The Big Bang Theory
It means that the light from galaxies is losing energy. The only reasonable explanation for this is the cosmoligical redshift - that is, that the Universe is expanding.
The most plausible explanation for the redshift is that galaxies are moving away from us. This is similar to the Doppler effect, but it is normally believed that space itself is expanding, so the situation is a bit different from the "normal" Doppler effect.
The possessive form for the plural noun galaxies is galaxies'.Example: Their galaxies' paths do not coordinate.
Galaxies are classified based on their shape and structure. The main types of galaxies are spiral, elliptical, and irregular. Spiral galaxies have distinct arms of stars, elliptical galaxies are more oval-shaped with older stars, and irregular galaxies have a less defined shape.
There are three main types of galaxies: spiral galaxies (like the Milky Way), elliptical galaxies (oval or spherical in shape), and irregular galaxies (lacking a distinct shape). These classifications are based on the galaxies' shapes and structures.
A possible explanation is called a hypothesis.
no.
It means that the light from galaxies is losing energy. The only reasonable explanation for this is the cosmoligical redshift - that is, that the Universe is expanding.
"To one who has faith, no explanation is necessary. To one without faith, no explanation is possible." ― St. Thomas Aquinas
Around 42 named galaxies, with 13 possible additions. See related question.
There are galaxies that orbit our galaxy that are believed to be filled with a lot of dark matter. Segue 1 is one of about two dozen dwarf galaxies around ours that have light outputs equal to only a few hundred times that of our sun. There are probably untold numbers of other such galaxies around the more visible galaxies. This is a possible explanation for the discrepancy in the predicted mass of the universe and the observed mass. Some theories postulate that 90% of the mass of the universe is composed of this unobservable "dark matter". The existence of these dim dwarf galaxies help explain the discrepancy.
A hypothesis.
Hypothesis
conclusion
A hypothesis.
A hypothesis
The light from distant galaxies is redshifted. The only reasonable explanation for that is that the galaxies are moving away from us.