Exact Number of Alternate Universes = 10^10^16 - How many zeros is that?

[The Brain]

It does sound a bit extreme when you put it that way. 

As a layman, I don't see how that is possible.

I also doubt it. As it was pointed out, for the theory to be true, every single change, even at a particle/photon level would lead to a new alternate universe, and so on...

Most people believe this nonsense because they only think about Human history, say: "Caesar not murdered in 44 b.C. - History changes" and accept it, but alternative universes would be far, far, far more than that, every change in anything would change everything, and this would happen during every microsecond for billions of years.

In other words, not even a hundred zillion trillion billion zeroes after the 1 would suffice to number them. Not even by a longshot.

You can certainly play around with the number of particles in the known universe and possible states and configurations etc. Then you end up with a number. The number will be big enough if you pile on the zeroes. What may be hard to grasp for a layman is how large large numbers are.

Consider: how many orders of magnitude do you need to describe the universe? Not that many.

[Neil]

The really interesting changes are of the constants and forces anyways.  I am unconvinced by the concept of doppleganger universes.

[grumbler]

http://www.popsci.com/science/article/2009-10/physicists-calculate-exact-number-alternate-universes

Physicists Calculate Exact Number of Alternate Universes
The physicists, Andrei Linde and Vitaly Vanchurin, calculated the number by first going all the way back to the Big Bang. Linde and Vanchurin posit that the stellar organization and physics of our universe resulted from small perturbations in the otherwise uniform mass of matter and energy that existed milliseconds after the Big Bang. So, the number of possible variations of those perturbations represents the upper limit of possible alternate universes, or about 10^10^10^7 possible alternate universes.

However, because of the physical limits of the human brain, no individual could perceive more than 10^10^16 realities different from our own. And since the perspective of the viewer factors into the calculations (like time dilation in relativity), that's the number of possible alternate universes.

This isn't science per se, but rather entertainment couched in the form of science, and the author of the story caught the mood of the scientists quite well.  That is rare and commendable.

[BuddhaRhubarb]

52. unless it's marvel, then there's like a bunch. most are really gay though ( and not in a fun homosexual way)

[jimmy olsen]

The Onion does Alternate History. 

http://www.theonion.com/content/news/alternate_universe_sci_fi_channel?utm_source=onion_rss_daily

[dps]

Great, now Timmay's managed to taint The Onion.   

[Martinus]

I want a universe with rainbow ponies.