Quote:
Originally Posted by Weltevreden SA
Points well made and taken, Steven. I wasn't referring to the Narliker treatment but to the notion that atoms get "fat" simply because the universe is expanding and so everything in it should expand too. The populist usage does not address inertial mass or that G, the gravitational constant, decreases with time.
|
Expansion doesn't occur at atomic scales for two reasons.
At local (non cosmological scales) the recession velocity is very small.
At atomic scales the velocity is essentially zero.
You can use Hubble's constant which a value of 67.8 km/s
per megaparsec to calculate the velocity at atomic scales.
Secondly gravity puts the brakes on expansion.
If you take a larger scale such as the Earth-Sun distance, the distance isn't increasing as gravity constrains expansion.
G doesn't decrease with time. G is a constant which defines the strength of the gravitational force.
Interestingly there is a paper that suggests that G exhibits periodicity over small time scales.
http://phys.org/news/2015-04-gravita...tant-vary.html
Steven