
Originally Posted by
snowflakeuniverse
Hi Lyndon
You are right, I read the chart wrong, the density in the second reference you gave is 100 electrons per cubic meter for intergalactic space, not 1000. (On my computer, the chart shows up vertically and when I tip my head over it gets a bit difficult to read it.)
So instead of your relationship being off from observation by a factor of 2000, we are now down to 200. Things are getting better. Also the chart does indicate that the number of electrons in space should be less than this. Things are getting even better. But it is still fairly far off from being convincing.
The electron density of .1 electrons per cubic meter is closer to the value you need, which is reputed to be somewhere in Peebles, “Principles of Physical Cosmology”. I have not been able to find it, and I spent almost an hour looking thorough the text. My fear is that the original source that you used to lead to your value may have been a made up the figure and you may be the victim of someone else’s error. Maybe they had to turn their head on the side to read a chart and they got it wrong. As far as I can tell there is no evidence of an electron density in space of .1 electrons in Peebles 1993 text and until someone finds it, or explains how they derived it from assumptions from Peebles, I would tend to not have much faith in the number. Also, Peebles would have this figure as a reference, it really would be good to have the original source. If we do not, there is the real risk that a faulty figure could become some kind of universally accepted figure when it should not.
The third, and latest reference you provided, lists an electron density of 10 per meter cubed, or less. This is within a factor of 20 of your desired relationship, which is not too bad, considering the guesswork involved in establishing electron density. (Could there be a very dense electron cloud around a galaxy and between it there is “empty” space? (photons and neutrinos fill space) Are there studies of signal/frequency spread detected when the signal passes through the edge of a galaxy?). It would be good if he provided the source for his estimates. I got the impression that he that did not determine the delay in signal based upon frequency but someone else did. Also, the date of the source is from 1978, seems we should have a better figure by now. (Hopefully a .05 electrons per meter cubed value)
Until we pin down the .1 electron density from a confirmed source, I do not believe it should be used. , (There is no evidence of it in Peebles, as far as I can tell). The only figures we have are between 20 to 200 times the necessary densities to conform to your relationship.
This again is not too bad, but it is not that good either.
Snowflake