Naked Science Forum

On the Lighter Side => New Theories => Topic started by: Hal on 09/09/2019 13:52:05

Title: Can the CMBR be just Doppler shifted light from receding superluminal galaxies ?
Post by: Hal on 09/09/2019 13:52:05
 A speculation on CMBR:

The CMBR may be Doppler (red) shifted light from receding superluminal galaxies.
Due to the high relative velocity of some galaxies, Doppler effect can cause visible light to be
 shifted down to microwave frequencies.

This theory may also explain the cosmic x-ray background radiation, which is proposed to be   
Doppler (blue) shifted light from approaching superluminal galaxies.

My paper is found on Vixra:
“Can the Cosmic Microwave Background Radiation be Doppler Shifted Light
from Receding Superluminal Galaxies ? “


Title: Re: Can the CMBR be just Doppler shifted light from receding superluminal galaxies ?
Post by: Kryptid on 09/09/2019 14:24:11
Microwaves from beyond the boundary of the visible Universe can't reach us, so superluminal galaxies can't be the cause. The Big Bang theory does a good job of accurately predicting the appearance of the cosmic microwave background based on the assumption that it was produced by a uniform, hot gas early in its history.
Title: Re: Can the CMBR be just Doppler shifted light from receding superluminal galaxies ?
Post by: Halc on 09/09/2019 14:56:28
Doppler (blue) shifted light from approaching superluminal galaxies.
Only a few nearby galaxies are approaching at all.  Any distant one is receding.

There are superluminal objects only in a coordinate system that allows superluminal speeds.  There are plenty of such coordinate systems, but an inertial frame isn't one of them.
Title: Re: Can the CMBR be just Doppler shifted light from receding superluminal galaxies ?
Post by: evan_au on 10/09/2019 00:00:11
Galaxies shine by starlight, and starlight contains spectral lines from the atoms and ions in its atmosphere.

The CMBR doesn't have spectral lines.

The standard theory has CMBR being produced as thermal spectrum by the plasma (ionised hot gas, mostly hydrogen, some helium) that existed around 300,000 years after the big bang.

When temperatures dropped below about 3000K, hydrogen and helium started to form atoms, and became transparent to this thermal spectrum. It has subsequently been red-shifted from around 3000K to 2.7K.
See: https://en.wikipedia.org/wiki/Cosmic_microwave_background
Title: Re: Can the CMBR be just Doppler shifted light from receding superluminal galaxies ?
Post by: Kryptid on 10/09/2019 01:57:57
Since Hal is too new to post links, I'll post it here: http://vixra.org/pdf/1908.0409v2.pdf

An interesting claim from the article:

Quote
Superluminal galaxies have already been observed and in fact this has become one of the
evidences against the special theory of relativity.

It looks like our guest here is yet another relativity denialist.

Quote
Given the fact that galaxy velocities of about nine times the speed of light have already been
observed, this result seems realistic.

I'm curious to know what "superluminal galaxies" he is talking about. Perhaps this "superluminal" motion he speaks of is actually illusory: http://math.ucr.edu/home/baez/physics/Relativity/SpeedOfLight/Superluminal/superluminal.html

Quote
Receding galaxy emits light at , λ = 650 nm

Galaxies emit light at many different wavelengths. There are objects that are very cold, very hot and everything in between within them. This results in a mix of radio, microwave, infrared, visible, ultraviolet, x-ray and gamma rays. So by assuming a single wavelength, you are already starting off with a wildly incorrect assumption.
Title: Re: Can the CMBR be just Doppler shifted light from receding superluminal galaxies ?
Post by: Halc on 10/09/2019 03:10:11
Since Hal is too new to post links, I'll post it here: http://vixra.org/pdf/1908.0409v2.pdf

An interesting claim from the article:

Quote
Superluminal galaxies have already been observed and in fact this has become one of the
evidences against the special theory of relativity.

It looks like our guest here is yet another relativity denialist.

Quote
Given the fact that galaxy velocities of about nine times the speed of light have already been
observed, this result seems realistic.
Superluminal objects are very much observable.  That's why one measurement of the radius of the visible universe is ~45 BLY and not just 14.  But the claim of 9x light speed isn't consistent with that figure.  GN-z11 (the fastest galaxy seen to date) is 'currently' 32BLY away which is about 2.4c, nowhere near 9c.
Perhaps they mean the redshift comes in at about 9.  Gn-z11 has a redshift of about 11 actually.

As I said in my post, distances and speed are all about which coordinate system is used.  That galaxy does not have a superluminal speed in the inertial frame of Earth, but astronomers don't use inertial frames (or 'short scale') when discussing massive distances like that.
Title: Re: Can the CMBR be just Doppler shifted light from receding superluminal galaxies ?
Post by: Kryptid on 10/09/2019 04:13:15
That galaxy does not have a superluminal speed in the inertial frame of Earth, but astronomers don't use inertial frames (or 'short scale') when discussing massive distances like that.

In what reference frame is it superluminal then?
Title: Re: Can the CMBR be just Doppler shifted light from receding superluminal galaxies ?
Post by: Halc on 10/09/2019 12:47:21
That galaxy does not have a superluminal speed in the inertial frame of Earth, but astronomers don't use inertial frames (or 'short scale') when discussing massive distances like that.

In what reference frame is it superluminal then?
I'll drag the picture out again:
(https://i.stack.imgur.com/6yzwk.jpg)
Both images use a comoving reference frame, not an inertial one.  The upper image uses proper distance to measure separation of objects, and the lower one uses comoving distance.  Either image can be directly generated by the other by multiplication/division by the scalefactor on the right.  Our galaxy GN-z11 is approximately the dark line labeled 'worldline of comoving object on our particle horizon at a=0.5. The slope of that line in the upper picture is about 2.4c. That line crosses the red light cone line (easier to see in the bottom picture), and thus we see the galaxy as it was back then.  The red line crosses older galaxies, but those were so young back then that they hadn't yet been born, so we don't see them.

The reference frame is not inertial.  If galaxy A is us, galaxy B is going .7c away from us, and C is moving .7c away from B, then in an inertial frame, C would be going away from A at .94c, but in comoving reference frame, C is moving at 1.4c away from A, which is why they say things move faster than light.

The horizontal 'now' line represents a curved line in inertial space which represents all the points in spacetime where the age of the universe appears to be 13.8 billion years old to a typical object like a galaxy (an object that is moving more or less at the mean velocity of the material in its vicinity).  In an inertial frame, those fast moving galaxies are aging much more slowly due to time dilation, and the age of the universe from them gets lower and lower as distance increases.

I had drawn the same picture using inertial coordinates in this post:
http://www.thenakedscientists.com/forum/index.php?topic=76976.msg577095#msg577095
The blue 'now' line in that picture corresponds to the blue line in the above picture.  Horizontal line in the middle is the inertial 'now'.  The brown v=2c line on the right is the galaxy moving at 'twice light speed' as measured in the comoving frame.  It only took 6.9 billion years for the light to reach us from the CMB.  No light we see is older than that in such a frame.

Note that all the really distant things like stuff beyond the visible universe all get squashed up against that purple line.  It's really hard to talk about it in frames where its length contraction reduces distances to nothing.  So the comoving frame above is used, but such a frame (like any non-inertial frame) allows object to move faster than c.  This is also true of rotating or accelerating frames.  Rotating and comoving frames both foliate space.  Accelerating frames do not.
Title: Re: Can the CMBR be just Doppler shifted light from receding superluminal galaxies ?
Post by: Hal on 10/09/2019 14:20:22
Kryptid:
Thank you for posting the link.

To: evan_au

“ The CMBR doesn't have spectral lines. ”

If there are large number of receding superluminal galaxies with range of velocities around some average velocity               ( for example, Vav = 7.97 c ), when seen in any direction, there will not be any spectral lines at microwave frequencies; the spectrum will be continuous because of the continuous distribution of galaxy velocities. For example, the velocity distribution of large number of galaxies in any direction could be such that the CMBR will approach a blackbody radiation. In this case the 2.7 K ‘temperature’ would just mean that on average galaxies are receding away from us at 7.97c.
Title: Re: Can the CMBR be just Doppler shifted light from receding superluminal galaxies ?
Post by: Kryptid on 10/09/2019 14:38:03
I have moved this topic to "New Theories".

The "Physics, Astronomy & Cosmology" board is for accepted, mainstream science discussions.