Let’s explore some of the most common questions concerning red shifts and blue shifts, gravity, and black holes in relation to a contracting universe below. We will keep adding to the list, but feel free to leave comments with questions about red shifts and blue shifts or whatever you are curious about!

red shifts and blue shifts

1. What is a red shift?

Red shifts in the spectra of light means that the emitter of the light and the receiver of the light are moving farther apart. If they are moving apart, it will take the light longer to reach the receiver than if they were both still. This causes the crests of the light waves to reach the receiver at a lower frequency. Light waves at lower frequencies appear on the red side of the spectrum.

2. What is a blue shift?

Blue shifts occurs when the emitter and receiver are moving closer together. This causes the waves of light to reach the receiver at a faster/higher frequency than if they both were still. Higher frequencies appear on the blue side of the spectrum.

3. What is Newton’s Universal Law of Gravitation?

With a force directly proportional to the product of the masses and inversely proportional to the square of the distance between them, every particle attracts every other particle in the universe.

4. What is Dark Matter?

Dark Matter is “dark” because it is difficult to detect since it does not interact with the electromagnetic field (so no electromagnetic radiation to detect). It is still a hypothetical form of matter.

5. What is Dark Energy?

In short, unknown. Dark energy is a hypothetical form of energy to explain how the universe is expanding and suspected to make up most of the mass-energy content of the universe.

6. What is a black hole?

A black hole is a region of spacetime with gravity that is so strong that no light or particles can escape from it.