In physics, what is the Hubble Constant?

The unit of measurement that describes expansion of universe

The correct answer is option 3. The unit of measurement that describes expansion of universe.

In physics, the Hubble Constant is the unit of measurement that describes expansion of the universe.

The Hubble Constant is a fundamental parameter in cosmology that describes the rate at which the universe is expanding. It quantifies the relationship between the distance to a distant object in the universe and the velocity at which it is moving away from an observer due to the expansion of space. Mathematically, the Hubble Constant is expressed as \(H_0\), and its value is typically given in units of kilometers per second per megaparsec (km/s/Mpc), where a megaparsec is a unit of distance equal to about 3.26 million light-years. The Hubble Constant plays a crucial role in understanding the age, size, and future evolution of the universe. It was first calculated by the astronomer Edwin Hubble in the early 20th century based on his observations of distant galaxies and their redshifts, providing key evidence for the expanding universe model.