How can they know the distance of the most distant galaxies and then say the Red Shift is lower? They use the Red Shift to determine that distance. Redshifts are determined by estimating the distances to objects via other distance measuring techniques. Then a distance is associated with that particular redshift.
From the article: "Hubble and Gaia performed their measurements by examining Cepheid variables, a type of star that brightens and dims in a predictable pattern. The pattern allows scientists to learn how far away these stars are from us. The data is then used to measure the universe's expansion rate, which is also called the Hubble constant. That constant is also used to estimate the age of the universe, which makes it a fundamental equation for astronomers."
“In physics, redshift happens when light or other electromagnetic radiation from an object is increased in wavelength, or shifted to the red end of the spectrum.
In general, whether or not the radiation is within the visible spectrum, “redder” means an increase in wavelength – equivalent to a lower frequency and a lower photon energy, in accordance with, respectively, the wave and quantum theories of light.
Some redshifts are an example of the Doppler effect, familiar in the change of apparent pitches of sirens and frequency of the sound waves emitted by speeding vehicles. A redshift occurs whenever a light source moves away from an observer.
A special instance of this is the cosmological redshift, which is due to the expansion of the universe, and sufficiently distant light sources (generally more than a few million light years away) show redshift corresponding to the rate of increase in their distance from Earth.
Finally, gravitational redshift is a relativistic effect observed in electromagnetic radiation moving out of gravitational fields.
Conversely, a decrease in wavelength is called blueshift and is generally seen when a light-emitting object moves toward an observer or when electromagnetic radiation moves into a gravitational field.
However, redshift is a more common term and sometimes blueshift is referred to as negative redshift.
Knowledge of redshifts and blueshifts has been applied to develop several terrestrial technologies such as Doppler radar and radar guns.[1]
Redshifts are also seen in the spectroscopic observations of astronomical objects.[2] Its value is represented by the letter z.
A special relativistic redshift formula (and its classical approximation) can be used to calculate the redshift of a nearby object when spacetime is flat.
However, in many contexts, such as black holes and Big Bang cosmology, redshifts must be calculated using general relativity.[3]
Special relativistic, gravitational, and cosmological redshifts can be understood under the umbrella of frame transformation laws.
There exist other physical processes that can lead to a shift in the frequency of electromagnetic radiation, including scattering and optical effects; however, the resulting changes are distinguishable from true redshift and are not generally referred to as such (see section on physical optics and radiative transfer).”
https://en.wikipedia.org/wiki/Redshift
From the article: "Hubble and Gaia performed their measurements by examining Cepheid variables, a type of star that brightens and dims in a predictable pattern. The pattern allows scientists to learn how far away these stars are from us. The data is then used to measure the universe's expansion rate, which is also called the Hubble constant. That constant is also used to estimate the age of the universe, which makes it a fundamental equation for astronomers." I suspect that is a bit misleading. I don't think they are measuring Cepheid variables at 14,000,000,000 light years.
Well, I guess they don't need to. If they can measure them at 10,000,000 light years and see the redshift variation nearby and then extrapolate.
It is a lot like we are not at the center of the Big Bang which I don't believe in.
Redshift refers to the displacement of a set of spectral lines which identify a particular chemical compound.
The chemical "ID" is like a bar code for merchandise at the store, only, that with chemicals, each line represents a particular chemical element with a known frequency and wavelength, such that, if the elements appear at a different frequency/wavelength, they know that the object is either moving away from us or towards us. If the sequence is shifted to a lower frequency/longer wavelength, then the host object is assumed to be moving away. ie, redshifted. Vice-versa for objects with lines shifted to higher frequencies/shorter wavelengths. ie, blueshifted
