4 ms·

Not in all frames of reference. There is a frame of reference in which the object appeared just 30.5 years ago. This would be a frame of reference which would b

by zohebv 16y ago

Not in all frames of reference. There is a frame of reference in which the object appeared just 30.5 years ago. This would be a frame of reference which would be moving from the star towards the earth at 0.9999999999999999*c

steve19 16y ago
Don't we generally report the age of objects relative to themselves (generally not in astronomy or physics)? You are not -1 or +5 in age (relative to myself).
- zohebv 16y ago
  Generally yes (but not at astronomical scales), when everyone shares the same frame of reference. Moreover the star and earth in all likelihood don't share the same frame of reference. The distance between the two of us is very tiny. The error in simultaneity between the two of us would be the time it takes a light ray to travel between the two of us. 84 milliseconds in the worst case. So I cannot have a -1 or +5 in age difference with you. The wiggle room is around 84 ms. If you are 1 light year away, the wiggle room now expands to 1 year! Depending on the observer I am 0 or +1 years older than you. On astronomical scales the wiggle room is quite huge. For example there is a frame of reference in which the blackhole celebrates its 30th birthday AFTER the year 2009. When such a frame exists it does not make sense to say that the star is now 50M years old. There is no notion of simultaneity. The word "now" is profoundly misleading. There is no absolute time. Lets say you are a soldier that drops a bomb that kills 30 people. However from your POV you see only 3 dead people. You cannot claim that in your frame of reference only 3 people died. You can only say "I saw 3 dead people". In reality 30 people died. Similarly, there are innumerable frames of reference in which the 30th birthday of the blackhole occured after the year 2009 on earth. So it is misleading to say that the star is now 50M years old.

by zohebv 16y ago

steve19 16y ago

Don't we generally report the age of objects relative to themselves (generally not in astronomy or physics)? You are not -1 or +5 in age (relative to myself).

zohebv 16y ago
Generally yes (but not at astronomical scales), when everyone shares the same frame of reference. Moreover the star and earth in all likelihood don't share the same frame of reference. The distance between the two of us is very tiny. The error in simultaneity between the two of us would be the time it takes a light ray to travel between the two of us. 84 milliseconds in the worst case. So I cannot have a -1 or +5 in age difference with you. The wiggle room is around 84 ms. If you are 1 light year away, the wiggle room now expands to 1 year! Depending on the observer I am 0 or +1 years older than you. On astronomical scales the wiggle room is quite huge. For example there is a frame of reference in which the blackhole celebrates its 30th birthday AFTER the year 2009. When such a frame exists it does not make sense to say that the star is now 50M years old. There is no notion of simultaneity. The word "now" is profoundly misleading. There is no absolute time. Lets say you are a soldier that drops a bomb that kills 30 people. However from your POV you see only 3 dead people. You cannot claim that in your frame of reference only 3 people died. You can only say "I saw 3 dead people". In reality 30 people died. Similarly, there are innumerable frames of reference in which the 30th birthday of the blackhole occured after the year 2009 on earth. So it is misleading to say that the star is now 50M years old.