Boltzman Brains?

[JustARandomPanda]

Wow. I was unaware of this until tonight. It is an interesting hypothesis if ours is a Boltzmann Brain Universe.

 

Wiki entry on Boltzmann Brains

 

 

In the 18 August 2007 issue of New Scientist there is an article Spooks in space by Mason Inman about so-called Boltzmann brains. Quoting from the introduction to the article

 

Boltzmann posed the question of whether the universe could have arisen from a thermal fluctuation; his work presaged the idea that a fluctuation could also give rise to a conscious entity that sees the universe. In this regard Boltzmann brains are not necessarily actual brains, but rather are a metaphor for observers of the universe that might appear spontaneously.

 

Thus a Boltzmann brain is a conscious entity that instantaneously pops into existence as a spontaneous fluctuation of matter into a highly ordered form, rather than gradually coming into existence like us through the slow process of evolution gradually rearranging matter into a highly ordered form. The probability of a whole brain suddenly popping into existence in this way is extremely small, because the internal structure of the Boltzmann brain has to be exactly right so that it works as a brain, so you have to wait a very long time for there to be a significant likelihood of a Boltzmann brain coming into existence. This likelihood problem is very deftly avoided by evolution, because it breaks the overall problem of making a brain into very small steps, each of which is much more likely to occur than the whole big jump from start to finish; of course, evolution doesn't know in advance that this is what is going on.

 

More generally, you could imagine a whole spectrum of processes ranging from the instantaneous rearrangement of matter at one extreme (e.g. Boltzmann brain) all the way through to the gradual rearrangement of matter at the other extreme (e.g. evolution).

 

In a sufficiently large and long-lived universe Boltzmann brains will come into existence, because then the extremely small likelihood of one coming into existence at any given place and time is offset by the large number of alternative places and times that are available in the whole universe (i.e. space-time). Our universe looks exactly like the sort of place where these conditions are (or will be in the far future) satisfied, so Boltzmann brains will eventually come into existence here.

 

The eventual existence of Boltzmann brains worries cosmologists, because the laws of physics that are deduced by a Boltzmann brain (which is a conscious observer) would be different from the laws that are deduced by us. The reason for this difference is that Boltzmann brains would typically come into existence a very long time in our future when the universe is much larger, emptier and colder than now, so the typical observations made by a Boltzmann brain would be very different from the typical observations made by us, so a Boltzmann brain would deduce laws of physics that are very different from ours.

 

This fact worries cosmologists so much that they would very much like to find a way to "banish" Boltzmann brains from existence, for instance by finding some property of the currently known laws of physics that prevents favourable conditions for Boltmann brains from ever arising.

Edited August 1, 2009 by SereneBlue

[joeblast]

The eventual existence of Boltzmann brains worries cosmologists, because the laws of physics that are deduced by a Boltzmann brain (which is a conscious observer) would be different from the laws that are deduced by us. The reason for this difference is that Boltzmann brains would typically come into existence a very long time in our future when the universe is much larger, emptier and colder than now, so the typical observations made by a Boltzmann brain would be very different from the typical observations made by us, so a Boltzmann brain would deduce laws of physics that are very different from ours.

 

This fact worries cosmologists so much that they would very much like to find a way to "banish" Boltzmann brains from existence, for instance by finding some property of the currently known laws of physics that prevents favourable conditions for Boltmann brains from ever arising.

who wrote that??? that is hilarious

[Vajrahridaya]

Perfect time to "OMG"!!