Stephen Hawking Thinks Aliens Likely

OMNIpotusCOM writes "Noted astrophysicist Stephen Hawking thinks that alien life is likely, albeit primitive, according to a lecture delivered at George Washington University in honor of NASA's 50th anniversary. It begs the question of if we need to consider a Prime Directive before exploring or sending signals too far into the depths of space."

Comments

Re:Why is this newsworthy?

[JustinOpinion]

It is nevertheless still entirely possible, however unlikely, that our own civilization might actually be the only one in the whole universe. We certainly don't know for sure yet. But, if the universe is infinite (our current best measurements indicate that the universe is flat and infinite), and if the initial conditions were ergodic (which is indeed the prediction of our best model, inflation, and is consistent with the data, e.g. the microwave background), then there are an infinite number of causally-disconnected Hubble volumes, which essentially guarantees that life exists at multiple locations in the universe.

What this means is that in an infinite universe that has totally random initial conditions, every possible state will be realized somewhere. That means that somewhere in the universe, conditions very similar to our local conditions will be realized. Not only does this mathematically guarantee that life exists somwhere, but also that "copies" of Earth and you and me exist somewhere. All possible variants of matter organization are realized somewhere in the infinite universe (and in fact may be repeated over and over). Of course, the distances over which you will see a repeat may be fantastically large (much, much larger than the observable universe, for instance). Also, life-forms in causally-disconnected volumes can never communicate with each other. (So you may say... who cares?)

In any case, it's not known with certainty that the universe is infinite (or that the big bang was ergodic)... but our current theories allow for models where the multiple emergence of life (and all physically reasonable variants) is in fact mathematically guaranteed. Kinda interesting.