How does red shift provide evidence of an expanding universe?(5 points)

Redshift provides evidence of an expanding universe through the following points:

1. **Doppler Effect**: Redshift is a result of the Doppler effect, where the wavelengths of light from an object moving away from an observer are stretched, making them appear more red. This phenomenon suggests that galaxies are moving away from us.

2. **Hubble's Law**: Edwin Hubble discovered that the farther away a galaxy is, the faster it appears to be moving away. This relationship, expressed in Hubble's Law, indicates a linear correlation between distance and redshift, reinforcing the idea that the universe is expanding uniformly.

3. **Cosmological Redshift**: Unlike standard Doppler redshift caused by motion through space, cosmological redshift occurs due to the expansion of space itself. As the universe expands, the fabric of space stretches, lengthening the wavelengths of light traveling through it, which provides direct evidence of an expanding cosmos.

4. **Observation of Distant Galaxies**: Observations of distant galaxies reveal a consistent pattern of redshift, aligning with the predictions of an expanding universe model. This universal redshift supports the idea that the universe has been expanding since the Big Bang.

5. **Cosmic Microwave Background Radiation**: The redshift of light from distant galaxies complements the evidence provided by the cosmic microwave background radiation, which is a remnant of the early universe. Its uniformity and redshift confirm that the universe has expanded and cooled over time, consistent with cosmic expansion theories.

Together, these points form a robust framework for understanding the implications of redshift in the context of an expanding universe.