Did all the universe's energy begin at the same time as the universe?

[ImaLooser]

I believe light loses energy over time due to redshift from expansion.

I thought that total energy was conserved. Energy density of radiation decreases because the volume of the universe increases. Energy density times volume is a constant, as far as I know in a finite Universe. In an infinite Universe then energy density divided by matter density would be a constant.

 

[Chalnoth]

I thought that total energy was conserved. Energy density of radiation decreases because the volume of the universe increases. Energy density times volume is a constant, as far as I know in a finite Universe. In an infinite Universe then energy density divided by matter density would be a constant.

Nope. See my first post in this thread.

 

[Chronos]

Keep in mind some forms of energy are positive, and others [e.g., gravity] are considered negative. At the moment, negative energy appears to dominate the universe.