What force, if any, is required to keep the earth moving forward through space?

Question

but if the earth is moving at a constant speed, does that mean that there's any force involved?

Answer 1

Actually, no force is necessary to keep the earth moving in the vacuum of space.
Newton's laws on motion cover it pretty well.
"An object placed in motion, stays in motion until another force
changes it's motion". (I'm paraphrasing here but I'm sure you get the idea)

If you could float in space and throw a rock, it would just keep going in that direction until it finally hits something. As it goes by larger objects, the gravity from these objects may change the direction of the rock slightly but it would take a very large object (think planet or moon) to really change the direction of the rock dramatically.

Gravity is the force that simply keeps the earth in it's relative distance from the sun, counteracting the centrifugal force from our revolving around the sun, thereby keeping us from flying off in a tangent, never to be seen again. ;-)

I hope this helps you.
Good Luck!

Answer 2

The electromagnetic force. We are constantly being tugged around by these electric currents, which in turn generate our magnetic field. We can't detect them because they are so big and the difference in charge per square foot is too small for us to detect, and what we experience as "neutral" is actually whatever the strength of the current allows us at the time.

But the strength changes, and what we get are tornadoes and lightning and hurricanes. This is probably what our ancient ancestors were witnessing when they described the Gods hurling lightning bolts, so much so that the sky looked like it was fileld with arrows. They witnessed something that if we were them, there'd be no more claims that space is electrically neutral.

This is really why the galaxies don't fly apart, and why some stars can orbit around each other in a matter of hours. Read through some of my questions, or some of my best answers. Saying the same stuff over and over gets tiring, but if you go through I guarantee you you'll see what I'm talking about.

Everyone in the scientific community these days are too scared to step out of line and question the dogma established by the wise men of past, like Einstein. But these old guys didn't have all the awesome equipment we do these days, and they could never see the sunspot filaments so clearly, and they could never know that there would be so many magnetic fields everywhere in space.

Answer 3

First, the Earth is moving through space in many different ways: (1) Earth revolves around the Sun, (2) The Earth and the entire Solar System revolves around the center of the Milky Way, our galaxy, (3) The Earth and the entire Milky Way galaxy is revolving around the gravitation center of the Local Group (a collection of galaxies of which the Milky Way belong), (4) the Milky Way and the Local Group is moving away from all other galaxies or groups of galaxies in the Universe (this is due to the Big Bang).

So what force is required to keep Earth moving forward? Mostly it is gravity that keeps Earth revolving around the Sun, the Sun around the galactic center of Milky Way, and the Milky Way around the Local Group. The only motion not due to gravity is the expansion of the Universe, which is due to space expanding/growing between all galaxies.

You mentioned that the Earth is moving at a constant speed. I would say that the Earth is revolving around the Sun at a constant rotational speed. That is because the Earth is in freefall around the Sun (see http://en.wikipedia.org/wiki/Freefall).

Answer 4

Physics dude got this one exactly right.

But let me add something to answer your question about "if the earth is moving at constant speed, is there no force involved."

The gravitational pull of the sun is a net force on the earth. It causes the earth to accelerate - but not change speeds. How is this possible?

Velocity has both magnitude (speed) and direction. When there is a net acceleration, the velocity changes but not necessarily the speed.

Because the sun's gravitational force is always at right angles to the eath's motion, no work is done by the force and the speed does not change. Only the direction changes.

So the earth's velocity is changing constantly with reference to the sun - but in direction only, not speed.

By the way, the speed of the earth does change slightly in its orbit because the orbit is not a perfect circle but an ellipse - the earth's speed is slightly faster when it is closest to the sun and slightly slower when it is further.

Answer 5

No force is required to keep the earth moving forward through space. Newton’s First Law of Motion states: Every object continues in its state of rest, or of uniform motion in a straight line, unless it is compelled to change that state by forces impressed upon it. An object continues to do whatever it happens to be doing unless a force is exerted upon it. Since the Earth is already moving, it will keep moving at the same speed as long as there is no other force on it. Aristotle did not recognize the idea of inertia because he did not see that all moving things follow the same rules. Newton, on the other hand, saw that all moving things follow the same rules. He believed that moving things require no force to keep moving if there are no opposing forces, such as friction.

BTW, are you in Mr. Barish's Physics 108 class from Ohlone College?

Answer 6

hi.

frankly talking no one have a clear idea how the earth got initial movement. it was believed the universe came to exist from an big explosion. during this explosion many small and big planets came to exist.

it was said that earth keep moving since this explosion. and keeping the same velocity since then. This is because in space its vacuum so no friction to bring the earth to stop.

and Newton could explain How earth could keep its constant orbit around the sun. This is because of centripetal and centrifugal force acting opposite each other , could keep earth in fixed orbit. but this is not in the case of planet mercury, it keep shifting its orbit in its each revolution.

i can easily make u understand via an example. If u saw how athletes performing hammer throws. the athlete will revolve the hammer around him to achieve acceleration. A string will be pulling the hammer towards the athlete and hammer will oppose and try to go away from the athlete. and when the athlete release the string the hammer will fly away , here the hold of athlete is sun (center of gravity) and hammer is earth opposing the gravity. these forces keep earth in a steady orbit.

and if u ask why earths orbit is not pure circle, its because any thing in the space will move in the path having lowest resistance(Explained by Albert Einstein)

hope u got it
regards
edu

Answer 7

Since the Earth is already moving, it will keep moving at the same speed as long as there is no other force on it. This is described in one of Newton's laws. As you're likely to know, the sun is pulling on it due to gravity, but this mostly just turns the Earth, since it already has enough speed.

When you throw a ball, it will keep moving forward in a similar way, but air will slow it down. To get the ball to seem not to fall like the Earth seems to not into the sun, you'd have to throw it very, very, very hard so that it goes around the word over and over.

Answer 8

There is a vacuum in space and no friction so newtons first law of motion comes into play here it is --
I. Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it. So what this means is it would take a severe collision or action from an outside force to stop the movement we are already in.

Answer 9

Gravity, baby! Gravity pulls the earth towards the sun, our momentum pushes the earth in a straight line tangent to our orbit. The net result is our nice, neat, elliptical orbit.

Answer 10

centripetal force of the sun ....it is the centre seeking force that provides a tangential acceleration that keeps earth moving forward...ie revolution...actually when centripetal force of the sun equals gravitational pull of earth that keeps everything in a balance.....satisfied...?