🚀 go-pugleaf

jbaez@riesz.mit.edu (John C. Baez) writes:

>In article <Aug.3.15.57.23.1992.22500@ruhets.rutgers.edu> bweiner@ruhets.rutgers.edu (Benjamin Weiner) writes:

>>Now for the astronomy viewpoint:
>>The Hubble constant (H_0) has dimensions velocity/distance (so is an inverse
>>time, really) and is currently thought to be somewhere in the range
>>50-100 km/s/Mpc. 

>The amusing part is that there is one camp of people who are SURE it's
>close to 50, while the other camp is SURE it's close to 100, and they
>argue and argue about it, so everyone else opts for about 75 as a round
>figure.  I can imagine learned expert X saying "the world is round" and
>learned expert Y saying "the world is flat" and the nonexperts splitting
>the difference and saying "it's round on one side and flat on the
>other."  

Recently those who think it the Hubble constant is 50 have come up to 
around 60 km/s/Mpc and those who think it is 100 have come down to
around 90 km/s/Mpc. Maybe in a few years all the Hubble constant 
people will converge on 75 km/s/Mpc.

>>Additionally there is the deceleration parameter q_0 (no fair calling
>>it a fudge John.  The cosmological constant ... now there's a fudge)

>I'm sorry, I agree that in GR it's to be expected; I just like teasing
>cosmologists (see above).

Jim Buell