×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

The Texas Petawatt Laser

kdawson posted about 6 years ago | from the you-can-pet-a-dog-or-you-can-pet-a-cat dept.

Power 174

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.

cancel ×
This is a preview of your comment

No Comment Title Entered

Anonymous Coward 1 minute ago

No Comment Entered

174 comments

We're all wondering... (5, Funny)

dj_tla (1048764) | about 6 years ago | (#23010580)

Will this laser have to be attached to significantly more powerful sharks?

Re:We're all wondering... (4, Funny)

Icarium (1109647) | about 6 years ago | (#23010636)

Wouldn't firing this laser underwater make the water uncomfortably hot? Please people, think of the sharks!

Re:We're all wondering... (2, Interesting)

Brian Gordon (987471) | about 6 years ago | (#23010900)

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.

Re:We're all wondering... (4, Informative)

odourpreventer (898853) | about 6 years ago | (#23010932)

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

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

Re:We're all wondering... (3, Interesting)

interiot (50685) | about 6 years ago | (#23011516)

It looks like this [rl.ac.uk]. Pictures like that bring a tear to my eye. If you have even a small subset of those capacitors, you can do some seriously cool shit [tesladownunder.com].

Re:We're all wondering... (5, Informative)

yoavi (868428) | about 6 years ago | (#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.

Re:We're all wondering... (3, Funny)

garett_spencley (193892) | about 6 years ago | (#23011184)

"Btw, for the same reason, this type of laser is completely useless as a weapon."

Thanks. Another slashdotter crushes another one of my hopes and dreams. Jerk :(

Re:We're all wondering... (1)

s_p_oneil (795792) | about 6 years ago | (#23011414)

10 Watts? So this thing is approximately twice as powerful as one of those 5W key-chain laser pointers? That's good to know. ;-)

Nope. You are a factor of 1000 out. (2, Informative)

Maddog Batty (112434) | about 6 years ago | (#23011480)

Nope. The key ring laser pointers are 1mW to 5mW so this thing is 2000 to 10000 times the average power. A 10W laser is very good at setting fire to things but won't drill a hole through your still twitching body.

Re:Nope. You are a factor of 1000 out. (1)

s_p_oneil (795792) | about 6 years ago | (#23011724)

It was meant to be a joke, but you're right, I messed it up. ;-) If we're being serious though, we also need to account for the fact that the keychain lasers use 1-5mW in a full second, not in 100 femtoseconds, so you would need to scale that number up by several orders of magnitude.

Re:We're all wondering... (1)

jiriw (444695) | about 6 years ago | (#23011076)

Where do they get the power to run this thing anyway?
Thats where batteries are for... probably a huge array. Or capacitors, or a spinning object storing a huge load of kinetic energy or any other form of energy storage. It's the same way as KEMA (an electronics testing and certification institute I live near) stores it's energy for huge lightning bolts and power overloads they use to test kilovolt transformers, massive power breakers and other high voltage equipment.
They could store the energy for those 200 femtoseconds. Notice it's only 200 femtoseconds ... so if you load an array for 1 second with only 1*10^-10th of all the power all U.S. powerplants are producing in that timeframe you hold all the energy needed to fire the laser ... neglecting any transfer losses.

Re:We're all wondering... (4, Informative)

The Bender (801382) | about 6 years ago | (#23011132)

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...

Re:We're all wondering... (4, Funny)

Tribbin (565963) | about 6 years ago | (#23010982)

It will look a little like this:

http://upload.wikimedia.org/wikipedia/en/d/d3/BFG9000doom2.jpg [wikimedia.org]

Re:We're all wondering... (0)

Anonymous Coward | about 6 years ago | (#23011666)

I prefer the chainsaw in that room. Not many projectiles so why waste your ammo?

Re:We're all wondering... (3, Funny)

walt-sjc (145127) | about 6 years ago | (#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..."

Re:We're all wondering... (0)

Anonymous Coward | about 6 years ago | (#23011340)

This was developed in support of securing the Texas border. If people break into our homes, we get to shoot'em; and now when people cross the border illegally, we get to zap'em.

pocket size (1)

p51d007 (656414) | about 6 years ago | (#23011708)

Oh goodie! Now in a couple of years, when they figure out a way to make a laser pointer out of this, we can have these burning holes in everything LOL.

Pish. (2, Funny)

AndGodSed (968378) | about 6 years ago | (#23010600)

I am holding out for Laser Eye Implants.

(Just don't go glaring at yourself in the mirror...)

Re:Pish. (1)

hashax (1190057) | about 6 years ago | (#23010620)

don't, its not good for geeks. if ever in your lifetime a girl likes you, you'll fry her with your intense gaze.

Re:Pish. (1)

symes (835608) | about 6 years ago | (#23010644)

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:Pish. (3, Funny)

Anonymous Coward | about 6 years ago | (#23010708)

It's all good, so long as you remember to shout "BEHOLD! OPTIC BLAST!" before doing it.

Re:Pish. (1)

Walruzoar (514362) | about 6 years ago | (#23010862)

Well I'm holding out for a handheld laser pointer version, in green of course.
Will if come with a heavy duty mains lead, or a BIG box of AA cells?

global warming (-1, Flamebait)

timmarhy (659436) | about 6 years ago | (#23010612)

let me guess, someone will point out how this is making global warming worse, we need to hug some tree's to offset the carbon.

Re:global warming (-1, Offtopic)

Whiney Mac Fanboy (963289) | about 6 years ago | (#23010894)

let me guess, someone will point out how this is making global warming worse,

Let me guess. Someone with no understanding of the mechanisms of climate change or Lasers will jump into this discussion with a piece of irrelevant flamebait.

we need to hug some tree's to offset the carbon.

Guess what? Lasers produce heat, not carbon. (you fucking idiot).

Re:global warming (0)

QuantumG (50515) | about 6 years ago | (#23011012)

Petawatt Lasers use, wait for this, petawatts of power. How you think that power is generated? Nice clean nuclear? Hahahaha.

Re:global warming (2, Informative)

Whiney Mac Fanboy (963289) | about 6 years ago | (#23011276)

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.

Re:global warming (-1, Troll)

Anonymous Coward | about 6 years ago | (#23011158)

Guess what? Lasers produce heat, not carbon. (you fucking idiot).
Guess what? We hate the carbon DIOXIDE because

wait for it...

it generates, umm, HEAT.

Hence the phrase "global warming".

You sure as hell got the "Whiney" part right.

And at your level of anal-retentive idiocy, I doubt you're fucking anything. You need to loosen up. Go fuck your own rectum with one of your fingers. Or maybe even most of your fingers. Even better, why don't you go shove a telephone pole up your ass? Make sure to select a used one that had 10,000 lineman climb it over its lifetime, so it's got millions of finger-sized splinters poking out of it.

Re:global warming (-1, Troll)

Anonymous Coward | about 6 years ago | (#23011202)

Guess what? We hate the carbon DIOXIDE because *snip* it generates, umm, HEAT.

Bzzzzzzt. Incorrect. C02 does not generate heat - it traps heat (you fucking idiot).

Warning: (0)

Anonymous Coward | about 6 years ago | (#23010622)

Do not attempt to block laser with remaining hand.

Sorry boys (4, Funny)

martin-boundary (547041) | about 6 years ago | (#23010632)

It'll never work. There's just no peta tonne shark to put it on.

So what? (0, Troll)

damburger (981828) | about 6 years ago | (#23010660)

To be honest, its hard to get excited about this with the LHC coming online soon. I guess this is of interest to Americans though.

Re:So what? (1, Flamebait)

DNS-and-BIND (461968) | about 6 years ago | (#23010764)

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:So what? (2, Insightful)

YeeHaW_Jelte (451855) | about 6 years ago | (#23010790)

"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.

Re:So what? (1)

damburger (981828) | about 6 years ago | (#23010898)

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.

Re:So what? (1)

DNS-and-BIND (461968) | about 6 years ago | (#23011094)

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?

But... (4, Funny)

Rix (54095) | about 6 years ago | (#23010688)

Can it levitate a squirrel?

Re:But... (1)

EdIII (1114411) | about 6 years ago | (#23010742)

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...

Re:But... (1)

morgan_greywolf (835522) | about 6 years ago | (#23011438)

Have you seen a squirrel's nuts?
I dunno about you, but I'm not a biologist, so I don't go out of my way to look at other species' gonads, no.

I have wrote plenty of blogs on the impending apocalypse where the squirrels will make us all their slaves.
Wrong rodents. It's the mice that have made us all their slaves.

I don't know about you, but I, for one, welcome our new laser-propelled rodent overlords.

Re:But... (0)

Anonymous Coward | about 6 years ago | (#23010806)

Thank you Mr. XKCD...

Time duration? (1, Funny)

superash (1045796) | about 6 years ago | (#23010718)

During a tenth of a femtosecond this laser is ... brighter than sunlight on the surface of the Sun That is 10 to the power of -16 of a second. Such comparisons are ridiculous because even I can say my torch is brighter than the sunlight on the surface of the sun for 1 gazillionth of a second. :P

Re:Time duration? (3, Insightful)

famebait (450028) | about 6 years ago | (#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.

Re:Time duration? (4, Informative)

MLCT (1148749) | about 6 years ago | (#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]

Re:Time duration? (1)

Fizzl (209397) | about 6 years ago | (#23011454)

Roland has always been good at making mundane shit sound exciting.
I always got angry when I got lured into his blog by fancy summary, because there is never any substance to his fantastic tales.

Twofo Goatse (-1, Redundant)

Anonymous Coward | about 6 years ago | (#23010722)

Goatse. [twofo.co.uk][goatse.ch]

You nerds love it.

Re:Twofo Goatse (0)

Anonymous Coward | about 6 years ago | (#23010904)

You love it more. I don't see the nerds posing it on a daily basis, now go change your shorts.

the fools! (1)

apodyopsis (1048476) | about 6 years ago | (#23010734)

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.

Re:the fools! (1)

Hojima (1228978) | about 6 years ago | (#23010872)

You're joking right? I hope that you're aware that we've been creating black holes and other "mini cosmic catastrophes" with particle accelerators for years now. Many crazy scientists (or just overly concerned) have been worried about such things while failing to realize that cosmic rays (which have been colliding for eons) should theoretically produce them since they are based on the same principles. There are even odd super particles that have odd quark configurations that are supposed to convert all matter in to it, so long as the creation process can be sustained, but if this theory was correct, neutron stars would have produced them by now. Believe me, humans aren't capable of reproducing catastrophes any better than the extreme conditions of space. These people have a good idea about what they're doing since they've observed the effects in space (though not closely enough, which is why they built the accelerators to begin with).

Re:the fools! (1)

Poorcku (831174) | about 6 years ago | (#23011048)

micro-black holes already created? when? For all i know only LHC will have this kind of power. And i am too a little worried :) - you know, because the Hawking radiation has not been proven yet. If it doesn't exist, we are screwed :)

Re:the fools! (2, Insightful)

Digestromath (1190577) | about 6 years ago | (#23010886)

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 human. We replicate out of control consuming any natural resources we can get our hands on. We're just not really efficient grey goo.

Re:the fools! (1)

Taint Bearer (957479) | about 6 years ago | (#23010968)

Grey goo? Seriously, you're a human. We replicate out of control consuming any natural resources we can get our hands on. We're just not really efficient grey goo.
All that means is that we are going to get taken over by a more efficient grey goo.

WARNING (0)

Anonymous Coward | about 6 years ago | (#23010754)

Do not stare into beam with remaining eye

For a tenth of a femtosecond... (2, Funny)

weremook (899309) | about 6 years ago | (#23010854)

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.

Re:For a tenth of a femtosecond... (1)

D4rk Fx (862399) | about 6 years ago | (#23011504)

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.
Death caused by an electric shock is referred to as electrocution. Maybe you want to look up your vocabulary a bit more before you keep repeating this. because you were seriously not electrocuted.

Re:For a tenth of a femtosecond... (0)

Anonymous Coward | about 6 years ago | (#23011762)

Death caused by an electric shock is referred to as electrocution. Maybe you want to look up your vocabulary a bit more before you keep repeating this. because you were seriously not electrocuted.

Maybe you should realise that word meanings change and the dictionary definition of a word is by no means definitive. Here [oreilly.com] is some evidence that about 80% (at least) of people (based on a sample of about 420) would include non-lethal electric shock in the definition of electrocution. If you say they are 'wrong' that is meaningless; in English, words mean what people take them to mean, and if a significant number of people 'misuse' a word then the new meaning is an alternative definition of the word and will generally appear in the dictionary eventually.

Wrong about the Sun and petawatts (4, Informative)

Ancient_Hacker (751168) | about 6 years ago | (#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.

not to be a pedant, but... (2, Interesting)

The Bender (801382) | about 6 years ago | (#23011058)

To be fair, a 5mW laser point would need to be focused to a diameter of ~10 microns [calctool.org] to reach the sun's surface intensity of ~6kW/cm^2.
And a cheap laser pointer can't be focused to that size.

But of course you're right. They're just going for the unwashed public wow factor.

Re:Wrong about the Sun and petawatts (0)

Anonymous Coward | about 6 years ago | (#23011294)

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.

Yes, a cheap laser pointer has surface power density comparable to the sun's radiation on earth (about 1kW/m^2), but that's a little different than the power density on the surface of the sun, don't you think? Take the ratio between 1AU (distance from sun to earth) and the radius of the sun (it's about 200), cube it, and that's the difference between what you wrote and what they actually said. So you're only off by 6 or 7 orders of magnitude.

Incidentally, the earth only receives about 5*10^-10 of the sun's energy. If we made a device using that much energy for even a femtosecond, it would dissipate as much heat as a ton of TNT, except it would do so 100 times faster than the largest nuclear device ever detonated. Not exactly something that you could use and then expect it or its human operators to function a second time.

Re:Wrong about the Sun and petawatts (1)

maxume (22995) | about 6 years ago | (#23011304)

I generally take "brighter...the surface of the sun" to refer to intensity and to naturally refer to the output for some area.

(Your point that it doesn't mean very much stands, but it is kind of neat that we pathetic humans can touch the power of the universe, so I understand why they refer to it)

Re:Wrong about the Sun and petawatts (1)

tinkerton (199273) | about 6 years ago | (#23011560)

It's worse than not meaning much, it's very misleading because it places the parts of the comparison in the same ballpark. Dinosaurs roamed the earth even before we had book printing too.

Re:Wrong about the Sun and petawatts (1)

maxume (22995) | about 6 years ago | (#23011606)

I don't think it is misleading at all. It might be a little esoteric(because most people don't have any prior knowledge of the nominal power of the sun or a good grasp of just how short the pulse is), but it doesn't draw the reader into a poor conclusion, it just leaves the poor conclusion available.

Re:Wrong about the Sun and petawatts (3, Funny)

Swampash (1131503) | about 6 years ago | (#23011540)

I would be happier if they expressed the power of this laser in the recognized units of "Libraries of Congress" and "football fields".

picosecond, not femtosecond (2, Informative)

The Bender (801382) | about 6 years ago | (#23010956)

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.

Re:picosecond, not femtosecond (0)

Anonymous Coward | about 6 years ago | (#23011316)

Sort of...you can do a lot better than 100 fs, the laser I'm working on at the moment can do ~10 fs pulses, and I'm pretty sure you can go slightly better than that.

On the other hand, 0.1 fs is deep into the UV, and almost into X-ray frequencies. These lasers typically operate at infrared frequencies - a couple of femtoseconds in period, and it's definitely a typo in the article.

Obvious mistake in TFA (5, Informative)

justkeeper (1139245) | about 6 years ago | (#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.

Re:Obvious mistake in TFA (1)

RockMFR (1022315) | about 6 years ago | (#23011462)

Looks like the summary is the only place where femtosecond is mentioned. The actual article has it right.

Soon to be a Dime a Dozen (5, Informative)

djtachyon (975314) | about 6 years ago | (#23011044)

University of Rochester is building a petawatt laser of capable of picosecond pulse lengths. http://omegaep.lle.rochester.edu/ [rochester.edu]

why do they keep telling us about new ones? (0)

v1 (525388) | about 6 years ago | (#23011148)

This is what, "superlaser" nuber four in the last couple months. Always with a firing time down in the femptoseconds or something like that.

New rule. You cannot call it "world's most powerful laser" until you understand the definition of power . I don't care if you ARE dumping jiggawats into it, if the time period is dividing it by a trillion to come up with the power which ends up somewhere around a AA battery, I don't need to hear about it.

So ..... (0)

codehoser (538299) | about 6 years ago | (#23011154)

Can someone clarify -- the details confuse me: I should or should _not_ point this at my eyeball while active.

Serious Question (0)

Anonymous Coward | about 6 years ago | (#23011900)

Would it actually blind you as it only lasts for "a 10th of a trillionth of a second"?
Load More Comments
Slashdot Account

Need an Account?

Forgot your password?

Don't worry, we never post anything without your permission.

Submission Text Formatting Tips

We support a small subset of HTML, namely these tags:

  • b
  • i
  • p
  • br
  • a
  • ol
  • ul
  • li
  • dl
  • dt
  • dd
  • em
  • strong
  • tt
  • blockquote
  • div
  • quote
  • ecode

"ecode" can be used for code snippets, for example:

<ecode>    while(1) { do_something(); } </ecode>
Sign up for Slashdot Newsletters
Create a Slashdot Account

Loading...