Dark matter remains one of physics ’ missing puzzle pieces . Only about 4 % of the universe is made up of “ normal ” matter . Do we live in a universe that is not 100 % full ?
M . M .
L . R .
I ’ m not sure what a full universe would be ! Clearly there is a lot of empty space in the universe — on the whole it is not very dense and the temperature is very low . One definition of 100 % full as you say would be that the universe contains critical density — the density in which it is flat . That does indeed seem to be the case .
What about the dark energy ?
M . M .
L . R .
The dark energy is truly mysterious — more mysterious than dark matter in my opinion . It is energy that is spread throughout the universe but is not carried by matter . It doesn ’ t clump under gravitational influence . Instead it drives an acceleration of the expansion of the universe . It is not surprising in some sense that such energy should exist — it is completely allowed .
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Dark matter remains one of physics ’ missing puzzle pieces . Only about 4 % of the universe is made up of “ normal ” matter . Do we live in a universe that is not 100 % full ?
M . M .
L . R .
I ’ m not sure what a full universe would be ! Clearly there is a lot of empty space in the universe — on the whole it is not very dense and the temperature is very low . One definition of 100 % full as you say would be that the universe contains critical density — the density in which it is flat . That does indeed seem to be the case .
What about the dark energy ?
M . M .
L . R .
The dark energy is truly mysterious — more mysterious than dark matter in my opinion . It is energy that is spread throughout the universe but is not carried by matter . It doesn ’ t clump under gravitational influence . Instead it drives an acceleration of the expansion of the universe . It is not surprising in some sense that such energy should exist — it is completely allowed .