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
