# Homework Help: Natural State of Matter Rest or Motion?

1. Dec 26, 2011

### GreenPrint

Hi,

I'm studying Roman culture and civilizations in a course at my university and I'm learning how poets and philosophers argued that the natural state of matter is in motion, that everything is always in motion and never at rest, that there is an empty void that exists between objects and within objects themselves... blah blah blah

but this is all just philosophy and not science, but I read how the "void" between objects and withing objects themselves allows for objects to move, if there was no emptiness between objects objects wouldn't be able to move... and that if one thing moves all the particles around move and the ones around it move... this just goes on forever sense the universe is boundless and has no bottom...

Like this some weird mumbo jumbo stuff that when I think about it actually seems to make some sense... but Newton's law of motion states that all objects at rest remain at rest until an external force causes it to move... the natural state of matter is at rest...

So... why exactly that ancient Greek and Roman philosophers are wrong and that the natural state of matter is at rest? I'm reading On the Nature of Things by Lucretius and it's very interesting. I have to read it very slowly and sometimes reread passages to fully understand the concept, it's pretty convincing.

2. Dec 26, 2011

### ehild

You do not know Newton's first law correctly. Read what he wrote in his "Principia"

Rest and motion are relative. What looks rest for one observer, it is motion for an other. Rest and motion along a straight line with uniform velocity are equivalent.

ehild

3. Dec 26, 2011

### GreenPrint

hm... this is my first time ever seeing how it was originally written... interesting thanks!

4. Dec 27, 2011

### ehild

Last edited: Dec 27, 2011
5. Dec 27, 2011

### D H

Staff Emeritus
It makes sense to you because you (along with those ancient philosophers) have a rather limited view of how things work. A rock rolls down a hill and stops. One must constantly apply a force keep an object such as a cart in motion. Stop exerting this motile force and the cart will soon come to a stop. Everything eventually comes to a stop, right?

Wrong. Newton's first law, "Every body persists in its state of being at rest or of moving uniformly straight forward, except insofar as it is compelled to change its state by force impressed," says that this ancient view of the physical world is wrong. He wrote this as his very first law as a confrontational expression of the inherent incorrectness of this Aristotelean point of view.

6. Dec 27, 2011

### D H

Staff Emeritus
Throwing out everything we know to be "true" (or relegating as some minor special case that what we think to be universally true) is one of those things science needs to do. Physicists have done this quite a few times. Aristotle was quite revolutionary in his day, yet very little of his physics now survives. Relativity and quantum mechanics collectively relegated Newtonian mechanics as a special case rather than the universal truth that Newton thought it was.

From other posts of yours, you are just now taking freshman physics. You almost certainly did not read any of Newton's Principia for that class. There's a good reason for that. It's verbose, the math is archaic and convoluted, and there are even a few mistakes. There's a dirty little secret of science education: The compact, self-consistent, and modernized presentation of science taught to students took hundreds of years of development.