Emerging Technology from the arXiv

A View from Emerging Technology from the arXiv

Why The Universe Is Not a Computer After All

The idea that our Universe is a giant cosmic computer pervades modern science. Now one physicists says this assumption is dangerously wrong

  • December 4, 2012

One of the driving forces in modern science is the idea that the Universe “computes” the future, taking some initial state as an input and generating future states as an output. This is a powerful approach that has produced much insight. Some scientists go as far as to say that the Universe is a giant computer.

Is this a reasonable assumption? Today, Ken Wharton at San Jose State University in California, makes an important argument that it is not.  His fear is that the idea of the universe as a computer is worryingly anthropocentric.  “It’s basically the assumption that the way we humans solve physics problems must be the way the universe actually operates,” he says.

What’s more, the idea has spread through science without any proper consideration of its validity or any examination of the alternatives. “This assumption…is so strong that many physicists can’t even articulate what other type of universe might be conceptually possible,” says Wharton. 

He argues that a close look at the notion of the cosmos as a computer reveals important problems. Wharton examines several. For example, a computation involves three steps. First, the physical world has to be mapped onto some mathematical state. Next, this state mathematically evolves into a new state. And finally, the new state is mapped back onto the physical world.  

In quantum mechanics, this can only happen if this final step is probabilistic. As Wharton puts it: “Not even the universe knows which particular outcome will occur.”

And yet, when the universe is measured, a specific outcome does occur. The operation of a computer cannot account for this. For Wharton, this is a crucial flaw that most physicists just overlook.

It’s also an important clue that idea of the universe is a computer is merely an assumption and one that has never been rigorously questioned. “It is the least-questioned (and most fundamental) assumptions that have the greatest potential to lead us astray,” he says.

The consequences of this are profound. “Thanks to this deep bias, it’s possible that we have missed the bigger picture: the mounting evidence that the fundamental rules that govern our universe cannot be expressed in terms of [a traditional computation].”

To demonstrate the point, Wharton spends a significant part of his paper explaining an alternative view of the cosmos which does not rely on traditional computation. This is Lagrange’s formulation of the laws of physics based on the principle of least action.

An example is the principle that light travels the shortest distance between two points. Lagrange’s method is essentially to stipulate the start point and end point, examine all possible paths and choose the shortest. “In this view, the reason light bends at an air/water interface is not because of any algorithm-like chain of cause-and-eect, but rather because it’s globally more ecient,” explains Wharton.

Anybody familiar with this approach will know its great elegance and beauty.   But critics ask how the light ray can know its end point when it starts its journey. Wharton says these critics argue like this: “Yes, [Lagrange’s method] may be beautiful, it may be powerful, but it’s not how our universe really works. It’s just a useful trick we’ve discovered.” 

But this argument is itself powerfully anthropocentric, says Wharton. It assumes the Universe must work in the way we solve problems–that the Universe is as “in the dark” about the future as we are.  

Of course, there are plenty of good arguments for thinking that the Universe works like a conventional computer. The point Wharton makes is that there are other ways of thinking about the cosmos too and that these may provide important new insights. We ignore them at our peril. 

Interesting reading.

Ref: arxiv.org/abs/1211.7081: The Universe As Not A Computer

The latest Insider Conversation is live! Listen to the story behind the story.

Subscribe today
Already a Premium subscriber? Log in.

Uh oh–you've read all of your free articles for this month.

Insider Premium
$179.95/yr US PRICE

More from Intelligent Machines

Artificial intelligence and robots are transforming how we work and live.

Want more award-winning journalism? Subscribe to Insider Premium.
  • Insider Premium {! insider.prices.premium !}*

    {! insider.display.menuOptionsLabel !}

    Our award winning magazine, unlimited access to our story archive, special discounts to MIT Technology Review Events, and exclusive content.

    See details+

    What's Included

    Bimonthly home delivery and unlimited 24/7 access to MIT Technology Review’s website.

    The Download. Our daily newsletter of what's important in technology and innovation.

    Access to the Magazine archive. Over 24,000 articles going back to 1899 at your fingertips.

    Special Discounts to select partner offerings

    Discount to MIT Technology Review events

    Ad-free web experience

    First Look. Exclusive early access to stories.

    Insider Conversations. Listen in as our editors talk to innovators from around the world.

You've read all of your free articles this month. This is your last free article this month. You've read of free articles this month. or  for unlimited online access.