Surely if the Sun's gravity is pulling everything in then we shouldn't be remaining a largely unfirm distance away?
2007-04-26 01:09:13 · 10 answers · asked by Nelson 1 in Science & Mathematics ➔ Astronomy & Space
Two words. Angular momentum. Basically, it is the high orbital speed that keeps the planets from falling all the way into the Sun. And since there is no friction in the vacuum of space, that speed doesn't slow down like it would if there were air friction.
By the way, Earth does NOT remain at a uniform distance away; it is in an elliptical orbit. All the planets are. Earth is closer to the Sun every January and farther from the Sun every July, and this repeats every year.
2007-04-26 02:12:12 · answer #1 · answered by campbelp2002 7 · 1⤊ 0⤋
Everything is falling into the sun. Anything that was 'stationary' in the solar system has long since fallen in leaving only stuff that had a sideways motion. The maths is hairy and it is not even easy to visualise but basically the Earth is moving at 25 Km/s sideways and the sun is pulling the Earth in but at the same rate that the Earth moving in a straight line would move out.
Newton would not be happy with that explanation but it will have to do.
2007-04-27 14:56:16 · answer #2 · answered by m.paley 3 · 0⤊ 0⤋
The matter that forms planets was created on the death of a previous star. The matter was already in motion in space (see above answers for reference to Newton's First Law) before falling under the gravitational attraction of the Sun. The straight trajectory of the matter was curved by the gravity of the Sun and the matter slowly changed direction until the it was near enough that the gravitational strength of the Sun matched the momentum of the matter (gravitational strength is dependent on distance as well as mass of star). The matter now is in a regular orbit and at this point equilibrium is achieved and the centripedal force (the Sun's gravity) and the centrifugal force (original momentum of matter) balance. Neither force will win as the Sun cannot increase in gravitational strength and the planets cannot move faster than their original momentum.
2007-04-26 09:59:37 · answer #3 · answered by Andrew H 2 · 0⤊ 0⤋
The system is being pulled or "sucked" toward the sun, but the problem is we keep missing, aka we are in orbit around the sun. This happens because even though we are accelerating towards the sun, our velocity is still perpendicular to it, and this allows us to travel in a circle around it. Check out wikipedia for a better explenation of orbits and uniform circular motion.
Edit: Centrifugal force is not a real force (at least in this case), the only force acting on the planets around the sun is gravity, this is called a ceptripetal force, or the force that keeps an object moving in uniform circluar motion.
2007-04-26 08:16:47 · answer #4 · answered by eviljebus 3 · 2⤊ 0⤋
Planetary motion is intrinsically straight line in accordance with Newton's 1st Law
"a body in motion will follow a straight line unless acted upon by an external force."
The sun's gravity provides the external force that changes this straight line Newtonian motion to curvilinear orbital motion.
The earth's orbital speed is about 66,600 miles an hour and that speed determines the equilibrium distance that the earth is from the sun. If the earth slowed down it would move closer to the sun.
If it speeded up it would move out further from the sun
So we are at equilibrium at a radius of 93,000,000 miles.
But here's the interesting part : Earth's orbital circle is (2 x 93,000,000) = 186,000,000 miles. The speed of light is 186,000 miles per second, so the orbital circle is 1000 times the speed of light.
james
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2007-04-26 08:31:38 · answer #5 · answered by james 3 · 1⤊ 0⤋
If we were not already moving in orbit that would be the case. The speed of orbit conveniently exactly counteracts the pull of the sun.
2007-04-26 08:15:16 · answer #6 · answered by Anonymous · 0⤊ 0⤋
this is due to the same amount of velocity of the planets and other things ,occurring with the same amount of gravity pull, that causes the balance and keeps the solar system on track. one thing wrong in the balance and it will go all hay wile. :D
2007-04-26 14:11:13 · answer #7 · answered by b££ 2 · 0⤊ 0⤋
Of course it is but that is counteracted by the fact that the planets are in orbit. The so called "centrifugal" force of orbiting counteracts the gravity.
2007-04-26 08:13:09 · answer #8 · answered by Gene 7 · 2⤊ 0⤋
I thnk sun is in the solar system......then how come solar system will be sucked in by sun........
2007-04-26 08:22:38 · answer #9 · answered by Anonymous · 1⤊ 1⤋
What is this sun you speak of?
2007-04-26 08:12:43 · answer #10 · answered by Anonymous · 0⤊ 3⤋