Newton's Apple - by Sandip

The most famous apple tree in the world is in England, UK

Some six grandfathers ago there lived a curly haired young man famous today as Sir Isaac Newton. Of course he was not Sir Isaac Newton when he was born on a Christmas night, and was known in school as Isaac Newton, Jr. for his father’s name was also Isaac Newton.

Newton, Jr. who we will refer to from now only as Newton [who else except you and I know his father had the same name?], lived with his grandma in a creaky wooden house next to an orchard in a hamlet. When he grew up to be a curious young man he went to college, paying for his education by working as a valet.

Then came the plague, caused by bacteria [which are bigger cousins of viruses, one of which is causing lockdowns now]. The plague also resulted in a lockdown: schools and colleges were closed, and Newton returned to his grandma’s home by an orchard.

As the doctors say now, so the doctors said then: breathe fresh air but stay away from others. So there sat Newton “under the shade of some apple trees”, with his pet dog Diamond, when an apple fell. Newton wondered why the apple fell straight to the ground, and not float down sideways like flurries, nor rise into the sky like airplanes. He tapped ripe fruits on the trees and watched them too fall “straight to the ground”: none floated, nor rose.

It took all of twenty years for Newton to think through this and write a fat book with a long name; people call it “Principia” in short. The book made him famous – few people read it, even fewer understood it, so everybody concluded it was great.

Newton wrote that every object in the universe is attracted to every other object [somewhat like a magnet]. The attraction is stronger for bigger objects and rapidly weakens for farther objects.

It is this attraction which causes an apple to fall to the earth. This also causes meatballs to be as attracted to you as you are to them. It is this attraction which makes our Moon go around the planet Earth, the Earth around our nearest star Sun [hard to believe the Sun is a star, right?] and the Sun, which is the centre of our solar system, around the centre of our spiral galaxy Milky Way [think many planets, their moons and the stars].

This was great reasoning, and to honour him we measure this attraction not in spoons but in "Newtons". The attraction is called gravitation. When talking about gravitation where one of the two objects is the Earth, most people call it gravity. You may also hear them talk about zero gravity; what they mean is microgravity [gravity can be little, very little, but never zero].

Can you scribble with a pen on a notebook above you?

Have you seen the high tides caused by a full moon?

If we had a seesaw with you at one end on Earth and Mommy at the other end on the moon, Mommy's legs would not touch the moon's surface. Why?

Can you catch water from your bottle to drink in a spacecraft?

Did you know that you can float from one end to the other [quite like Superman] inside the International Space Station, 3 sleeps away? Strange fact: you reach the Space Station in 8 minutes but reaching inside takes the remaining time.

Write your answers in Comment section below. You may even win a gift from me.

[Some questions are more related to free fall – where you fall towards the earth but never reach it as you are falling around the earth – than to gravitation.]

"The Royal Society is a Fellowship of many of the world's most eminent scientists and is the oldest scientific academy in continuous existence". In their huge vaults are millions of books, among them one written by Newton's friend William Stukeley. Titled "Memoirs of Sir Isaac Newton's life", it recounts his life as told by Newton to his friend. Above is a photo of the page where Newton tells the tale of the apple. Legend has it the apple fell on his head but Newton has not said so. Maybe he forgot, and when asked, Diamond said 'Nuf, not Woof.

Credits:

Videos courtesy Canadian Space Agency, European Space Agency, NASA and National Geographic.

Cover image by Fumiaki Hayashi on Unsplash.