Invasion Of The Floating Space Brains

2 comments January 15th, 2008at 11:35am Posted by Eli

This may very well be the most bizarre theory I have ever seen:

The basic problem is that across the eons of time, the standard theories suggest, the universe can recur over and over again in an endless cycle of big bangs, but it’s hard for nature to make a whole universe. It’s much easier to make fragments of one, like planets, yourself maybe in a spacesuit or even — in the most absurd and troubling example — a naked brain floating in space. Nature tends to do what is easiest, from the standpoint of energy and probability. And so these fragments — in particular the brains — would appear far more frequently than real full-fledged universes, or than us. Or they might be us.Alan Guth, a cosmologist at the Massachusetts Institute of Technology who agrees this overabundance is absurd, pointed out that some calculations result in an infinite number of free-floating brains for every normal brain, making it “infinitely unlikely for us to be normal brains.” Welcome to what physicists call the Boltzmann brain problem, named after the 19th-century Austrian physicist Ludwig Boltzmann, who suggested the mechanism by which such fluctuations could happen in a gas or in the universe. Cosmologists also refer to them as “freaky observers,” in contrast to regular or “ordered” observers of the cosmos like ourselves. Cosmologists are desperate to eliminate these freaks from their theories, but so far they can’t even agree on how or even on whether they are making any progress.


The expansion of the universe seems to be accelerating, making galaxies fly away from one another faster and faster. If the leading dark-energy suspect, a universal repulsion Einstein called the cosmological constant, is true, this runaway process will last forever, and distant galaxies will eventually be moving apart so quickly that they cannot communicate with one another. Being in such a space would be like being surrounded by a black hole.

Rather than simply going to black like “The Sopranos” conclusion, however, the cosmic horizon would glow, emitting a feeble spray of elementary particles and radiation, with a temperature of a fraction of a billionth of a degree, courtesy of quantum uncertainty. That radiation bath will be subject to random fluctuations just like Boltzmann’s eternal universe, however, and every once in a very long, long time, one of those fluctuations would be big enough to recreate the Big Bang. In the fullness of time this process could lead to the endless series of recurring universes. Our present universe could be part of that chain.

In such a recurrent setup, however, Dr. Susskind of Stanford, Lisa Dyson, now of the University of California, Berkeley, and Matthew Kleban, now at New York University, pointed out in 2002 that Boltzmann’s idea might work too well, filling the megaverse with more Boltzmann brains than universes or real people.

In the same way the odds of a real word showing up when you shake a box of Scrabble letters are greater than a whole sentence or paragraph forming, these “regular” universes would be vastly outnumbered by weird ones, including flawed variations on our own all the way down to naked brains, a result foreshadowed by Martin Rees, a cosmologist at the University of Cambridge, in his 1997 book, “Before the Beginning.”

The conclusions of Dr. Dyson and her colleagues were quickly challenged by Andreas Albrecht and Lorenzo Sorbo of the University of California, Davis, who used an alternate approach. They found that the Big Bang was actually more likely than Boltzmann’s brain.

“In the end, inflation saves us from Boltzmann’s brain,” Dr. Albrecht said, while admitting that the calculations were contentious. Indeed, the “invasion of Boltzmann brains,” as Dr. Linde once referred to it, was just beginning.

In an interview Dr. Linde described these brains as a form of reincarnation. Over the course of eternity, he said, anything is possible. After some Big Bang in the far future, he said, “it’s possible that you yourself will re-emerge. Eventually you will appear with your table and your computer.”

But it’s more likely, he went on, that you will be reincarnated as an isolated brain, without the baggage of stars and galaxies. In terms of probability, he said, “It’s cheaper.”

Craziness. And I’ve only excerpted maybe a quarter of the whole thing.

I have to say, if I really am a spontaneously-formed random electric brain floating in space, and everything else is a figment of my imagination, then I must be a helluva lot smarter and more creative than I ever thought possible.

Entry Filed under: Science,Weirdness


  • 1. ellroon  |  January 16th, 2008 at 2:23 am

    Is this all we get to choose from? Big Bangs or Floating Brains? Couldn’t we get something a little more … useful?

    Besides, brains are nothing new. Didn’t they have a floating brain in the Teenage Mutant Ninja Turtles cartoon?

  • 2. Eli  |  January 16th, 2008 at 11:10 am

    Is this all we get to choose from? Big Bangs or Floating Brains? Couldnt we get something a little more useful?

    How about a brain in a jar? Sure, there’s a little more overhead (so to speak), but it’s nowhere near as complex as a whole person… or universe.

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