NASA Achieves Breakthrough Black Hole Simulation 281
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.""
IP violation (Score:5, Funny)
Wouldn't Kraft Foods have prior art on this?
Yes. (Score:5, Funny)
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.
Re:IP violation (Score:2)
Re:IP violation (Score:3, Funny)
This is the USPTO we're talkin about here.
Cheers.
Re:IP violation (Score:2)
Finally.... (Score:2, Funny)
Re:Finally.... (Score:2)
Re:Finally.... (Score:2)
Headline should read: (Score:5, Funny)
Re:Headline should read: (Score:2)
How about something more useful? (Score:5, Funny)
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.
They did do something useful (Score:2, Funny)
They finally managed to use up all of those Itanium processors hanging about in storage. Well done!
Re:How about something more useful? (Score:2)
Seriously, I'd imagine there are a total of probably 30 people on earth who understand the math behind what's going on here. Not really news, even for nerds.
I think what we really want to know is... (Score:5, Funny)
Meh (Score:4, Informative)
Re:I know you're being funny but (Score:2)
If Einstein had had those supercomputers ... (Score:5, Funny)
Re:If Einstein had had those supercomputers ... (Score:2)
Re:If Einstein had had those supercomputers ... (Score:2)
Re:If Einstein had had those supercomputers ... (Score:2)
Re:If Einstein had had those supercomputers ... (Score:2)
Re:If Einstein had had those supercomputers ... (Score:2)
There are two kinds of physicist (Score:2, Informative)
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.
Re: (Score:2)
Re:There are two kinds of physicist (Score:3, Insightful)
These days there are really more than two kinds of physicists. To your list I would add two types that fit in between experimentalists and theorists: observationalists and simulationists.
Observationalist observe nature. Observationalists are like experimentalist, but the nature of their work precludes controlled experiments. They make observation of the natural world - t
Re:If Einstein had had those supercomputers ... (Score:2)
Oh come on! This is Einstein we are talking about
He'd be playing "Red Alert: Command and Conquer"
Re:If Einstein had had those supercomputers ... (Score:2, Insightful)
It is important to have self-awareness that this is an issue and put hard-line limits on things, including drinking or playing a game. "I will only play 3 hours a day" or "I will stop playing at midnight". Hard stops are usually easier to deal with than "I won't play too much" as that leaves too much open for interpretation, which is bad if you have an addictive personality.
The game isn't the issue.
Re:If Einstein had had those supercomputers ... (Score:2)
Although I completely agree with you, you left out one point. While adults are often able to make the kind of analysis that you are suggesting, children generally are not.
This is not a perfect world and if someone can take advantage of the imperfections by selling Tobacco, Alcohol, Games, Christianity and drugs to children who are unprepared to recognize their addictive and dangerous effects, they will. Paren
Re:If Einstein had had those supercomputers ... (Score:2)
Re:If Einstein had had those supercomputers ... (Score:2)
While there may be something to the concept of addictive personality [netdoctor.co.uk] or genetic predispositions [unc.edu], other important issues are easy access to the drug and the engineering of the drug to the individual.
Most work environments don't allow drug dealers to visit your workstation, but screening out gaming is hard. More alarmingly, it is only a matter of time before games modify the individual user experience to maximize time spent playing them.
Re:If Einstein had had those supercomputers ... (Score:2)
I beg to differ, I was addicted to Unreal Tournament before, and it wasn't even close to as destructive as WoW can me.
Re:If Einstein had had those supercomputers ... (Score:2, Funny)
Are there non-spinning black holes? (Score:4, Interesting)
Re:Are there non-spinning black holes? (Score:5, Informative)
Re:Are there non-spinning black holes? (Score:5, Informative)
Re:Are there non-spinning black holes? (Score:2)
Another question would be: Can the ergosphere apply energy to the BH making it spin faster? I.E. If a body crashes into the ergosphere almost grazing, but is captured, does it tr
Re:Are there non-spinning black holes? (Score:2)
Re:Are there non-spinning black holes? (Score:2)
Re:Are there non-spinning black holes? (Score:2)
I think you'll find it a given that ALL stars rotate..., even if some rotate very slowly or they're too far away for us to detect the rotation signature in their spectra, but they ALL rotate
Re:Are there non-spinning black holes? (Score:3, Informative)
Re:Are there non-spinning black holes? (Score:3, Informative)
Once they have some experience with this simulator I'm sure they will move on to spinning black holes.
True. In fact, some steps have already been taken in this direction by other groups. For instance, my group at U.T. Brownsville -- whose non-spinning simulations were published simultaneously with the NASA results (but we don't have the same PR machine) -- have put up a preprint on the orbits of black-hole binaries where the individual holes have spins parallel to (or antiparallel to) the orbital angular mo
Non-spinning black holes?! (Score:2)
Must've been playing Nowhere Man [lyricsfreak.com] in the background when they came up with this idea.
And if Einstein is wrong... (Score:5, Funny)
And if he's wrong then all the scientists can make "loser" signs at him on their foreheads...
translate article (Score:3, Funny)
Re:translate article (Score:2)
Are they really testing what they think? (Score:5, Insightful)
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)
Re:Are they really testing what they think? (Score:2)
More like, did they guess right with their "mathematical intuition" in creating the computer code. Or did they just muck with it until they got a pretty video that wouldn't crash the system. This could be just another NASA problem with
Re:Are they really testing what they think? (Score:5, Informative)
First, with regard to intel, there is essentially no risk from this, as the math libraries used by everyone involved in such work wave test exercises that verify the accuracy of the hardware. It's not uncommon to run every calculation on two physical processors to assure that no single processor malfunction can introduce a significant error.
Second, with regards to the correct approximation of Einsteins equations, either the approximation is exact, in which case there is no risk, or the error size for the approximation is closely known, in which case when we observe the black hole merger, we will have one of 3 conditions: confident to some error size that he was right (actual results match simulation, but we can't rule out his theory being slightly wrong at a finer level), confident that he was wrong (actual results lie outside of error range for simulation), or no result (actual results indicate the possibility he was wrong, but lie within error range).
Exactly (Score:2)
That's new to me. (Score:4, Interesting)
Is there such a thing?
Re:That's new to me. (Score:2)
Is there such a thing?
Can a single point spin?
Although, I don't know if the center of a black hole is more than a single point
Re:That's new to me. (Score:2)
Re:That's new to me. (Score:5, Funny)
Re:That's new to me. (Score:2)
As my professor back in P1 said, "There are three types of orbits: elliptical, parabolic, and hyperbolic. There is no suck orbit." Thus, no matter how many times you use the word thus, you still have no clue what you're talking about.
Re:Wikipedia link (Score:2)
It MAY be possible that a black hole in the center of a dense cluster is non-kerr, but not very likely.
Angular momentum REALLY wants to go somewhere, you know...
OAQ (Score:5, Funny)
Ick! (Score:4, Funny)
Watching massive things merging.. jiggling like jell-o... Good heavens, space is a pervert!!!
Re:Ick! (Score:2)
I don't think it's space/the universe which is being a pervert. Just FYI.
For the last time folks, they're not black holes! (Score:2, Funny)
A Long HIstory of Calculations (Score:3, Interesting)
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.
Equations too complex? (Score:5, Interesting)
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.
Re:Equations too complex? (Score:5, Informative)
the propagation of
describes the time evolution of a tensor for which all the
components are not independent- for instance they obey
Bianchi identities.
http://mathworld.wolfram.com/BianchiIdentities.ht
Simple numerical integrators destroy these identities
at order dt^n for some small but finite n. Run the code
forwards and one can find finite time blow ups due to
the stepping algorithm- however even after a single
time step the numerical solution has unphysical aspects
Finding
http://www.ima.umn.edu/nr/abstracts/6-24abs.html [umn.edu]
Re: (Score:2)
Re:Equations too complex? (Score:2)
"Black holes are where God divided by zero." -- Steven Wright
Re:Equations too complex? (Score:2)
Black hole simulation (Score:4, Funny)
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.
non-spinning? (Score:2)
Speaking of Relativity (Score:2, Interesting)
Stats.. (Score:2, Informative)
In case anyone was wondering how Columbia stacks against their rig, check out:
http://www.top500.org/ [top500.org]
Here's the November 2005 list:
http://www.top500.org/lists/2005/11/TOP10_Nov2005. pdf [top500.org]
It shows Columbia with:
51.87 Rmax (teraflops/second).. It also states that it moved from #3 ranking to #4.
Grab a seat (Score:2)
NASA Achieves Breakthrough Black Hole Simulation (Score:2, Funny)
Better be careful (Score:2)
As long as assumptions are accurate... (Score:2)
It never ceases to amaze me .... (Score:2)
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. =)
From a member of the group (Score:5, Informative)
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!
Re:I bet... (Score:2)
Re:Wasted funding? (Score:3, Funny)
Re:Wasted funding? (Score:2, Insightful)
Exempli gratis (and it's way out there):
Using this new data, someone observes a black hole merger. It doesn't fit the data. Relativity is redone, so to speak. Someone sees a great way to unify Relativity and quantum mechanics because of the new formulation. Bam. Like that, unified theory of everything. Those spinning superconductors generating magnetogravitic fields are understood. Artificial gravity and anti-gravity are discovered. Moon-flights are near ch
Re:Wasted funding? (Score:5, Insightful)
more knowledge about the universe and how it might work.
Will this help create more energy-efficiency in the world?
maybe, who can say what future developments and understanding of this area of physics will bring.
Will it help us find technology that humanity can actually use to make a better society?
maybe, see above. it depends on the definition of "better".
when general relativity was first thought of in 1915 there was no application, for the average person. today GPS relies on general relativity.
Will it increase our safety, or decrease power of madmen and dictators?
the obvious answer is probably not. and while these are important questions, this one is not topical in this discussion.
Re:Wasted funding? (Score:3, Insightful)
Also, understanding does NOT require the tie to experiment since you can have mathematical understanding of a particular theory independant of whether that theory properly models reality. For instance, I can
Re:Wasted funding? (Score:5, Insightful)
Call me utopist if you want, but finding something that "increase our safety, or decrease power of madmen and dictators" gets the #1 naive award (always thinking big shields and weapons, what a world).
Re:Wasted funding? (Score:2)
Re:Wasted funding? (Score:2)
The testing the merger of two black holes is quite the contrary,, and we'd be the ones destroyed if we'd get too close. The only solution is through astronomic observation, so we're waiting for the phenomenon to appear. However, how to compare with our current laws of physics (in the case, Einstein's theories) if we don't simu
Re:Wasted funding? (Score:2, Insightful)
Re:Wasted funding? (Score:2)
Re:Wasted funding? (Score:3, Informative)
Re: (Score:2)
Re:Wasted funding? (Score:2)
I would question your definition of "seems" and "gain". It's people like you that are a large part of the reason why we don't have colonies on the moon and Mars, why we've not been to the stars and found other habitable planets. It's not like this one is going to last forever, and it's not like we are going to stop screwing with it. Understanding how gravity
Re:Wasted funding? (Score:2)
Comments like yours make me feel sad. Why do this? What about the pure hell of it? Of finding out things that no-one else knows, of pushing back the boundaries of human understanding?
In short, what's wrong with pure research for research's sake?
Besides which, who knows what the applications might be in the future? There were lasers lying in research labs for a decade or more before anyone thought of a practical use for them. Now I personally have at least 8 in my house; peo
Re:Wasted funding? (Score:2)
To make the internet work on a physical level requires really good understanding of theoretical physics, because when you pipe huge amounts of information around the planet, or bounce it off satellites, you need to account for relativistic effects.
And I think we can agree that the internet is extremely helpful in making the world a better place: distributing free information, reducing the energy spent communicating, and even promoting recycling through eBay, Freecycle [freecycle.org] et cetera.
Re:Wasted funding? (Score:2)
If they already have bought the machine, it's actually a hell of a lot more wasteful NOT to use it. TFA indicates that it was ranked for the Top 500 in November 2005... and since it had to be purchased a fair bit of time before its delivery date, it could a year or more since the original funding allocation and subsequent purchasing decision were made.
I'm sure the exact date of the purchase order could be dug up by someone more determined than I am.
And for the record, a manned mission to sightsee o
Re:Wasted funding? (Score:2)
Re:Wasted funding? (Score:2, Interesting)
Re:Supersucker (Score:2, Funny)
I really think the goatse guy could claim prior art on this.
Re:Next thing U know (Score:2)
Re:OK... Wait... (Score:4, Insightful)
Re:OK... Wait... (Score:2)
Yes. But please keep this fact to yourself.
Sincerely,
NASA Project Manager Who Got the $1.1 Gazillion Project Approved
Re:OK... Wait... (Score:2)
You don't use the model to predict what the model will do, you use it to predict what (in this case) actual black holes will do. And so if your model predicts something else than what happens in nature (within the limitations of the model), you know your theory is bust.
Re:OK... Wait... (Score:3, Insightful)
Re:OK... Wait... (Score:3, Insightful)
No. In Physics a theory makes claims that can be falsified by an experiment. The theory (general relativity) is already there and the experiments will be carried out by LIGO and LISA (the latter having been delayed indefinitely thanks to Bush's plans).
However, we strongly assume that General Relativity must break down at some point and give way to some theory of quantum gravity. There are several such the