# Curious Question: Relationship between energy and graviy?

• gfeing4935
In summary, if gravity is a property of matter, then when it is converted to energy (for instance light), energy also has the property of gravity. However, the total mass of all that light emitted during an explosion is exactly...2kg. While gravity IS a property of matter, as you state, gravity is also a property of energy and pressure. All three forms have gravitational effects. Assuming conservation of energy in a system, the conversion of a given amount of mass to energy does not change it's gravitational potential...although the shape of the gravitational field may change. While pressure is contained with it, I am unsure if the second part is accurate.
gfeing4935
Simple Yes or No Question but how would you prove?

If gravity is a property of matter, when it gets converted to energy (for instance light) does energy also have the property of gravity? If so how could it be proven as a very large amount of energy would be required to equal a small amount of matter, and a small amount of matter has a small amount of gravity? Energy (for instance light) can be affected by gravity.

If not what happens to the gravity property of matter when it gets converted to energy?

Just a curious question from watching a show about Einstein last night.

Thank You,
Greg

matter is NOT 'converted' to energy and vice versa
They are EQUIVALENT.

When you annihilate 1Kg of matter + 1kg antimatter for example, you have an enormous explosion, and popular sources say 'matter is converted into energy'

However, the total mass of all that light emitted during an explosion is exactly... guess what... 2Kg!

While gravity IS a property of matter,as you state, gravity is also a property of energy and pressure. All three forms have gravitational effects. Assuming conservation of energy in a system, the conversion of a given amount of mass to energy does not change it's gravitational potential...although the shape of the gravitational field may change.

Naty1 said:
While gravity IS a property of matter,as you state, gravity is also a property of energy and pressure.

Can you explain what you mean by 'pressure'

gfeing4935 said:
If gravity is a property of matter, ...

Maybe should be rephrased to "If matter is a property of gravity, ". Probably not entirely true but more so than the other way round.

Can you explain what you mean by 'pressure'

A closed jack in the box (A toy with compressed spring) exerting a positive pressure has more energy and hence weighs just a tiny,tiny bit more than an open box...with an uncompressed spring. The energy is the result of the work exerted to close the box and compress the spring. Such a compressed box has ever so slightly more gravitational force.

There are also situations in which the pressure in a region can be negative and such negative pressure exerts repulsive gravity...gravity is NOT always an attractive force! While immesureably tiny, such negative pressure becomes strong over vast cosmological distances...this is Einsteins (repulsive) cosmological constant! dark energy manifests itself as negative pressure. It is what powers the expansion of the entire cosmos.

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I just quickly skimmed Wikipedia hoping it would discuss negative pressure but it does not. Nor did I find it under General Relativity nor stress energy tensor...but pressure is contained with it.
Alan Guth of inflationary theory fame based his proposal on the fact that a supercooled HIGGS field provides the underlying negative pressure that caused inflationary exmpansion just after the big bang...those wishing the check further can also try that approach. But such a HIGGS field (in a termporary and very unstable high energy plateau) would act like a huge cosmological constant for only an ever so brief period...the existing cosmological constant exerts a negative pressure pressure steadily and constantly in all space.

A non technical description of gravitational pressure of roughly 15 pages can be found in Biran Greene's FABRIC OF THE COSMOS, chapter 10.

It's one of the many reasons I like to think that "space IS something". Others here, who may know a lot more than I, maintain space is nothing but a mathematical construct.

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Naty1 said:
A closed jack in the box (A toy with compressed spring) exerting a positive pressure has more energy and hence weighs just a tiny,tiny bit more than an open box...with an uncompressed spring. The energy is the result of the work exerted to close the box and compress the spring. Such a compressed box has ever so slightly more gravitational force.

When the spring is compressed heat energy will be released to the environment equivalent to the energy required to shut the lid. When the spring is released the same amount of energy will be retrieved from the environment so maybe no extra weight while compressed.

Maybe should be rephrased to "If matter is a property of gravity, ". Probably not entirely true but more so than the other way round.

I am unsure if the second part is accurate but I like that kind of thinking!: maybe gravity IS fundamental and after it's emergence from the high energy unstable early universe in turn "decays" in part to mass, energy and pressure...I had not thought of it that way before.
Physics today usually talks of the four forces being initially unified (combined into one super force)...

A very interesting question for me is what may have popped out from the initial big bang first...what is fundamental and what is subsequently emergent? Today we have time,mass,energy, four forces,space, etc...but I don't think physics knows which comes "first" nor why!

## What is the relationship between energy and gravity?

The relationship between energy and gravity is a fundamental concept in physics. According to Einstein's theory of general relativity, gravity is not a force, but rather a curvature of space and time caused by the presence of mass or energy. This means that any object with mass or energy will have a gravitational pull on other objects, and the strength of this pull is directly proportional to the object's mass or energy.

## How does gravity affect energy?

Gravity can cause energy to change forms or be converted into different types. For example, potential energy, which is energy stored in an object due to its position, is affected by gravity. As an object moves closer to a massive object, such as the Earth, its potential energy decreases and is converted into kinetic energy, which is the energy of motion. Additionally, gravity can also cause changes in the wavelength and frequency of light, which is a form of energy.

## Can energy be used to manipulate gravity?

Currently, there is no known way to manipulate gravity with energy. However, some scientists are exploring the possibility of using extremely high levels of energy to create gravitational waves, which are ripples in the fabric of space-time that can travel through the universe. These waves could potentially be used to detect and study objects in the universe, but they cannot be used to manipulate gravity itself.

## What is the role of energy in the concept of black holes?

Black holes are objects with such strong gravitational pull that they can even trap light. The strength of this gravitational pull is directly related to the mass of the black hole, which also means that it is related to the amount of energy contained within the black hole. As matter falls into a black hole, it gains energy and contributes to the overall mass and gravitational pull of the black hole.

## How does the relationship between energy and gravity impact the universe?

The relationship between energy and gravity is crucial in understanding the structure and evolution of the universe. It plays a role in the formation of galaxies, stars, and other celestial bodies, as well as their movements and interactions. Additionally, the amount of energy and matter in the universe affects the overall gravitational pull, which in turn influences the expansion and contraction of the universe.

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