2. WHAT’S THE ATTRACTION?
 Gravity remains one of the greatest scientific
mysteries of all times

3. GRAVITY’S IDENTITY
 grav·i·ty (grv-t) n. 1. Physics a. The natural force of attraction
exerted by a celestial body, such as Earth, upon objects at or
near its surface, tending to draw them toward the center of the
body.
 b. The natural force of attraction between any two massive
bodies, which is directly proportional to the product of their
masses and inversely proportional to the square of the
distance between them.

4. GRAVITY’S BIRTH ON EARTH
In the beginning of the universe, after the Big Bang, gravity
pulled atoms together to make planets and stars. Gravity kept
these planets in an orbit around the stars, and their moons
orbiting around the planets. Gravity also keeps an atmosphere
around the planet.

5. MAN’S DISCOVERY OF GRAVITY
 Physicist/Mathematician Sir Issac Newton discovered there existed a
force required to change the speed or direction of a moving object.
 Newton defined this force stating: “Every particle of matter in the
universe attracts every other particle with a force that is directly
proportional to the product of the masses of the particles and
inversely proportional to the square of the distance between them.”

6. GRAVITY’S RELATIONSHIPS
 Gravity is affected by mass, distance, and placement.
 The more massive an object, the more gravity
 The closer objects are, the more gravity
 Gravity varies at different planetary locations

7. SCIENCE POPS THE QUESTION…
 Does the Earth’s magnetism cause gravity?

8. THE ANSWER…
 There is no evidence that gravity is caused by Earth’s magnetic field.
 Gravity and the Earth’s magnetic field are two separate and distinct forces.
 Gravity is a force that acts between two objects with mass.
 No matter what the masses are made of….gravity acts on them.
 Magnetism depends on specific properties of the mass.
 A magnet is an object that produces a magnetic field around itself. This field enables the objects to
attract or repel other types of metals made of ferromagnetic materials like iron and things that
contain iron, such as steel.
 This photo shows iron filings oriented around a bar magnet creating its electromagnetic field.

9. EARTH’S MAGNETISM REVEALED ?
 Theory of Earth’s magnetism:
 Some metals on Earth are magnetic and can only attract or
repel certain objects.
 The Earth’s inner core is made of molten iron.
 This metallic fluid has a charge.
 As the Earth rotates, the charged fluid rotates which creates
an electric current responsible for the magnetic field
surrounding Earth.

10. GRAVITY’S INTENSITY
Gravity’s got a hold on me.

 Newton discovered while under a tree;
 When apples fall to the ground;
 A certain force brings them down.
 Magnets attract and repel.
 Could Earth’s magnet cause gravity as well?
 Theories proven don’t show this to be.
 All I know is, we can’t live without gravity!

11. CREDITS:
 Physics 142
 Fall 2011
 Extra Credit