Stories
Slash Boxes
Comments

News for nerds, stuff that matters

Slashdot Log In

Log In

Create Account  |  Retrieve Password

The Texas Petawatt Laser

Posted by kdawson on Wed Apr 09, 2008 04:33 AM
from the you-can-pet-a-dog-or-you-can-pet-a-cat dept.
Roland Piquepaille notes the hype surrounding what the University of Texas at Austin is calling the world's most powerful laser. During a tenth of a femtosecond this laser is 2,000 times more powerful than all the power plants in the US, and is brighter than sunlight on the surface of the Sun. On his own blog Roland points out that UT's is not the first petawatt laser; that distinction belongs to a system installed at Lawrence Livermore National Laboratory in 1996.
+ -
story

Related Stories

This discussion has been archived. No new comments can be posted.
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
 Full
 Abbreviated
 Hidden
More
Loading... please wait.
  • Will this laser have to be attached to significantly more powerful sharks?
    • by Icarium (1109647) on Wednesday April 09 2008, @04:47AM (#23010636)
      Wouldn't firing this laser underwater make the water uncomfortably hot? Please people, think of the sharks!
      • Re: (Score:3, Interesting)

        Wouldn't firing this laser anywhere causally connected with the known universe make earth's water uncomfortably hot? Where do they get the power to run this thing anyway? Do they just jack into all of the power plants in the US for 200 femtoseconds and then release it all in a tenth of a femtosecond? And how does it make sense to refer to the generating capacity of all the power plants the US in terms of energy? There are no times, femtosecond or not, involved, watts are rates of energy consumption.
        • by odourpreventer (898853) on Wednesday April 09 2008, @06:08AM (#23010932)

          Where do they get the power to run this thing anyway?

          In case this was a serious question: Giant capacitors, connected in parallel.

        • by yoavi (868428) on Wednesday April 09 2008, @06:34AM (#23011052)
          This is not accurate. Watts are indeed rates of energy consumption, that is, the amount of energy consumed per unit time (Watt stands for Joule per second). Now, if we squeeze 100 Joules in into 10^-13 of a second, then the *instantaneous* power during those 100 femtoseconds (and yes, the story has got it wrong, it's a tenth of a picosecond, not femtosecond, which makes a hundred femtoseconds) is one petawatt. The average power, assuming we operate at 0.1Hz (which I think will be the laser's repetition rate) is only 10 Watts.

          This also answers the "heating" problem. These lasers carry a relatively small amount of energy, and produce very little heat. However, the electric field that is produced when the beam is focused is huge, and many interesting phenomena can be studied with such a laser.

          Btw, for the same reason, this type of laser is completely useless as a weapon. In order to cause any real damage one has to deposit energy into the substance that is to be damaged, and again, these laser pulses carry a relatively small amount of energy.
        • by The Bender (801382) on Wednesday April 09 2008, @06:51AM (#23011132) Homepage
          Obviously the energy is built up over the period between pulses. And since the repetition rate is only 1 shot per HOUR, the average power output is only 0.1 W [calctool.org]!

          That wouldn't even put a dent in my electricity bill.

          Yes I know, I know...
      • by Tribbin (565963) on Wednesday April 09 2008, @06:21AM (#23010982) Homepage
        It will look a little like this:

        http://upload.wikimedia.org/wikipedia/en/d/d3/BFG9000doom2.jpg [wikimedia.org]
    • by walt-sjc (145127) on Wednesday April 09 2008, @06:06AM (#23010924)
      Bah - who needs sharks... They will just install them in military jets for when they need a LOT of popcorn...

      "Kent, this is Jesus.... And stop playing with yourself..."
  • Pish. (Score:3, Funny)

    by AndGodSed (968378) on Wednesday April 09 2008, @04:39AM (#23010600) Homepage Journal
    I am holding out for Laser Eye Implants.

    (Just don't go glaring at yourself in the mirror...)
    • Re:Pish. (Score:4, Funny)

      by l1gunman (463233) on Wednesday April 09 2008, @07:02AM (#23011196)
      WARNING: Do not look directly into laser with remaining eye.
      • don't, its not good for geeks. if ever in your lifetime a girl likes you, you'll fry her with your intense gaze.
        lol! Now I definitely want laser implants - but not for the ability to light candles on romantic evenings with a bat of an eyelid. It's too late for that. I want to fry the mother-in-law!
      • Re: (Score:3, Funny)

        by Anonymous Coward
        It's all good, so long as you remember to shout "BEHOLD! OPTIC BLAST!" before doing it.
      • One less restraining order I have to deal with. Win-Win.
  • Sorry boys (Score:5, Funny)

    by martin-boundary (547041) on Wednesday April 09 2008, @04:46AM (#23010632)
    It'll never work. There's just no peta tonne shark to put it on.
  • link to project page (Score:5, Informative)

    by dermond (33903) on Wednesday April 09 2008, @04:52AM (#23010658)
  • But... (Score:5, Funny)

    by Rix (54095) on Wednesday April 09 2008, @05:00AM (#23010688)
    Can it levitate a squirrel?
    • If you strapped on a laser propulsion getup onto his nutsack. That is not that far fetched either. Have you seen a squirrel's nuts?

      Of course that would not be "levitating" as much as it would be "rocketing off into space" at a fantastically high rate of speed.

      That would be fine with me as I have wrote plenty of blogs on the impending apocalypse where the squirrels will make us all their slaves. Everybody says I'm nuts... but you just wait...
  • FTFA: "They will create mini-supernovas."

    the Fools! the Fools! what could possibly go wrong? Actually I'm not so worried about a mini supernova as I am a mini black hole, because I don't see a mini supervova as possibly self sustaining (might take out a few scientists though - there's always plenty more), whilst a mini black whole near a large mass might last long enough to eat us all. Still, a better way to go then the grey goo.
    • You can have mini-black holes, but you can't really have mini-novae or mini-supernovae (mini-super would be a contradiction anyways right?).

      However, your right be concerned about the potential bouts of uncontrollable fusion/fission and thier scientist vaporizing shockwaves.

      The mini black holes aren't a worry. It's when they become large enough to devour scientists, and thier space/time warping event horizons encroach on your personal boundaries, then you should worry.

      Grey goo? Seriously, you're a huma

  • Uses? (Score:3, Funny)

    by sjs132 (631745) on Wednesday April 09 2008, @05:39AM (#23010814) Journal
    Am I the only one thinking about "Real Genius"? http://www.imdb.com/title/tt0089886/ [imdb.com]

    Lets get ready to cook some popcorn!
  • I am the greatest lover that ever lived.

    But seriously,I have been electrocuted by 20,000V at significant current several times. But only for a few hundred nanoseconds at a time. Sparks plugs rock.
  • by Ancient_Hacker (751168) on Wednesday April 09 2008, @06:00AM (#23010906)
    A petawatt is only 10^15 watts.

    Our Sun puts out about 4 x 10^24 watts, continuously, for billions of years.

    So this laser is only putting out about one four-billionth of the Sun, and only for a very split second.

    It's also very misleading if they intended to compare brightness per unit area. Even a cheap laser pointer is brighter than the surface of the Sun.

  • The pulse length is ~100 fs (0.1 ps), not 0.1 fs. 100 fs is already about as short as laser pulses can get - and 0.1 fs is much shorter than the length of a single electromagnetic wave.
  • Now to put it on a F***ing sharks heads [youtube.com]
  • by justkeeper (1139245) on Wednesday April 09 2008, @06:23AM (#23010996)
    One femtoseocnd is 10 to the power of -15 of a second,NOT one trillionth of a second.Thus the pulse duration should be 100 fs,which is realistic.State of the art technology can't yet produce high power sub-femtosecond(i.e attosecond) pulses ,due to low conversion efficiency of energy concentrated on the low-frequency spectrum to the high-frequency spectrum using currently available methods(for an attosecond pulse a Fourier Transform will show that you have mostly X-ray frequency components in the frequency spectrum). Discaimer:I'm a Ph.D student working on high-power laser systems.
  • by djtachyon (975314) on Wednesday April 09 2008, @06:32AM (#23011044) Homepage Journal
    University of Rochester is building a petawatt laser of capable of picosecond pulse lengths. http://omegaep.lle.rochester.edu/ [rochester.edu]
  • by cnosh (1073210) on Wednesday April 09 2008, @08:42AM (#23012068)
    You have to put this in perspective. They may have made a laser with highest peak intensities but it's nowhere near the most energetic laser out there. According to their press release their pulses have 150 J of energy. Compare this to the National Ignition Facility at Lawrence Livermore laser, which will produce 1.8 MJ per shot when it is completed next year, or to the laser at the University of Rochester, which will produce several kJ. Though not yet finished, both these lasers have already demonstrated many kJ of energies.
  • by Animats (122034) on Wednesday April 09 2008, @10:01AM (#23013028) Homepage

    More Roland the Plogger blogspam, driving traffic to his useless ad-laden blog. To get around the block on links to his own site, he's now submitting links disguised via "tinyurl".

    Slashdot covered this laser weeks ago.

  • by SocietyoftheFist (316444) * on Wednesday April 09 2008, @10:04AM (#23013072)
    They have a freshman wonder kid and a graduating senior working together on breakthrough laser designs.
    • Re:Time duration? (Score:4, Insightful)

      by famebait (450028) on Wednesday April 09 2008, @05:19AM (#23010748)
      even I can say my torch is brighter than the sunlight on the surface of the sun for 1 gazillionth of a second.

      You could say it, but it wouldn't be true.
    • And some of us would rather our torches didn't explode.
    • Re:Time duration? (Score:5, Informative)

      by MLCT (1148749) on Wednesday April 09 2008, @07:27AM (#23011370)
      They aren't ridiculous - and you are ill informed to say that they are. Average power vs. peak power. Those two variables are highly relevent for a pulsed laser. Your "torch" isn't even pulsed.

      A lot of ground breaking research is undertaken *utilising* the ability to deliver very short very high energy pulses - for doing that you can deliver a huge amount of energy in a very tiny amount of time - then observe what happens. Indeed a lot of the very high energy regions cannot be accessed with anything but ultrafast pulsed systems, as CW setups would just destroy themselves (and even using UF systems chirping "tricks" are used to reduce peak powers until the final moment to ensure the optics aren't burnt out).

      See http://en.wikipedia.org/wiki/Chirped_pulse_amplification [wikipedia.org]
    • Because a big freaking laser is interesting? Jeez, lay off the America-bashing for a while - it's unhealthy to fixate on such things. It's odd that the first thing that you thought of was how Americans suck and how Europeans are so great with their LHC. What do we call that, "projection"? This laser has got nothing to do with the LHC, which I am also excited to see.
      • Re: (Score:3, Insightful)

        "It's odd that the first thing that you thought of was how Americans suck and how Europeans are so great with their LHC."

        Those are your words, not his.
      • I'm not bashing America, but this seems like a local story in science not a global one. By the end of this year we may have found the Higgs Boson, which is a big story.
        • It's a big laser beam. Of course it's news for nerds. If the LHC works, great, but that's just one story. Instead of moaning about how provincial it is, how about going to the site and reading the specs of that thing?
    • Re:So what? (Score:4, Funny)

      by kalirion (728907) on Wednesday April 09 2008, @08:42AM (#23012058)
      To be honest, its hard to get excited about this with the LHC coming online soon.

      True, what's the most this laser could do, cut the Earth in half? Pretty tame compared with the LHC recreating the Big Bang and destroying the universe as we know it.
      • And what exactly powers it? Oh wait coal.
        • Petawatt Lasers use, wait for this, petawatts of power.

          Yes, peta watts (10 ^ 15) for less than a femto (10 ^ -15) second)

          A mere blip compared to other power uses. I don't think this research is particularly relevant to climate change, the OP was trying to start a flamewar.

          How you think that power is generated? Nice clean nuclear? Hahahaha.

          Probably natural gas. And carbon-neutral is a better way to describe nuclear than clean.