Chapter 10.1

What did Hubble notice when he was observing the light from the galaxies?

Edwin Hubble noticed that the light of the galaxies he was studying showed spectral lines that were distinctly shifted toward the red end.

What is Electromagnetic Radiation?

Energy that is carried, or radiated, in the form of waves.

What colour has the longest wave lengths?

Red

What are Spectral lines?

Standing out across the bands of colour in a star's spectrum

What does a "red-shifting" indicate?

It shows when something is moving away from Earth and its wavelengths are getting longer

Briefly describe the 7 types of electromagnetic radiation

- Radio Waves - Microwaves - Infrared Radiation - Visible Light - Ultraviolet Radiation - X-Rays - Gamma Rays

What is the use of a spectroscope?

Allows the user to view the spectral lines produced by a light source and to measure their wavelengths.

Who is Edwin Hubble? What was he the first to identify and what did he discover about galaxies?

An American astronomer that was the first to identify other galaxies besides from the Milky Way Galaxy. He was also so famous the Hubble Space Telescope was named after him.

What is a Spectroscope?

An optical instrument that acts like a prism to separate light into its basic component colours.

What idea did astronomers put forward as a result of red-shifting?

Because of the red shifting the scientists purposed that the universe was expanding

What do spectral lines tell us about a star?

It shows us what elements a star has.

Who is Edwin Hubble? What did Edwin Hubble be the first to identify and what did he discover about galaxies?

The first astronomer to identify other galaxies besides from the Milky Way Galaxy. By the year 1929, he had estimated the distance from Earth to 46 galaxies. He released that all of the galaxies that he was studying seemed to be movie rather than staying still, they were moving away from each other.

What did Hubble notice about the speed at which galaxies move apart related to their distance from each other?

The speed that they were moving apart varied depending on the galaxies.

What was Hubble's Proposal? Compare his observations to baking a loaf of raisin bread.

The universe was expanding. This was done in raisin bread. When the raisin bread isn't cooked it shows that the universe and the bread are smaller but when the bread becomes cooked the bread/universe expands and the planets become further apart.

What colour has the shortest wave lengths?

Violet

Describe how a red shift occurs?

When something is moving away from Earth

What is a red shift?

a shifting of light from an object toward the red (longer wavelength) end of the spectrum as the object moves away from Earth