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Ep. 28, Page 47
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Comic 2097 - Ep. 28, Page 47

8th Mar 2016, 9:02 PM in Episode 28 :: Save My Place | Load My Place
Average Rating: 5 (2 votes)

Author Notes:

smbhax 8th Mar 2016, 9:02 PM edit delete
Three or some weeks back I wrote a little bit about some of the most distant objects known—small and very old galaxies, for the most part—and wouldn't you know it but a new one just popped up, as I found out in a recent BBC article: galaxy GN-z11 is 32 billion light years away, and its light reaching us now is 13.4 billion years old, as measured spectroscopically by Hubble; this is 200 million years older than the previous record holder, and is pretty much as far back as Hubble is expected to be able to look, because not long before that, the universe was still a plasma-filled glowy thing that you couldn't really see stars through; the BBC article mentions that Hubble's successor space telescope, the infrared James Webb telescope, should be able to see through that stuff and catch the first stars as they began to burn in it (and burn it away), another 200 million years earlier.

The BBC article was updated to note that the dating of GN-z11 as 13.4 billion years old was made by an instrument on Hubble that is lower resolution than the earthbound instruments normally used to measure the age of light coming from very distant objects (this is done by measuring how much the spectrum of light from the object has stretched, or "redshifted," as it has traveled through the expanding universe), so its age will still have an asterisk next to it in certain scientific circles until it can be confirmed by other instruments.

Anyway, as Wikipedia says, "compared to the Milky Way galaxy, GN-z11 is twenty-five times smaller, has 1% of the mass, and is forming new stars about twenty times faster" and "the fact that a galaxy so massive existed so soon after the first stars started to form is a challenge for some current theoretical models for the formation of galaxies." So maybe that's because it isn't really quite as old as Hubble's instrument says it is, or maybe it's back to the drawing board for galaxy formation theories!


cattservant 9th Mar 2016, 5:50 AM edit delete reply
The nerve!
smbhax 9th Mar 2016, 9:51 PM edit delete reply
moizmad 9th Mar 2016, 10:44 AM edit delete reply
Hey that's my ring, come back thief!
smbhax 9th Mar 2016, 9:51 PM edit delete reply
: o