Hubble’s Law Calculator

Hubble’s Law Calculator:

Enter the values of Hubble constant, H_{0​(km/s/Mpc)} and distance, d_(Mpc) to determine the value of Velocity, v_(km/s).

Enter Hubble Constant:		km/s/Mpc
Enter Distance of the Galaxy from Earth:		Mpc
Result – Velocity:		km/s

Hubble’s Law Formula:

Hubble’s Law is a fundamental principle in cosmology that describes the expansion of the universe. It states that the velocity at which a galaxy moves away from an observer is directly proportional to its distance from the observer. This law was formulated by Edwin Hubble in 1929 based on observations of distant galaxies.

It provides strong evidence for the Big Bang theory, which suggests that the universe originated from a singular point and has been expanding ever since. The proportionality constant in Hubble’s Law is called the Hubble constant (H₀), which represents the rate of expansion of the universe.

The velocity of a receding galaxy increases with its distance from Earth, indicating that galaxies farther away are moving faster. This relationship helps astronomers determine the age and scale of the universe. Hubble’s Law is crucial for estimating distances to faraway galaxies, making it an essential tool in astrophysics.

The law implies that the universe is not static but continuously expanding, influencing models of cosmic evolution. The expansion rate of the universe changes over time due to dark energy and gravitational interactions.

Measuring Hubble’s constant accurately remains a significant challenge, with different methods yielding slightly different values. Observations from telescopes such as Hubble Space Telescope and Planck Satellite refine our understanding of cosmic expansion. The law has been instrumental in the discovery of dark energy, which is believed to accelerate the universe’s expansion. Hubble’s Law is mathematically represented as a simple linear equation involving velocity, distance, and the Hubble constant.

Velocity, v_(km/s) in kilometres per second of a galaxy moving away from Earth equals the Hubble constant, H_{0​(km/s/Mpc)} in kilometres per second per megaparsec multiplied by the distance, d_(Mpc) in mega parsec between the galaxy and Earth.

Velocity, v_(km/s) = H_{0​(km/s/Mpc)} * d_(Mpc)

v_(km/s) = velocity in kilometres per second, km/s.

H_{0​(km/s/Mpc)} = Hubble constant in kilometres per second per megaparsec, km/s/Mpc.

d_(Mpc) = distance of the galaxy from Earth in megaparsecs, Mpc.

Hubble’s Law Calculation:

1. A galaxy is observed at a distance of 500 Mpc from Earth. If the Hubble constant is 70 km/s/Mpc, find the velocity at which the galaxy is receding.

Given: H_{0​(km/s/Mpc)} = 70 km/s/Mpc, d_(Mpc) = 500Mpc.

Velocity, v_(km/s) = H_{0​(km/s/Mpc)} * d_(Mpc)

v_(km/s) = 70 * 500

v_(km/s) = 35000km/s.

2. A galaxy is moving away from Earth at a velocity of 14,000 km/s. If the Hubble constant is 67 km/s/Mpc, calculate the distance of the galaxy.

Given: H_{0​(km/s/Mpc)} = 67 km/s/Mpc, v_(km/s) = 14000km/s.

Velocity, v_(km/s) = H_{0​(km/s/Mpc)} * d_(Mpc)

d_(Mpc) = v_{(km/s) /} H_{0​(km/s/Mpc)}

d_(Mpc) = 14000 / 67

d_(Mpc) = 208.96Mpc.