| | I sort of follow that -- and sort not. Space is expanding between unbound objects but distances are not? That's not exactly what you said, but it is what it sounded like. A moment ago you said lightyear is a measurement of distance, not time. Now you've basically inverted that saying lightyears are measurements of time. I don't wish to sound pedantic or critical, you really are helping sort this out. [[User:RobSmith|Rob Smith]] 21:53, 30 January 2012 (EST) | | I sort of follow that -- and sort not. Space is expanding between unbound objects but distances are not? That's not exactly what you said, but it is what it sounded like. A moment ago you said lightyear is a measurement of distance, not time. Now you've basically inverted that saying lightyears are measurements of time. I don't wish to sound pedantic or critical, you really are helping sort this out. [[User:RobSmith|Rob Smith]] 21:53, 30 January 2012 (EST) |
| − | :Well not really. What happens is that because space is expanding, by the time the light that leaves an object reaches us the object is further away than the distance the light has travelled. Imagine I'm standing in the back of a truck driving south at 50 ft/s, while you run north at 10 ft/s. At 200 feet from you I shoot an arrow at you, which travels at 100 ft/s. By the time the arrow lands at your feet it has travelled 220 feet, but the distance between us is 320 feet. It's sort of like that. If the light travel distance to an object is 10 billion light years (bya) then we're seeing the object as it looked 10 billion years ago (sorry, I'm an OEC) but also as it looked when it was, say, 6 bya away. By the time we see it the object is maybe 23 bya away. Light travels at a constant speed through space that is (mostly) expanding at an accelerating rate. It does get confusing. --[[User:GeorgeLi|GeorgeLi]] 22:10, 30 January 2012 (EST) | + | :Well not really. What happens is that because space is expanding, by the time the light that leaves an object reaches us the object is further away than the distance the light has travelled. Imagine I'm standing in the back of a truck driving south at 50 ft/s, while you run north at 10 ft/s. At 200 feet from you I shoot an arrow at you, which travels at 100 ft/s. By the time the arrow lands at your feet it has travelled 220 feet, but the distance between us is 320 feet. It's sort of like that. If the light travel distance to an object is 10 billion light years (bly) then we're seeing the object as it looked 10 billion years ago (sorry, I'm an OEC) but also as it looked when it was, say, 6 bly away. By the time we see it the object is maybe 23 bya away. Light travels at a constant speed through space that is (mostly) expanding at an accelerating rate. It does get confusing. --[[User:GeorgeLi|GeorgeLi]] 22:10, 30 January 2012 (EST) |
| | ::::::::::Rachel, Aschalfly says that he saw "numerous references" to people talking about observable stars 39 billion light years away. I have an open mind, and want to be able to have him share his knowledge with me. [[User:ScottDG|ScottDG]] [[User talk:ScottDG|Talk]] <b>Is Gingrich an orphan? Conservapedia says yes. Why does nobody else? </b> 21:02, 30 January 2012 (EST) | | ::::::::::Rachel, Aschalfly says that he saw "numerous references" to people talking about observable stars 39 billion light years away. I have an open mind, and want to be able to have him share his knowledge with me. [[User:ScottDG|ScottDG]] [[User talk:ScottDG|Talk]] <b>Is Gingrich an orphan? Conservapedia says yes. Why does nobody else? </b> 21:02, 30 January 2012 (EST) |