You have to define "symmetry of the universe". "Symmetry" implies "perfect symmetry" which implies for every action, there is an equal and opposite reaction. But that can only be to attempt to "maintain symmetry" so symmetry can never be.
Just some wild thoughts from my wild mind.
"Symmetry" implies "perfect symmetry" which implies for every action, there is an equal and opposite reaction. But that can only be to attempt to "maintain symmetry" so symmetry can never be. If the universe existed in perfect symmetry, we'd have a universe full of gamma rays and nothing else. It's the asymmetry that gave rise to matter.
And for what it's worth, I always considered "dark matter" to be the astrophysicists' equivalent of "dragons" on old world maps. Might as well say "The Force Formerly Known As Prince".
Frowning takes 68 muscles.
Smiling takes 6.
Pulling this trigger takes 2.
I'm lazy.