Astronomers spotted something perplexing near the beginning of time - They have found galaxies where according to current understanding of the laws of physics, there shouldn't be any. It's very interesting but I obviously have a lack of knowledge about how these measurements are being made. I find it quite confusing. When light hits the telescope, how do they determine how far the light has travelled? How can they differentiate between light from very far away and light from the very ancient universe? How do they know they aren't seing light that originated from a distance twice the length of the observable universe, created twice as long ago as the current estimate for the age of the universe? These are probably dumb questions, but I feel like I don't currently have good answers to them. There are likely a lot more if I spent some time to write them down. www.vox.com #