Measuring c (split from Is foundational physics stuck?)

[Mordred]

1 hour ago, DanMP said:

Exactly (thanks), I just tried to describe what is happening. 

I know it sounds silly, but I consider the DM particle as a very stable "system". When a photon gets in, the particle/ system becomes unstable and promptly "spits" the photon out. Don't ask me how, because it's like asking Koch when he just discovered bacteria about its DNA. Take it as a definition of my model. Let experimental tests I proposed to decide if the model is good. 

 

I can live with bad terminology so now that is addressed we can move on. DM assuming it is a particle is considered professionally as being very stable so no issue there.

The issue however still remains that even via absorption and emission of a photon your still involving medium like properties so time of flight for the photon beam is being additionally delayed. The other problem that makes this interaction distinct from redshift is accordingly via Snell's law the refraction angles (emission of photons will be frequency dependent on an equivalent refraction index.

This leads to diffusion or divergence of the waveforms which is not the case with redshift. The redshift relation has no refraction index redshift has no frequency dependence on refraction. As redshift equates to time dilation ie gravitational time dilation, relativistic Doppler shift or even cosmological shift (with corrections beyond Hubble horizon) this is relevant and shouldn't be ignored.

Granted the other detail I hadn't mentioned is such an interaction would also affect the KE terms so there should be a temperature increase/decrease 

Edited November 24 by Mordred

[swansont]

3 hours ago, DanMP said:

 I know it sounds silly, but I consider the DM particle as a very stable "system". When a photon gets in, the particle/ system becomes unstable and promptly "spits" the photon out. Don't ask me how, because it's like asking Koch when he just discovered bacteria about its DNA. Take it as a definition of my model. Let experimental tests I proposed to decide if the model is good. 

How does DM form a system? Now you need two particles, you have to have an interaction to form the bound system, and you have to be able to virtually absorb photons but not have resonant absorption or dissociation, and you need electromagnetic interactions.

 

3 hours ago, DanMP said:

You need a clock to measure the mirror speed. So it's not much different than the Fizeau apparatus in the opening post. 

You could use a pendulum clock for that.

[Mordred]

This is more a related FYI and its not something one finds in textbooks. I can pretty much guarantee very few if any members will be aware of this little side detail. As we are all aware our universe is expanding. What is often overlooked when it comes to light propagation in this expanding volume is something called Absorption distance. I will try to keep this as simple as possible however the essence of absorption distance is that the higher the density of a particle ensemble the greater the likely hood of mean free path interference resulting in a reduction in number density of received photons.

In order to factor this is will involve the absorption or scattering cross section of the particle population as well as the cross section of photons. Were going to assign X(z) to the absorption distance. \(n_0\) as the number density, \(\sigma_0\) as the cross section. Latter two being present epoch density. The evolution of number density as a function of redshift is

\[n(z)=n_o(1+z)^3\]

I won't get into the mathematical proof of the above it will invariably involve the density evolution of matter and radiation via the FLRW metric. We will be using the proper distance increment \( dl\) (take a ruler and keep the number of divisions on that ruler the same but as you go further back in time the spacing between each division decreases) 

\[dl=\frac{a(t)}{a_0}D_c=\frac{D_c}{1+z}\]

where D_c is the commoving distance unfortunately the cross section of a photon beam is not consistent with redshift however we can choose to ignore geometric effects of orientation and orientation of gas structures for simplicity. 

In a commoving cosmic volume along the proper distance increment centered on the Z beam the probable number of targets (absorption/ scatterings)that can potentially interact with the beam is

\[DN_t)=n_z\sigma_b(z)dl=n_o\sigma_b(z)(1+z)^3dl\]

where

\[dl=cdt=\frac{c}{H_o}\frac{d_z}{(1+z)}{(E(z)}=D_H\frac{dz}{(1+z)E(z)}\]

\[DN=dn_t(z)[\frac{\sigma_o}{\sigma_b(z)}]\]

where

\[\frac{\sigma_o}{\sigma_b(z)}\]

is the fractional area per structure the redshift dependence of DN/dz can be written as a dimensionless quantity

\[\frac{DX}{Dz}=\frac{1+z^2}{E_z}\]

upon integration we get the Absorption distance

\[X_z=\int^z_o\frac{DX}{d_z}dz\]

Now consider the above if for example DM was interacting with the photon beam the entire time of flight travel. Would we ever get the signal at say z=1100 ? conditions affecting the mean free path of photons after surface of last scattering is relatively clear and we are all aware of the opacity previous to last scattering on the mean free path of light.

Just for consideration of a likely side effect should photons interact with DM along the mean free path via absorption/emission

@DanMP this is the side effect I am referring to should DM interact with photons along the mean free flight path though the only cross section I have atm for DM would be under assumption of sterile neutrinos being DM. As that is part of my current research I have been doing in my Nucleosynthesis thread.

 

 

Edited November 24 by Mordred

[Mordred]

4 hours ago, Mordred said:

(with corrections beyond Hubble horizon)

as I always prefer to include the mathematics for my statements where applicable or I have handy here are the corrections for peculiar velocity (recessive velocity beyond Hubble Horizon

Recessive Velocity corrections past Hubble Horizon approx z=1.46

\[E_Z=[\Omega_R(1+z)^4+\Omega_m(1+z)^3+\Omega_k(1+z)^2+\Omega_\Lambda]^{1/2}\]

\[v_{r}=\frac{\dot{a}}{a_0}D\]

\[\frac{\dot{a}(t_0)}{a_o}=\frac{H(z_0)}{1+z_o)}=\frac{H_0E(z_o)}{1+z_O}\]

\[v_r=\frac{cE(z_o)}{1+z_o}\int^{z^{obs}}_0\frac{dz}{1+z_o}\frac{D_c(Z_o,Z_s)}{D_H}\]

\(Z_{os}\) is the reduced redshift

\[1+z_{os}=\frac{1+z_s}{1+z_o}\]

for observerd source redshift z_s

present epoch Observer \(z_0=0 ,E(Z_o)/1+(z_o)=1\)

\[v_r=(o,z)=c\int^z_o\frac{dz}{E(z)}=c\frac{D_c(z)}{D_H}\]

gives redshift as a multiple of speed of light

The above is time dilation effects due to expansion and commoving volume to a commoving observer. Below is how to determine the ae of the Universe as a function of redshift 

the Hubble parameter can be written as 

\[H=\frac{d}{dt}ln(\frac{a(t)}{a_0}=\frac{d}{dt}ln(\frac{1}{1+z})=\frac{-1}{1+z}\frac{dz}{dt}\]

Notice you have a natural logarithmic function in the last statement for scaling  

look back time given as Ie how to calculate Universe age

\[t=\int^{t(a)}_0\frac{d\acute{a}}{\acute{\dot{a}}}\]

\[\frac{dt}{dz}=H_0^{-1}\frac{-1}{1+z}\frac{1}{[\Omega_{rad}(1+z^4)+\Omega^0_m(1=z0^3+\Omega^0_k(1+z)^2+\Omega_\Lambda^0]^{1/2}}\]

\[t_0-t=h_1\int^z_0\frac{\acute{dz}}{(1+\acute{z})[\Omega^0_{rad}(1+\acute{z})^4+\Omega^0_m(1+\acute{z})^3=\Omega^0_k(1+\acute{z})^2+\Omega^0_\Lambda]^{1/2}}\]

Edited November 24 by Mordred

[DanMP]

1 hour ago, swansont said:

How does DM form a system? Now you need two particles, you have to have an interaction to form the bound system, and you have to be able to virtually absorb photons but not have resonant absorption or dissociation, and you need electromagnetic interactions.

5 hours ago, DanMP said:

Don't ask me how, because it's like asking Koch when he just discovered bacteria about its DNA. Take it as a definition of my model. Let experimental tests I proposed to decide if the model is good

 

4 hours ago, Mordred said:

the refraction angles (emission of photons will be frequency dependent on an equivalent refraction index.

On 11/23/2024 at 5:50 PM, DanMP said:

Quasi (or failed) absorption immediately followed by re-emission is not scattering. The definition of scattering is: "the process whereby a beam of waves or particles is dispersed by collisions or similar interactions". There are no collisions ... and the change in direction at re-emission is very limited, because the time between quasi-absorptions and re-emissions is too short. Normal matter, as opposed to DM, can form atoms and molecules, structures able to use (actually absorb) the photons if the photon energy is the one needed by the electron to "jump" to a higher energy level. So, the time between quasi-absorptions and re-emissions is longer, giving the time for the electron to move around (Bohr model) and emit in other directions than the original. The time needed to "decide" if the photon can be used depend on its energy, therefore light/photons travel at different speeds in transparent materials and the refraction is energy/frequency dependent

For DM particles, as I wrote above (see especially what I underlined), the photons "inside" time is very very short and the same for all frequencies, unlike the "inside" time for atoms and molecules. So, the index of refraction in DM gas is the same for all frequencies. No different speeds and no "rainbow" at the refraction responsible for gravitational lensing. Also, the change in direction (dispersion) is very limited. 

I'll be busy next days, so I won't be able to reply for a while. 

[Mordred]

53 minutes ago, DanMP said:

 

For DM particles, as I wrote above (see especially what I underlined), the photons "inside" time is very very short and the same for all frequencies, unlike the "inside" time for atoms and molecules. So, the index of refraction in DM gas is the same for all frequencies. No different speeds and no "rainbow" at the refraction responsible for gravitational lensing. Also, the change in direction (dispersion) is very limited. 

I'll be busy next days, so I won't be able to reply for a while. 

won't particularly matter when you consider absorption distance  section.

The quoted section makes no sense ALL frequencies are time dependent. The time element is determined via the frequencies in question. So that quoted section will need more than just some handwave statement specifically some form of mathematical proof. You cannot have the same time for all frequencies that is impossible by the very definition of frequency

I also hate that terminology " inside time" sorry but that terminology doesn't work and gives the visualization of little matter balls for particles instead of field excitations which is something modern physics now teaches example under QFT

I would assume you have some mathematics to your conjecture as its been on your books the past 6 years if not longer and there is absolutely no mathematics for your 2018 thread nothing more than blanket statements. Have you not  done any mathematical development in the past 6 years ????

Without the related mathematics you literally have nothing of any substantial worth.

You can't even prove to yourself mathematical viability let alone anyone else.

Edited November 25 by Mordred

[swansont]

55 minutes ago, DanMP said:

For DM particles, as I wrote above (see especially what I underlined), the photons "inside" time is very very short and the same for all frequencies, unlike the "inside" time for atoms and molecules. So, the index of refraction in DM gas is the same for all frequencies. No different speeds and no "rainbow" at the refraction responsible for gravitational lensing. Also, the change in direction (dispersion) is very limited. 

So, it’s magic

55 minutes ago, DanMP said:

I'll be busy next days, so I won't be able to reply for a while. 

!

Moderator Note

Or at all, since you have given us nothing but hand-waving. No model, no evidence. As such, this doesn’t fulfill the requirements for discussion