Can an object in motion travel forever through space?

Question

I was reading this physics book and it was talking about how if an object in motion does not encounter fiction, it will keep on moving foever, theorectically.

So I need to ask, does space have friction? Will an object that is moving in space travel forever through it? And do the gravity fields emitted by the planets act as friction to slow the object down?

Thanks Guys/Gals!

Answer 1

There are several factors to consider here and still others that I am unaware of.

Space is not a perfect vacuum, with gas atoms occuring at about 10 to 100 per cubic meter (Wikipedia). Over time these atoms will slow down the object in motion as collisions occur.

Gravity from other objects in space will always act upon the moving object, although this is not friction. Gravity will alter the speed and direction of the object in motion. The greater the proximity or mass of a celestial body, the greater the gravitational pull it exerts on other objects.

A third factor is photons, or light. Photons colliding with the object in motion (light hitting it) will transfer very small amounts of energy to it.

These are all factors to consider when you are talking about an infinite amount of time. In practical terms, the object would continue unless it were to hit by something else of size. The planets of this solar system have been orbiting the sun for billions of years and nothing has stopped them yet.

Answer 2

Two things that can cause a moving object to slow down are friction and gravity. Because space is an almost perfect vacuum, there is practically no friction. For many years scientists have debated whether the total amount of matter in the universe was enough so that gravitational force would eventually cause everything to stop expanding, then collapse back down to a singularity and start over with another big bang.

Answer 3

the objects will move through space forever because friction slows things down. When a car is moving and then it stops, it stops because of friction, when in space, since there is none the objects will never stop. When it hits into something, it might break into peices, but those peices will still move forever also.

Answer 4

You know that things in motion remain in motion if no unbalanced forces are acting upon them. Our notions of motion today are very different from those of our ancestors. Aristotle did not recognise the idea of inertia because he did not see that all moving things follow the same rules. He imagined that rules for motion in the heavens were very different from rules of motion on earth. He saw vertical motion as natural but horozontal motion as unnatural, requiring sustained force.

Galileo and Newton, on the other hand, saw that all moving things follow the same rules. To them, moving things require no force to keep moving if there are no opposing forces, such as friction. We can only wonder how differently science would ahve progressed if Aristotle had recognised the unity of all kinds of motion.

Answer 5

It will move through space forever but not necessarily in a straight line. It may be attracted to a sun or planet by gravity and begin orbiting it. This is unless it hits something first.

Answer 6

You are right. Something moving in space will continue to move on forever unless it smacks into something (highly unlikely considering that the universe is mostly empty space).

Answer 7

unless there's a counteracting force acting upon it, like gravity fields or blackholes ,it will be in perpetual motion

Answer 8

yes, because of Newton's 1st law of motion.

"Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it."

Answer 9

Assuming something doesn't hit it and destroy it, yes.