Question

1 multiple choice 2 points base your answers to the questions on the diagram below and on your knowledge of earth science. the diagram represents the expansion of a portion of the universe from its origin until the present. the timeline represents billions of years. letter x indicates two celestial objects. two pieces of evidence that support the theory that the universe is expanding are the red shift of light from distant stars and the existence of nuclear fusion red shift of light from distant stars and the existence of cosmic background radiation blue shift of light from distant stars and the existence of nuclear fusion blue shift of light from distant stars and the existence of cosmic background

Explanation:

• Red - shift of light: When an object is moving away from an observer, the light waves it emits get stretched, causing a shift towards the red end of the spectrum. This is observed for distant stars, indicating they are moving away from us, which supports the idea of an expanding universe.
• Cosmic background radiation: It is considered the "after - glow" of the Big Bang. The even distribution of this radiation across the universe is consistent with the model of an expanding universe that originated from a hot, dense state.
• Nuclear fusion: It is a process that occurs in stars to produce energy. While important for stellar evolution, it does not directly provide evidence for the expansion of the universe.
• Blue - shift: Occurs when an object is moving towards an observer (light waves are compressed). Since we observe a red - shift for most distant objects (indicating they are moving away), blue - shift is not evidence for an expanding universe.

Answer:

red shift of light from distant stars and the existence of cosmic background radiation