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.
Without gravity, galaxies would not be able to maintain their structure, as gravity is the fundamental force that holds stars, gas, and dark matter together. Stars would drift apart, leading to the disintegration of galaxies into isolated stars and cosmic debris. Over time, these individual stars would move freely through space, resulting in a universe where galaxies cease to exist as cohesive entities. Ultimately, the organized formations we observe would dissolve into a vast, chaotic expanse of matter.
The possessive form for the plural noun galaxies is galaxies'.Example: Their galaxies' paths do not coordinate.
The expansion of the Universe results in the light from faraway galaxies being redshifted. This is called the "cosmological redshift"; it can be compared with the Doppler effect (which also causes a redshift), but the details are somewhat difference.It is an observed fact that most galaxies are redshifted; the explanation that seems most reasonable is that it is caused by the cosmological redshift. This means that space itself is expanding.
A possible explanation is called a hypothesis.
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.
no.
"To one who has faith, no explanation is necessary. To one without faith, no explanation is possible." ― St. Thomas Aquinas
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.
Around 42 named galaxies, with 13 possible additions. See related question.
The light from distant galaxies is redshifted. The only reasonable explanation for that is that the galaxies are moving away from us.
A hypothesis.
Hypothesis
conclusion
A hypothesis.
A hypothesis