What is Newton's First Law?

Science for Writers:  Newton's First Law
'Apple on books' from stockvault.net. Science for Writers Logo and text created by me.

Welcome to the latest Science for Writers post. Last time we discussed storing data in DNA. In this, the first of a three part mini-series, I will explain Newton's First Law of motion.

I have put important words in bold. These words are important in physics and I will refer to them throughout the post. It isn't overly important for you to know the exact meaning, so long as you get the gist of what I'm talking about you will be fine following this post.

Writing Links are in italics and these discuss how the science could be used in writing.

What does it state?

Newton wrote in his book, Principa:

Law I:  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.

Lets break it down before going further:

• A body, is an object. An apple is a body. A car is a body. You are a body.
• To persist means 'to continue'.
• A state is the condition something is in.
• Rest means not moving. Being in a state of rest means the body is not moving.
• Uniform means constant. Being in the state of uniform motion means moving in a straight line at a constant velocity (for now just think of velocity as speed).
• Change means to do something different to what it is currently doing.
• A force makes a body do something.
• Impressed is just a fancy way of saying that the force acts on the body.

Now we've split it up, it is easier to understand. In actuality it is just a wordy way of saying, 'Every object continues what it is doing until a force acts on it that makes it change.'

As with all good laws in physics there is an equation to go with it: