what stops the world from lets say falling?

Question

its just floating in mid air its mind bogling stuff

whats with the other planets? god made it my **** excuse da french

gravity is on earth please think about your answer properly
what im saying is think about it just floating in space look at the sun y doesnt it move why dont all the planets and sun go up and down and all over the place

ok u all misss my point

Answer 1

Sandman is correct- there is no up or down in space.

kcpaul makes a sound arguement- In order to understand the answer to this question, one needs to have an elementary understanding of the force called gravity. Gravity is not a magnetic force as a previous answerer stated.

It was Isaac Newton who discovered that all objects with mass (even atoms) attract all other objects with mass. He formulated that this attraction was increased by the greater mass an object had. The attraction is greater when objects are closer and less when the objects are far away from each other. In fact, if they are twice as far away, their attraction will be 1/2. This force of attraction between the two objects is called gravity. It would seem that your previous concept of gravity was that it only occured on the Earth. This is not true. ALL objects everywhere in space, including our Sun, are affected by gravity from other objects.

When our Solar System coallesced from a spinning gas nebula, it formed a disc-like cloud. This is why our Solar System seems to be in a flat plane. Solar systems can form at many different angles so there really is no up or down in the galaxy or in the Universe.

Objects could maybe be called floating but remember there is only one force that can have an effect upon an object in space- another object. Gravity.

If the nebula that formed our Solar System was not spinning fast enough, all of the matter would have been attracted to the center of it. It would have just been one big ball. It would have formed one giant star (Sun) and would not have had any planets orbiting it.

If the nebula had spun much faster than it did, the dust and gas would have been ejected out into space and not formed a Sun or planets.

It was the proper spin of the nebula cloud that allowed the Sun to form in the middle of the cloud, and the rest of the dust and gasses to form into planets and asteroids and comets.

The Sun is an object. Therefore, it has a gravitational pull upon all other objects in the Solar System including the Earth. Why don't the objects 'fall' into the Sun? They have not stopped spinning around the Sun since the nebula formed them. Remember, there is no atmosphere in space. That means there is no friction to slow down the planets. Everything just keeps spinning like it did when they were first formed.

This is a simple explanation. Of course, there are complications involved with planetary revolutions such as stabilized orbital resonances and the like but this is a generalized answer to your question.

Here are some links to better understand the force of gravity:

http://www.astronomycafe.net/gravity/gravity.html

http://www.qrg.northwestern.edu/projects/vss/docs/space-environment/1-what-is-gravity.html

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We are missing your point? Restate your question.
Objects in space are only affected by the gravity of other objects in space. In order for the Sun or planets to go 'up' or 'down' or all over the place, they need to be pulled that way by the gravity from another object. If a planet was above the Earth, it would pull the Earth 'up' towards it. If a planet was below the Earth, it's gravity would pull the Earth 'down' towards it. The Sun is pulled slightly by the gravity of Jupiter and the Sun is pulled towards the center of the Milky Way. That is why the Sun revolves the Milky Way. In order for the Sun to go 'up' or 'down', a very large object would have to be 'above' or 'below' the Sun to make it move that way. An object in motion tends to stay in motion unless acted upon by an external source. Thus, objects in space will not just bounce up and down or any other direction unless acted upon by the gravity from another body in space.

What is it that you don't seem to understand?

Answer 2

If you have a string in your hand and a stone tied to the string and it's rotating around your hand, what prevent it to come towards your hand and hitch it? The fact that it's velocity is perpendicular to the force that ties it to the string, that is the centripetal force. If the strings breaks, what will the stone do? It won't be trying to come closer to your hand, in fact, it will continue with the movement it had at the very moment that the string splitt into two pieces. So, gravity prevents that we move far away from the Sun.

It's not easy to understand but think about a ball moving on a table until it gets to the moment when the table ends and it begins to fall. At this moment it will have a velocity that will in fact be the sum of two velocities, one that is the same that it used to have, vox (let's call x the direction the ball was having when it began to fall) and one that is perpendicular to x, vy. In the very moment that the ball begins to fall, vy_0 is 0. But then gravity begins to act and vy grows. So, it's not 0 anymore. And these 2 vectors are sumed and the velocity at a due point (until the ball gets to the floor) has a direction that isn't x anymore, and that isn't y, either. If forms an angle that will vary because vx will still be the same because of the inertia, but vy is increasing because the acceleration g is acting on the ball.

So, coming back to the Earth, at *any* moment it has a vx, that tries that the Earth goes out of its orbit and a g that it's perpendicular to it and that tries that the Earth gains a vy. It's more or less the same case than the ball in the table and the Earth is in fact "falling" to the Sun everytime. But, the direction of g is not the same when the Earth has moved a tiny bit since the vector r has a different direction and so has the g. The same that happens to the stone and the string example. And the same way that ths stone keeps rotating around the string, the Earth is rotating around the Sun and actually trying to leave it's orbit, not trying to move towards the Sun

Ilusion


Ilusion

Answer 3

The fact is that the Earth IS falling, towards the Sun. When on Earth, if you were to let go of a stone, its drops straight down to the ground, but if you throw it, it still falls to the ground but also covers a short distance of the Earths surface. Now, if that stone was thrown fast enough it would continue to follow the curvature of the Earth and so would be in a continual fall, also known as in orbit around the planet. The same thing is happening with Earth and the Sun. We are falling toward the Sun but are also moving extremely fast, thus we are in a continual fall around the Sun. The reason we don't appear to be moving is because of the large scale of the solar system. Hope that helps.

Answer 4

I think I understand what you are asking. Also, I do not believe your question can be easily answered; but I will do my best.

The Sun (and entire galaxies for that matter) are moving. Here is an example from Hawking. First, to understand this example you must understand that the universe is expanding after the big bang. Now imagine that you are making raisin bread. when you begin there is a small peice of long rolled dough barely an inch high and an inch wide. Now, as it cooks the raisins inside will all expand and move away from one-another simultaneously. that is what is happeniong in our universe.

Why it doesn't fall. well, if you took a tennis ball and launched it while in space it would travel straight and at a constant speed untill interupted by another object's gravity. As the universe expands "and the raisins seperate" things do "fall," asteroids hit objects--collsions viewed from hubble etc. etc. Also, those collisions are what make planets and stars.

Because we are in a world that is likely trillions of years old, the universe has had much time to settle, we can fly (our galaxy, with the sun in it, with the earth rotating around it) in our straight line away from what got us moving untill that force is countered or stopped or interrupted (well no one knows what is really going to happen to the universe, in fact that fate is currently a hot debate).

hope it helped.

Answer 5

The earth is not floating in mid air. It is actually falling through space and its trajectory around the sun is dictated by the relationship between its speed and the gravity caused by the sun.

Answer 6

Several good answers above but I will give my version as well.
The Earth is falling towards the sun all the time but it is also moving sideways. If you think about it moving sideways will increase the distance between the Earth and the Sun, in a circular orbit this exactly counters the falling in.
There is a really good open university program that explains orbits - I suggest you try and track it down

Answer 7

Some excellent answers here. Demiurge42, in particular hit the nail on the head. But I think from you later comments, you are trying to ask why this ball we call Earth doesn't fly away, fall etc.

Well you and I, and everyone else, have been born and raised on Earth where the gravity of Earth is dominant, so we are used to small inanimate objects just falling to the ground

But in considering a space enviroment, the layout is different.

Yes, the Earth is suspended in space but it IS also falling not in a straight line but in an elliptical orbit around the Sun. You may have heard of the term freefall.

Well objects in freefall behave as though they were in a (near) zero gravity enviroment. I'm just glad that the gravity of the Earth itself keeps us from falling into the Sun!

Answer 8

Gravity keeps the planets from being slung away from the sun and the sun is travelling around the Milky Way and all the galaxies are travelling through the universe and so on and so on. If you haven't learned about what causes gravity, then there's no point any of us trying to explain it to you.

Answer 9

The Earth is falling though space.
The sun is travelling at about 200km per second through space and the Earth is tumbling through space with it. Gravity makes sure the Earth sticks with the sun as it travels and its the same with all the planets.

The trouble is that there is no up or down in space, so its not neccesarily faling down, it might be faling up.
This is the honest truth. You cant feel this travel because your body is accustomed to it, but the world is spinning at about 1000mph and you dont feel that either.

Answer 10

The question is easier to answer if you ask "what's keeping the world from flying away from the sun?"
The Earth moves at almost 30 km/s around the sun. Gravity keeps it from flying away.

So if you want, it's that the Earth is moving so fast that keeps it from falling.