[HN Gopher] The US has a new most powerful laser hitting 2 petaw...
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The US has a new most powerful laser hitting 2 petawatts
Author : voxadam
Score : 77 points
Date : 2025-05-21 15:17 UTC (7 hours ago)
(HTM) web link (news.engin.umich.edu)
(TXT) w3m dump (news.engin.umich.edu)
| cnees wrote:
| I got a tour of the lab during construction. As a software
| engineer, what I found most incredible about the project was how
| well they stuck to their delivery proposal and timeline over the
| course of five years of development.
| int0x29 wrote:
| > "Having a national resource like this, which awards time to
| users whose experimental concepts are most promising for
| advancing scientific priorities, is really bringing high-
| intensity laser science back to the U.S."
|
| Try not to deport the researchers or slash federal research
| funding if you really want that. Although at this point the US's
| reputation is damaged enough that getting and retaining
| researchers may be challenging.
|
| Its a bit depressing how little universities are doing to stand
| up to the removal of their students
| frollogaston wrote:
| This doesn't really have anything to do with the article
| lostlogin wrote:
| That university has made cuts due to Trump policies and the
| funding for that laser has come from The National Science
| Foundation, which has had its funding cut.
|
| https://theconversation.com/unprecedented-cuts-to-the-
| nation...
| perihelions wrote:
| I can't steelman the position that "the topic of the article
| might disappear at any moment because of funding cuts" is
| unrelated to the article. If it were a post about a startup
| releasing a new product, and the top comment was "hey FYI,
| this startup has filed for Chapter 11 bankruptcy", would that
| be off-topic too?
|
| And: the article _itself_ puffs about how this is attracting
| physics research to the US; how can contradicting claims the
| article makes be off-topic to discussion about self-same
| article? It can 't be a "they're allowed to speak but we're
| not allowed to contradict"--this is HN! Discussion is the
| whole point!
| perihelions wrote:
| That's a howler of a line indeed, given the NSF was slashed
| >50% just weeks ago (the federal agency funding this physics
| research).
| lurk2 wrote:
| Which researchers have been deported?
| Jabbles wrote:
| https://archive.ph/w5yDx
| lurk2 wrote:
| > In one, a kidney transplant specialist at Brown
| University in Providence, Rhode Island, was deported to
| Lebanon after trying to re-enter the United States with a
| valid visa. It was later reported that pictures on her
| phone had linked her with Hezbollah, which US authorities
| consider a foreign terrorist organization.
|
| This is the only example in the article.
| otteromkram wrote:
| > Optical devices called diffraction gratings stretch it out in
| time so that when the pump lasers dump power into the pulse, it
| doesn't get so intense that it starts tearing the air apart.
|
| Oh,my.
|
| > "The crystal that we're going to get in the summer will get us
| to 3 petawatts, and it took four and a half years to manufacture"
|
| This entire thing is beyond cool. I hope the rest of the process
| goes smoothly for the teams involved!
| hinkley wrote:
| I was hoping I could hear it make noise but it operates for
| millionths of nanoseconds. Human ears have trouble with
| anything less than 30 ms so when it runs a trillion times
| longer we'll be able to hear it make a sound.
| mitthrowaway2 wrote:
| You can hear femtosecond lasers because they ionize the air,
| creating a spark. They buzz at the pulse repetition
| frequency.
| hinkley wrote:
| Do you know how often this one pulses? I was getting the
| impression it fires once per hour given the power levels.
| FiatLuxDave wrote:
| Big powerful lasers can actually be quite noisy. Once I was
| talking on the phone with a friend who was working on one of
| the big lasers (don't remember which one, but it was in the
| bay area) and he said,"What? What? I'm sorry I can't hear you
| over the sound of my laser!". When he could hear me, I told
| him that was one of the coolest things I'd ever heard anyone
| say.
| chneu wrote:
| It's usually the accessories and support equipment that
| makes lasers loud. Cooling equipment, electrical stuff,
| etc.
|
| If those can be put in another room then the noise goes way
| down.
| ourmandave wrote:
| Mount it in a jet and you could pop an entire house full of
| popcorn in seconds.
| cnees wrote:
| In femtoseconds!
| hinkley wrote:
| That's popcorn. Get it away from me, I can't stand popcorn. I
| hate popcorn.
| loloquwowndueo wrote:
| More for us, then!
| MisterTea wrote:
| It's an on topic movie quote: https://www.imdb.com/title/tt
| 0089886/quotes/?item=qt0435723&...
| amelius wrote:
| Point it downwards and make that hole through the center of
| Earth.
| megous wrote:
| I don't think anyone should be impressed by watts. Jouls are
| where all the real work is.
|
| Asside for the PR article. What's the use case for pettawatt
| laser pulse lasting 25 quintillionths of a second?
| cnees wrote:
| A previous press release lists some research applications and
| potential practical developments.
| https://news.engin.umich.edu/2019/09/most-powerful-laser-in-...
| megous wrote:
| Thanks. :)
| hinkley wrote:
| Laser pulses can ablate materials and the shorter the pulse the
| crisper the edges. Back in the 90's or early 00's they
| demonstrated pulses laser cutting of tissue where the heat
| damage to surrounding tissue had a width of a single cell.
| ourmandave wrote:
| What, like a surgical laser?
|
| "Okay, hold _really_ still... "
| hinkley wrote:
| Yeah and I think this and radiological tools are why chemo
| tattoos exist. The system has to react to the twitch you
| can't control when a weird noise happens next to your head.
| Instead of stabbing bolts into your skull through your skin
| with a device Torquemada would have been proud of, they
| target versus the dots and if the dots move? Well this is
| where my knowledge runs out. Either they shut down the beam
| or they target in realtime. But either way the payload is
| delivered where it's supposed to be or not at all.
|
| I don't know if they are using laser scalpels in surgery.
| My medical fascination mostly ends at diagonostics and
| experimental procedures. If I don't know anyone with a
| disorder I tend not to hear about new procedures. My friend
| in college was helping a prof work on picosecond violet
| lasers and now we are on femtosecond.
| gosub100 wrote:
| Some radiation therapy machines use metal fiducial
| markers and can account for movement such has patient
| breathing
| hinkley wrote:
| So it's for targeting rather than aborting a treatment?
| mmastrac wrote:
| At femtoseconds, assuming your tracking matches, you could
| probably sit a sugar-loaded kid in a chair without
| instructions and just make it work.
| hinkley wrote:
| Probably like watching people play war sims with a sniper
| rifle. Just waiting for the crosshairs to bounce over the
| target's head and then blam.
|
| Bigger problem I suspect is children with white coat
| syndrome. When I was a kid doctors got away with being
| monstrous to children.
| fragmede wrote:
| Why the Dougie Howser hate?
| frollogaston wrote:
| Well you probably don't want a petawatt laser lasting a second,
| cause it'll obliterate a lot more than what you wanted to.
| ta1243 wrote:
| Including of course the laser. It's about 240 kilotons of
| TNT, or over 10 times the power of the nagasaki or hiroshmia
| bombs.
| frollogaston wrote:
| Yeah, or even if it were some more reasonable amount of
| energy that doesn't self-destruct it, there are probably
| applications where you want to hit a small area quickly
| without burning things around it.
| EnPissant wrote:
| Watts are just joules per second.
|
| It doesn't make any sense to measure joules alone. _Any_ laser
| can output 2 petajoules. The only question is how long it takes
| to do that: hence Watts.
| floxy wrote:
| Seems like you always start somewhere. First you have 25E-18,
| then bump it up to 1e-15, and maybe someday you are at 1e-9 and
| are doing inertial confinement fusion.
| spookie wrote:
| For anyone interested, the most powerful one is in Romania at the
| Extreme Light Infrastructure (ELI) in Magurele. It's about 10
| petawatts.
| Alifatisk wrote:
| In that case, the titles claim is false, right?
| 0xffff2 wrote:
| No. Maybe slightly ambiguous, but I immediately read the
| title as "most powerful laser in the US".
| pitaj wrote:
| The title can be interpreted as "there's a new laser that is
| now America's most powerful"
| baxtr wrote:
| Instead of petawatts I'd love to hear what it can destroy.
|
| I imagine a scale like:
|
| 1: Mosquito
|
| ...
|
| 10000: Planet (Death Star)
| vlmutolo wrote:
| To kill a mosquito, you need "a few tens of millijoules,
| delivered within a few milliseconds" [0], so let's say 10W. To
| destroy the Earth (so that it turns into scattered dust and
| never reforms) you need about 10^32 J [1]; if we assume this is
| applied over maybe 100s, the laser would be 10^30W.
|
| So the log10 scale goes from 1-30, where mosquitos die at 1 and
| the Earth dies at 30. The 2 PW in the article is about a 15.3.
| The Vulcan 20-20 project (set to complete in 2029) will
| register at about 20PW, or a 16.3 on the mosquito-Death Star
| scale [2].
|
| So on a log scale, we're over halfway to building the Death
| Star.
|
| [0]: https://spectrum.ieee.org/backyard-star-wars
|
| [1]: https://www.scientificamerican.com/article/how-much-
| energy-w...
|
| [2]: https://news.sky.com/story/worlds-most-powerful-laser-to-
| be-...
| jvanderbot wrote:
| Thank you for this, I will be using this for the rest of my
| life!
| baxtr wrote:
| This is awesome! Thank you!!
|
| I'm still not sure what 15.3 on the MDS scale can destroy but
| I am sure the Emperor will be pleased to hear that we are
| half-way to building the Death Star.
| codyb wrote:
| The on a log scale is doing a fair amount of lifting here I
| think
| amelius wrote:
| Next question: on what planet/moon should the mosquito be to
| be _just_ safe from the laser?
| zahlman wrote:
| Well, mass scales as the cube of radius, and we have 15
| orders of magnitude to work with, so I guess it should be
| an object on the order of hundreds of meters in radius. But
| as noted, the duration of firing matters as well. Given
| https://news.ycombinator.com/item?id=44054239, the actual
| laser can only vaporize much smaller things.
| dyauspitr wrote:
| I don't like log scales, they're not intuitive.
| SamBam wrote:
| > if we assume this is applied over maybe 100s
|
| I think this is the crux of the assumption right here. It
| sounds like this is apply for well under a nanosecond.
|
| I think we're closer to maybe killing a mosquito than "half
| way to building a Death Star on a log scale" (which, I guess
| is already much closer to a mosquito than a planet).
| Dylan16807 wrote:
| If we're comparing lasers that go for seconds and lasers that
| go for femtoseconds, I think measuring watts is _way_ too
| misleading.
|
| Measured in simple joules, mosquito is .04, earth is 10^32,
| and this laser is 50.
|
| If we make a joules version of the 1-30 scale, the laser in
| the article would only score a 4.
| Hikikomori wrote:
| So I could kill all the mosquitoes in my yard in one pulse
| with this laser.
| beAbU wrote:
| Every step is a doubling of the previous step, no?
|
| So true "half way to a death star" is step 29/30?
| hnuser123456 wrote:
| They used log10, so each step is 10x the previous, so in a
| linear sense, it would double when going from about 29.7 to
| 30. But it seems that humans tend to improve tech at
| exponential rates, where we are constantly making
| improvements here and there that keep stacking up, when it
| comes to things that are actually in a developmental stage
| anyways.
|
| Say your "endstage" goal is GPU with 200 billion
| transistors. Using linear scale, the current biggest GPU is
| only halfway there, and it took all of human civilization
| to get this far, and it will take another civilization to
| get to 200b. In reality, we'll have that in a couple years
| with our current civilization.
| outadoc wrote:
| What if we tried more power?
| Sohcahtoa82 wrote:
| I'm assuming this is an XKCD reference.
|
| https://what-if.xkcd.com/13/
| pryelluw wrote:
| I am embarrassed to admit of thinking there's a Family Guy joke
| somewhere in that headline.
| pugworthy wrote:
| Could you explain the joke?
| SietrixDev wrote:
| Probably Peta => Peter who is one of the main characters in
| the show.
| tonyhart7 wrote:
| star wars??? space wars???
| metalman wrote:
| china is on track to have a 100pettawatt laser operating this
| year called "The Station of Extream Light", SEL for short, which
| is going to be used to try and seperate energy and matter by
| breaking empty space. think that this links to the place building
| it
| http://english.siom.cas.cn/Newsroom/rp/202207/t20220701_3071...
| all in all good to have a competitive environment in
| reseach.......though the US government, cough, cough, might,
| nudge, think about, some funding there
| torcete wrote:
| In this very interesting video, a Russian drone developer gives
| his thoughts about laser weapons. In theory they work, they test
| it always on ideal atmospheric conditions. In practice, they
| don't.
|
| https://www.youtube.com/watch?v=RmfNUM2CbbM
| owenversteeg wrote:
| I see a number of comments here misunderstanding the power of
| this laser. Laser facilities like this one are designed for
| incredibly short pulses that are femtoseconds long, and total
| energy per pulse is typically on the order of tens of joules,
| roughly equivalent to a few seconds of your phone flashlight.
| They can't destroy much of anything on human scales. They are
| made to do physics research, and there is absolutely no pathway
| from a 2 petawatt laser that delivers a few joules a minute to a
| 2 petawatt laser that hits full output power for a few seconds:
| that would be 10^16 times more energy, and of course that brief
| pulse would use more electricity than all the US uses in a year
| and completely destroy the University of Michigan in spectacular
| fashion (very roughly equivalent to a five megaton nuclear
| explosion.)
|
| If you're interested in the most energy per pulse, you want the
| "most energetic" laser, which is the NIF at LLNL. That's about 2
| megajoules per pulse or half a kilowatt hour. Definitely enough
| to kill a mosquito, but it doesn't even register on the scale of
| Death Star style lasers from fiction.
|
| And if you want the most destructive power, those are all
| military lasers. Which can absolutely destroy things science
| fiction style, but on a fairly small scale and with some
| important limitations.
| babyent wrote:
| So.. We just need to figure out wormholes and make an infinite
| loop the laser goes through and harness its true power!!
| Dylan16807 wrote:
| I understand that you're being silly, but even in this silly
| theory land how is that supposed to work? While the laser is
| in a loop it's not hitting anything, and if you let it out
| it's the same as when you put it in.
| babyent wrote:
| You're right, I am being silly because I am too uneducated
| to really make sense of any of it.
|
| I love smart people who work on this stuff, a lot of what I
| take for granted is due to their efforts :)
| z2 wrote:
| I figure it's a matter of stacking/charging the laser in
| that loop with a lot of pulses, then letting that all out
| at once? Like, what if we shot pulses into the orbit of a
| mini black hole, but then managed to unwind it back out
| into a single direction?
| Dylan16807 wrote:
| In that case the problem is you're only charging the loop
| with about 1 watt of laser on average. It's going to take
| two weeks just to reach a megajoule. So you can do one
| really cool shot, and then you have to wait months.
| ta1243 wrote:
| The article said 2 Petawatts for 25 quintillionths of a second.
| That's about 50mJ.
|
| That's about the amount of power used in your phone's _flash_
| when taking a picture, not a few seconds, but the LED being on
| for about 50-100 milliseconds.
| owenversteeg wrote:
| Not sure if the article is accurate (the accuracy of numbers
| in written text took a nosedive concurrent with the rise of
| LLMs), but the capabilities page of the laser's website
| claims 23 femtoseconds pulse duration, 2 PW power, 50 J
| energy, and 1 shot per minute. 50 J is roughly a 3W light for
| 15 seconds.
|
| https://zeus.engin.umich.edu/about/capabilities/
| mschuster91 wrote:
| > Not sure if the article is accurate (the accuracy of
| numbers in written text took a nosedive concurrent with the
| rise of LLMs)
|
| Written text accuracy took a nosedive in the early '00s as
| newspapers couldn't afford to hire journalists with a
| scientific background, followed by universities not hiring
| scientists to write press releases any more. GIGO - garbage
| in, garbage out.
| yongjik wrote:
| > completely destroy the University of Michigan in spectacular
| fashion
|
| Sure, Ann Arbor may be destroyed, but that's a sacrifice I'm
| willing to make. For Science. /insert Lord Farquaad meme here
| rl3 wrote:
| > _And if you want the most destructive power, those are all
| military lasers. Which can absolutely destroy things science
| fiction style, but on a fairly small scale and with some
| important limitations._
|
| https://en.wikipedia.org/wiki/Project_Excalibur
|
| Once upon a time we tried developing a nuclear-pumped X-ray
| laser for use in strategic defense, which if my napkin math is
| correct was probably in the neighborhood of NIF in terms of
| energy output (despite the conversion efficiency being
| terrible). Notable is that NIF continues existing after it
| fires.
| doctorwho42 wrote:
| Also NIF is actually 192 laser beams with about 3 football
| fields of lab grade warehouse to house all those laser beams
| optics for beam pumping, shaping, etc.
|
| Not sure you can move NIF like you would move excalibur
| reaperducer wrote:
| _Laser facilities like this one are designed for incredibly
| short pulses that are femtoseconds long_
|
| "Look at the facts. Very high power, portable, limited firing
| time, unlimited range. All you'd need is a big spinning mirror
| and you could vaporize a human target from space."
| killjoywashere wrote:
| Fun fact: these laser pulses are so short they are no longer a
| single wavelength. They have a spectrum due to the uncertainty
| principle. And at this short of a time scale, it's pretty
| broad.
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