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NASA Achieves Breakthrough Black Hole Simulation
DoctorBit writes "NASA scientists have achieved a breakthrough in simulating the merging of two same-size non-spinning black holes based on a new translation of Einstein's general relativity equations. The scientists accomplished the feat by using some brand-new tensor calculus translations on the Linux-running, 10,240 Itanium processor SGI Altix Columbia supercomputer. These are reportedly the largest astrophysical calculations ever performed on a NASA supercomputer. According to NASA's Chief Scientist, "Now when we observe a black hole merger with LIGO or LISA, we can test Einstein's theory and see whether or not he was right.""
From the article: "when two massive black holes merge, all of space jiggles like a bowl of Jell-O"
Wouldn't Kraft Foods have prior art on this?
....a machine that can tell me where my lost left socks have gone!
You apparently use a supercomputer to generate a problem to a hole that sucks everything in. To me, this seems contradictory. But it's a huge achievement, go NASA!
Give me a productive error over a boring, mundane and unproductive fact any day. ~Anon
"Itanium chips actually get used"
The catastrophic results of merging Microsoft and Linux?
The hilarious results of merging Intel and AMD.
The unexpected results of merging a spinning Steve Jobs (Intel is Evil/Intel is the best, brightest, future of Apple) and the O'Reilly No-Spin Zone.
Those I'd buy tickets for.
"It's the height of ridiculousness to say for those 9 lines you get hundreds of millions."
What kind of framerate do you get on that machine when playing Half-Life 2?
...would he have developed General Relativity sooner, or just played WarCraft?
--- Attorneys Assisting Citizen-Soldiers & Families -
Based on observations, what percentage of black holes are non-spinning vs spinning?
... non-spinning black holes ...
Must've been playing Nowhere Man in the background when they came up with this idea.
What about merger of the Giver and the hole of Anonymous Coward?
Emacs is good operating system, but it has one flaw: Its text editor could be better.
http://funroll-loops.org/
This wouldn't be at all comparable to a home machine designed to play HL2.
You wouldn't use a semi truck in a NASCAR race, and you wouldn't use a NASCAR vehicle to haul large boxes. They just aren't comparable.
Now when we observe a black hole merger with LIGO or LISA, we can test Einstein's theory and see whether or not he was right.
And if he's wrong then all the scientists can make "loser" signs at him on their foreheads...
Summation 2
anyone know if google has a science-nerd-jargon translator?
"Simplify, simplify, simplify!" Thoreau
And even more likely: Whether or not the computers performed the calculations correctly (the chips are made from Intel, and we all know the history of Intel screwing up floating point math)
They finally managed to use up all of those Itanium processors hanging about in storage. Well done!
Faster! Faster! Faster would be better!
Non spinning black holes?
Is there such a thing?
Democrats or Republicans. They are both taking us to the same place and they are not afraid of us anymore.
Not mentioned in the article of course, is that shortly after the simulation, the software collapsed in on itself as it underwent a Massive Total Existence Failure.
There are experimenters. The guys who ran the simulation were experimenters.
There are theoreticians. Einstein was a theoretician. He asked relatively simple questions and followed the logical consequences. I suspect that having to use a computer would have been a giant distraction and might have delayed or prevented the theory of relativity.
I thought NASA was having financial difficulties and no real direction in where they'll "lead" us in the future. This seems like an terrible waste of taxpayer dollars.
What is the actual outcome from this research? Will this help create more energy-efficiency in the world? Will it help us find technology that humanity can actually use to make a better society? Will it increase our safety, or decrease power of madmen and dictators?
Stories like this make me feel sad that many people feel we need public funding for research that seems to have no real gain for those paying for it. Sure, I love physics and astrophysics, but I would rather voluntarily give a few hundred greenbacks a year to a private research company that see it wasted on publicans who get paid no matter what they're doing.
We will loose it in the center of the hearth and using it as a bouncing laser mirror to propel cities into space, while a mother at home will infect the 'net' and kill anything that threaten her mastery of her "domain".
:)
Sigh..
assert(expired(knowldege)); core dump
Watching massive things merging.. jiggling like jell-o... Good heavens, space is a pervert!!!
Slashdot Burying Stories About Slashdot Media Owned
They're not black holes, they're just a result of Intelligent Darkness. Seriously, why do we teach kids today the theory of black holes without not also teaching them about Intelligent Darkness?
I performed the same simulaton once, but I forgot to save the results :(
Simulation means nothing with validation.
I do not believe in karma. "Funny"=-6. Do good and forbid evil. Yours, Oft-Offtopic Flamebaiting Troll.
I've been riding past a black hole on my Kodo for months now in Silithus. For the Horde!!!
"Simplify, simplify, simplify!" Thoreau
What about merger of the Giver and the hole of Anonymous Coward?
::shudder::
Surely you don't mean goatse - I think they'd need more computer power to properly calculate a black hole of that magnitude.
Scientists has been doing similar calculations for a long time. For example
Larry Smarr, "Gravitational Radiation from Distant Encounters and Head-On Collisions of Black Holes: The Zero Frequency Limit," Phys. Rev., D15, 2069-2077, 1977.
I cite this paper because Larry Smarr is one of the Nasa panelists for this project, and I heard his talk on this paper at the University of Texas at Austin in the late 1970s. Come to think of it, I remember seeing one of the other panelists, Joan Centrella, at the same talk.
OK, I'm no general relativist, but I am a computational physicist -- what could the article possibly mean when it says earlier attempts were "plagued by computer crashes -- the equations were far too complex"?
I can imagine a situation where a poorly-arranged computation of an equation might give you an underflow in an intermediate result, or where a badly-arranged summation might give you noise. But crashing the computer? Sounds more like array-bounds, which can happen no matter how simple the equations are.
2*3*3*3*3*11*251
http://en.wikipedia.org/wiki/Schwarzschild_black_h ole
That must be like half the Itaniums ever sold!
It's easy to simulate a black hole.
Just fill your car with gasoline. The money just disappears into a deep black hole.
"The simplest tensor calculus equations require thousands of lines of computer coding. The expansions, called formulations, can be written in many ways. Through mathematical intuition, the Goddard team has found the appropriate formulations to lead to suitable simulations."
Does anyone have further info on this apparently new way of implementing tensor calculus on a computer?
https://www.accountkiller.com/removal-requested
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...in Soviet astrophysics simulations, black holes merge with YOU!
Why? Who cares? Stop wasting money.
And I whole heartily encourage all patent and IP lawyers to go to those black holes and ether Subpoena them or deliver a notice of possible infringement.
This should solve all lot of problem here on earth as well, if we can get them to all go.
Unless that is the Black hole decides to show up for its court date.
From the article: Black holes alter spacetime. Therein lies the difficulty in creating black hole models: Space and time shift; density becomes infinite and time can come to a standstill. Such variables cause computer simulations to crash.
But they succeeded with Linux. There you have it, your collision between Microsoft and Linux. Let's buy a full page in the New York Times and title it with something like: Light year ahead of Windows; don't try this at home.
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at the same time as the simulation with that much CPU power.
And painted on eyed robots?
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HL2 is singlethreaded so the performance would be the same as on one Itanium. Also x86 code has to be emulated on Itaniums = slow. Oh and no GPU which means pixel/vertex shaders would have to run on software. Educated guess: 0.1 fps.
That's nothing--the WB and UPN are merging in September, producing a vortex of TV so sucky that not even brain cells will be able to escape.
The interesting question is whether the CW black hole will rotate or not. I for one hope that TV execs will be able to sit on it and spin.
GCHQ Quantum Insert installed. If only our tongues were made of glass, how much more careful we would be when we speak
the Linux-running, 10,240 Itanium processor
If only they would use windows. Then we would see the kind of things Einstein couldn't visualize.
This sounds more like a "milestone" then a "breakthrough". non-spinning sounds like a huge simplifying assumption as I doubt there are many non-spinniong black holes except for very, very small ones.
How often do we hear - "And the real world observations are EXACTLY what scientists predicted" versus "Based on these unexpected results, scientists will have to go back to the drawing board"
Prof. Farnsworth - "Oh a lesson in not changing history from Mr I'm-My-Own-Grandpa!"
What is the actual outcome from this research?
More knowledge about how to model the universe and the validity of our current understanding of it.
Yes, it's worthwhile for that reason, but we don't actually gain any new knowledge about the universe. Simulation is about testing theory, about processing the knowledge we now have, not adding to it. By analogy, simulating future environmental change doesn't add to our knowledge about such change in and of itself, just tests the theories we have about how it works and how it changes. The benefit is that we're able to test the predictive power of our current theory and see if that coresponds to the hard data we have about the universe. The outcome of such comparisons generates new knowledge, but the simulation itself just provides the basis for comparisons.
Maybe that's what you're getting at, so sorry if I'm niggling, but if you want to correct someone on the benefits of any kind of research--especially someone doubting the worth of that research--I think it's important to be as clear amd unambiguous as possible.
/. is what happens when geeks talk. get used to it.
This isn't the only testing that NASA is doing of Einstein's theories. For those that are interested, there is also the Gravity Probe-B. Really interesting stuff!
In case anyone was wondering how Columbia stacks against their rig, check out:
http://www.top500.org/
Here's the November 2005 list:
http://www.top500.org/lists/2005/11/TOP10_Nov2005. pdf
It shows Columbia with:
51.87 Rmax (teraflops/second).. It also states that it moved from #3 ranking to #4.
This space for rent. Call 1-800-STEAK4U
Caltech (Kip Thorne) has an NSF grant (the largest ever) to detect gravitational waves in order to confirm GR. The expected source of these the collision and eventual merging of two black holes. The problem is that they couldn't simulate the process they were going to detect in a computer or even a single balck hole by itself for even a 10000 or so steps with diverging. Two merging black holes were out of the question.
The issue is that there are 10 equations (for the metric tensor of space time), four of which are 4 constraints (conservation laws). You step all 10 equations then check to see that your 4 constraints are still satisfied (which they will be in the continuous case, but you discretized), and they are more or less, but not exactly. As you move forward the error grows hugely. The equations only specify what should happen when the constraints are satisfied. Once you get off, all bets are off and you need to start making up ad-hoc procedures to get them back or better your initial step to keep them from getting off in the first place.
The equations are conservative (no energy loss), extreemely non-linear and complicated. It's akin to simulating EM, except the equations are non linear.
Umm do nonspinning same size black hole mergers appear in real life? Would this happen or would a more true to life example be differing sizes and spins on different axes? Its just a ramble of an internal dialogue.. sorry to inflict it on all of you
What, they sent another budget request to Congress ? :-)
They build a computer model "based on a new translation of Einstein's general relativity equations" so that they "can test Einstein's theory and see whether or not he was right." They're going to use his equations to verify his theories? I want to publish an equation that says "7=13" and then theorize that "7*2=26". Won't building a model based on an equation automatically prove a theory that is based on that equation?
I find it astonishing that it took this long to begin to test Einstiens theorys
I think this is the paper which summarizes the results discussed in the article. If so, the "formulation" alluded to in the article is the conformal BSSN formulation; more details of their method here, and the BS of BSSN (Baumgarte-Shapiro) paper here (the SN paper, Shibata-Nakamura, isn't online).
Does it run vista?
If these scientists are not careful, they could start a chain reaction and convert ALL of cyberspace into one big blackhole!!
There is a fine line between being a cultivated citizen and being someone else's crop. - A. J. Patrick Liszkie
Whoa hold up here. We're having to use thousands of processors running in tandem to prove something einstien did with pen and paper? Maybe NASA should ditch the computer and work with pen and paper. This would then elimiate the time lost browsing for pr0n at x^n speed.
* * * OMG Ponies * * *
I beleive that the breakthrough will come when NASA gets a budget through Congress WITHOUT it being cut.
-=Steve
How can you test a theory by running a simulation on a computer whose program's assumptions are based on other un-proven theories ? To test a theory you have to conduct an experiment in the real world, admittedly somewhat difficult using real black holes. The best you can say is that the house of theories is self consistent.
NASA's been simulating a black hole for years now. For example, engineers warn management that the shuttle could explode, the managers absorb this information irrevocably (thus destroying everything but its mass) and occasionally emit X-rays.
steampunk web design
If the simulation results seem to say that Einstein was wrong, that still doesn't prove that he was wrong, because they have not actually merged two black holes together in the real world. Simulation != real world. If there are any flaws in the assumptions, parameters, or algorithms they use to perform the simulation, then it invalidates the whole exercise.
All that computer power and they only come out with a video clip that I can do on a Pentium I. Good job NASA, seriously, but give us something to "ooh" and "ahh" over.
"brix_zx2, What is your sole purpose in this forum!?!?!"
"To do whatever you tell me MODERATOR!!!!"
Is that silicon graphics logo on those rackmounts. Since when sgi uses intel cpus?
The oontributions of Einstein never cease to amaze me.
Decades after his death, they're still finding new ways to look at his work, and really appreciate the stuff he did work out. And much of what he said still seems to turn out to be right.
I'm fairly sure I can't accurately predict what will be for dinner tonight, let alone how the whole freaking Universe seems to work.
Ah well, if he was wrong about everything, he probably wouldn't be nearly as famous. =)
Lost at C:>. Found at C.
the merging of two same-size black holes
...not that there's anything wrong with it.
I thought that was banned in 19 states?
So /. gets a nice interesting article covering both theoretical physics and supercomputing, and the first 20 comments (and 95% of the rest) are all lame one-liners. AND they all get modded up. What are we, geeks or stand-up comics? Am I showing my age if I remember when the science was discussed on /. and posters got modded for contributing something relevent.
It's funny to think in 50 years we will probably look back at a machine like that and laugh. "Ha, my PDA is faster than that huge clunker!"
It's a fact that all matter has spin. A non-spinning black hole is contrary to this universe's physics.
Etc...
Arxiv.org
Because sometimes, you might want more than a press release.
I came here for a good argument
Where's the picture?
Sorry, Left. Can't have it both ways! But perhaps you were simply referring to the fact that there are still Bush3 and Bush4 family members in the potential wings.
According to Einstein (pls correct me if I'm wrong), everything is relative to everything else. "When you're with a pretty woman, an hour seems like a minute. When your hand is on a hot stove, a second is a very long time. That's relativity."
So, with a spinning black hole, is the black hole spinning inside the universe, or is the universe spinning around the black hole? Or is it both and neither at the same time?
If I'm travelling at 98% of lightspeed relative to you, Einstein says time slows down. But if I'm travelling that fast relative to you, you're travelling that fast relative to me...
*head explodes*
(MRC="consider")
I'm a recent member of this group, so I'd like to put in my 2 cents.
:) (some competing groups use Cactus which is C++ based, although it also allows C and Fortran).
1) This is a first -- no other group has achieved this before. yay! (after decades of work!)
2) This is hard for the following reasons:
a) since you are doing calculations near (or on/in) a black hole, you tend to get a lot of
infinities, which 1) crash your code and 2) exacerbate your errors
b) for most simulations, your grid remains fixed. For black holes though, they *deform* the
spacetime around them -- which means your grid points have to move (in a non-predictable
manner)!
c) what happens when two black holes merge is not well understood (ie, what should happen?),
so this is new science
d) initial data is hard to get and unreliable. If two black holes are far apart, you can
write an exact solution (at least within some error), but to get them close to where they
are interating, you pretty much need this kind of simulation anyways. This is such a large
problem that there are only a handful (a dozen or two?) initial data sets currently.
3) Everything is written in Fortran!
4) It runs on a variety of architectures (x86, Itanium, PA-RISC, Alpha, etc etc)...pretty much
anything that supports ifc (faster) or gcc.
5) There are several approaches to some of the issues above, from puncture splitting (using a
different spacetime metric like 1/r vs r to remove the singularity), excision (not evolving
inside the event horizon, since that's not "interesting" anyways), and other methods. Our
new method actually doesn't need any of those "tricks", which is pretty interesting.
6) This data helps drive the LISA and LIGO projects from a theoretical standpoint--basically
knowing what kind of gravitional waves they should be seeing, and to correlate what they see
and what their data may represent (ie, if you see a waveform like this, this means that it's
two merging black holes, vs just co-rotating black holes).
6a) We study black holes b/c they are pretty much the only thing that'll generate detectable
gravitational waves.
so yay!
"You have the option of insanity. I do not. And that makes me crazy!" - Brian to Angela, My So-Called Life
...5% of all the intanium chips in the world used for a single simulation, and they were given to the customer free, gratis and for nothing because otherwise they'd have bought an Opteron cluster...
Stick Men
"10,240 Itanium processor"
They could have done the same with 7,869 Athlon 64 processors.
Sounds like someone bought up all the Itaniums that Intel ever managed to sell, and put them into one system.
You see? You see? Your stupid minds! Stupid! Stupid!
And just how slowly would something have to spin before you agreed that it wasn't spinning? 1 revolution/day, 1 revolution/year, 1 revolution/century, 1 revolution/million years?
"The White House is not an intelligence-gathering agency," -- Scott McClellan, Whitehouse spokesman.
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I simulated three black holes once with the help of my little brother (God rest his soul).
Watching the video, I felt drawn in...
Strange, when I clicked the link I swear it said Black Hole Stimulation.
BBL
The scientists were surprised to find that the answer to this age old puzzle was 4.
You can only observe it indirectly by witnessing the blinking lights on the Infiniband switches that interconnect the nodes...
There exists no way of exchanging information without making judgments. --Bene Gesserit Axiom
They ran this sim on a -Lisa-?
whoa! Now -that's- some seriously optimized programming!
What could be more appropriate ?!
-- All your bass are below two Hz
I often wonder, is it possible that the black holes out there in space were lab-based experiments into black holes by some alien race that went horribly wrong?
Genesis 1:32 And God typed
It would have been even more nice if they could've made a simuation where they illustrate how the light is bent around the merging black holes, by showing how the position of stars behind would have shifted, perhaps including a possibly exeggerated view of the red/blueshift to demonstrate the spacial anomaly. The waves we see in the simulations are not real eg. we talk about a change in the curvature of space here, which is one dimenstion above what we can really can imagine. So ordinary waves will not truly demonstrate the shifting of the curvature of space, other than as an analogy. Anyway, the space 'brane' we exist in, is very 'stiff' that is - the curving and bending is extremely small, not like what you could imagine from any 'Star Trek'-episode, so regarding to this, our Universe is very "boring" with most probably no wormholes, or timeloops and so on. This would demand a more 'elastic' brane, however it is not clear wether life could excist in such an Universe. A less stiff brane would possibly have meant a much lower speed of light, though much easier warp travel, but these will remain wild speculation inspired by the 'Wheel Chair' guy...
How can this simulation be valid to prove Einstein theory when the premise to start is flawed. Black holes, like evrything else, spins and have directional movement.
An open mind is as vast as the universe