Big Bang Birthday: Sean Carroll (Introduction)

by David Turell , Monday, March 24, 2014, 14:42 (3897 days ago) @ David Turell

Another multiverse guy gives his take:-"The triumph, unfortunately, is not a completely clean one. If inflation occurs, the conditions we observe in the early universe are completely natural. But is the occurrence of inflation itself completely natural?
 
"That depends. The original hope was that inflation would naturally arise as the early universe expanded and cooled, or perhaps that it would simply start somewhere (even if not everywhere) as a result of chaotically fluctuating initial conditions. But closer examination reveals that inflation itself requires a very specific starting point — conditions that, one must say, appear to be quite delicately tuned and unnatural. From this perspective, inflation by itself doesn't fully explain the early universe; it simply changes the kind of explanation we are seeking.
 
"Fortunately — maybe — there is a complication. Soon after Guth proposed inflation, the physicists Alexander Vilenkin and Andrei Linde pointed out that the process of inflation can go on forever. Instead of the inflaton energy converting into ordinary particles all throughout the universe, it can convert in some places but not others, creating localized "Big Bangs." Elsewhere inflation continues, eventually producing other separate "universes," eventually an infinite number. From an attempt to explain conditions in the single universe that we see, cosmologists end up predicting a "multiverse.""-
http://opinionator.blogs.nytimes.com/2014/03/23/when-nature-looks-unnatural/?_php=true&_type=blogs&emc=edit_th_20140324&nl=todaysheadlines&nlid=60788861&_r=0