NASA Discovers Most Distant Galaxy In Known Universe 105
An anonymous reader writes with this snippet from cbc.ca: "'NASA's Hubble and Spitzer space telescopes (not to be outdone by the Kepler Space Telescope) have discovered the most distant galaxy identified so far in the universe... the galaxy is 13.3 billion light years away and only a tiny fraction of the size of the Milky Way. Due to the time it takes light to travel through space, the images seen from Earth now show what the galaxy looked like when the universe was just 420 million years old, according to a press statement released from NASA. The newly discovered galaxy (is) named MACS0647-JD."
Re:I don't get it (Score:5, Insightful)
Just to actually answer your question, the original inflation of space (supposedly) took only a very, very short time, so even if the two points were "close together" at the instant of the big bang itself, they ended up very far apart (and moving farther apart) at the end of a second or so. The parts of the universe in question did not exceed the speed of light because speed is distance over time in spacetime and it is the latter that was inflating. Think of a very small balloon with a picture of the Universe printed on its surface being suddenly blown up -- when the balloon is small, everything is compact, but when it is inflated it is much further apart. Then make it a balloon with a three dimensional "surface" and no interior...
There is a lot more to learn about this, much of it in e.g. wikipedia pages as noted in the thread or in astronomy textbooks, and it is actually a lot of fun to learn. One very interesting thing, for example, is to follow the scientific argument from parallax, blackbody radiation, and our knowledge of how radiation intensity drops off with distance, through the discovery of the Hubble constant, out to how we estimate/compute the size and age of the Universe. Another interesting thing is to learn about "the Great Dark" that followed the big bang up until the formation of the earliest stars some 200 million years later, the chain of nucleosynthesis within those starts and the supernovae that ended them, and the gradual accumulation of "metals" (elements heavier than hydrogen and helium) in the ashes of those stars. The entire planet Earth and we ourselves are composed of stardust, the ash of ancient stars that gave rise to the elements that make up our bodies in their dying explosions.
It's well worth it to take a course in astronomy at some point if this sort of thing interests you, although a lot of it is covered in discovery channel stuff and shows you can probably find on netflix if that's too time or money consuming for you.
rgb (who occasionally teaches astronomy and hasn't lost his sense of wonder at how it all works out)
Re:I don't get it (Score:3, Insightful)