Post #3

This thread adds content about the gravitational component of the red shift and why the energy density of space does not act as a medium for the propagation of light waves, i.e. a luminiferous aether. Various experiments using interferometers have been designed to find the aether out there that serves as the medium for the propagation of light waves but none have been successful. This post explains why that is the case in the ISU even though there is a perfect background consisting of the energy density of space.

First though, what causes the growing separation of galaxies in the first place?

When mass forms it is given momentum by the background within which it forms.

The perfect background of an arena in the ISU is expanding. Even before matter forms in an arena of the ISU, the perfect background, i.e. the energy density of space in the arena is expanding. It expands because its high energy density is in the process of being equalized with the lower energy density of the greater universe.

Matter that forms from the energy density of the background has an initial movement away from all other matter since it forms “from and within” this expanding energy density environment.

Any secondary mass that forms from that original matter (as a result of the attraction due to gravity) carries the signature of the movement that was initially imparted to the original matter.

This means stars that form in an expanding energy density environment will still be moving apart due to the initial momentum of the matter from which the stars formed. Galaxies that form will still be moving away from all other galaxies due to the initial momentum of the “dust and stars” that make up the separate galaxies.

Using galaxies as an example, the typical galaxy is therefore moving away from us. The red shift is caused by the movement of the galaxies as they separate just like in the mainstream.

The gravity component of the red shift:

However, there is also a gravitational effect or component of the red shift. Though that effect is a tiny fraction of the separation effect, the net affect of gravity on the wave length of photons traversing galactic space is measurable if there is a difference in the strength of the gravitational fields involved.

For accuracy we know that the various gravitational fields are infinite and overlap, but for this example light observed arriving in our galaxy from a distant galaxy can be said to have left the gravitational field of the emitting galaxy and entered the gravitational field of our galaxy.

If those two gravitational fields are equal the effect on the red shift is zero because the photons are red shifted when thy leave the emitting galaxy and are equally blue shifted when the entry our galaxy.

But if there is a meaningful difference in the strength of the two gravitational fields there will be a measurable effect on the amount of red shift observed, though insignificant relative to the red shift caused by the expansion component.

I point this out to establish that gravity influences photons that travel through gravitational fields.

So two effects have been pointed out; matter that forms from the energy density of space is moving apart because the energy density of space is expanding when the matter forms, and gravity which courses through the energy density of space can affect the wave length of photons.

The point I want to make is that the energy density of space does not propagate the light waves that pass through it. It simply influences the path that photons take through it to the extent that gravitational fields exist. Propagation would involve the reaction of the energy density of space to perpetuate the wave length as it passed through space. More accurately, the energy density does not “notice” the photon but the photon “notices” the gravitational fields that course through it. Gravitational fields do not have “wave length”; they are a shift in the density of the EEPs in space between the objects.

The position of every EEP in space is constantly adjusted by the gravitational fields coursing through space. On the other hand, the passing of a photon has no effect on the EEPs in the background because the photon does not exert gravity. Only gravity and expansion affect the position of individual EEPs in space.

Light beams emitted simultaneously from separate galaxies, if joined somewhere in at equidistant mid-space would show a difference in the shift in the positions of the interference fringes when measured by an interferometer; a shift equivalent to the relative difference between their respective gravitational fields.

A light beam emitted from Earth and traveling through just the Earth’s gravitational field will not show noticeable interference fringes when rejoined after being split and diverted along different and varying paths when measured by an interferometer.

These split light beams will not be affected by the energy density of the perfect background that they travel through because that background itself is unaffected by the movement of the photon which does not exert gravity. The background is however constantly responding to the movement of the Earth and the Earth’s gravitational field.

The split beams will be ever-so-slightly affected by the shape of the gravitational fields through which they pass to the extent that those gravitational fields differ over the path taken by each split of the beam.

On Earth, unlike the inter-galactic experiment I alluded to above, this effect would not be noticeable in the interference fringes when the split beams are rejoined because Earth’s gravitational field would affect both splits, and the net difference between the effects due to varying distances traveled would be ever so slight; negligible with the measuring equipment used today that eliminates most of the error.

Therefore though there is a gravitational effect as photons pass through the perfect background which consists of EEPs in the energy density of space, that perfect background in no way acts like a luminiferous aether across which light waves were once thought to be propagated.