"Physicists have identified a set of fundamental symmetries in nature. The three most important symmetries are: charge (if you flip the charges of all the particles involved in an interaction to their opposite charge, you'll get the same interaction); parity (if you look at the mirror image of an interaction, you get the same result); and time (if you run an interaction backward in time, it looks the same).

Physical interactions obey most of these symmetries most of the time, which means that there are sometimes violations. But physicists have never observed a violation of a combination of all three symmetries at the same time. If you take every single interaction observed in nature and flip the charges, take the mirror image, and run it backward in time, those interactions behave exactly the same.

This fundamental symmetry is given a name: CPT symmetry, for charge (C), parity (P) and time (T).

In a new paper recently accepted for publication in the journal Annals of Physics, scientists propose extending this combined symmetry. Usually this symmetry only applies to interactions — the forces and fields that make up the physics of the cosmos. But perhaps, if this is such an incredibly important symmetry, it applies to the whole entire universe itself. In other words, this idea extends this symmetry from applying to just the "actors" of the universe (forces and fields) to the "stage" itself, the entire physical object of the universe."

    • fratsarerats [none/use name]
      ·
      3 years ago

      I mean most cosmological theories at this point are speculative right? As long as the math is pretty people seem to like it (e.g. string theory).

      • modsarefascist [he/him]
        ·
        3 years ago

        Yeah cus it's bout damn impossible to test for things like string theory with our current tech/energy level.

        Hell we just now confirmed the higgs boson and it's been speculated to exist since the 50s.

        Our capacity to theorize is far beyond our capacity to test. That doesn't mean testing is impossible but it's slow af compared to pure theory

        • fratsarerats [none/use name]
          ·
          3 years ago

          Yeah I get that but I dunno why the commentor above thought it was "speculative shit from paper churning clout chasers." Kinda odd

          • modsarefascist [he/him]
            ·
            edit-2
            3 years ago

            There's a real strong bubble forming in the left wing internet (socialist left). People think they because economists are mostly propagandist and political scientists are so right wing as to be mostly useless that it means that ALL science is up to the interpreter.

            I used to think being a leftist meant you had to be smart enough to see through the propaganda haze but these days I think it's just damn luck that leads people to leftism. Luck and morals, with the morals making them left wing and the luck being how they saw through the propaganda. Maybe I spent too much time on Latestagecapitalism, I swear that sub is so bad it might be a psyop.

            • bigboopballs [he/him]
              ·
              3 years ago

              Maybe I spent too much time on Latestagecapitalism, I swear that sub is so bad it might be a psyop.

              I think it's safe to consider reddit a big psyop.

          • Llituro [he/him, they/them]
            ·
            3 years ago

            I called it that because you could never prove this and it doesn't add any new explanations. A worthwhile novel theory needs to add some prediction that is testable, and not just say there might be a mirror universe out in the multiverse. The fact this got picked up by lay publications is also very clout chasing.

    • zifnab25 [he/him, any]
      ·
      3 years ago

      Its headline gore, as "runs backwards in time" is being shamelessly substituted for "is composed of particles with different fundamental properties produced through a symmetry during the initialization of the universe".

      It also isn't something terribly new. Just a theory that's being continuously explored and fleshed out as incremental discovers in fundamental physics trickle in.