4,115,000,000 The Moon does not just go around the Earth. In reality,

4,114,000,000 the two objects orbit about a common gravitational midpoint,

4,113,000,000 called a barycenter. Centrifugal force causes water on the

4,112,000,000 far side to bulge out (pushed away) and the moons gravity

4,111,000,000 attracts water on the other side, causing another bulge in

4,110,000,000 the earth's oceans. There are two high tides at the same time

4,109,000,000 on opposite sides of the earth. At this time, an earth day and

4,108,000,000 night is 6 hours. Massive tides occur every 3 hours.

4,107,000,000 The earth is still being bombarded by asteroids and comets. Some

4,106,000,000 of the earth's surface was melted at the site of large impacts.

4,105,000,000 Most of the earth's water's remained cool enough to sustain

4,104,000,000 the microbes that arrived from space. Comets continue to bring

4,103,000,000 water to the earth and sulfur bacteria continue to make water.

3,826,000,000 Archaea are the dominate life form on earth, They

3,825,000,000 absorb green light for energy and reflect red and blue.

3,824,000,000 The ocean has a purple hue.

3,823,000,000 In the sea cyanobacteria are found floating on a layer beneath

3,822,000,000 the archaea. Cyanobacteria receive little green light and must

3,821,000,000 adapt to the red and blue light they receive for energy.

3,003,000,000 Small micro pieces of land sticking out above the water

3,002,000,000 came together to form a very small continent called Ur.

3,001,000,000 Small pieces of this continent can be found in current

3,000,000,000 day Africa, India, Australia and Antarctica.

2,718,000,000 The amount of dissolved nickel in the sea is declining. Nickel is a

2,717,000,000 key ingredient in an enzyme archaea need to make methane. Methane

2,716,000,000 production by archaea is declining.

510,000,000 A soft-bodied slug-like animal left trails as it slimmed along on land for

509,000,000 short periods moving from pond to pond.

422,000,000 First fish with jaws.

13,000,000 * impact

7,000,000 -Pleistocene-

6,000,000 A large asteroid explodes 3.6 mya giving rise to many of today's

5,000,000 small earth-crossing asteroids.

4,000,000 Humans and chimps diverged (Ardipithecus)

3,000,000 Lucy: bipedal, small brain, long arms, short legs.

2,000,000 Early man (stone tools)

1,000,000 * impact

0 All of human's written history has occurred

in the most recent 10,000 years, or 1% of

the time in this last million year increment.