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Comment by mvlipwig | Hacker News Reader

This might be a result of me not understanding theoretical physics, but this seems "not even wrong." How could you even go about testing this?

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Maybe you could disprove it by observing a electron/positron pair being created and then annihilating each other, forming a closed loop that couldn't be part of the single path traced by a single particle.

How would you observe that?

IANP, but Ive always thought you should be able to observe reverse causality in a positron if true. That’s the primary effect of going backwards in time - a reverse in entropy.

The other side of the theory is the positron hidden in the proton. I assume a particle collider should be able to falsify this.

But it turns out antimatter isn’t supposed to actually move backwards in time but follows the same causality as everything else. It’s just that they represent their matter pairs configuration mathematically by reversing the time orientation. This isn’t super obvious but it’s very much different than going backwards in time literally. Sad!

This is yet another case where a layman-written wiki article about physics is highly confusing to other laypeople, because it only tells you half the story. Particularly because it seems to be based on a chapter of Feynman's popular science book. But the book actually goes on and points out how Feynman immediately dismissed Wheeler's hypothesis, because the universe contains a lot more electrons than positrons. You'd have to explain that imbalance first if you want to entertain this line of thought.

As a layperson myself - how can we tell that a distant celestial object is not made from antimatter? Afaik, it doesn't behave differently from matter, other than it annihilates on contact.

Also even if we could, that would only describe the practically and theoretically observable universe, which doesn't rule out other places looking very different (on its own)

Because distant celestial objects accelerate a lot of matter away from them as parts of different processes. For example if there were a sizeable chunk of space were antimatter than at the edge of this space there would be a constant glow of annihilation. We don't see that anywhere (well except things like quasars doing this at small scales.

So, yea, it would have to be outside the observable universe in which that means we can do no empirical science on it therefore it not being real to us.

What if most galaxies are actually dark matter, and we are the exception?

Depends exactly how your phrasing this.

Dark matter represents far more of the universe than 'light' matter by volume if our physics is correct, so by that most galaxies are mostly dark matter by default. We have found a few very small ones that don't seem to be.

With this said dark matter still influences the curvature of space time so its not completely invisible. We could see a dark galaxy because it would alter the images of galaxies behind it with things like Einstein rings and crosses.

Yea, it's really more about the fact that all electrons are exactly the same regardless of the level of precision we look at them. It would be like if we found another earth and that earth was the exact same earth. Not earth like, not very close to earth. The exact same earth down to the smallest fundamental level.

We have something like a spinor network in 4D space, where some portions are opposite others in parameters.

Is this a diagram of particles interacting or a single thread weaving through time? Pick your metaphor.

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