Estimated # of unique chess games

exactly why every possible game will not be played. If it played every possible move there are going to be games with a lot of hanging pieces

 That estimate is only up to move 40

The universe may be larger and grander than we can comprehend, but it is finite.  I guess the same can be said about chess.

First, it should be made clear that there is a difference between number of possible positions (state space) and number of possible games (game tree).  The size of the state space has been estimated to be around 10^50 while the size of the game tree has been estimated to be around 10^120.  If we assume that someone clever could compute the latter number exactly by just examining the state space, we are looking at the following time frame.  With price of hardware dropping exponentially, it is always best to wait a few years.  Asume we want to get it computed in a year once we buy the hardware, and assume that some clever programmer can code to only use a single operation per state in the state space.  We would then need:

10^50 states / 10^9 states per GFLOP / seconds per year

    = 10^38 GFLOP of hardware

The current price of a GFLOP is $0.20, with the number roughly halving every six months.  We are thus looking at at least half a century before the hardware would become afordable to the combined wealth of the world.

 maybe the author meant the *known* universe?

Actaully the physicists of the world have had a stab at estimating the total mass of the universe, based on mathematical analysis of the Big Bang, Inflationary Theory, Planck's number and a whole bunch of other groovy stuff. 10^79 is the (ahem) "generally agreed" number, not that there is any meaningful way of proving it conclusively at present.

(again) i was quoting the author. 

/golfclap for you, though.

I don't quite follow your logic.  Almost by definition the "known" universe is a subset of the universe, so if the universe is finite then the "known" universe is finite and probably smaller than the universe.  By extension the number of electrons is also finite.

Yes, because 10 to the 120th power is more than the number of electrons in the universe. Ches was invented in it's MODERN form only a couple hundred years ago. in that time it's is impossible because even if all 6 billion people played at the sme time, the number would decrease to 10 to the 111th power divided by 6, and that's if everyone is playing a computer, not each other.it thakes about 275,000 years to Count to a trillion, which is 10 to the 9th power. so you would take 275,000x10 to the 102nd power for a person to count  the number of games he or she has to play against a computer. And of course, it takes much longer to play a chess game than to say how many games you've played so far. Of course, people usually play against other people, which makes it harder to play all those possibilities. We probably won't find all of them before humans go extinct and another, smarter specis replaces us and invents a newer version of chess that's different from the old one.

First of all, you probably meant "games possible". Second of all, this number is actually and estimate for chess's "game tree complexity" (which is smaller than the number of possible games), according to this wikipedia article.