See how the universe evolved

Scientists have created a computer simulation that produces a realistic picture of the evolution of the universe, starting from just after the Big Bang to the present, compressing the 13.7 billion years into just over two minutes.

You can read the paper by the simulation’s authors here. Here’s the abstract.

Previous simulations of the growth of cosmic structures have broadly reproduced the ‘cosmic web’ of galaxies that we see in the Universe, but failed to create a mixed population of elliptical and spiral galaxies, because of numerical inaccuracies and incomplete physical models. Moreover, they were unable to track the small-scale evolution of gas and stars to the present epoch within a representative portion of the Universe. Here we report a simulation that starts 12 million years after the Big Bang, and traces 13 billion years of cosmic evolution with 12 billion resolution elements in a cube of 106.5 megaparsecs a side. It yields a reasonable population of ellipticals and spirals, reproduces the observed distribution of galaxies in clusters and characteristics of hydrogen on large scales, and at the same time matches the ‘metal’ and hydrogen content of galaxies on small scales.

Elizabeth Gibney has more on how it was done. The point is that the simulation is not merely descriptive in that they just created pretty pictures for what we know about the evolution of the universe. What they did was to input the information we have about the universe at just 12 million years of age and see how well its subsequent evolution matches what we observed.

Mark Vogelsberger, a physicist at the Massachusetts Institute of Technology in Cambridge, and his colleagues created a model of the Universe that follows the evolution of both visible and dark matter starting just 12 million years after the Big Bang (see video). While previous models have either been small and detailed or large and coarse, this simulation covers a region of space big enough to be representative of the whole Universe — a cube 106.5 megaparsecs (350 million light years) across — but is detailed enough to resolve small-scale structures, such as individual galaxies. Unlike previous simulations, it produces a mixture of galaxy shapes that fit observations well. Its also accurately recreates the large-scale distribution of galaxy clusters and neutral gas in the Universe, as well as the hydrogen and heavy element content of galaxies.

Only in recent years has it been possible to use this model to simulate galaxies that match a range of observed properties. That Vogelsberger and his colleagues’ model reproduces the variety of galaxy types seen in the real Universe puts the standard model on firmer ground, says Brook. From now on, such simulations will become much more useful for predicting and interpreting observational results, he adds.

Although the model agrees well with observations of the Universe, it does have anomalies. For example, it shows low-mass galaxies building up too early. “The idea now is to try to understand why this is happening and see what we are missing in terms of galaxy formation,” says Vogelsberger.

That’s science!


  1. astrosmash says

    I could be overly dull here, but if they’re working this model from data points, what if anything is keeping them from predicting forward a couple hundred million years of so (w/ margin of error increases of course)…Shurly that is something on the docket to do with this info…

  2. Al Dente says

    Just a reminder. “Metal” is astronomer-talk for any element heavier than helium.

  3. Pierce R. Butler says

    The universe and galaxies and everything evolved without a sound track??!?

    How did all those other vids get that part wrong?

  4. StevoR : Free West Papua, free Tibet, let the Chagossians return! says

    @4. Al Dente : “Just a reminder. “Metal” is astronomer-talk for any element heavier than helium.”

    Sorry, but I think that’s one element (at least) out – helium is an astronomical “non-metal” too.

    Yes, it is absurd from a chemically correct perspective – but then most of our cosmos is composed of those two elements. Well in terms of normal baryonic matter anyhow!

  5. parasiteboy says

    I had always thought that out universe was like a bubble with most of the matter on the surface of the bubble and then less of it as you moved in until there was nothing at the center where the big bang happened. I got this image in my head because it is often described that way and if the universe started with the big bang then it would make sense that when it exploded that all matter was sent out in all directions in roughly an even manner.

    This simulation and what I have read about it seems to state that matter traveled along the lines of dark energy. As a biologist this would be somewhat analogous to microtubules forming in cells to transport material from one place to another. Is this a correct way of thinking about it? Also, is there a website with a 3D image of the universe to look at it’s shape and explore the clustering of matter.

    It’s been an exiting couple of months in physic (for a non-physic scientist) between this model and proof of cosmic inflation.

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