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Don't Cross the LHC Stream! (Maybe) 171

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.
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Don't Cross the LHC Stream! (Maybe)

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  • Simple (Score:4, Funny)

    by Anonymous Coward on Saturday September 25, 2010 @06:29PM (#33699542)

    You get a built-in tool that makes it easier to masturbate.

    • A third hand? Sweet!

    • Re: (Score:3, Funny)

      Here is an explanation of the LHC. []

      Just stumbled across it, had to post.

    • Re: (Score:2, Funny)

      by Ssherby ( 1429933 )

      "What happens if you put your hand in the beam of the Large Hadron Collider?"

      You become famous for about 2.48154 nano seconds as the origin of the end of the universe.

      • ... earn yourself a permanent spot in the Darwin Awards category, right alongside people who lay down in front of 100+ car trains, people who put their hands in front of oxy-acetylene torches (just to see if it hurts, y'know) and many of the other idiots out there.

          Next question... why is this even a question? There are two types of people, dead extremist masochists, and the rest of us...


  • But when I put my bottom in front of it I ended up with a huge black hole.
    • But when I put my bottom in front of it I ended up with a huge black hole.

      Let me guess, you are dyslexic and thought it was large hardon instead of hadron?

      Sounds like it probed Uranus instead of creating a huge black hole.

  • by John Jorsett ( 171560 ) on Saturday September 25, 2010 @06:33PM (#33699576)

    They'd just stick a pig foot in there.

  • by Anonymous Coward on Saturday September 25, 2010 @06:33PM (#33699580)

    "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. []

    • Re: (Score:3, Informative)

      by wisnoskij ( 1206448 )

      That quote makes it sound like he died.
      Apparently he lived with no major disabilities.
      it sounded like he was just very ungly afterwards and had seizors, but retained similar mental capabilities.

      • Re: (Score:3, Informative)

        by durrr ( 1316311 )
        Apparently he's still alive, atleast wikipedia doesn't state he have died of any causes.
      • Well, some people survive a few dozen nails shot in their brain by a nailgun.
        But most don't.
        He just got one very thin but radioactive nail crossing the entirety of his head.
        I'm pretty sure he had a big chance to die, that beam was apparently able to burn through veins, it could have hit some main vein in his brain.

        • My rough analysis says that if a high-energy electron beam can cut holes in metal, then a high-energy beam of much more massive protons with high kinetic energy would have an effect on tissue mass it encounters. My guess then is that the beam could slice through tissue like a thin blade. Maybe like the fabled monomolecular blade of science fiction would. Obviously a heavy stream of protons would break bonds between molecules and act like a cutter. It would be a high density stream of positive charges, and t
          • The symptoms described within the article sound very similar to that of a stroke. Seems this supports your idea.

      • Sounds like his symptoms were closer to that of a stroke victim.

        Makes sense, considering the type of damage a stroke causes would be similar to that which he experienced.

    • by bcmm ( 768152 ) on Saturday September 25, 2010 @07:19PM (#33699894)

      (though we don't know of anyone else who has been exposed to radiation in the form of a proton beam moving at about the speed of sound) [My emphasis]

      This was where I stopped reading and just read Anatoli Bugorski []'s Wikipedia article instead.

    • Sounds like the time two Texas A&M vet students in the late 70s who were smart enough to overcome the interlocks on the cyclotron but not smart enough not to look upstream at the beam they were aiming at an animal. They thought it would look like a fluoroscope without the screen. They were expelled.
    • Re: (Score:3, Interesting)

      by vlueboy ( 1799360 )

      That man's survival due to head/brain injury in the face of certain death reminds me of another "believe it or not" jewel duscussed OT on /. few weeks back [].

      A XIX century miner named Phineas Gage long survived a mining explosion that put a 13 pound metal rod of 3.5 feet [] across a room, after leaving a vertical hole in his head.

      Wikipedia's mention of seizures for both, and the related links citing auras and other pre-seizure electrical phenomena sound like a sobering human depiction of how power lines in movie

  • by Kagura ( 843695 ) on Saturday September 25, 2010 @06:33PM (#33699582)
    This is a man who looked into a proton beam accelerator [] that he thought was non-operational. It's already happened once before.
    • It says those protons were going about speed of sound. That doesn't sound right to me...
    • That solely cites the already-mentioned Wikipedia article [], which mentions that its own references may not be reliable. Notice that the only English-language reference is Let me put it another way:

      The inside of his head continued to burn away: all the nerves on the left were gone in two years, paralyzing that side of his face.

      The story talks about the particle beam (basically) melting the left side of his face, and the left side of his brain. Why, then, does it continue to talk about him losing control of whatever still existed on the left-side of his face? Is it not common knowledge that the brain does a little switcharoo?

      • Is it not common knowledge that the brain does a little switcharoo? You know, the left-brain controls the right side of the body and the right-brain controls the left side of the body.

        Anatomy was never my strong point, but I was taught that the "switcharoo" occurs in the neck. So while the left brain controls the right hand, the left brain controls the left side of the head.

  • by siddesu ( 698447 ) on Saturday September 25, 2010 @06:42PM (#33699632)

    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.

    • Odd (Score:5, Informative)

      by Sycraft-fu ( 314770 ) on Saturday September 25, 2010 @07:10PM (#33699838)

      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.

      • by siddesu ( 698447 )

        Well, I thought it odd too, but that is the explanation he got from the people who treated him and he swears the laser was red, so it probably was.

        Anyway, my point was it is dangerous to get in the way of any beam, including the supposedly safe and low-powered laser pointers.

    • by Arthur Grumbine ( 1086397 ) on Saturday September 25, 2010 @07:29PM (#33699934) Journal

      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.

    • by celtic_hackr ( 579828 ) on Saturday September 25, 2010 @11:28PM (#33700970) Journal

      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.

      • Incorrect. It has to do with IR inasmuch as you _do not see IR light_. Thus, the apparent brightness is a _lot_ lower than the true light output. Obviously, the fact that IR is great to transport heat helps in burning tissue.

        Also, with lasers, you do not need to focus any more precisely _because_ the beams are parallel (it gets focused within the laser's casing). This (and the fact that they waves are in sync) is why a laser can cut steel while a flashlight can't.

        • Wrong again!

          Laser = Light Amplification by Stimulated Emission of Radiation.

          A laser has two partially mirrored lenses (say 99% and 80%) on either side of a medium, let's say ruby. you inject some high energy light (say a flash from a Xenon strobe light) into the ruby. This creates a photon cascade event. Some of the photons shoot out in directions parallel to the two lenses. But they get reflected by the mirrors. One mirror is less mirrored than the other. The photons then bounce back, and knock ou

          • by RichiH ( 749257 )

            None of what you said contradicts anything I said.

            I should have stated that my comments regarding IR are for green (and IR ;) lasers only, though. Re-reading what I said, I could have made this more explicit. OTOH, I directly replied to what you said without contradicting you.

            Oh well, lesson learned for both of us :)

  • Acrylic... (Score:5, Interesting)

    by Freddybear ( 1805256 ) on Saturday September 25, 2010 @06:44PM (#33699646)

    An artist makes unusual "sculptures" by putting acrylic blocks into the beam path of a relatively small electron accelerator: []

    • Re:Acrylic... (Score:5, Informative)

      by XiaoMing ( 1574363 ) on Saturday September 25, 2010 @07:59PM (#33700108)

      Slightly different, as what the artist does is actually charge up the acrylic block with excess electrons (like a supersaturated chemical solution) that have nowhere to go because of the acrylic and surrounding air acting as an insulator. Then he takes a nail to the start of the "lightning", and hammers it in which creates a ground (just like what happens in charged thunderclouds when lightning strikes), creating the effect so reminiscent of lightning.

      You can see it in this video: []

      They start with a charged up piece of acrylic, and it's obvious that the effect is not from the beam itself but from the geometry of the piece of acrylic and the grounding path they introduce.

  • Sounds like a idea for a sci-fi channel b movie!

  • 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


    • by caffeinated_bunsen ( 179721 ) on Saturday September 25, 2010 @07:49PM (#33700046)
      I think this is the comment you're referring to:
      12. Bethany Says:
      September 21st, 2010 at 8:20 am

      Alright, here's what I calculated:
      The protons are high energy with lorentz factor of gamma=7500, kinetic energy is about K=7×10^6 eV. The paper cited below says that the stopping power of a proton going 10^6 eV is about 2.5×10^8 eV cm^2 g^-1. Using the density of muscular tissue rho=1g cm^3 and the thickness of my hand of 1 cm, the energy deposited is 2.5×10^8 eV. In other units its 1.07×10^-11 calories, 4.49×10^-11 Joules, and 1×10^-14 grams of TNT. If there are hundred billion protons per bunch in the beam (as the video said) then for every bunch you get 4.49 Joules or 0.001 grams of TNT of energy.
      (emphasis mine)

      There are two beams, each of which contains 2808 bunches. Don't worry about the effect of multiple passes, though, since there won't be any tissue left in the beam's path by the time the first pass is over.

      A more informative comment showed up later:
      31. Xerxes Says:
      September 21st, 2010 at 10:45 am

      I think the hand-beam question is best answered by this document: []

      Granted, a carbon block isn't an exact model of the human hand, but it's probably close enough. The key points are:

      1) "this energy deposit over 85 s is long enough to change the density of the target material. The density decreases at the inner part of the beam heated region because of the outgoing shock waves in the transverse direction. As an example, after the impact of 200 bunches with a size of = 0.2 mm, a maximum temperature of 7000K and a density decrease by a factor of 4 is expected." The results of heating your hand to 7000K and increasing its volume by a factor of 4 are probably best not imagined. Since a full beam is 2808 bunches instead of 200, you might want to scale that by a factor of 10 too.

      2) But on the other hand (hehe): "The beam tunnels through the target and deposits the energy with a penetration depth of 10 m to 15 m" Since your hand is not 10m thick, you won't pick up the full effect. This paper goes into some detail of the spatial distribution of the energy dump: [] So at hand-thickness of 2ish cm, you'd only get maybe an eighth of the effects of #1, so your hand will only reach the more modest temperature of 1000K (times 10 for a full 2808 bunches?). The shockwave from the blast will extend several cm in the transverse direction; translation, the rest of your hand will be blown off by the middle of your hand exploding. Probably the part of the accelerator apparatus downstream of your hand picks up the rest of the energy. The rest of you probably wouldn't want to be standing next to it when it blows.

      Cool pictures of the effects of a low-energy (450-GeV) beam on copper plates are in []

      (I spent so much time looking up references, several other people made the same points. Oh well.)

      Note particularly the fact that if one beam hit the solid graphite beam dump without being swept around during the pass, the surface would be at 7000 C, and would be well in the process of exploding, by the time the first 200 bunches had hit. Your hand, having a lower boiling point than graphite, would begin to remove itself from the path of the beam somewhat sooner, and would therefore probably absorb rather less energy. That may be small consolation, though, since it pretty much means that the splattered remnants of your hand wouldn't be as intensely radioactive as the carbon in the beam dump would be.
  • by viking80 ( 697716 ) on Saturday September 25, 2010 @07:46PM (#33700026) Journal

    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".

    • > It would be hard to get your hand into vacuum...

      The only "practical" way to do it would be to modify the line running to the beam dump by inserting an air gap (the windows would have to be tungsten or something). You'd place the hand in the gap and then divert the beam into the dump line.

      > ...imagine a space suit arm attached to a sandblast cabinet.

      As you swung your arm into position the beam would blow a hole in the edge of the glove. Hitting the glove would disrupt it enough that it would scatte

      • Having read the Fermilab report I see that there is no point in making the windows tungsten. I also see that if they really wanted to know what the beam would do to a slab of meat they could model it pretty accurately.

    • I'm afraid you're missing one point.
      Sure all the local effects would be as described.
      But your hand is composed mostly of water. About 2mm diameter by some 2cm length cylinder inside your hand would turn into massively superheated steal over few nanoseconds. Steam that hot, from that amount of water, in that volume has enormous pressure. Maybe the resulting explosion would end near your wrist, but I suspect shrapnels of your own hand bones would kill you.

  • You can look into you LHC & lasers and what not.

    me, i'm waiting for the test of a gamma bomb, so I can sneak out on the test range.

    Just don't make me angry.

  • by Myrv ( 305480 ) on Saturday September 25, 2010 @08:36PM (#33700306)

    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: []

  • by snspdaarf ( 1314399 ) on Saturday September 25, 2010 @08:55PM (#33700406)
    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!"
  • I haven't read the article... here's my semi-educated guess: It would feel like you stuck your hand in the path of a lightning bolt. Then you'd die an unpleasant death from the massive radiation overdose resulting from the interaction of the high energy particles with the nuclei in your hand. I'm not recommending anyone try it.
  • ...tried it in 1978 at the IHEP. But not with his hand []!

  • The "Large Hadron" collider is a hoax. Everyone knows Hadrons are extremely small.

    My local pub offers hadron flavoured beer.

    • You must be dyslexic. You've actually been drinking hardon flavoured beer! Which, to it's credit, is a lot stronger than American beer...
  • I saw the special on PBS in which they show'd the workers and scientists building it. They specifically asked the lead guy what would happen if they lost confinement of the beam and he said the total energy in the beam is about equivalent to a buss traveling at 65mph. He went on to say they believe and area of approximate 8feet by 8feet would be instantaneously vaporized... and it why the facility is underground. It's been a couple of years since I saw that episoned so I might have a couple of the numbers w
  • I'm pretty sure plenty of scientists must have looked at this, after all someone had to design the beam dumps. From []

    In 2003, two-thirds of the superconducting magnets in the Tevatron’s six-kilometer ring quenched at the same time. The beam drilled a hole in one collimator and created a 30-centimeter groove in another. That accident, while serious, was the only one in the accelerator’s 20-year history, and the machine was back up and running within two weeks. Could something similar happen on a larger scale at the LHC?

    “In a bad accident, the beam could go off course and drill a hole through one or two magnets,” says Schmidt. While this would not destroy the LHC, it would still require time and money for repair.

    I'm pretty sure something that can drill a hole in a super conducting magnet would make a hole in someone's hand...

  • What happens if you put your hand in the beam of the Large Hadron Collider?

    What do you mean exactly? What happens to your hand - or which results could you expect from the experiment?

    The experimental data are hard to predict - a hand is a very complex target, and many reactions are possible. Quite likely the measurements will be too overcrowded to make much sense.

    What will happen to the hand is perhaps easier to predict. Firstly there is the hard vacuum, which will make the blood boil - the resulting water vapour will disrupt the beam, so nothing further will happen until the hand

Contemptuous lights flashed flashed across the computer's console. -- Hitchhiker's Guide to the Galaxy