Earth and Space Scienes: The Origins of the Universe

The Big Bang Theory

The theory that the universe began with and big bang:

-expanded within fractions of a second

-basic and simple molecules formed minutes after, ex.: hydrogen, helium

Evidence: background radiation left over

How do you tell the make-up of a star?

by comparing and adding emission or absorption lines to each other

Continuous Spectrum

A continuous flow of light, looks like a rainbow

Electromagnetic radiation

EMR are waves that travel at the speed of light

Emission Spectrum

A pattern of lines that is caused by frequencies of electromagnetic radiation emitted due to electrons transitioning from a high energy state, to a low one.

Absorption Spectrum

A pattern showing the specific wavelengths of electromagnetic radiation absorbed by a substance as light passes through it.

S Waves

Aka: secondary waves

S waves move in a side-to-side motion, sound and light waves are S waves, that’s why they have wavelengths

Compression Waves

Waves that are made by compression (think of the slinky experiment)

How does sound relate to waves?

There are sound waves, which are S waves, meaning they are measured by frequency and wavelength. Such as a higher frequency is a higher pitch, and a low frequency is a lower pitch.

Doppler Effect/Shift

An observed change or shift in frequency or wavelength due to motion

Law of Conservation of Matter and Energy

The law of conservation of matter and energy states that within a closed system, matter and energy can change form, but the total amount of matter and energy is constant.

What happens to star’s wavelengths when the universe continues to expand?

They stretch, getting longer

What did temperature and density look like throughout the timeline of the universe?

The early universe was dense and hot, but after the Big Bang, the universe keeps expanding and cooling down

How long along was the Big Bang?

About 13.8 billion years, 14 if you round