Slashdot Mirror
Simulating the Whole Universe
Roland Piquepaille writes "An international group of cosmologists, the Virgo Consortium, has realized the first simulation of the entire universe, starting 380,000 years after the Big Bang and going up to now. In 'Computing the Cosmos,' IEEE Spectrum writes that the scientists used a 4.2 teraflops system at the Max Planck Society's Computing Center in Garching, Germany, to do the computations. The whole universe was simulated by ten billion particles, each having a mass a billion times that of our sun. As it was necessary to compute the gravitational interactions between each of the ten billion mass points and all the others, a task that needed 60,000 years, the computer scientists devised a couple of tricks to reduce the amount of computations. And in June 2004, the first simulation of our universe was completed. The resulting data, which represents about 20 terabytes, will be available to everyone in the months to come, at least to people with a high-bandwidth connection. Read more here about the computing aspects of the simulation, but if you're interested by cosmology, the long original article is a must-read."
Does the simulation include simulated scientists simulating the universe?
"I always wanted to be God." said Dr. Johnson. "When they announced this project, the first words out of my mouth were 'Dibs on God!' I even have plans to introduce a son in a few billion simulated years. This is going to be exciting."
This isn't an ad for anything on think geek !
Has a mistake been made?
NOT AN ADVERTISMENT FOR THINK GEEK !!
I can search it to find out where I left my cell phone last night.
The only acceptable defense of scientific results is to say that they were the product of the Scientific Method.
Fire up your bittorrents, people!
The answer is 42. Just google it
Do you have a 1:1 scale map of the world I can use?
Uh yes, but it's being used right now.
I was going to comment on the absurdity of the claim to simulate everything, but due to a slashcode hiccup, I got "nothing to see here, move along." What The? I thought that EVERYTHING was here?
Oh, and the ObStevenWright: You can't have (simulate?) everything. Where would you put it?
--
GMail invites for iPod referrals
"time to put this 56.7k line to work"...
Hellenologophobia, n. -- a fear of Greek terms or complex terminology
Now just imagine a beowulf cluster of... damned!
Does anyone else see the striking similarities to the Hitchikers Guide?
Simulating the Universe to find answers and the number 4.2 can't be a coincidence, can it?
Sounds like the first Hyperspace Nav-Computer to me...
Before you non-astrophysics types start trying to be clever, it's "cosmology" not "cosmetology." Stars, not pop stars.
:P
You can tell, I get this one a lot.
"All your base are belong to this file I send in order to have your advice."
How can you accurately simulate the computer that is simulating the entire universe?
Basically, you'd end up infinitely short on processing power. The faster you make the computer, the faster you need the computer to be. It's like working out so that you can get strong enough to pick yourself up by the bootstraps. The stronger you get, the more you weigh and you make the impossible less possible.
LK
"Hi. This is my friend, Jack Shit, and you don't know him." - Lord Kano
Or does this sound like the movie "The Thirteenth Floor"? More importantly, does this guy have the power to crash the universe?
But did they try to build a simulator that would simulate the entire universe in the simulated universe?
Did they get a giant sign million light years across floating in space, saying:
Simulating universe in a simulated universe is not going to work.
You just have to try it, didn't you?
We know when The Internet Meltdown predicted on Slashdot will arrive.
/.
When THAT 20 terabytes result data will be linked on
that should only take around 6 and a half minute to download
How long before denizens of the simulated universe start demanding equal rights and for our universe to stop negatively impacting their destiny?
I wonder if our universe is just a simulation sometimes...
Do not look into laser with remaining eye.
they recreated the universe [1], and gave it away to anyone who was interested !
.
so somehow the big news will be the big news and not how some amazingly large amount of unique and never before constructed data will be given away free and not copy writed !
my mind simply implodes like some thing out of a capital punishment device ina HHGTTG story
[1] I now it was simulated.
And thats why Firecrackers and kittens don't mix.
"the computer scientists devised a couple of tricks to reduce the amount of computations..."
Somehow I don't see how adding a few more shortcuts to the assumptions made matters, since they convienently decided to "reduce" mass to particles a billion times the mass of our sun. Really, what kind of useful calculations can you make when you vary that significantly from your target system.
Or did they assume the mass of each scientist's brain was also a billion times the mass of our sun?
How many of you read that as "stimulating the whole universe" and immediately thought of pr0n?
Oh...
just me...
"a task that needed 60,000 years, the computer scientists devised a couple of tricks to reduce the amount of computations"
OR
60,000 Computers all running accrros the globe in a simulated computing project.
http://boinc.berkeley.edu/
Now i know theres problems with this. They were using a more powerful computer than any of us have in our homes, plus the problems with simulations going wrong but overall its possible i think.
http://climateprediction.net/ manage to predict the the weather (well, we think they have!).
- http://www.milkme.co.uk
They'll have a slashdot link to a 20 terrabyte file. Server PWNAGE. :)
wait... what does makeup have to do with the universe? cosmetologists figured this stuff out? ooooh... cosmologists... nevermind, i get it... yea, very cool.. i still think it would have been more interesting if cosmetologists had figured the universe out though...
--- Caffeine is directly responsible for some of my greatest ideas, and some of my most embarrassing moments...
It's turtles all the way down.
Now, where can I find the scientists working on a reality-hacking machine?
We slashdotted the entire universe. Way to go.
Dim UNIVERSE AS INT
III.IIVIVIXIIVIVIIIVVIIIIXVIIIXIIIIIIIIVIIIIVVIII
Now that the hard simulations are out of the way maybe the simulations can work on other tough issues. For example, why is it that bacon makes other foods taste so much better?
Ummmmm, baaaccoonnn (obligatory simpsons quote)
Directly from the article: The machine, a cluster of powerful IBM Unix computers, has a total of 812 processors and 2 terabytes of memory, for a peak performance of 4.2 teraflops, or trillions of calculations per second. It took 31st place late last year in the Top500 list, a ranking of the world's most powerful computers by Jack Dongarra, a professor of computer science at the University of Tennessee in Knoxville, and other supercomputer experts.
But as it turns out, even the most powerful machine on Earth couldn't possibly replicate exactly the matter distribution conditions of the 380 000-year-old universe the Virgo group chose as the simulation's starting point.
Slight failure of basic logic here...
Feel that power? That's mah MOUSING FINGER
... the intergalactic branch of the RIAA has filed a "Cease and Desist" order against the scientists, citing Copyright law; that anyone giving out free copies of the universe without first seeking permission from the copyright holder is a violation of intergalactic intellectual property rights.
Vintage computer adverts: http://www.vintageadbrowser.com/computers-and-software-ads
...downloading naked pictures of everyone?
"These results, which represent 64 snapshots of a virtual universe, will be available to all of us in the months to come."
Wow, only 64 snapshots, and all they simulated is gravity. What exactly will anybody find out this? That the particles attract each other?
It seems like an incredible waste of time and computing power.
Furthermore, the algorithmic tricks they used don't sound like anything new. Ask one of the top 10 on http://www.topcoder.com and they'll probably find out a couple more tricks that would reduce the running time required by 100x.
I think they would've done a much better job with 1 million particles of possibly different types, simulating several other forces.
The last time I checked, we didn't know a whole lot about the nature of the universe as it stands... how the hell are these guys claiming that they
a) Know how it was at the start
and
b) can compare it to whats out there already when its done?
What he can't kill, he has sex on. Trent.
But due to space restrictions, mine and the one you see had to be represented as one post.
Self-referential sigs do not a humourous poster make.
Sounds like that MultiTheftAuto engine can do all this AND support drive-bys!
The same way you simulate anything else. You simplify the problem down to a manageable number of particles that represent larger units of whatever you are simulating. Since in looks like they are interested in mass and gravity at the galactic supercluster scale, they can use particles that weigh much more than any individual star.
The article indicates that the "tricks" these researchers used were the octree and multipole expansion--both of which have been used in gravity and potential theory for many years. They reduce the N^2 interaction problem to N or N Log(N), depending upon implementation. The story makes it sound like these researchers invented the technique; I assume the writer misunderstood the scientists, because it certainly predates them.
...just an infinite number of expansion packs. Sims: Makin Mulitverses!, Sims: Hot, Naked Sinularities, etc....
Couldn't we just go back and look to see if there really was a second gunman? __
Apparently this requires more stack space than exists in this universe.
more fun to sinulate it. That would also fit with some new theories about "action at a distance".
You are assuming that the author is stating that the machine in question is the most powerful in the world. Those three sentences do not convey that meaning, however. The author is stating that 'even [if we were using] the most powerful machine on Earth'.
HBI's Law: Frequency of calling others Nazis is directly correlated with the likelihood of the accuser being Communist.
Given that this group is called "the Virgo Consortium", is it any wonder that they have to resort to a "simulated" "Big Bang"?
Did these guys also simulate intelligent life on other planets? If so, it would be nice to see if we humans will contact them in the next decades. And what about black holes and other fuzzy things? How can you simulate something without knowing how it works?
Perhaps now David Braben and Frontier Developments will be able to write the long-awaited next version of Elite!
...used by Duke Nukem: Forever.
They simulated a universe. They didn't simulate the universe. Unless our universe suddenly only has a subset of the laws it used to and now consists of nothing but a billion very massive particl[NO EXISTENTIAL CARRIER]
I know eBay ads come up often, but I just find the fact that ebay bought ads for "42" (and apparently other numbers) just astounding. Do they really think a lot of people want to buy numbers on eBay? I, for one, buy my numbers down on the corner from a guy named Mickey.
A lot of Slahdotters live in the US you insensitive clod.
To you and all the other (-1, Redundant) posts on how the system can't simulate every single detail in the Universe: it's a *simulation*, not the real thing, OK?
The first thing you need to do when you plan a simulation is to determine exactly what's significant or not. In this case, they decided that a set of particles with a billion times the mass of our sun would be appropriate. That's because what they are studying is mostly the long range effects of gravitation, where "long range" is defined as a sphere that contains a mass of ten billion suns.
When and if someone wants to study the workings of the Universe at a smaller scale than that, then they will have to simulate at a smaller scale. Phew, people are so dense! Next thing they will say that because a photograph didn't capture every single hair in a person's head or every single pore in their skin, that photo doesn't represent that person at all...
Wow. What did the threads look like in this app?! The article describes it as a 'simple program', but concurrency over these data structures is very impressive
Also, I wonder if they used GMP for their math?
std::disclaimer<std::legalese> sig=new std::disclaimer; sig->dump(); delete sig;
The Read more here link leads to a few pity sentences framing lengthy excerpts from the IEEE article.
BTW, the machine in question, the Max-Planck-Gesellschaft MPI/IPP, is currently ranked 66th. It looks to be a fairly ordinary cluster with none of the exoticism that Cray says we so desperately need
Can't even simulate a game of Counter Strike source. Damn scientists get all the good hardware.
scientists cant even simulate a hurricane and where it is going, but they can simulate the whole universe? waste of time and resources.
my ass. This is just a simulation of what would happen if our univers was made up of a bunch of particles a billion times more massive than our sun. Last time I checked, it's not, and to try to pass this simulation off as representing how the universe would behave is silly.
Why sell it as something it's not? Oh grant money, right...
The resulting data, which represents about 20 terabytes, will be available to everyone in the months to come, at least to people with a high-bandwidth connection.
And a lot of fucking storage.
LK
"Hi. This is my friend, Jack Shit, and you don't know him." - Lord Kano
I just hope it has a "You are Here-->" indicator so we all know where we are.
1.Netcraft confirms:In Soviet Russia all your base welcomes a beowolf cluster of CowboyNeal overlords. 2.? 3.Profit!!1!
something tells me that the ANSI int DWORD won't cut it.
Someone had to ask: wonder if anyone's simulated the universe using MOND. How did the researchers account for all this dark matter that's supposed to be around? It's far more likely that we got the force law wrong. Do these dark matter guys still believe in Santa Claus? BTW has anyone successfully simulated a galaxy and produced results that correspond to observations? I think this problem is still open...
Are they modeling any of the physical (star formation, etc) interactions of matter or just the gravitational interaction. It seemed like the latter, but the article did mention the apparent non-interaction of dark matter.
Bleh!
He wasn't a scientist, just a thriller writer, but sometimes he came with some brilliant phrases. Like: "If God were omnipotent and omniscient in any literal sense, he wouldn't have bothered to make the Universe at all."
("Playback", 1958)
he doesnt give a shit about the story, slashdot is just an ends to a means as long as people keep clicking he will keep spamming
the dickhead is just a plagairist, steals content and then reposts it for profit, its pretty obvious the editors are getting kickbacks so just just add his site(s) to your hosts file and ignore the french fuck
127.0.0.1 radio.weblogs.com
127.0.0.1 www.blogads.com
127.0.0.1 blogads.com
... gives me a discount on imaginaries and a good deal on irrationals. Buy 2 irrationals and your next trancendental is 1/2 off! He must be crazy!
That's right. All your base.
goodbye roland
Everyone know you can't buy numbers, just vows. Sheesh, have they learned nothing.
500 dollar reward for tip(s) leading to the arrest of the person(s) who stole my sig.
goodbye Rolands advertisers
mod parent up
goodbye
Last I heard there was some question as to the speed of gravitational attraction. IE if the effect of gravity is only as fast as that of light then the earth is being acted on by the gravity from the point the sun was at 8 minutes ago or some such while the sun is similarly being affected by the earths poistion from 8 minutes ago.
s /NCOR.11.16.D/display.html
As these mass points get further and further apart this would have a huge effect on the results. Unless of course Gravity is instentaneous across any distance opening the door to some interesting possibilities. Namely the ability to communicate across large distances without delay. Perhaps even FTL travel.
While I find this excercise interesting I also find it a tad ridiculose. So many simplifications have to be made to even attempt it and the whole thing is based on some assumptions that are not necesarrily cold hard fact... such as the mass of the universe. Theory says one thing, observation says another. Dark matter was invented to close the gap. Don't get me wrong, there are a lot of smart people that have come up with an awful lot of observation which seems to confirm its existence, but it could be that our point of veiw is insufficient. After all by all observations the Ptolemaic model of the movement of the heavens was accurate and it had all sorts of added rules for handling what was observed.
Also there is the issue of the N body problem where N is greater than 2. Did you know we cannot accurately model our solar system just using keplers laws ? We have to create stabilising factors in the system to keep the planets paths from becoming unstable in their orbits. And yet here they are attempting to simulate an N body problem where N = 10 billion.
http://www.lactamme.polytechnique.fr/Mosaic/image
That link shows what happens with a pure Keplerian system of equations for 9 bodies.
Thus introducing such things as mass simplification for objects farther away ( creating groupings etc ) and the tree approach for close objects all creates an introduction of error into the equation. Further more they have to use some means of stabilizing the equations similar to solar system models which is a value based on observation but with no understanding for what really controls it ( if they don't do this then the system of equations can't model our own solar system much less 10 billion mass points expanding since 380k years after the big bang ). This is all chance for more error to creep into the equation. Then with all of this they run a simulation for a simplified mass points using simplified interactions with an unkown stabilizing force over the course of billions of years and then expect people to believe that what they wind up with has any significant correlation to reality.
Do not be decieved by impressive things like 4 teraflops and 20 terabytes of information. To me this seems an interesting intellectual excercise, but the chances of the results being meaningful are pretty slim.
I don't ask you to be me. I only ask you not expect me to be you.
I often work with simulations and this matter of simulation the 'whole universe' had come across sometimes. The conclusion I always reached though, is that a simulation of the *whole universe* is by definition impossible.
If we are to simulate the state of the *whole* universe up to the present moment, particle by particle, the storage space needed to save the simulations results would never be enough.
Let's suppose for example that we were to be able to store the information about each particle in (really conservative assumption) 10 kbytes. And that these 10 kbytes were to be stored in some sort of media that took the physical space of 10 'particles' (pick whatever you want here, atoms, electrons). By definition, If we want to be able to store information about the evolution of every particle, we have to take in account the particles that are being used right now to store the state of the system, but then we would need to use the whole universe as a giant harddisk to store the data on the simulation, which of course would be impossible.
RTFAing one sees that they're actually simulating 0.003 of the observable universe's total mass.
Hmm, is this the beginning of his theories? ;)
I fought the corporate America, and the corporate America bought the law.
Cosmological redshift is *not* the same thing as the Doppler shift. Cosmological redshift occurs because space is expanding and as space stretches the waves of light embedded in it are stretched as well. A Doppler redshift occurs when an object is moving away from you *through* space, so that whenever, say, a peak in the wave is emitted, the object is a little farther away, thus stretching the perceived wavelength. Then there is gravitational redshift, where light loses energy climbing out of a gravity well, causing the wavelength to increase as wavelength is inversely proportional to the energy of the photon.
--- Brian
quite a nifty java app.
Since all the Hamiltonians involved are time-reversible, wouldn't it make just as much sense to start with the current conditions and work backwards? Unless they think they have a better understanding of the initial conditions than of the present conditions. Which seems quite unlikely to me.
Mathematics is not a crime.
thx
I'm Rick James with mod points biatch!
Too bad the "big bang" theory has been proven a fake!
42.
will thay have enough power to similatate the similation of the ubiverse?
The Kruger Dunning explains most post on
That's what I call "News for Nerds. Stuff that matters!
Great story. Thanks.
Dark Helmet: What the Hell am I looking at?! When does this happen in the movie?!
Col. Sandurz: Now! You're looking at "now," sir. Everything that happens now is happening "now."
Dark Helmet: What happened to "then?"
Col. Sandurz: We passed it.
Dark Helmet: When?
Col. Sandurz: Just now. We're at now "now."
Dark Helmet: Go back to "then."
Col. Sandurz: When?
Dark Helmet: Now.
Col. Sandurz: Now?!
Dark Helmet: Now!
Col. Sandurz: I can't.
Dark Helmet: Why?
Col. Sandurz: We missed it.
Dark Helmet: When?
Col. Sandurz: Just now.
Dark Helmet: When will "then" be "now?"
Col. Sandurz: Soon.
Dark Helmet: How soon?
Brain the size of a planet and here I am with you suckers.
These guys modeled the universe, so lets use their model and fiddle with it. Gravity in our universe is an attractive force. Change it to a repelling force of the same scalar quantity with respect to mass, so the only thing that changes is the + sign becomes a - sign in the appropriate equations.
Instead of using the model like these folks did, starting at 380,000 years aBB (after Big Bang), could you start in the present and apply this negative gravity instead?
Would you then be watching the universe unfold - er, fold up, I guess - in reverse? Would it be essentially time travel (within the model, of course)?
"Even for Slashdot, that was a very obscure reference!" - Anonymous Coward
(disclaimer: I Am An N-Body Modeller, and although I'm not part of the Virgo collaboration, a large fraction of what I do is study cosmological models like the one described)
It doesn't quite come out in the article, but what's really groundbreaking about this work is the number of particles they're using. When you make models like these, you always have to prioritize how large a volume you want to simulate (the more volume you have, the more representative a fraction of the universe you have and the larger number of structures you can analyze) vs how massive the particles are (the smaller the particles, the smaller structures you can analyze).
The more total particles you have, the less you need to compromise your volume or particle mass. Until now, simulating such a large a fraction of the universe (NOTE: unlike what the submitter said, this is not the full universe; as the article itself says, it's about 0.003 of the Hubble volume) required such large particles that it was impossible to say anything about individual galaxies.
However, with 10^10 particles, the mass of their particles is only about 10^9 solar masses, so they can reliably resolve structures of 10^11 solar masses. For reference, the mass of the Milky Way is roughly 10^12 solar masses. This is a fantastic leap forward - most other modern simulations have 10^8 - 10^9 particles, and so either can only simulate a much smaller fraction of the universe (like the simulations I study), or cannot say anything about galaxies, only massive galaxy clusters.
[TMB]
I have a feeling somebody has some serious problems with his wife.
This sounds like the beginning of the Total Perspective Vortex, they just need to figure out how to implement a piece of fairy cake now.
But hey, you're all just figments of my derranged imagination anyway, so I'm not worried...
Those sissy Virgans are going about the sim backwards. Take their engine, plug in data on the Universe's particles' state now, and run the sim forward, discarding the data until they get to the simulated day after they publish the results. Then extract from that state the particles composing the simulated published report, and then actually publish it. By simulating only a few months, rather than 15By, they can increase the resolution enough that they won't even have to pick the font: it'll be in the simulation.
/stock market (.{999999999})/g as the discarded days go by to /dev/null .
You're welcome - all I ask in return is to grep ~=
--
make install -not war
http://www.simulation-argument.com/
This paper argues that at least one of the following propositions is true: (1) the human species is very likely to go extinct before reaching a "posthuman" stage; (2) any posthuman civilization is extremely unlikely to run a significant number of simulations of their evolutionary history (or variations thereof); (3) we are almost certainly living in a computer simulation. It follows that the belief that there is a significant chance that we will one day become posthumans who run ancestor-simulations is false, unless we are currently living in a simulation. A number of other consequences of this result are also discussed.
..don't panic
Thank you for that whopping post of info. Makes me want to do some side research (more than the armchair varity) into orbital mechanics. On a side note, I have an (unlikely) suspicion that the 3+ body problem may have a perfect equation, but the mathematics are just not here yet. I say really unlikely because I'm under the impression that the 3 body problem was proven to be unsolvable this way. (within modern mathematics)
That's right. All your base.
1) Either the scientists deemed the record industry too "insignificant" to bother with and didn't simulate music--don't ever let the RIAA catch you calling them, "insignificant"... or
2) they simulated the music in which case they're in copyright violation--unless of course they paid simulated money.
I vote we start paying everyone with simulated money (except for me naturally). "And one more thing, none of them ever wants to pay taxes again... ever." -- Bruce Willis (Armageddon).
No man's an island, unless he's had too much to drink and wets the bed.
2) they simulated the music in which case they're in copyright violation--unless of course they paid simulated money.
According to this article, Black holes produce the lowest note in the universe, at 57 octaves below middle C. It will be interesting to see what the movie of this simulation looks like.
Vintage computer adverts: http://www.vintageadbrowser.com/computers-and-software-ads
The brief says 'gravitation'. I have a strong feeling that the points should be considered as charged particles in a cosmic magnetic field. See Alfven's later works.
Thought so. The universe is pre-alpha, which is why every feature sucks.
simulation of the entire universe
Ok, very impressive...
The whole universe was simulated by ten billion particles
Hmm? Less than that contained in a grain of sand?
each having a mass a billion times that of our sun
WTF?
the computer scientists devised a couple of tricks...
Hmm...
The resulting data, which represents about 20 terabytes, will be available to everyone in the months to come
Indeed.
Caveat Emptor is not a business model.
Hmm, lets see - will I use my Vic20 or drag out the Altair?
10 billion particles cannot simulate a glass of milk, let alone the universe.
Just in terms of mass, each particle in the "universe" simulation must represent between 10 and 100 galaxies.
So the simulation actually represents the gravitational interactions of groups of early galaxies, not really the whole "universe".
HCG 50a = 2MASX J11170638+5455016
11h17m06.4s +54d55m02s
Sounds like a job for...
*duh duh duh-duh!*
BitTorrent!
That would be beautiful, thousands of HUGE files posted to one massive bittorrent tracker!
Wow, Roland has actually posted a couple of articles where the blatant self-promoting links to his stupid blog now just say "read more" or "read more here", rather than his usual "this link contains more details and references", or "...this link for pictures and a summary". Maybe he knew people were recognizing his pattern too easily? Although I can still tell a Roland story when I read the summary, without looking at the name, and they still stink just as much.
So they are simulating a universe full of black holes?
It seems to me that if you you were to just modify an experiment I read about where they were measuring the gravitational force of the sun (or something like that). They had a few large rods with a precisely known mass, and measured the change in forces during the day.
If you were to do something like that and take into account the change in distance from the sun and tidal effects, you could compare the force data to the observed relative position of the sun, find the amount of delay, and then calculate the speed of gravity.
What is the URL address to download that 20 TB data? Me and my 56K modem can't wait to start getting them. Preferably, the server supports resumable download, if you please.
Does the simulation simulate a computer that is simulating the universe which is simulating the universe that includes a simulation of the univer....
My head hurts
Now I know what an aneurysm feels like.
"The resulting data, which represents about 20 terabytes, will be available to everyone in the months to come, at least to people with a high-bandwidth connection."
Well, at least we know that we will be around for a few months. Do we have to download the whole bloody thing to find out when the world ends?
Thats more than possible. The worlds weightlifting champion woman can life twice her weight, the camp man can lift more than 2.5 times his weight.
Anyone who can do chin-ups can lift their own weight..
There are other physical reasons why you cant lift yourself by the bootstraps, including the fact that you really have to push the earth downwards somehow.
Beside that, your points taken.
"Give orange me give eat orange me eat orange give me eat orange give me you." -Nim Chimpsky
Well, that might be true in your country but here in the US, Microsoft has patented 0, 1, 40 and 64. Just in case you were wondering, this post cost me 40$.
Oops, make that 50$!
-Dizzle
"I most likely AM so interested in myself."
Roland, apparently noticing that people are aware of his standard post, has changed his wording from "check the overview here" to "Read more", has changed his ways...
But he's still the same spammer, and while I don't expect Slashdot editors who don't even check for duplicate postings to notice, *we* can at least make them aware of it.
The guy gets a posting just about every other day (undoubtedly on something that gets him money) and I'm sick of Slashdot being the Roland fansite.
After 10*15 hours downloading this file on my modem, I've got a pretty big movie on my laptop. I'm about to sit down to watch it. Might skip to our solar system. Play time is listed as 4.5 billion years. Popcorn?
And politicians, don't forget them.
I might not be a wit, but at least I am more than half way there.
I am a little bit new here and haven't been able to locate the killfile.
Is there some way I can block all articles that reference "Roland Piquepaille".
As an aside, have those scientists who are predicting global warming in 50 years done the same kind of work with their models? They can't seem to get their local (micro) forcasts to work too well but maybe their global (macro) forcasts work better.
I might not be a wit, but at least I am more than half way there.
I tried to simulate the universe on my Apple II. The simulation was amazingly accurate. Too bad it ran in roughly real time...
Mass != Weight.
If similar to the compression rate quoted for smaller project on the homepage,
60% compression of 20TB result set possible to 8TB. But this will still take a week to download at 100Mbps.
Article quotes higher figures than I found on hompage, but says 4.2 teraflops, 812 cpus, 2TB memory.
However in comparison, the GRAPE-6 (GRAvity PipE) system is 64 teraflops and a typical simulation is 1 million stars x 100 million timesteps (1.6 Tflops).
So obviously why didn't they ask to use GRAPE-6 instead of this outdated equipment, is it because they needed more system memory?
Requires 70 hours x 512 cpus x 128MB/cpu memory. Modelling 1 billion point masses I do not see any use of Gravity Pipe (GRAPE) hardware. Currently Japan's GRAPE has more computing power for gravitational simulations than any other Top 500 computer. Of interest in GRAPE: http://www.sit.ac.jp/user/kawai/pkg/grape5/g5cata
This page shows the kind of cones they are talking about (click for variations of the giant image below).
The snapshots page (click on an image size, needs javascript) shows that they can test for different values of physical constants, this is when speed of light is infinite.
So is this system used because of memory requirements or what? Sounds like If they asked to use the GRAPE-6 they would get another magnitude of resolution or more timesteps.
... in his office.
-- Watch the REAL Jon Katz.
coming next: the total perspective vortex.
--A witty sig proves nothing.--
If we can simulate reality on a supercomputer, then what would human consciousness be structured as on it?
If we can simulate reality on a supercomputer, and thus simulate thinking, conscious beings like humans, then why shouldn't we be able to do the same with pen and paper, or with some crude mechanical contraption with moving parts? Then *what* is the difference?
How can consciousness be replicated on paper, assuming we're following simple algorithmic rules?
I for one simulate a welcome to our new simulated overlords!
(I hope those nerdy researchers remembered to at least make them simulated overlords, overladies.)
Not only did they start out with the preposterous assumptions of the universe consiting of mega massive particles, the didn't even do all the calculations. What the hell where they simulating? Sure not my universe.
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No power in the 'verse can stop me