Time doesn’t go backward, and that is a problem in current physics.
From Quanta:
Why should the fundamental laws have that bizarre and problem-posing property, T invariance?
The answer we can offer today is incomparably deeper and more sophisticated than that we could offer 50 years ago. Today’s understanding emerged from a brilliant interplay of experimental discovery and theoretical analysis, which yielded several Nobel prizes. Yet our answer still contains a serious loophole. As I’ll explain, closing that loophole may well lead us, as an unexpected bonus, to identify the cosmological “dark matter.”
…
We are told, there are “grounds for optimism.” A theortical paarticle called the “axion”:
The theory of axions predicts, in a general way, that axions should be very light, very long-lived particles whose interactions with ordinary matter are very feeble. But to compare theory and experiment we need to be quantitative. And here we meet ambiguity, because existing theory does not fix the value of the axion’s mass. If we know the axion’s mass we can predict all its other properties. But the mass itself can vary over a wide range. (The same basic problem arose for the charmed quark, the Higgs particle, the top quark and several other others. Before each of those particles was discovered, theory predicted all of its properties except for the value of its mass.) It turns out that the strength of the axion’s interactions is proportional to its mass. So as the assumed value for axion mass decreases, the axion becomes more elusive.
…
Do axions exist? We still don’t know for sure. Their existence would bring the story of time’s reversible arrow to a dramatic, satisfying conclusion, and very possibly solve the riddle of the dark matter, to boot. The game is afoot. More.
We expect it will be going on for a while.
See also: Cosmologist tells us how time got its arrow Something is wrong here. Just recording, just recording…
Studying time’s arrow with philosophers
Did time’s arrow originate in a quantum source?
and
The bill arrives for cosmology’s free lunch
Follow UD News at Twitter!
My comment at the end of Quanta’s crackpot article is still in moderation. I copied it below:
Here’s a link to Popper’s paper: Conjectures (PDF)
[edit:] I suspect Quanta’s moderators will trash my comment. The physics community is gutless like that. LOL
Crackpot comment? So the hare never catches the turtle, and the arrow never moves? I believe Zeno brought these problems up long ago.
I’m still trying to understand what this is supposed to mean. Have any reputable physicists or philosophers spelled it out in greater detail than “v = dt/dt is nonsensical”, or “time is abstract, bruh”?
daveS:
It’s no more complicated than “v = dt/dt is nonsensical”. It means that changing time is self-referential. The simplicity of it all is so devastating to the physics community, they just ignore it and act as if Einstein’s time dimension is a fait accompli. As I said earlier, the physics community is gutless that way.
By the way, “reputable physicists” has nothing to do with it. It’s a simple explanation that anybody can understand if they put their minds to it. I see you are one of those who must always have someone else do your thinking for you. That’s lame, man. You are condemned to believe in lies because our world is filled with lies. The more reputable they are, the bigger are their lies.
Time’s arrow is explained by the idea that the universe is a “virtual” reality, that is, an algorithmically implemented system.
Mapou,
v = dt/dt is totally sensical to me, but I think we’ve been over this before. Does anyone else agree with you, and have they published on this topic?
The fact that dt/dt is self-referential in some sense also isn’t problematic to me. As an example, take a finite nonempty set S of real numbers. We can define the minimum of this set by:
which is self-referential.
For another example, define x to be the real number such that x = (x^2 + 9)/6.
Again, x is defined in terms of itself, so this is another case of self-reference.
Well, I tried.
See ya around, daveS.