How Much Energy Does The Universe Have? - Zero Energy Universe.

We probably know the law of conservation of energy. 

'Energy can neither be created nor destroyed.'

So if we think about it for a while, a natural and obvious question arises, What is the total amount of energy available in the universe? There must be a constant value of energy in the universe since the energy can neither be created nor destroyed. So let's answer this question in this blog.

What if I say that there is zero total amount of energy in the Universe? In other words, nothing is not nothing. Nothing can arrange itself in such a way that it becomes something. This hypothesis, that the total amount of energy in the universe is exactly zero and such a Universe is called a zero-energy universe.

For eg : 0 can be written as 0 = -1 +1 = -1987632 + 1987632 = +89000000 - 89000000. but actually, 0 is divided into +10 power 69 and -10 power 69 joules of energy in the universe.

Similarly, there is positive energy in the form of matter-energy and negative energy in the form of gravitational energy And the amount of matter-energy is canceled out by the exact same amount of gravitational energy.

In his book, The Theory of Everything, Stephen Hawkings talks about this cancellation concept by saying

"The matter in the universe is made out of positive energy. However, the matter is all attracting itself by gravity Two pieces of matter that are close to each other have less energy than the same two pieces a long way apart This is because you have to expend energy to separate them. You have to pull against the gravitational force, attracting them together. Thus, in a sense, the gravitational field has negative energy In the case of the whole universe, one can show that this negative gravitational energy exactly cancels the positive energy of the matter. So the total energy of the universe is 0."

Another interesting question that we may encounter in this discussion is, how does the positive and negative energy of equal amounts arise from nothing?

The answer is Quantum Fluctuations. Quantum theory describes 'nothing' as fundamental energy fields And if we conclude these energy fields in a single term, we call it Quantum Foam. This Quantum Foam has the infinite potential of energy and is always fluctuating. These fluctuations in Quantum Foam are Quantum Fluctuations. let's be clear that we are talking about this on a very small scale which is Planck scale (10 power -35 meters). At the small scale space is always jiggling and wiggling. Space is not smooth at a quantum level.

This wiggly nature in terms of field is called Quantum Fluctuation. In terms of particles, they are called virtual particles.

Quantum Fluctuation in Proton's Empty Space

Do virtual particles violate the law of conservation of energy?

Virtual particles appear and disappear in quantum form so quickly that it seems like they didn't even appear in the first place. The time scale at which they appear and disappear is Planck's time( 10 power -44 sec). At this scale, the temporary violation of the Law of conservation of energy is allowed according to Heisenberg's uncertainty principle. In other words, we can say virtual particles may seem to violate the law of conservation of energy. But since at such a small scale, temporary violation is allowed, virtual particles don't actually violate the law of conservation energy.

What would be the shape of the universe if the total amount of energy in the universe is zero?

The simple answer is it would be flat. Only if the universe is flat, the total amount of energy of the universe will be zero. According to Einstein's General relativity, mass and energy bend the space-time fabric. So in a zero-energy universe, the positive energy cancels out negative energy, making the universe flat. If it was dominated by net positive energy, that is matter-energy, the universe would be the shape of a saddle. If it was dominated by net negative energy that is, gravitational energy, then the universe would have been spherical in shape.

However, many different researches have shown that the observable universe is indeed flat, with a 0.4 percent margin of error.

To this date, there is no experimental proof due to experimental constraints that provide substantial proof for the zero energy universe hypothesis.

There is another important question to be addressed, Why the universe is expanding? and how it correlates with zero energy universe? I would like to address this question in upcoming blogs.