# “The Knowledge Library”

#### Knowledge for All, without Barriers…

##### An Initiative by: Kausik Chakraborty.
05/02/2023 11:50 PM

# “The Knowledge Library”

Knowledge for All, without Barriers…

# “The Knowledge Library”

Knowledge for All, without Barriers……….

# The Knowledge Library

## 1. The Moon stays in place because of gravity.

If gravity didn’t exist then the Moon would have probably floated away by now!

It is kept in place by the gravitational force from Earth.

Luckily the moon is travelling at the perfect speed.

If the speed was any different, it would go off into another direction or come closer to Earth!

## 2. Isaac Newton discovered gravity.

Isaac Newton is the scientist who discovered gravity.

It is believed that he came up with the gravitational theory after he watched an apple fall from a tree.

It made him wonder why the apple fell straight down to the ground, rather than left or right… or even up into the sky!

This was in 1665 or 1666.

## 3. Gravity causes the tides in the sea.

Did you know that gravity causes the tides in our seas and oceans?

This is because gravity makes everything in the universe pull on each other.

The Moon pulls on Earth and in turn, makes the water move!

As Earth rotates, the water in our seas and oceans will build up on the side closest to the Moon.

This is why we have high and low tides.

## 4. Gravity saves our lives!

Gravity is very important…

If we didn’t have gravity then we wouldn’t even be here…

We would take off and be floating in space!

All thanks to gravity we can stay grounded and go about our daily life!

## 5. The larger the mass of an object, the more gravity!

Mass is different to weight. Mass is made up from how many atoms are in the object.

Weight is different because if you weighed yourself on Earth and then weighed yourself in space, it would be completely different!

The mass of an object never changes.

The larger the mass of an object, the more gravity there will be on that object.

## 6. In the whole universe, black holes have the biggest gravitational pull.

We need to stay away from black holes!

They have the biggest gravitational pull in the whole universe.

Don’t worry, Earth is very far away from one.

Nothing can escape their gravitational pull… and this even includes light!

## 7. Each planet has a different gravitational pull.

Gravity varies on each planet.

This is because each planet has a different gravitational pull as each planet has a different mass.

An object that weights 100 pounds on Earth, would weigh 38 pounds on Mercury!

## 8. Without gravity, Earth wouldn’t orbit the sun!

If gravity didn’t exist then Earth wouldn’t orbit the Sun.

This time it’s the Sun’s gravity that keeps us orbiting it.

We’re very lucky as it keeps Earth at the perfect temperature so it’s not too hot or cold!

## 9. Gravity isn’t evenly spread on Earth.

That’s right! Gravity isn’t evenly spread on Earth.

This is because Earth isn’t a perfect sphere. The mass of Earth also isn’t even.

This means that gravity can vary slightly in different places.

## 10. Gravity is making you shrink!

Did you know that you are taller first thing in the morning than when you go to bed at night?

That’s because gravity is pushing you down all day and is causing your spine to shrink.

When you go to bed at night, your spine has a chance to stretch back out!

You are about half an inch taller in the morning than you are at night.

Get a tape measure and test it out!