A recent “Frontline” program speculated that there's probably an abundance of life in the universe, and said the task of hunting for it is becoming better focused.
I've often wondered how big it is, and so did a certain 13-year old Dane. Astrophysicist Paul Butterworth offered a good answer here [3]. Notice his footnote: we can only “see” out about 10 billion light-years, so we know it has a radius at least that big, but if may be bigger yet.
However, that set my contradiction-detector a-jangle. If nothing can move faster than light, how could rocks travel further than 10 billion light-years in only 10 billion years?
More: those stars we can detect on the edge, 10 BLYs away, must have taken longer than 10 billion years to get there; hence to arrive and be seen must have taken more than 20 billion years, round-trip. Yet the Universe is thought to be no older than 15 billion years.
There's something fishy going on. Is Hoyle's [4] Steady-State theory about to stage a comeback? Was Einstein mistaken about the speed limit?
Inquiring minds would like to know.
