They normally use parallax-seconds, i.e. parsecs, for long distance objects.
Comment on Seconds
m0darn@lemmy.ca 2 months ago
Don’t they measure distance and time by redshift (ie colour)
Allero@lemmy.today 2 months ago
m0darn@lemmy.ca 2 months ago
I think you need to be more specific than ‘long distance’, yes they use parsecs for ‘long distances’ but I believe only for intra-galactic objects. I think other galaxies are too distant for parallax seconds to be useful.
Allero@lemmy.today 2 months ago
Fair!
Thanks for this bit of clarification
Generous1146@beehaw.org 2 months ago
What even is color if not seconds^-1?
m0darn@lemmy.ca 2 months ago
Yeah true, but I think they actually use wavelength of red shift, which is distance… traveled by light in the time it takes to make a full cycle. So I guess we’re back to seconds again.
I think they use this for distance and time because at scales being dealt with they have the same implications.