The mass of the universe

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smifffy

When the scientists worked out the mass of the universe , they found that there was not enough to balance the equations of the big bany theroy. They found only 5% of the matter.

This led to dark energy and dark mass being "discovered" , in which they say that 23% is dark mass an 72% is dark energy leaving 5% visible matter.

I checked wikipedia http://en.wikipedia.org/wiki/Observable_universe

It appears to me that to work out the mass of the universe , they work on the average amount of stars / galaxies and work out how many hydrogen atoms there roughly is.

What surprises me is that there is no account for energy. Since E=Mc^2 then a good proportion of the mass in the universe must be in the form of energy.

Is it this energy that would make the equations work without the need of dark matter/energy?

I guess its pretty hard to work out all the energy in the universe , but it wouldn`t surprise me if it totaled the missing 95% visible mass when converted.

Any thoughts or facts please people.

aspen101

You might be onto something there ! This is so complicated it's not even funny.

Cool 

Elroch

I think they may have thought of it. Smile Of course light has no mass, but it is the amount of energy they are really interested in. But only a small fraction is light, so it didn't make the total energy correct.

Conflagration_Planet

What form does this energy take?

smifffy

our sun converts 600 million tons of hydrogen into 596 million tons of helium every second . So , 4 million tons of matter are converted into energy on just the conversion of hydrogen into helium , the helium gets converted and so on.

This gets converted into energy , in the form of the entire electro magnetic spectrum ( but not gamma ) . But we only see the small section we see as visible light

aspen101

Gamma is good energy. Gamma is only visible with ?

smifffy

a device that detects gamma rays :)

Elroch

There are gamma ray telescopes in orbit. A difficulty with gamma rays is that it is very hard to focus them.

Niven42

In theory, there isn't any difference between energy and mass.  The difference between the observed effects of gravity and the observed mass of the universe implies that there must be a "missing mass", and the term "dark energy" has been coined to represent this missing mass.  We know that the mass is real, since the effects are observable, even though the mass itself cannot be observed.

 

Some of the forms hypothesized for dark energy include not-so-strange things like neutrinos (which may have a nearly undetectable mass), and WIMPS (weakly-interacting massive particles).  But then there are odd things like primordial black holes, which due to their age, have nearly disappeared by Hawking radiation, yet are still quite massive despite having small (20 microgram) size.

 

http://www.astro.ucla.edu/~wright/cosmology_faq.html#DM

Elroch

I don't think the idea of black holes that have mostly evaporated makes any sense at all. If they have almost evaporated, they can obviously only account for a small amount of the energy in the universe (in fact of the energy in photons). Also, black holes evaporate very slowly until they get very small, so to evaporate much they would have to have started small. But then they would be very near the end of their finite life, so most of them would have simply exploded entirely.

Also "dark energy" is a repulsive force, so cannot be black holes, matter or photons.

It is "dark matter" (the missing mass that is necessary to explain the way stuff moves) that might be partly explained by black holes.