The constancy of the energy of the universe?

Hi,

Given that the universe is a closed and isolated system, suppose it should satisfy the following equation:
EP+EK=constant.

However, it appears to be that it is impossible that the energy of the universe can be constant after all. Specific higher dimensional theories (such as String/M-Theory) predict that gravity can leak through higher dimensions and so called p-branes due to its special properties (roughly speaking closed loop strings cannot be attached to the p-branes because there are no loose ends). Thus, energy of the universe is variable because it simply leaks.

I would also like to point out the fact that QM may have parallel universes. This could have an impact of the total energy of the universe as well, primarily because the gravity may leak from such universes to our one.

Indeed it appears to be that the universe is not isolated at all and the total energy may be increasing or decreasing to that respect.

Thanks for all the responses!

Best regards, Cygni

 

Indeed I am slightly premature, I just finished my GCSEs. But i was just wandering whether my statement is correct or not. I am not trying to show off or anything - I am being curious because I enjoy physics and i want to know the answers.

Best Regards, Cygni.

P.S. Thanks for your response anyway.

 

Indeed it looks like it. I know the certain implications that arise in string/m-theory which look pretty ugly though (e.g. working on background-dependent theories constrained by a lot of symmetries, 10^500 of vacuums etc.). String/m-theory is not proven, however such assumptions that I have stated do have some sense in that respect.

Best regards, Cygni.

 

No, I am not wrong, closed system in thermodynamics refers to that matter may not cross the boundary, this does not apply to energy, however, thermodynamics does not fully incorporate with string theory because one can imply that EM or S or W forces would be able to escape the boundary but they cannot due to specific dynamics and properties of such strings.

Best regards, Cygni.

P.S.

I would like to apoligise to the forum readers - I have made a terrible mistake - in my first post I have stated that universe is an isolated system - what i meant was tat universe is partly closed system which allows only gravity to "leak". The reason why is written above.
Sorry again about the inconsistencies.

 

Hi,

Unfortunately, the universe itself cannot "leak" excluding special cases of black holes where the matter may escape due to the fact that black holes can have connections to the other universes.

There may be very small amount of evidence that two separate observers would perceive differing cosmological boundaries i.e. energy. However, such changes in the energy of the universe would be uniform as the universe itself is homogeneous and isotropic. Thus we would expect very uniform energy changes throughout the universe which could be completely unnoticeable due to the fact that gravity is a weak force and approx. 70% of the universe contains dark energy.

I believe certain constants would change, particularly those constants that describe the properties and quantities of the fields, but again they would probably be minuscule and barely would have any impact on the laws of physics operating in our universe.

Due to the fact that the universe may be partly isolated (allowing only one type of energy to pass) the energy is not conserved globally. However, we do not know how much of the "energy" we receive from other universes, therefore we can presume that energy is/is not conserved.

Best regards, Cygni.

 

I appreciate your response, I will try to buy this book as soon as i can.

 

Sorry for the double post. I just went on wikipedia and the total energy is defined as EK + EP = Constant.

Quote: In classical physics, the total energy of an object is the sum of its potential energy and its kinetic energy. Note that since all other forms of energy can be derived from these two types, the total energy is effectively the theoretical maximum amount of energy that could be taken from the object. It also represent the net amount of energy on/of an object.

In modern physics, the total energy of an object is the sum of its rest energy, its total kinetic energy, and its potential energy.

Reference: http://en.wikipedia.org/wiki/Total_energy

Best regards, Cygni