How Cosmological Supercomputers Evolve the Universe All Over Again
the_newsbeagle writes "To study the mysterious phenomena of dark matter and dark energy, astronomers are turning to supercomputers that can simulate the entire evolution of the universe. One such simulation, the Bolshoi projection, recently did a complete run-through. It started with the state the universe was in around 13.7 billion years ago (not long after the Big Bang) and modeled the evolution of dark matter and energy up to the present day. The run used 14,000 CPUs on NASA's fastest supercomputer."
Bolshoit!
How long will it be until we can build a supercomputer that can span the Universe and if the Universe suffers a heat death it could just remake the whole Universe as it stored the state of everything within? Therefore humanity could survive even the end of the whole Universe in 100,000,000,000,000 years time. The short story the Last Question made quite an impression on me and surely with the current evolution in technology we could create a God computer eventually that would exist outside of anything we could comprehend. That would be mind-blowing.
liberare massarum ex ignorantia, clausa descendit molestie.
I wonder who they say will win the election next month.
It started with the state the universe was in around 13.7 billion years ago (not long after the Big Bang) and modeled the evolution of dark matter and energy up to the present day.
so... what happened when it reached the simulation of the simulation, and then eventually the simulation of the simulation of the simulation? I've long been told that it's turtles all the way down, but I'd like to see a citation.
The Admin and the Engineer
Did anyone else think this was going to be about some sort of Universe-scale natural phenomenon being modeled as a supercomputer?
by Cyphase ( 907627 )
...astronomers are turning to supercomputers that can simulate the entire evolution of the universe.
I'm thinking the intent here is to mean this qualified "up to a certain point in time", as I'm pretty sure that to say this as a general, even theoretical, possibility is a Godelian-type logical impossibility. Since the supercomputers would be part of the universe you are simulating, you have to simulate the simulation of the supercomputer, which requires simulating the simulation of the computer simulating the computer... ad infinitum.
But then again, I may be wrong. Best simulate my thought processes to be sure.
~ Whence do you come, slayer of men, or where are you going, conqueror of space?
Have gnu, will travel.
Have gnu, will travel.
Maybe my expectations are too high.
If you think slashdotters are tired of First Posts....
Table-ized A.I.
Mitt Obamney: He taxes the rich to pay for birth certificate forgeries and dog racks on top of all GM cars. He told the UK Olympians that their skeet shooters are bitter gun clingers.
Table-ized A.I.
First off, "entire evolution of the universe" should obviously be qualified with "on cosmological scales", unless they've built the matrix. That said, how big is the domain? Is it just set to match the observable universe? 2048 grid points across the entire universe (or just the observable universe) seems rather... low-res. The TFA mentions an adaptive grid, but fails to mention what factor that can increase the local resolution by.
Also, how exactly do we model dark matter when we don't really know WTF it is beyond the fact that it has gravitational mass? Does it work because gravitational effects are the only thing that really matters on cosmological scales?
I must say I like the use of periodic boundary conditions, though, simply because it makes their simulated universe conform to the Modest Mouse lyric "The universe is shaped exactly like the earth, if you go straight long enough you end up where you were".
Scientists build the ultimate computer. The first thing they ask it is, "is there a god?". The computer answers "there is now!"
A complete run-through of the universe up to present day? It's not a complete run-through, then, is it? I would imagine it should include a heat death or a big freeze to be considered anywhere near complete.
It appears that the model reproduces some large scale statistical properties of the universe with reasonable accuracy. That seems reasonable. It's a far cry from being able to say "the model reproduced the Milky Way", but the statistical information by itself could very well be useful as a tool for developing new hypotheses. Of course, if the model is all wrong those hypotheses will be useless, but let's see what they can do with the data before we make that conclusion.
The only garbage here is your post, I suspect what you are doing is projecting your own personality flaws onto others.
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
Or maybe I just watch to many sci-fi movies. Feels like one of those "knowledge man was not yet ready to possess" storylines in the works.
I swear to God...I swear to God! That is NOT how you treat your human!
So, as you seem to be saying, they take a model and use it to make predictions about the observable universe, then compared those predictions to actual observations, tossing out the model if it doesn't match. And this is wrong?
You could be trying to make a subtler point about over-fitting, where they have freedom to choose so many parameters they can find whole classes of models that would work. But do you actually know how many input parameters they have control over, and how many independent data points they are comparing this to? Or are you just assuming their actions happen to match your preconceived notions, resulting in you having horrible accuracy due to assumptions?
There has been no perturbation testing of the model. It does not seem that they did any runs that were intended to produce a result that did not match observations. They have no idea what range of input or modeling change produce a result that matches observations.
The greatest utility of these simulations is when they don't match observations. This opens the possibility that the current ideas are incorrect, and that new ideas are needed.
I also wonder about scaling issues. The three simulations at different scales are unconnected. There is no way to see how events at one scale effect events at other scales.
The author also said one specific thing that bothered me:
I am not a physicist or cosmologist, but that seems to be a huge assumption. We have no idea what dark energy or dark matter are, but they can be modeled by "simple linear equations."
I know that the shear cost and complexity of these computational experiments means that they are hard to accomplish. Even so, I will be less skeptical about their value when they are done in ways that test how the simulations fail, as well as how they verify current ideas.
Why is Snark Required?
And if the beginning parameters of the model were off from actual history by even the tiniest fraction, the extrapolated results won't be worth much. We pretend otherwise, but we really still don't know the current state and composition of the universe, much less how it started... assuming it started. There's a reason that they're called theories.
I'm sure eventually we'll get enough size and resolution:
It's the simulation that doesn't end.
Yes, it goes on and on my friend.
Someone started running it not knowing what it was,
And they'll continue singing it forever just because...
Well to be perfectly honest:
(1) Most people don't realise they're in a simulation
(2) The few with "suspicions" have no idea where the off switch is
Visit CryptoGnome in his home.
I'd like to know stock prices next week, next month, next year, etc. Who won the Super Bowl, etc...
There are hundreds of pure assumptions and estimations put in to the point where the accuracy is terrible.
You sound like you know what you're talking about; able to point us in the direction of a few dozen of those hundreds of assumptions?
I do not want your cheap brainburning drugs. They are useless for work. And I am a working man today.
I recommend you get rid of this Stalin fella in the next iteration. He's up to no good.
Proud member of the Ferengi Socialist Party.
How foolish to think that any number of modern CPUs, in their current state, could come close to being an accurate model of the universe. Our field of vision of the universe is but a miniscule slice and it is quite clear that though we will always "know more than we ever have before", the model is nothing but a model of our thoughts on what small parts we know of, not any real representation of what our universe really is.
I'm curious what purpose this research serves, other than the obvious "need-to-know."
Some ideas I've considered include creating a more realistic video game (e.g. Mass Effect 4), ideas for a new Ron Howard movie, or perhaps the outcome of this simulation will resolve a $20 bet between two astrophysicists. I'm guessing none of these are the actual answer, of course...
Your work would be done by someone else if you didn't do it. Your discoveries won't be noticed by the rest of the world, the children you produce would have come from someone else if you hadn't been born.
So what purpose do you serve?
Or is the question, like yours, meaningless and that the purpose of existence is to exist.
> astronomers are turning to supercomputers that can simulate the entire evolution of the universe
does the simulation simulate supercomputers that simulate the entire evolution of the universe?
And that cluster is 11th? Nice!!
Blogging because I can...
You may think it's a long way to the chemist's but that's peanuts compared to space!
(Just kidding! Thanks for your informative post!)
You didn't read all five books, did you? The meaning of 42 is revealed:
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We apologize for the inconvenience.
Free Martian Whores!
It would be cool if their simulations actually led to me! I would be most flattered! ;)
It's 'sheer' cost. Wouldn't have brought it up, but you raised the bar with the rest of your post.
Consciousness is a myth. Trust me.