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Astronomers Explode Virtual Supernova
DynaSoar writes "Scientists at the University of Chicago's Center for Astrophysical Thermonuclear Flashes have created a simulation of a white dwarf exploding into a type 1a supernova. Using 700 processors and 58,000 hours, they produced a three second movie showing the initial burst that is thought to be the source of much of the iron in the universe. Understanding these supernovas is also important to testing current cosmological theories regarding dark matter and dark energy, as their brightness is used as a measurement of distance, and discrepancies found in the brightness of very distant supernovas consistently seem to indicate a change in the speed of expansion of the universe over time."
What's better....
Exploding a supernova
Exploding in a mare
http://flash.uchicago.edu/website/research/gallery /home.py
for all alternative OS users out there.
7000 processors and 58000 hours? SG-1 Did that in a single episode! On a TV special effects budget no less!
So, they started the simulation over six years ago?
Repton.
They say that only an experienced wizard can do the tengu shuffle.
"Astronomers Explode Virtual Supernova"
Pfft! That's nothing. I exploded a virtual condom.
Those greedy mining companies will use any excuse to try to find more iron to dig up to make more profit for their greedy shareholders.
Does anyone else see the "face" that is created during this explosion? I see closed eyes, a nose and even a mouth(all tongue in cheek) ROFLMAO... sorry poor joke..... would love to see this at full speed.
hee hee
I don't need no instructions to know how to rock!!!!
> created a simulation of a white dwarf exploding into a type 1a supernova. Using 700 processors and 58,000 hours,
They probably got Federal Funding for this by explaining it was "like sticking a giant firecracker up a giant frog"
You insensative clods! They killed my virtual friends and my virtual dog orbiting around that star on a virtual planet! Just because they are bits instead of molecules is no reason to demean them.
Table-ized A.I.
They literally blew a wod of cash
Table-ized A.I.
supernovas
Shouldn't that be supernovae?
Have you read my journal today?
I'm sorry, I had to check when their acronym spells CATFUC.
Help poke pirates in the eyepatch, arr.
Bob: But we'll never get funding with a three second image. This thing had to have caused something useful .. ... how about something specific like Kevin Federline?
Joe: Well, um
Bob: No, panders too much to popular culture.
Joe: That's too bad because my next thought was heavy metal music. Oh, how about some type of boring "metal" like iron ore. It's in some vitamins too which will interest the average consumer.
Bob: That'll do. We have to get the funding proposal out by noon.
Marvin the Martian 58000 hours before Bugs Bunny arrived...
There was supposed to be a simulated Ka-Boom. A simulated earth shattering Ka-Boom.
SciTechPulse. Geek News Netcast. Hot Polynesian Geek Chick Silulu.
looks like projectile diarrhea. i dont need 700 processors for that, just a 1.3 pound steak.
The 700 CPUs is not that much. What if they try the same simulation on 100000 CPUs?
= osstats
Btw: The Folding@home released a PS3 client and it has already overtaken all current platforms:
http://fah-web.stanford.edu/cgi-bin/main.py?qtype
...but why do these people persist in blowing so much time and effort and money on stuff like this when there are far more deserving and serious problems to be solved right here and now on good old earth. Hell, we can't even tame hydrogen --> helium let alone oxygen --> iron or whatever it is. Good, solid science for sure, but the priorities seem to be way, way wrong if you ask me.
Gah that article is awful. They link to pretty pictures and blurbs mostly and never really explain what these things are, why they are important or give you any real sense of scale. So since I like to beat on the drum of better communication of science, here is a little more detail to add to the good einhverfr's post.
The progenitors of SNIa are most likely white dwarfs composed of carbon nitrogen and oxygen, probably with a companion star from which they are stripping matter. They are very compact on the order of a few thousand kilometers at most, and really dense - more than the mass of the sun. They aren't hot enough to support fusion - they are supported by Pauli pressure; quantum mechanics doesn't allow two electrons in the same state at the same time so though gravity tries to compact these objects there is a Pauli pressure outward to balance it.
This can't go on forever in these progenitor systems however, and if the white dwarf strips enough matter of its companion to get to ~1.4 solar masses (the Chandrashekar limit) then Pauli pressure isn't strong enough to balance gravity and the star begins to collapse and when that happens pressure and temperature rises and somewhere a nuclear fusion flame ignites. Details about what happens near collapse, and where and how the flame ignites, and how many there are and how they progress are still debated. In this particular model they are considering only a single flame (so far) and its a "gravitationally confined detonation" (GCD - the name of this particular model).
Its a little difficult to get a sense of scale from those videos, though there are numbers in the bottom corner. The flame starts of near or just of center and becomes bubble/mushroom shaped through a Rayleigh-Taylor instability and breaks the stellar surface in under a second. Its less than another second before the ash and flame from the bubble collides at the opposite end of the star. This flame crashing into itself (see video 1) causes compression and a detonation.
Theres been a lot of debate as to whether its a deflagration or a detonation or whether it transitions from one to the other and how and when that happens and us poor graduate students just hope they don't go crazy over details of the progenitors during our qualifying examinations. This is notable because there appears to be a growing number of voices who are saying that a detonation is necessary. These events are so standard because they all become SNIa if they get near 1.4 solar masses. There is a fair bit of diversity (and some just crazy objects) and most of that probably arises from details during the explosion which is why modeling them is partly why the models are so important.
There is still a lot of modeling left to do. This flame is producing a lot of heavy elements (there is O, S, Ca, Mg and Si in the early spectra - the silicon feature is around 6150 angstrom in the rest frame and is the marker of a Ia at low to moderate redshifts). As the outer layers expand and become more transparent you see more of the material produced during the explosion and a lot of this is Nickel (Ni-56) which decays to cobalt and powers the light curve so you get this typically 2 week rise and then a slow fall off. Later times most of the Ni has become cobalt which is decaying to iron and you see these elements in the spectrum. The energies we are talking about here are about 10^45 Joules. A H bomb by contrast is 10^15 Joules so 30 order of magnitude. Unless you can picture 10^30 H bombs going off its hard to get a feeling for this number but thats generally the case with numbers in cosmology.
There are a lot of empirical relations you see from the lightcurve, which are exploited to standardize them (for instance the brighter the supernova, the slower its rate of decline, and there are relations for the colour...) and if a model can replicate them and match the observed lightcurves and spectra then this is a very impressive accomplishment. I skim
Reality must take precedence over public relations, for nature cannot be fooled.
There's a much better, and more recent article on this simulation hosted at www.nasa.gov - but the site is unbelievably slow to load as of late. You can see the nasa.gov article mirrored at http://douginadress.com/news/spaceexploration/berk eley_labs_supernova_data_crunching.html
Ace
As I have stated before here in other postings, I believe that simulation is the unrecognized and discounted factor that accounts for the Fermi Paradox, the fudge factor in the Drake equation that explains why we don't have aliens walking among us today. We are getting quite good at simulating reality ourselves, and there is no reason why extraterrestrial intelligences wouldn't do the exact same thing.
At some point soon, the synthesis of our scientific knowledge will allow us to assume, with considerable certainty, that aliens with similar biology and physics exist, probably in other solar systems in this galaxy and almost certainly in other galaxies.
They have of course reached the same conclusions and that is why they aren't trying to contact us.
We don't have to go exploring to find them. It's cheaper to just imagine them and simulate them. The real problem is what do we do if we decide to believe this?
it's a blue bright blue Saturday hey hey
In fact, the word is built out of two Latin adjectives, literally it means an "abovenew". Invented words follow this rule, hence the plural of octopus is octopuses, of satellite is satellites, and of millennium is millenniums. The plural of "vertebra" is "vertebrae" because it is an actual Latin word, not an invented modern one.
Incidentally, while pursuing this very pedantic note, "satellites" is correct plural but the singular of the original word is "satelles". And the original word is pronounced sat-ell-it-ees. We are a long way from Latin.
Pining for the fjords
"You seen one nova, you seen 'em all."
marketing surveys beyond th3 scope of the chhosing what provides the
... as if a million bits cried out at once and then were silenced!
A beouwulf cluster of these!!!
By the pricking of my thumbs, Something wicked this way comes: Open, locks, whoever knocks!
Looks like the 10 year visionary project paid off right at the end. Long term financing was required along with faith in the project's people.
Slashdot: Where nerds gather to pool their ignorance
I found that passage confusing, too. I did some googling and found another (quite readable) article that suggests it is the latter:
Scientists just recently learned new things about our closest star that are changing the way they study/view it. How is possible that we can create a reliable simulation based on information that's changing?
I'm no astrophysicist, but it seems sketchy. So they made a movie. So what?
FTFB: the initial burst that is thought to be the source of much of the iron in the universe
I always thought that iron was produced without the nova and that it was elements that are heavier than iron that were created by the blast. Am I wrong on this?
Dedicated Cthulhu Cultist since 4523 BC.
It was a pretty darned good nova, but I wouldn't go so far as to say it was super.
Now the '69 Yenko Nova (the ones with big blocks, not the LT-1 350's for 1970). That was a super Nova!
or does anybody else have a sudden craving for pop corn?
Parent is a troll and uses the same site over and over again
58,000 hrs for 3 secs, or 69,600,000 computational secs per sec real time. They'll need to do some performance tuning before they go for 1 minute simulations. ;)
What's fascinating to me is the behavior of the explosion front. At first it seems counterintuitive for it to 'burrow' towards the surface and burst asymetrically. But when you stop and think about it, that is the behavior you should expect - the expansion is the direction of least resistance, into regions of lower pressure.
What a waste of copmuter time and energy.
Didn't they have a good 3d application.
How about povray or 3d max joking..
but only 3 sec thats almost nothing...
1...2...3 and here is our electricity bill and hardware bill ping $1xx.xxx.xxx.-
I know you're out there. I can feel you now. I know that you're afraid. You're afraid of us. You're afraid of change.
Um, hi. Astronomer here (not that it matters).
The word nova in the astronomical context comes from Tycho Brahe, a Danish astronomer who was writing in Latin at the time. The plural is novae, not novas. Although supernova is an English construction, the etymology is derived more directly from this Latin word than other modern inventions. Although both plural forms are strictly correct due to the artificial construction, supernovae is used predominantly in our field.
It's a trap!!@#!#!@!@#!#@!
So astronomers can do what they like, but I for one will grit my teeth. I don't have any objection to neologism whatsoever, but trying to make it look like Latin is just pomposity.
Pining for the fjords
By the time the simulation finished the current processors are what, about 5 times faster?
Did they upgrade the processors as it ran or just let it run as-is? Seems like it could have been completed faster if they continually upgraded the processors.
If you need any help picturing what they're studying, this professor's here to tell you why a supernova would be totally awesome!
wudnt watch this with shitty macromedia flash or whatever it is. those idiots are trying to turn the internet into a tv.