What would be a good estimate of the energy content of the universe?

Question

As things move is there an energy loss, could the future of the Universe transfer all its energy and become just one big lump of mass? M=E/c^2

Answer 1

Energy content is still up in the air. Total energy (actually mass-energy because they are interchangeable) is made up of about 96% dark stuff (energy and mass) and 4% observable stuff. Galaxies should fly apart given the mass-energy we can see of them. But they don't...clearly...we're still here in the Milky Way. Something keeps them together, but what we see is not enough to do that...therefore, dark stuff was invented. The problem with that theory is that, until very recently, no one has ever seen or detected dark matter or energy, which is why they are called "dark".

Until recently, like yesterday when it was telecast in the news, there has been no evidence, other than circumstantial, that dark matter existed. However, yesterday Stanford U. announced that it has observed (key word here) dark matter around two galaxies colliding with each other. [Source: Headline News, Aug. 21, 2006]

As you indicated, there is an energy loss...of sorts. Energy is actually at a constant level in the universe...it can be neither created nor destroyed. E = mc^2, for example, is just a conversion equation because mass is energy, but in a different state or form. So total energy in the universe remains fixed from the day of the big bang.

What is lost is useful energy, called enthalpy. Useful energy becomes useless energy, called entropy. Entropy in our universe has been increasing, while enthalpy in our universe has been decreasing since the big bang. If you think in equations, we can write C = S + E; where C is total energy, S is entropy, and E is enthalpy. Since C is constant, when E decreases, S has to increase; and so it does.

So what happens as useful energy is lost over time...the universe runs down. To be sure, there are relatively small pockets of the universe where enthalpy is created, but, overall, the net effect is that enthalpy is decreasing while entropy is increasing.

No, mass is not created as enthalpy is lost. In fact, mass is full of useful energy (the E in E = mc^2). But as the useful energy runs down (e.g., through radioactive decay or oxydation) the solid mass tends to disassociate (crumble). Most cosmologists agree that our universe will snuff out like a burned down candle billions of years from now. In the end, they posit, our universe will reach absolute zero temperature, when C = S and no enthalpy remains.

Answer 2

Actually, there is a significant question as to whether the concept 'energy content of the universe' even makes sense. In essence, the energy of something depends on the frame of reference of the observer. Different observers can easily obtain different answer for the same object. When dealing with the universe as a whole, there is no canonical frame of reference.

But even worse is the fact that in a curved space time, the energy at one point of space time has to be 'parallel transported' to the observer before the total energy can be computed. But this process of parallel transport can give different answers depending on the path of the transport. The upshot is that there may not be a 'good' way of even defining what is meant by 'total energy of the universe'.

Now,it *is* possible to makes sense of this *if* the universe satisfies some very stringent conditions (asymptotic flatness is one). This leads to something called the ADM mass of the universe. But it is not clear if the actual universe satisfies the relevant conditions. There is active research both theoretically (to define what is meant) and experimentally (to get an answer) on this problem.

Answer 3

I don't even know what order of magnitude the energy content of the universe would be, but it's sure to be unfathomable. I'd estimate somewhere between the energy of several quintillion Hiroshima bombs and infinity.
What prohibits all the energy in the Universe from becoming mass is the Second Law of Thermodynamics, which states that the entropy, or amount of disorder, in the universe, is always increasing. In essence, mass is simply a highly-concentrated, highly-organized form of energy. Therefore, as time goes on, mass tends to decay into energy in the form of radiation, not the other way around.

Answer 4

It's estimated that there are about ten to the 80th power electrons in the universe. So, add in a similar amount for protons and neutrons (hydrogen and helium are by far the most prevalent elements, making up over 99.9999 % of the universe), and remember than protons and neutrons are approximately 2000 times more massive than electrons, so perhaps ten to the 84th power equivalent electron masses, including particles of all types. Now you can work out the total energy equivalent to all the mass in the universe. Your figure will probably be close enough for general use.

Answer 5

Actually the total amount of mass/energy in the universe may well be ZERO. How is this possible you ask. It is because gravitational potential energy ( the energy things get by opposing the force of gravity ) is negative and exactly ballances other mass/energy.

Answer 6

as we know the universe is expanding but after some time( this some may be very large) it will start contracting and big bang will reverse therefore energy of universe will become 0.
ie. from zero to infinity and then infinity to zero.

Answer 7

darkish potential permeates the universe like gravity does, in certainty it somewhat is considered as anti-gravity. whilst we are saying what makes up the "majority" of the universe, although, we mean the mass, the burden of all of the stuff in the universe. This includes all baryonic count and darkish count. We infer that darkish count has a multitude of mass by skill of ways it gravitationally impacts galactic rotation and consistent with danger galactic formation.

Answer 8

I think it's about 5.

Answer 9

How about a triple shitload and a half?


Doug