Says the random person on the internet in response to the quantum physics professor who says otherwise.
I take it you did not read the article.
I did, actually. So, what makes it “bullshit?”
Dude.
First off, it’s purely a hypothetical model. You can plop in negative time to equations and have them make sense, this doesn’t mean that negative time is possible.
However disregarding that. The abstract of the study:
We study the internal dynamics of a hypothetical spaceship traveling on a close timelike curve in an axially symmetric Universe. We choose the curve so that the generator of evolution in proper time is the angular momentum. Using Wigner’s theorem, we prove that the energy levels internal to the spaceship must undergo spontaneous discretization. The level separation turns out to be finely tuned so that, after completing a roundtrip of the curve, all systems are back to their initial state. This implies, for example, that the memories of an observer inside the spaceship are necessarily erased by the end of the journey. More in general, if there is an increase in entropy, a Poincaré cycle will eventually reverse it by the end of the loop, forcing entropy to decrease back to its initial value. We show that such decrease in entropy is in agreement with the eigenstate thermalization hypothesis. The non-existence of time-travel paradoxes follows as a rigorous corollary of our analysis.
So the study the article is based on concludes that time-travel paradoxes are impossible. Thus you can not kill your own grandfather because it’d create a paradox. What they’re saying is that you could be in a CTC (closed time-like curve) where in which time goes back and forth from your grandparents to you and back again, but the time going back would reduced entropy ie reverse things.
So you couldn’t “go back” because that’d mean your entropy ie your arrow of time, was still pointing forwards and not backwards.
This isn’t a case of some random Lemming against a professor saying otherwise. It’s Lemmings telling you you’ve bought into pop-science sensationalism.
The article does actually communicate what I explained there, but really almost hides it with the language, so I’m not surprised your either didn’t read it, missed it, or didn’t internalise it:
Circling back to a spry young grandfather courting your grandmother the first time, the time loop could make his untimely death reversible; your memory of why you ever wanted to murder him in the first place may be erasable. In other words, all bets are off in a closed loop where quantum physics smoothes out any intrusive entropy.
Ie nothing here is breaking the Novikov self-consistency principle
You violate causality, you better bring more than some popsci bullshit to the table.
And you’re the arbiter of what constitutes “popsci bullshit” rather than the quantum physics professor? Such hubris.
removed by mod
In my experience, people with rational reasons for rejecting claims can articulate said reasons, rather than simply calling them bullshit and telling other people to fuck off. I’m not convinced of the article’s claims, but I’m also not convinced you know what you’re talking about either. The difference is that the article admits its claims are speculative and hypothetical, while you’re just slinging insults.
Rejecting causality IS the rational reason. It is you who is irrational. When one scientist brings forth a claim that breaks ALL of physics, with ZERO empirical evidence support such an astounding theory, it is not the ones who doubt that are likely to be wrong.
It read to me like they provided a reason for denying causality though: that the associative breakdown in entropic state suggests causality can be violated. I don’t have the expertise to evaluate that claim, but if you do, why don’t you just explain to me why it’s wrong? Or is that demanding too much of a random person on the internet?
Uh, because the entire field of physics is completely fucked if causality is violable? I’m really done with you.
That’s good, because I’m pretty sick of you too. What an arrogant POS.
