newt

Sir Isaac Newton’s three laws of motion were first published in 1687 and continue to give a pretty accurate account of nature (with a few exceptions, like the behavior of things in distant space or inside of atoms). They represent some of humankind’s first great successes at using simple mathematical formulas to describe the natural world and form an elegant and intuitive physical theory that paved the way for later advances in physics. These laws apply to objects in the real world and have allowed us to do things like simulate car collisions, navigate spacecraft, and play billiards really well. Whether we are aware of them or not, Newton’s laws of motion are at play in nearly every physical action of our daily lives.
The First Law
Newton’s first law states that unless a body (such as a rubber ball, car, or planet) is acted upon by some force, a body in motion tends to remain in motion and a body at rest tends to remain at rest. This postulate is known as the law of inertia. What this means, practically speaking, is that a rolling ball or other object only slows down because of forces like gravity and friction. Even more intuitively, a resting ball isn’t going anywhere unless given a nudge or a toss. Given this law, a ball thrown in the vacuum of space would, theoretically, keep traveling at the same speed for as long as it could avoid impacts with celestial bodies and their pulls of gravity!