How does red-shift support the Big Bang Theory?

Red-shift supports the Big Bang Theory by showing that galaxies are moving away from us, indicating an expanding universe.

When we observe light from distant galaxies, we notice that the light is shifted towards the red end of the spectrum. This phenomenon is known as red-shift. According to the Doppler effect, when an object emitting light moves away from an observer, the light waves are stretched, making them appear redder. This red-shift suggests that these galaxies are receding from us.

The discovery of red-shift in the light from distant galaxies was first made by Edwin Hubble in the 1920s. Hubble observed that almost all galaxies exhibit red-shift, and he found a direct relationship between the distance of a galaxy and the extent of its red-shift. This relationship, known as Hubble's Law, implies that the farther away a galaxy is, the faster it is moving away from us.

This observation is crucial for the Big Bang Theory, which posits that the universe began as a singular, extremely hot and dense point approximately 13.8 billion years ago and has been expanding ever since. The red-shift of galaxies provides strong evidence for this expansion. If the universe is expanding, it means that in the past, galaxies were closer together, supporting the idea of a singular origin point.

Additionally, red-shift helps us understand the rate of expansion of the universe. By measuring the red-shift of various galaxies, scientists can estimate how fast the universe is expanding. This information is vital for constructing models of the universe's history and predicting its future.

In summary, red-shift is a key piece of evidence for the Big Bang Theory, demonstrating that the universe is expanding and supporting the idea of a singular beginning.