2007-07-20 22:30:31 · 5 answers · asked by nikmarpark 1 in Science & Mathematics ➔ Astronomy & Space
As mass collected to form the Earth it started obtaining a spin as the center of gravity was formed. As the ceter of gravity was forming its mass slung around giving the forming Earth its spin. As more mass gathered and heavier elements sank to the Earth's core the density of the heavier elements increased the Earth's angular velocity(spin velocity). The denser elements that formed the Earth's core increased gravity for the planet and pulled the mass around the core tighter to the core to give the Earth a smaller volume which, increased the angular velocity even more to have the Earth spin faster. So, the reason behind the Earth spinning is the gravity of its mass.
2007-07-20 22:57:47 · answer #1 · answered by Dan 3 · 1⤊ 0⤋
When our solar system recycled again, the third time now, with a lot more elements, all the material was pulled in from a vast region. It had probably been thrown out from the still somewhat small star into it's system which was probably all gas giants with a couple of ice giants or so. Given the nature and laws of the universe, gravity pulled this material together, starting slowly from one of the denser pockets of material. As all this stuff started to come together, jostling and drifting in, it gets pulled into a central region that starts to spiral and heat and gets denser. It will eventually become dense enough that the nuclear furnace of hydrogen begins to "burn as the conversion to helium lights the new star. It is rotating quickly and gets to a point where it becomes so hot and massive that the star which is our sun is born. The rest of the rotating materials form into the planets which are still rotating to this day. Below is a good basic link to an article that has a section about the formation of the system and the movement of it. Other articles on the planets talk further about it and there are other good links.
2007-07-21 05:55:52 · answer #2 · answered by mike453683 5 · 0⤊ 1⤋
The above answers are correct as far as they go. The earths tilt and final rotational period were probably determined during the event that formed the moon.
2007-07-21 14:13:23 · answer #3 · answered by Anonymous · 0⤊ 0⤋
Earth's spin came when it formed as matter was accreted through gravity. It is gradually slowing donw, although not noticably. It also got hit by a massive mars-sized object which formed the moon some time agon. THis is also why we have seasons.
2007-07-21 09:10:51 · answer #4 · answered by Bob B 7 · 0⤊ 0⤋
Bobby, that's who.... because that's how he rolls...
2007-07-21 09:04:25 · answer #5 · answered by Anonymous · 0⤊ 0⤋