Cart Before the Horse?

[Gibsense]

The common understanding is that the universe's expansion stretches the wavelengths of light, causing the cosmic microwave background (CMB) radiation to redshift. But flipping it around, if light pressure were causing the expansion, it would mean light is somehow pushing the universe to grow.
The early universe would have the greater pressure. Another Dark Energy contender - how daft is this?

 

[promytius]

I was taught light is massless photons; so what force can a photon apply? It's a result, not a cause.

 

[Gibsense]

I was taught light is massless photons; so what force can a photon apply? It's a result, not a cause.

You should have been taught that light has no rest mass. Rest Mass!
Light has energy and exerts force, hence its use in spacecraft and as a possible long-distance propulsion solution.

 

[Thermoman]

I was taught light is massless photons; so what force can a photon apply? It's a result, not a cause.

A Photon has mass-B !

Mass-B is a quantitative measure of inertia , a property of light by which it continues in its existing state of rest or uniform motion in a straight line. Mass-B can be considered a dynamic measure relative to the magnitude of light occupying the same place at the same time . Mass-B can be considered a necessity for all movement within a Quantum Mainframe

 

[Gibsense]

Thought experiment:

Two galaxies will receive light pressure from each other. Tiny though this may be it exists. Now consider the pressure interplay between all galaxies. The space between them will be stretched.
Logically this is Dark Energy (Even if it is only a tiny bit)

I have no idea how to quantify this and would not expect it to cause an acceleration of expansion (because I think acceleration is false) but it might explain why gravitation does not cause collapse, maybe

So I would look to find some 'near balance' mechanism. But I am too ignorant! lol.

 

[Atlan0001]

The universe is dark due to an infinite density of coordinate points photonic photo-frame past-future histories SPACETIME . . . the translucent, transparent, immaterially-materially Flatland universe-fine quantum 'aether'.

Oops, to be continued maybe . . . I'm being summoned by my lady!

 

[Gibsense]

Oops, to be continued maybe . . . I'm being summoned by my lady!

I know the feeling. Be quick. Good Luck!

 

[Atlan0001]

I'm back . . . and speaking of "back", there is no catching, no back, no rear, to single-sided photonic photo-frame past-future histories SPACETIME . . . just frontage only. Race into a front facing of light-SPACETIME and turn around only to always come face-to-face into another front facing of light-SPACETIME only (a single-sided 2-dimensional photonic photo-frame past-future histories SPACETIME).

Is it any wonder you can never outrun light to catch up to it since there is no such thing as a rear to catch up to to it?!

 

[Thermoman]

Is it any wonder you can never outrun light to catch up to it since there is no such thing as a rear to catch up to to it?!

A Train Engine pulls a Carriage around a circular Track. The Engine chases the Track as it follows the carriage at a constant speed and distance !