Hubble's 'cosmic redshift' of the cosmic signals raises question of a resulting redshift.

There are three known types of redshifts, - Doppler redshift, gravitational redshift and cosmological redshift.

The corresponding formulas for this redshift are

• Z = {λ(obs)-λ(rest)}/λ(rest);

• Z = Δλ/λ₀ and also

• Z = Δλ/λ₀,

Where, 

• Z denotes the redshift factor which represents the fractional change in wavelength;

• λ(obs) represents the observed wavelength of light;

• λ(rest) represents the rest wavelength of light;

• Δλ is the change in wavelength of light as observed;

• (λ₀) is the wavelength at the source.

In a post, “Hubble's 'cosmic redshift' of the cosmic signals overrules Einstein's 'gravitational redshift', and the act raises question of a resulting redshift.

=> λ(h) + λ(e) => λ(r)? #redshift “

Viewer Questioned, “I respect these mathematical symbols, but it would be a whole lot better for the numerically uninitiated if they could be translated into words. Is there any chance of that?

Author Replied, “Yes sir, let me text you the scenario replacing the symbol... in the comment below.

The wavelength of a wave is presented as λ.

1. So wavelength of a wave can be enlarged naturally, mostly in three conditions known as redshift.

2. These conditions are -

(a) due to Doppler effect

(b) due to gravitational effect

(c) due to cosmic effect

I will describe them briefly below.

3. Explanation in gravitational effect:

When light leaves a gravitational well like the Sun, it spends its energy to leave the well, but since speed of light is constant, it cannot reduce its speed as it leaves the well (Sun) rather reduces its frequency, correspondingly increases its wavelength, and this is presented as λ, as such it gets red shifted in the electromagnetic spectrum, known as Einstein's redshift. Let's represent it with the symbol λ(e) - represent red-shifted wavelength as per Einstein model. - Lambda (λ) wavelength and (e) suffix ‘e’ representing Einstein (Einstein's redshift)

4. The light wave when passes a long distance through intergalactic space, - most of the space is not dominated by gravity but dark energy - as such space expands (such expansion is not possible within gravity dominated space like within galaxies.)

Such light passing intergalactic space subject to face unusual wavelength dilation due to stretching of the fabric of space (Einstein was unaware of this) and gets red-shifted wavelength known as red-shifting of light due to cosmic expansion - that Edwin Hubble discovered. So let us represent this new form of red-shifting of light's wavelength as λ(h), similar to the earlier symbolic but, by replacing Einstein's (e) as Hubble's (h) i.e. λ(h).

5. So a light signal, if emits from the Sun and passes long distance through intergalactic space, the same light signal will experience both kinds of red-shifting i.e. Einstein's gravitational red-shifting as well as Hubble's cosmic red-shifting, as a result the said red-shifting of the same light wave would subject to addition of two red-shifting said.

So this was my question symbolically presented as λ(h) + λ(e) => λ(r), as it questions addition of values of {λ(h) + λ(e)} - generally it is used as frequency modulation in the applications on Earth, and also considered as per it's energy level using Planck’s relationship E=hf. I have to confirm the actual application in this. So I’m wondering.

End.

Author, “ Hope the above throws light on the reasons of my question, Sir.”

Viewer Answers, "You are clever, well-informed, and gentlemanly: a winning combination. Thank you."