0

I've always figured there must be a simpler explanation for the observed lack of red shifting that has lead astronomers to hypothesize Dark Energy. Or at least there must be a simpler explanation of Dark Energy than an ever-increasing amount of energy that pushes the universe apart.
However, now that we observed the GW170817 event in two independent ways, does this confirm that Dark Energy exists, or is there way too much uncertainty to use it to make inferences with?

Although light is often said to be weightless this is simply not true because photons have momentum and therefore bend spacetime. I had hypothesized that at a quantum level the photons could interact with their own gravitational bow wake in such a way as to stretch the waveform out, possibly while destructively interfering with the waves in front and behind it, thus making it appear as if the energy had been stretched out over time.
However, now that we have observed a gamma-ray burst from both the light and the gravitational waves emitted, does this disprove the idea that gravity could be the cause of the redshift?

An alternative explanation to both Dark Energy and my hypothesis would be that dark matter or something else in the galactic medium, just has a red shifting effect on light waves.
But if both the gravity wave and lightwave diminished in intensity exactly as expected, and that nothing affected the light that didn't affect the wave; wouldn't that then prove that they were in fact just as far away as we expected them to be? I doubt that we have enough information to make such expectations, but if so I might have to start accepting Dark Energy.

EDIT: Originally, I had said extra redshifting instead of lack of, but I've since realized that if universal expansion appears to be accelerating, then more distant objects have slightly less red shifting then what would be expected of them.

Caston
  • 101

2 Answers2

3

Your question is a mishmash of unrelated and incorrect ideas. Here're some of them:

  • The observed "redshifting" has been around since Hubble first measured it in the early 20th century. That was before the discovery of dark energy.
  • The current simplest explanation of dark energy is the cosmological constant, which is a constant, i.e. it is not an "ever increasing energy source".
  • Light is massless. The source you quote says as much. First five words: "The short answer is "no" ..."
  • The idea that something else is redshifting light is called tired light, which has become increasingly fringe because of a variety of observations.
  • Do you even know why we think dark energy exists? It's not just because of the redshift, or Hubble would've discovered dark energy. See Wiki.
Allure
  • 23,373
0

Please note that a photon mass is not necessarily the most economical hypothesis to work with. First you would have to establish that the effect you want to predict is different for different massless fields. If photons turn out to require the same effective "cosmological mass" than gravitons, you would have to reassess if you can think of your expected effect as some residual mass, or actually as a geometric correction that affects all null geodesics

lurscher
  • 14,933