How Does Space Expansion Affect the Velocity of Galaxies?

[Vanadium 50]

so I'd be very suspicious of a blanket figure like that.

We can at least see if it's in the ballpark. The sun's disk is 7 x 10^-5 steradians. Or 10^-5 of the sky. It's 2000x hotter than the CMBR so it puts out 2000x as much energy per unit frequency per unit area, or in total 2%.

You definitely can see the sun in static, by looking at day vs. night. I don't think it's a factor of 2 - maybe 1.5, but I'm just spitballing. I am going to call it a factor of 2. And that takes our 2% down to 1%.

So it's not a crazy number. My estimate/guess is that it's a little high but not crazy high.

 

[Vanadium 50]

Boy did I goof. The CMBR actually carries more energy than the sun: 50x as much, not 1/50 as much.

Therefore the day-night effect on static is not due directly to the sun. It's got to be the ionosphere, either directly, or indirectly (e.g. RF signals from far away lightning or other TV stations/multipath).

I now wonder if the 1% is an underestimate. At 1% that means there is a source 5000x brighter than the sun in RF that isn't the CMBR. And it has to be very, very cold (about 1K).

 

[Hornbein]

Ehm guys I don't have the background to fully grasp your replies but are you saying that GR even explains dark energy?

GR is a set of constraints. There are many states of the Universe that are consistent with these constraints. If your theory doesn't meet these constraints then doubt is darkly cast upon it. If your thesis does meet these constraints that's nice, but doesn't give any evidence that your idea is correct.

It appears to me they are saying that dark energy is consistent with GR.

 

[Bandersnatch]

What is this "static" of which you speak?

That I know not. But I heard tell of the mythical 'teevos' roaming the land in the days long past, when phones were rotary and news were made of paper. It was said that a teevo, if left to its own devices, would speak in 'static' to the befuddlement of onlookers.

 

[pinball1970]

Something is confusing me

Bob is on Earth and Alice is one of those galaxies at the edge of the observable universe which is C or greater than C (post 13)

What does that do to their respective clocks?

You plug velocities in the time dilation equation at or above C and things get strange.
I am getting something wrong here- not sure what it it

 

[Orodruin]

You plug velocities in the time dilation equation at or above C and things get strange.
I am getting something wrong here- not sure what it it

You cannot use the time dilation formula from special relativity. The description of the expanding universe requires general relativity.