What is gravity?

What is gravity?

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Gravity is very important to our existence, but do you know why it exists or what it is?

Why is something we cannot see important to our existence and the functioning of the solar system?

In this article, we will look at what gravity really is and how it works.

What is gravity and what does it do?

We all know that gravity exists and that it keeps us on the ground, gravity is the force that pulls things towards itself.

The word gravity is derived from the Latin word gravitas meaning weight.

On Earth, gravity gives weight to objects, while on the moon, gravity controls the tides of the earth.

Gravity can have many different roles in the solar system;

Here, the Earth's gravity is the reason things fall down when we drop them, just like when we jump, we land back to earth.

Who discovered gravity?

Sir Isaac Newton was an English mathematician and physicist who realized what gravity was when he was thinking about the forces of nature and seeing an apple fall from a tree.

He wondered why the apple fell and stopped moving and realized that some force was pulling it down to Earth.

Newton's thoughts began to wonder if this force went beyond the earth and existed in the solar system.

In 1632, he introduced the concept of gravity and created the law of gravity, helping other physicists at that time discover the behavior of the solar system.

Before gravity was discovered, the Greeks believed that the solar system was controlled by a god and followed a natural pattern.

How do we measure gravity?

Gravity is measured by what is called Gravimetry and it measures the strength of the gravitational field.

The instrument used to measure this is called a gravimetric, and to put it simply, it measures the constant acceleration of gravity in the downward direction.

Experiments using gravity have shown that the gravitational force even changes on the earth's surface by about ± 0.5%.

This is mainly because the constant movements of the sun and moon both affect the Earth's gravitational pull.

Gravimeters are mainly for measuring gravitational fields for geophysical, mining and seismic surveys.

Although gravity meters are only used on Earth, they can also be primarily used on other surfaces like the moon to measure the gravitational field.

What would happen to the Earth without gravity?

Although it is almost impossible for gravity to disappear, scientists still try to predict what would happen without it.

An article published by the BBC in 2016 explains that if the Earth had no gravity, it would most likely break into parts and drift away.

Anything that is not physically attached will be the first thing that appears, things like oceans, rivers, water will be washed away.

Next is the earth itself, the ground will break apart and we will float like particles in space.

A similar scenario would be with the sun, if there was no gravity to accommodate its core pressure, it would explode.

What if we don't have gravity?

As we know from the experience of astronauts, living without gravity is not only difficult but also has negative effects on the body.

For humans, there will be detrimental effects on our bodies because we have evolved along with gravity.

Certain muscle groups are challenged by gravity, and simple things like standing require the muscles to hold us against gravity.

NASA astronaut and doctor, Jay Buckey, discovered how our bodies respond to zero gravity.

In space where gravity is absent, for example, astronauts lose mass of their bones and muscles, lose strength.

This is because if there is no pull against us, we are not using our muscles, because we are just floating.

Not using muscles and not having to hold yourself upright can also have other effects on the body, such as loss of balance.

The human body has adapted to work with gravity that stresses our bodies every day and without it we slowly deteriorate by not using the muscles.

This is why astronauts have time limits on the amount of time they spend in space.

Studies show that if you stay in space for about three months, without gravity, it will take two to three years to regain lost bone density.

Is there gravity underwater?

You may think that there is little or no gravity in water because we float and we feel lighter, but gravity remains constant in water.

Although gravity in water is the same as on ground, gravity has to choose what it pulls on.

When an object or person is placed in water, gravity can still be exerted on the object, but only when an equal volume of water can go upward, in contrast to gravity.

This is called displacement and, therefore, gravity has to choose which element it will pull down, water or an object.

The floating force is making gravity make this decision and as a result it will choose which one has the greater mass, which is essentially more weight per certain mass.

If an object placed in water is denser than water, it will sink and its mass decreases a portion of the volume of the displaced water.

However, if the object has a density less than water, it will float until its mass matches the displacement of the water.

Do all planets have gravity?

Gravity is everywhere, but it's weaker in some places than in others.

On Earth for example, if you weigh 100 lb (45 kg) you would be a different weight on different planets.

The same person would weigh just 17lb (7.7 kg) on the moon, 38lb (17 kg) on Mercury and 253lb (114 kg) on Jupiter.

As you can see the weight changes depending on the planet, but humans remain unchanged.

This is because gravity varies between planets and throughout space, which causes our weights to be different.

If there is less gravity pulling you to the ground, you will feel weightless and hovering, similar to being in a swimming pool.

Gravity is very important to our existence and for the functions of our planet, without it, the Earth and the solar system would not be the same.

So next time you go swimming, use some weights to check displacement, or next time you throw a ball, watch gravity pull it back to earth.