Astronomical distance units -parsecs, light years and AU

[zmthoufique]

Very good explanation....thanks for uploading..

[magodeoz187]

wow man thanks for the explanation :)

[cannabishead4420]

I'm subscribing

[ispollock]

After a certain physicist (not sure who) heard that lovely song by Katie Melua, he wrote her and suggested that 12 billion light years was not a guess, but within "fairly small error bars." She wrote an addendum to the song reflecting the changes.

I think that is awesome. :P

[blobrana]

cool

[MrRAndom5]

interesting. 5/5