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RE: Do we still need to build models beyond the Standard Model of particle physics ?

in StemSocial2 months ago

Sorry for the delayed answer, once again. Busy week, buy week… and this discussion is interesting. I cannot answer it in one line :)

Dark matter as I understand it's description is proposed to comprise of WIMPs, weakly interacting massive particles, which have properties specifically that do not otherwise interact with other matter than gravitationally.

WIMPs are only one possibility amongst many. Those are dark matter candidates particularly targeted at current experiments. But you have many many other options, ranging from very light particles to much heavier black holes. The only common ground is that they have gravitational effects. The rest belongs to the details of each model.

[…] ordinary matter at other times is simply not observable because we perceive time as an instant, and have not understood the nature of spacetime with which ordinary matter interacts.

We can observe it through the byproducts of what this matter did in the past. For instance: cosmic rays. We just get them on Earth after a while. For that reason, when we observe the universe far far away, we in fact observe the universe as it was a while in the past.

From the rest of what you mentioned, there is actually one point on which I disagree. The arrow of time cannot be inverted. We can observe the present and the past (which corresponds to observing far away), but not the future. If I have well understood, it seems that you want to consider what is happening now, in the past and in the future. This is not possible. We can account for the first two in the calculations (including what is happening on the way and during history), but not for the latter. How would an event happening in the future impact us? This is what needs to be clarified, and this may be in contradictions with the known laws of physics.

Cheers!

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I am happy to be patient to be availed your great understanding at your convenience to criticize my poor layman's understanding.

I, poorly read, am unfamiliar with other models of dark matter. However, any of them seem unnecessary given my understanding that spacetime, which includes all times including those we perceive as past and future times, is affected by mass such that it warps.

Regarding the arrow of time, I reckon that applies to our perception of it, rather than the actual nature of it, because time does not exist. Spacetime exists, and, as such, I see no possibility that it only exists in one 'direction', but rather is a unitary whole. We may not be able to perceive that whole, but that whole exists nonetheless, and we can observe that space is not unidirectional in any way, so there is, IMHO, essentially proof that time cannot, since spacetime is one thing.

It is not possible for us to perceive the future. However, we can conceive of it, at least estimate it. IMHO the future is an artifact of our means of perceiving, not the nature of reality. I conceive of reality as a gestalt, a crystalline clockwork that incorporates such beginning and end in it's whole.

I cannot understand how spacetime could exist otherwise. Would spacetime somehow erupt from probability in planckian quanta from the vacuum? How could the totality of the universe be inextant and only become extant per time, when time does not exist? It is our perception that is limited, not the universe, IMHO.

Thanks!

, poorly read, am unfamiliar with other models of dark matter.

Please don’t worry. There are so many models available that is is hard to be up-to-date. I am definitely not myself fully up-to-date, although I know the big classes of models available (which is different from knowing all models taken individually).

However, any of them seem unnecessary given my understanding that spacetime, which includes all times including those we perceive as past and future times, is affected by mass such that it warps.

The issue I have with the above statement is that it has problems with various known laws of physics. For instance, causality would be deeply broken and thermodynamics too. It is all connected to the arrow of time (see below). There is a one-way observed direction of time, at least at the macroscopic level. How would your understanding deal with this? This is unclear to me.

Regarding the arrow of time, I reckon that applies to our perception of it, rather than the actual nature of it, because time does not exist.

This is another thing that is unclear to me. Time exists, and the same manner as space exists. They are both components of spacetime. The fact that we can unify them in a more general concept does not mean the individual concepts are incorrect or cannot be taken individually to solve certain problems.

It is not possible for us to perceive the future. However, we can conceive of it, at least estimate it. IMHO the future is an artifact of our means of perceiving, not the nature of reality. I conceive of reality as a gestalt, a crystalline clockwork that incorporates such beginning and end in it's whole.

Finally, predicting the future is different from having the future impacting the present. This is where causality hits us. As said above, this is where I don't understand your reasoning and where I would need more clarifications.

I cannot understand how spacetime could exist otherwise. Would spacetime somehow erupt from probability in planckian quanta from the vacuum? How could the totality of the universe be inextant and only become extant per time, when time does not exist? It is our perception that is limited, not the universe, IMHO.

Actually, you are not the only one who cannot understand this. This is a good question and hopefully we will see an answer, at least some day.

Have a nice week-end!

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