy will end up in the hand in a short time and it'd probably be cut by the beam as you inserted it.
What also intrigues me is whether a fatal does of radiation would occur from the 4 joules/pass that you would get. I think it would be about 8 Gray of radiation dose into the hand. A 5 Gray whole-body dose of radiation is usually fatal. The hand is less vulnerable to radiation than the body in general, however, this cannot be a good thing.
Here's my take:
multiple passes: either hand is sliced as it is inserted into the beam, or the hand explodes
single pass: might lose the hand, owner of hand might get pretty sick
--PM
And then when nothing happens, they'll repeat the experiment with 10kg of TNT strapped to the pig.
Come on, it's what they do in *every* episode.
Moral of the story - avoid high energy beams regardless of the wavelength or the particle kind because you never know what will slip by even in a supposedly "safe" circumstances.
Incorrect. Moral of the story: Do not look into laser with remaining eye.
Now that I think about it, I'm pretty sure everything I just said is completely wrong.
The total energy in the beam is 724 MJ (173 kilograms of TNT) (energy stored in magnets are 10x this) That is a bomb big enough to take out a school.
It would be hard to get your hand into vacuum, but imagine a space suit arm attached to a sandblast cabinet.
The beams energy would hit your hand in a spot d1mm. It would most certainly deposit all its energy there until that part of your hand became a vacuum. Probably similar to a laser knife. In addition, your flesh that obstructed the beam would give off a lot of radiation as it burned away. Imagine Hiroshima 1km away x10^8 on that part of your body.
Every proton would not hit something in your hand on first encounter, but if it missed, it would just loop around, and hit on a later time. The result would be the same. In a short time, your hand and your space glove would have a hole through it. More likely a straight cut from where you put it in. Anything nearby would be exposed to a good dose of radiation as these collisions would be quite "dirty".
don't cut it off www.mgmbill.org
Fermilab had a beam loss event in 2003 (beam came into contact with part of the ring). The beam drilled a 2.8 mm hole through a 5mm tungsten support. It also etched a groove 25 cm long and 1.5 mm deep into a stainless steel collimator (after passing through the tungsten). Apparently this took about 8.3 ms (over several turns of the beam) before the beam dissipated.
I'm guessing if you could insert your hand fast enough (not possible, even if there wasn't a vacuum tube) you would end up with a nice small hole drilled through your hand.
This is the report from the Fermi incident:
http://beamdocs.fnal.gov/DocDB/0011/001185/001/FN-751.pdf
A man comes home from his work at the deli, and tells his wife, "I have a strong desire to put my penis in the pickle slicer."
"That's sick!" replies his wife. "You need help."
"I don't see any reason it would be sick", retorts the man, "I think it would be fun!"
Two days later, his wife comes home from an errand, and her husbands car is in the driveway. "You're home early", she says.
"Yes, I put my penis in the pickle slicer!" he smiles.
"Oh my God!", gasps his wife, "What happened?"
"I got fired! So did she!"
Why, without your clothes, you're naked, Miss Dudley!
Come on, it's what they do in *every* episode.
You almost say it like it's a bad thing.
Canada: The US's more awesome sibling.
Incorrect. Lasers use a highly focused parallel high energy beam. Because it's high energy, it can burn. By projecting the focused parallel beam through a convex lens (the eye's lens) you refocus the beam and all the parallel high-energy photons focus on a point. This point light then burns the back of the cornea. Like looking directly at the Sun. Or focusing a magnifying glass on a leaf on a sunny day. Has nothing to do with IR and everything to do with optics and energy levels.
Glad to know I'm not the only one fuzzy on the whole good / bad thing.
Somebody tell him about the twinkie.
"I like to lick butts!" by MobileTatsu-NJG (#32700246) (Score:5, Informative)