Do we live in a computer simulation?

Press Release: Do we live in a computer simulation? UW researchers say idea can be tested

A decade ago, a British philosopher put forth the notion that the universe we live in might in fact be a computer simulation run by our descendants. While that seems far-fetched, perhaps even incomprehensible, a team of physicists at the University of Washington has come up with a potential test to see if the idea holds water.

The concept that current humanity could possibly be living in a computer simulation comes from a 2003 paper published in Philosophical Quarterly by Nick Bostrom, a philosophy professor at the University of Oxford. In the paper, he argued that at least one of three possibilities is true:

  • The human species is likely to go extinct before reaching a “posthuman” stage.
  • Any posthuman civilization is very unlikely to run a significant number of simulations of its evolutionary history.
  • We are almost certainly living in a computer simulation.

He also held 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.”

The conical (red) surface shows the relationship between energy and momentum in special relativity, a fundamental theory concerning space and time developed by Albert Einstein, and is the expected result if our universe is not a simulation. The flat (blue) surface illustrates the relationship between energy and momentum that would be expected if the universe is a simulation with an underlying cubic lattice. (Image courtesy Martin Savage of the University of Washington.)

With current limitations and trends in computing, it will be decades before researchers will be able to run even primitive simulations of the universe. But the UW team has suggested tests that can be performed now, or in the near future, that are sensitive to constraints imposed on future simulations by limited resources.

Martin Savage

Currently, supercomputers using a technique called lattice quantum chromodynamics and starting from the fundamental physical laws that govern the universe can simulate only a very small portion of the universe, on the scale of one 100-trillionth of a meter, a little larger than the nucleus of an atom, said Martin Savage, a UW physics professor.

Eventually, more powerful simulations will be able to model on the scale of a molecule, then a cell and even a human being. But it will take many generations of growth in computing power to be able to simulate a large enough chunk of the universe to understand the constraints on physical processes that would indicate we are living in a computer model.

However, Savage said, there are signatures of resource constraints in present-day simulations that are likely to exist as well in simulations in the distant future, including the imprint of an underlying lattice if one is used to model the space-time continuum.

The supercomputers performing lattice quantum chromodynamics calculations essentially divide space-time into a four-dimensional grid. That allows researchers to examine what is called the strong force, one of the four fundamental forces of nature and the one that binds subatomic particles called quarks and gluons together into neutrons and protons at the core of atoms.

“If you make the simulations big enough, something like our universe should emerge,” Savage said. Then it would be a matter of looking for a “signature” in our universe that has an analog in the current small-scale simulations.

Savage and colleagues Silas Beane of the University of New Hampshire, who collaborated while at the UW’s Institute for Nuclear Theory, and Zohreh Davoudi, a UW physics graduate student, suggest that the signature could show up as a limitation in the energy of cosmic rays.

In a paper they have posted on arXiv, an online archive for preprints of scientific papers in a number of fields, including physics, they say that the highest-energy cosmic rays would not travel along the edges of the lattice in the model but would travel diagonally, and they would not interact equally in all directions as they otherwise would be expected to do.

“This is the first testable signature of such an idea,” Savage said.

If such a concept turned out to be reality, it would raise other possibilities as well. For example, Davoudi suggests that if our universe is a simulation, then those running it could be running other simulations as well, essentially creating other universes parallel to our own.

“Then the question is, ‘Can you communicate with those other universes if they are running on the same platform?’” she said.

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21 Responses

  1.' Paul says:

    I remember reading about this when it was first proposed, and before that it did feature in a few sci-fi books and movies (eg: The Matrix).

    What could spin your mind more is: If we are living in a simulated reality, could the people simulating us be in a simulation themselves. We use simulations, so it is conceivable that if we are simulations ourselves, then simulation can attempt to simulate reality. This could (at least conceptually) go on infinitely with each “reality” being a simulation of one above it.

    Lets just hope they have the Hypergrid activated… 😀

    • Paul —

      It would definitely explain something things. Like: why do bad things happen? Answer: Would anyone want to be in a simulation where only good things happened? It would be like… paying PacMan with no ghosts. Or being on the easiest level of Tetris. Permanently.

      If you knew ahead of time the life you were living was just a simulation, then a lot of the bad things that happen wouldn’t feel as bad. Because you could always come back and try again with a new character.

      Which gives a whole new meaning to such phrases as “Life is just a play, and all the men and women merely actors…”, “Life is an illusion,” “Life is but a dream,” and so on and so forth.

      •' Minethere says:

        And ‘What Dreams May Come’, a really cool movie-))

      •' Frans says:

        We our selves are a part of the simulation, the bad things happen to us. There is no going back to try again for us, we are not operating it from the outside. If the simulation is restarted from a earlier point, it would not but us who had that bad thing happen, but it would be a younger version of us, who is different from the older one.

        •' Paul says:

          I agree, as we would be part of the simulation and not an operator of the simulation then when we are “de-rezed” we would not be able to come back. If the simulator had a backup facility, then our memories would be reset along with the rest of the simulation when the backup is restored.

          As for “Bad things” occurring then it would be a cruel operator that would deliberately create a simulation that contained intelligent sentient creatures and doing so that they would have to experience bad things. More over, it would be worse if these sentient creatures are intelligent enough to learn enough to be able to determine that their reality is just a simulation and therefore work out that it had been deliberately created to cause them suffering.

          There would not be much difference between this scenario and Hell.

          • Arrgh, that TOTALLY did not occur to me.

            I was thinking that we’d be the creators, the players, in the simulation.

            I didn’t think of us as NPCs… That WOULD suck.

    •' Minethere says:

      I did see a movie recently that did just that..I forget the name tho, bu ti was cool-)) [was in netflix]

  2. Ener Hax says:

    let’s reboot! =)

  3.' helsen says:

    Please Maria, improve the like and tweet gadget, this thing hide your article in my android phone….

    •' Minethere says:

      it also covers the text when my chrome browser is minimized-))

      • Okay, I just read up on responsive design and made the share buttons disappear for smaller screens. I tried moving the share buttons instead — say, to the bottom of a post — but that was apparently beyond my CSS skills.

        Try it out — ideally with some older pages, so they won’t be in your cache — and let me know if it works.

        •' Minethere says:

          well, i looked at a couple of pages i never had before, as well as i cleared my browser cache in my chrome browser, which is the most popular and my default…didn’t change, however, you must be suing IE as I tried it with that and it works just fine as you described-))

          • I’m using Chrome as well. But there are actually several levels of caching to the Hypergrid Business site, including CloudFlare, which caches pages up in the cloud somewhere so that they load even when the site is down.

        •' helsen says:

          Works perfect in my android 4.0, tks maria

  4.' Reiner Schneeberger says:

    Hello Staff. The idea behind “do we live in a computer simulation” is quite old. It was first published in 1967 by Konrad Zuse as “…. Rechnender Raum” (=Calculating Space or Computing Universe). Here is the paper in English:

    Its even used in art, see:

    First Prim, author of “The Primcurator”:

  5.' Frans says:

    So if we are in a simulation and are developing to create similar simulations, it is possible the computer we are simulated it in is simulated as well.
    Like the old Indian woman said: “It’s turtles all the way back” with the added rule that is also turtles all the way forward.

  6. I love Nick Bostrom’s Simulation Argument…just read about this again this morning so it’s cool seeing it show up on HB also. I definitely live in a sim in my head.

    Oh, and if you haven’t already, definitely read The Metamorphosis of Prime Intellect!

    I read that and about a month later discovered Second Life…and it was all over from there.

  7.' Reed says:

    If you read the holy Qur’an you will see that the great Allah says that on the day of resurrection the 7 skys will be on his right hand so we deduce that maybe he will withdraw a CD Rom from his computer, and the most important is that before removing the CD ROM it will take care to print everyone on paper in order to burn it if he wants!!! ( and to print it again and again infortunately for the unbelievers )