How can hubbles equation explain that the Universe is expanding?

During the 1920’s and 30’s, Edwin Hubble discovered that the Universe is expanding, with galaxies moving away from each other at a velocity given by an expression known as Hubble’s Law: v = H*r. So essentially, the Hubble constant sets the rate at which the Universe is expanding.

What does Hubble’s Law say about the relationship between the distance to galaxies and how fast they are moving away from us?

Hubble’s law, also known as the Hubble–Lemaître law, is the observation in physical cosmology that galaxies are moving away from Earth at speeds proportional to their distance. In other words, the farther they are the faster they are moving away from Earth.

Does the fact that we see all galaxies receding from us imply that our galaxy is in the center of the universe explain?

The fact that we see other galaxies moving away from us does not imply that we are the center of the universe! All galaxies will see other galaxies moving away from them in an expanding universe unless the other galaxies are part of the same gravitationally bound group or cluster of galaxies.

How did Slipher determine that many galaxies were moving away from Earth?

Yet if the light source is moving away, the lines are shifted into the red part of the spectrum. Analyzing the light from the nebulae, Slipher found that nearly all of them appeared to be moving away from Earth. Slipher knew that a shift toward red suggested the body was moving rapidly away from the observer.

What is Hubble’s law how is it used by astronomers to measure distances to galaxies?

Distant galaxies are observed to be receding from the Milky Way at rates that increase proportional to their distances from us. This relationship between recessional speed and distance is called Hubble’s law. The constant of proportionality in the law is Hubble’s constant.

What is the lookback time of the most distant galaxies we can observe?

billion light years
This phenomenon is called the lookback time. So, if you want to find a galaxy 5 billion years younger than the Milky Way, you should search for galaxies 5 billion light years away.

Is the Hubble expansion rate of the universe a constant?

If it’s not a line — i.e., if the slope changes — that tells us that the Hubble expansion rate of the Universe isn’t truly a constant after all! The reason we call it the Hubble constant is because the Universe expands at the same rate at every location in the Universe: the Hubble constant is constant throughout space.

Why do galaxies recede away from US?

Hubble showed that galaxies are receding away from us with a velocity that is proportional to their distance from us: more distant galaxies recede faster than nearby galaxies.

Does the radius of the Hubble sphere change over time?

Since the Hubble “constant” is a constant only in space, not in time, the radius of the Hubble sphere may increase or decrease over various time intervals. The subscript ‘0’ indicates the value of the Hubble constant today.

How did Hubble infer the recession velocity of the objects?

Hubble inferred the recession velocity of the objects from their redshifts, many of which were earlier measured and related to velocity by Vesto Slipher in 1917.