(John Baez) wrote in message ...
In article , John Baez wrote:

The reason why Smolin was interested in MOND is that this constant

a_0 = 2 x 10^{-10} m/sec^2

is supposedly about equal the acceleration of the expansion of
the universe due to the cosmological constant, for objects that are...
one Hubble away?

Does someone have the energy to check?

[Moderator's note: The order of magnitude is about right, anyway. -TB]

Okay, thanks. That's good enough: it's just one of those rough
numerical coincidences that makes you - or in this case, Smolin -
lie in bed staring at the ceiling wondering if there could be
something funny going on involving gravity and this particular
acceleration scale.

If I put an object one Hubble away, then from a Newtonian point of view,
to keep at rest w.r.t. me, I have to put a little rocket motor on it, firing
away from me. So, Hubble expansion would make Newtonian gravity
seem weaker, but MOND makes it seem stronger. So why should there
be any connection between a_0 and Hubble?