Gravity In Vacuum:7 Important Facts You Should Be Knowing


This article discusses about the topic gravity in vacuum. We all know about gravity as an attractive force that is responsible for objects coming down instead of going up.

Sir Isaac Newton discovered gravity when he observed that an apple fell down on his head instead of going up. In Astrophysics, Gravity is termed as a dent in space time fabric. We shall not go very deep in to the meaning of gravity, we shall discuss about how gravity is affected in different situations.

What is gravity?

Gravity is the force responsible for attraction of objects due to their mass. It is said that every object which contains mass is build up of gravitons which are responsible for the force of attraction.

If the mass of the object is more then the force of attraction will also be more. Although the effect of gravity will be same that is under free fall the object will fall with an acceleration of 9.8 m/s2. We shall study more about it in detail in further section.

gravity in vacuum
Image: Artist’s impression showing gravity pulling mass from a star

Image credits: ESO/L. Calçada/M.Kornmesser, A stellar black holeCC BY 4.0

Is there gravity in vacuum?

Yes the effects of gravity are present in vacuum too.  vacuum the effects of gravity is same on all the objects. For Earth, the acceleration due to gravity is 9.8 m/s2. The objects won’t move with a greater acceleration than this object.

The objects attain terminal velocity after attaining this acceleration. That is the object won’t move any faster than the velocity attained after accelerating at 9.8 m/s2. There was an experiment performed by astronauts on Moon. They dropped a hammer and a feather simultaneously, both of them touched the surface of Moon together. This proves that gravity acts in vacuum too.

Gravity value in in vacuum

We have discussed that gravity acts in vacuum too. Now we shall find out its value in vacuum. The value of gravity in vacuum is found using the relation given below

After substituting all the values we get the value of acceleration due to gravity as 9.80065 m/s2.

Force of gravity in vacuum

Mass and acceleration gives rise to force. When objects with mass interact with each other through gravity, they experience a force of attraction due gravity.

The gravitational force arises due to the mass and distance between them. The formula for calculating the force of gravitation is given below-

Acceleration due to gravity in vacuum

The acceleration attained by an object under the influence of gravity is called as acceleration due to gravity.

When an object is under the influence of Earth’s gravity, the object can attain an acceleration of 9.8 m’s2. This is the value of acceleration of gravity in vacuum. The formula to find the value of acceleration is already discussed in the section above.

Effect of gravity in vacuum

The effect of gravity in vacuum is same for all objects in vacuum and is independent of an object’s mass. Vacuum is a three dimensional space in which there is no air resistance.

Without air resistance, the objects will keep moving at the same speed throughout. The gravity causes all the objects to move at same rates and as there is no vacuum the objects will keep moving at equal velocities until an external force stops them.

Gravity in quantum vacuum

Quantum mechanics suggests that everything is made up of energy packets called as quanta. Gravity is considered to made up of energy packets called as gravitons.

These energy packets can behave as both particle and wave. To prove that the gravity is quantum we will need to prove that the quanta of gravity, gravitons, are real. Without detecting these gravitons it can’t be said that gravity is quantum. But doing this is very difficult because gravity is associated with objects having mass. Dealing with particles at atomic level means the gravitational force will be very negligible and hence will be very difficult to detect gravitons.

Speed of gravity in vacuum

We all know that speed of light is constant and its value is around 299,742,458 m/s. Light is said to be made of massless particles called as photons.

Similar to the speed of light, the distortion in space time fabric are also said to move at top speed. Meaning that the speed with which the effect of gravity will move is also equal to the speed of light or c that is 299,742,458 m/s.

Applications of gravity

We might think that gravity is simply a force that pulls us towards the surface of Earth. And we might consider it as something undesirable as it is pulling us down. But in reality it has got a wide range of applications that directly affect our daily life.

The applications of gravity might go unnoticed but they are essential for our survival. The applications of gravity are-

  • Revolution of Moon around Earth– Moon revolves around Earth due to their individual gravitational pull. Without gravitational pull the Moon would have pushed far away in deep space. It is the gravity that locks the Moon in an orbit around the Earth.
  • Objects staying on the surface – Objects will fly around if there is no gravity. Gravity keeps the objects grounded on the surface. It is very essential because it would be very difficult for us to move around in daily lives. In space when something is pushed in a particular direction it keeps on moving until and external force stops it. So gravity is that invisible force which brings us back.
  • Revolution of Earth– Similar to the movement of Moon around Earth, Earth also moves around Sun because of the gravitational influence, Sun’s gravity is very high due to its large mass. Had the mass of Sun be heavier than the Earth would have a different orbit. The orbit arises due to the outward motion of Earth of its own and gravity pulling it towards the Sun.
  • Tides– Due to the revolution of Moon around Earth, water bodies get affected. The high tides and low tides are directly associated with the position of Moon. The Moon’s gravity will pull the water bodies towards it resulting in tides.

Conclusion

In this article we discussed about different facts regarding gravity. Without gravity so many things would not have been easier as they are today. We know now that gravity can work in vacuum too. The gravity simply pulls objects towards the primary heavier object but that alone has many applications in our daily life.

Abhishek

I, Abhishek Khambhata, have pursued Btech in Mechanical Engineering. Throughout four years of my engineering, I have designed and flown unmanned aerial vehicles. My forte is fluid mechanics and thermal engineering. My fourth year project was based on performance enhancement of unmanned aerial vehicles using solar technology. I would like to connect with like minded people.

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