Gravity

Isaac Newton was the first to account for gravity.

An attracting force.

Gravity = mass/distance

So,

1. Massive objects have more gravity

2. Gravity lessens with distance.

Gravity

General Relativity

Albert Einstein revised Newtonian gravity.

Mass “warps” space… gravity is not instantaneous. It moves at the speed of light.

For small masses, Newton’s gravity still works.

Space-Time Warping

Doppler Effect

Objects moving away from you stretch wavelengths

Red Shift

Objects moving toward you compress wavelengths.

Blue Shift

Everything’s MovingIn space, everything is moving.

1. The universe is expanding… like raisin bread.

2. Galaxies are all red-shifted.

3. The farther away, the faster they move.

Big Bang Theory

All energy was concentrated in a small area, then released in an instant.

Mostly hydrogen and helium.

As the universe cooled, it became lumpy and formed stars and galaxies.

Big Bang Theory

Evidence for Big Bang?

1. Background radiation – radio/microwave2. Doppler Effect = red shift.

Map of Universe:Background Microwave Radiation