How do scientists determine the age of galaxies in pics taken by Hubble space telescope?
Posted January 11th, 2010 by admin 4 Comments »
Raymond asked:
I don’t quite understand how they determine that the galaxies in some ultra-deep-field pictures are billions of years old… How do they determine that? How do they know that they are looking into the past of the universe? If they determine that the distance of the galaxies is, for example, 13 billion light years, that means that the light the telescope is able to capture has been traveling for 13 billion years, right? But then how is it that they determine that those are the early galaxies in the universe and that those galaxies were formed soon after the Big Bang? Can someone please explain with simple and easy-to-understand terms? Maybe some examples? Thanks!
I don’t quite understand how they determine that the galaxies in some ultra-deep-field pictures are billions of years old… How do they determine that? How do they know that they are looking into the past of the universe? If they determine that the distance of the galaxies is, for example, 13 billion light years, that means that the light the telescope is able to capture has been traveling for 13 billion years, right? But then how is it that they determine that those are the early galaxies in the universe and that those galaxies were formed soon after the Big Bang? Can someone please explain with simple and easy-to-understand terms? Maybe some examples? Thanks!