Why do we believe Redshift is caused by universal expansion?

There is a surplus of new and old evidence disproving the sole, holy connection between Redshifting and the doppler effect. Notably, quasars in the arms of huge distant spiral galaxies, where the quasar's redshift places it exponentially further away from the Earth than its home galaxy, and the physical connection to said home galaxy is obvious.

Here is my personal logic, which may be flawed, and rests outside, and alongside, the evidence.

The doppler effect is generally accepted. It is a phenomenon where light traveling towards the Earth from galaxies far away becomes redshifted. The galaxy's motion cancels out the light's speed from our perspective, causing the wavelength to become redshifted (towards the lower-energy end of the light spectrum). Once distant celestial bodies travel faster than the speed of light away from the Earth, their light becomes so redshifted we can never see them, or interact with them. 

However, it is also generally accepted that these celestial objects are not physically moving away from The Earth, rather, that space itself is expanding. This means that all of the distant, redshifted, galaxies surrounding us are not actually moving away from the Earth at all, rather, space itself is growing around and in between, but not in or near, everything else.

These two ideas are not mutually exclusive!!

Light traveling from a motionless home through an expanding void would not redshift.

Why does light lose so much energy over its interstellar journey?

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  • Anonymous
    1 month ago
    Favourite answer

    Your ideas here were a viable counter-theory to standard cosmology back in the 1960s and 1970s and were at that time taken seriously by professional astronomers.

    If those ideas had been true, we would have accumulated a lot of supporting observational evidence for them in the intervening half century.  Instead, ALL of the subsequent observational data indicates these ideas are wrong, and so there is a "scientific consensus" that they are wrong and that the standard model (Lambda Cold Dark Matter Big Bang Cosmology) is basically correct.

    If you want to continue to ignore the most recent 50 years of astronomy, you are a kook.  I know it's fashionable in this decadent Trump era to dismiss the "scientific consensus" about things, but it's still wrong.  Learn some modern astronomy.

    In standard General Relativity, where the coordinate system is initially arbitrary, any and all redshifts can be expressed as either a gravitational redshift or a Doppler redshift, although of course it is more "natural" to apply one or the other depending on circumstances.  And the Equivalence Principle also excludes all other types of redshift.  The redshift "due to the expansion of space" is most naturally expressed as a Doppler redshift.

    • King1 month agoReport

      "If you want to continue to ignore the most recent 50 years of astronomy, you are a kook. I know it's fashionable in this decadent Trump era to dismiss the "scientific consensus" about things, but it's still wrong. Learn some modern astronomy." That's very fascist of you. Science is about debate.

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  • 1 month ago

    Because light has a doppler effect

    Just like Sound on Earth

     An Ambulance going down a street in Paris sounds like two gay men having sex

     with a lower tone as it heads away

    Red is the longer wavelength of light and equates to something traveling away from us

     like the gay ambulance

    Blue is the Shorter end of the wavelength and equates to the higher note of the A4Z Ambulance coming towards us

    HD 140283 in the Constellation Libra has a Blue shift and is worth Googling

    Attachment image
    Source(s): Nickname, Methusila the oldest star ever found
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  • 1 month ago

    Redshifting of light is thought to occur due to three different unrelated mechanisms. 1) the Doppler effect, due to differences in velocity through space, is a reality, and is well documented. 2) When light must climb out of a gravity well, especially a steep gravity well, a redshift will occur. This explains the quasar related redshift. 3) a redshift is thought to occur due to the actual expansion of space, which stretches the wavelength proportional to the amount of expansion over time. There is no direct proof of this phenomenon, but it is nevertheless the accepted cause of the cosmological redshift. Furthermore, the cosmological redshift is NOT a doppler effect, as was once thought. All of the billions and trillions of galaxies out there are said to be "at rest" with one another, except for relatively minor gravitational effects. 

    That is the current state of our theory at present. Who really knows if it is really true or not. That is how I see it. 

    • King1 month agoReport

      Accidentally gave the favorite answer to a different post, yours is a better answer though. 

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  • 1 month ago

    We do not. False premise. Redshift is due to BOTH the movement of stars and galaxies IN space AND the expansion of space. As you said, the two are NOT mutually exclusive. No one since Lemaitre and Hubble has said galaxies are NOT moving. There are a few galaxies that are blue shifted, like the Andromeda I (M31) galaxy local group.

    Light loses energy with the inverse square of the distance whether the light source is moving relative to the observer or not. This is why defining your inertial frame of reference and the origin point of your coordinate system is so important and stating whether the origin point of the coordinate system is hypothetically stationary or is moving is SO important. EVERYTHING in the Universe is moving relative to everything else.

    • hoarseman
      Lv 7
      1 month agoReport

      Light loses "intensity" with inverse square distance --"all things being equal" , photons do not .

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  • 1 month ago

    "disproving the sole, holy connection between Redshifting and the doppler effect."

    Sole???  There's cosmological and gravitational redshifting, plus effects introduced by interstellar / intergalactic dust.

    "Notably, quasars in the arms of huge distant spiral galaxies, where the quasar's redshift places it exponentially further away from the Earth than its home galaxy, and the physical connection to said home galaxy is obvious."

    There have been lots of studies of these apparent anomolies - they've all shown that the anomolies are just line of sight effects, and their frequency is inline with statistical expectations.  Die hard fan of Arp et al are free to disagree, but phrases like "the physical connection to said home galaxy is obvious" are just disingenuous.

    "Light traveling from a motionless home through an expanding void would not redshift."

    And yet it does!  That loss of energy is the cosmological redshift.

    • neb
      Lv 7
      1 month agoReport

      Yeah, how else would the CMBR be 2.7 degrees k.....

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  • John
    Lv 6
    1 month ago

    My job in the Navy was pulsed doppler missile tracking radar and I could hear the doppler from the speaker. The Doppler Effect is real. Splash Bogie Foxtrot 5. My bird was Tartar (ancient Greek Titan) which evolved into Standard and still in use today. DTRM, dual thrust rocket motor with expanding rod warhead. Send me to sea on a DDG (guided missile destroyer).

    • hoarseman
      Lv 7
      1 month agoReport

      No one is doubting Doppler shift due to changes in relative velocity during the propagation, or receipt of signals ,-- his point is about the red shift between comoving observers ,due to the expansion of the universe .

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