Regular readers of this blog (both of them) may remember the basically tedious and offensive but occasionally (accidentally) hilarious troll who keeps attempting to post comments like this:
I thought you might like to see the result of feeding the expression found in the above rant into Wolfram Alpha:
This is exactly the expression described above but produces nothing like the claimed value of the Hubble constant, and it’s in the wrong units too.
Update for the benefit of the extremely hard of thinking (especially Mr Hine):
π21 ≈ 2.75 × 1010 (dimensionless).
One parsec = 3.086 ×1016 m so one Megaparsec is 3.086 ×1022 m. Hence 2 × `a Mpc’ × c ≈ 2 × 3.086 ×1022 m × 3 × 108 m s-1 ≈ 1.83 × 1031 m2 s-1.
Thus the full expression is obtained by dividing this by the value for π21 obtained above giving a value approximately 6.7× 1020 m2 s-1 as demonstrated by Wolfram Alpha.
The correct value for the Hubble constant is about 2.2 × 10−18 s−1.
UPDATE: It’s interesting how the Megaparsec appears in the numerator in Mr Hine’s expression, but magically transfers to the denominator as far as the units are concerned:
ANOTHER UPDATE:
I think I may have cracked it. I believe Mr Hine’s calculation involves using light-years instead of Mpc or SI (for some reason) the calculation is in which case the calculation becomes:
π21 ≈ 2.75 × 1010 (dimensionless) as before
One parsec = 3.26 light years so one Megaparsec is 3.26 ×106 million light years. Hence 2 × `a Mpc’ × c ≈ 2 × 3.26 ×106 m × 3 × 105 m s-1, using c in km/s.
When divided by the value of π21 this gives a number around 71 (I couldn’t be bothered with the extra decimal places).
However, although it is a number around 71 the units are then km/s times light years, not the correct units which are km/s divided by Megapersecs. The fact that the number comes out close to 70 is just a numerical artefact of Mr Hine’s basic misunderstanding of units and dimensions. In other words, it’s gibberish. I know you’ll all be shocked by this revelation, but it’s true.
In the Dark 