Transcript gravity

GRAVITY
WHY THINGS FALL
aristotle - (384-322 B.C.)
Believed that heavier objects
fall faster than lighter ones.
GALILEO - (1564-1642)
Believed that ALL objects fall at
the same rate. (in the absence of
air resistance)
This is called FREE FALL
Galileo used INCLINED PLANES
to show this.
US ASTRONAUT - DAVID SCOTT
Apollo 15 Lunar Mission
- August 1971-
isaac newton - (1642-1727)
Watched apples falling from trees and noticed
they ALWAYS fell toward center of Earth - never
sideways.
Reasoned if gravity acts on the tops of trees
and the tops of mountains, maybe it went all the
way to the MOON!
Every particle is attracted to every other
particle.
This force (GRAVITY) is based on MASS and
DISTANCE.
GRAVITATIONAL LAW
1 m2
m
F = G r2
The larger the mass of the two objects, the greater the
gravitational force.
The greater the distance between the two objects, the lower the
gravitational force.
If you double the mass, you double the force.
If you double the distance, you reduce the force by four times.
Which has greater gravity?
A
B
Which has greater gravity?
C.
D.
albert einstein - (1879-1955)
Gravity is a distortion of SPACE & TIME,
caused by the local presence of MASS &
ENERGY.
Space is CURVED by gravity.
The more mass, the greater the curvature.
With enough mass (star), the curve would
become so great NOTHING COULD
ESCAPE - NOT EVEN LIGHT.
Gravity Bends Light
BLACK HOLES
http://www.youtube.com/watch?v=AzecHW-DTqY