Not directly related, but if you convert the units, 73 km/s/Mpc are 11.16 meters per year per AU (the distance between earth and the sun)
Somehow it blows my mind that the distance between the sun and earth increases by 11m per year due to the expansion of space itself.
But I still don't really understand how we can measure that expansion.
If space expands, wouldn't everything we can use as measuring stick expand as well?