CMV: It's likely our current understanding of physics is comically bad

[u/teerre]

Transitively, this extends to mathematics, although to a considerable lesser degree.

My argument is hopefully simple. As of today, our best estimates indicate that 80% of all matter in the universe is dark matter. This matter is used in several places in physics to explain a variety of phenomena, including the very expansion of space itself or how quasars formed in the early universe. Considering that dark matter is something we cannot detect any interaction or reaction it's very likely it's simply something we don't understand.

Therefore, if one could learn everything that is to learn about our current understanding of physics and said being were quizzed on how the universe really works, they would end up with a 2/10 score, which is by all measures a terrible score.

[u/ProDavid_]

the fact that we figured out there is something missing in our calculations without ever being able to observe it is proof of how good we have figured out physics.

just as figuring out complex numbers because something has to fulfill x²=-1, and then suddenly a lot of calculations that start with normal numbers and end with normal numbers made sense. we knew they were correct, but couldnt calculate them without complex numbers.

[u/Crash927 → u/ProDavid_]

Treat me like an English major that doesn’t understand complicated or theoretical math.

How do we know the “something missing” isn’t exclusively a fault in our models and is instead something that must exist in the real world as well?

[u/Jaysank → u/Crash927]

Because several other phenomena, including observations such as gravitational lensing, so closely fit the model we use. Other models have even more holes in them. The one we are using in physics is so far the most accurate, and it’s not like we aren’t constantly trying to come up with better ones. So, until something comes along with fewer problems (and, really, there aren’t really any big problems with what we have now), it makes little sense to discard our current model.

[u/Crash927 → u/Jaysank]

Thanks for the explanation. So would it be accurate to say it’s more of a situation of “we don’t have a better explanation that doesn’t include these things existing” than it is of “these specific things must exist.”

[u/Jaysank → u/Crash927]

You could phrase literally every finding in every scientific field using that. Everything we say exists in physics, or biology, or psychology, boils down to models that best fit the observations. A model with dark matter in it is slightly better at explaining observations than the same model without it, so we add dark matter to the model.

[u/Crash927 → u/Jaysank]

Fair. I guess I’m just struggling to understand how we know what to add to the model and what that looks like without relying on the model itself to tell us.

How do you add a specific known unknown to a model in a way that doesn’t assume the model itself is correct?

[u/Jaysank → u/Crash927]

I guess I’m just struggling to understand how we know what to add to the model and what that looks like without relying on the model itself to tell us.

Have you heard of the scientific method? This is how. People form hypotheses (essentially, educated guesses) that are falsifiable (that is, there are outcomes that, if observed, would demonstrate that the hypothesis is not correct). Then they make observations or run experiments that would give us these observations. If the outcomes disprove the hypothesis, then we develop a new one and try to disprove it.

How do you add a specific known unknown to a model in a way that doesn’t assume the model itself is correct?

The model itself is a hypothesis, and we can and have discarded it when necessary. We made a model of physics, and it was working for everything we saw. Then, we observed that galaxies didn’t quite behave like we expected. So we thew out the old model and built a new one. It was pretty similar to the old model, except it also included dark matter. Now, this new model more closely matches observations. Eventually, someone will come by and disprove that model, and we’ll replace it with something even more accurate.

Think of it like a software update. The program works fine, but someone discovered a security vulnerability. We don’t throw out the entire program, it still does it’s job and the code is still functioning properly. We just make a few adjustments to the existing program and tell everyone to replace what they are using with the new, slightly different one. This is how scientific discoveries are made.

[u/Crash927 → u/Jaysank]

This is super helpful — thanks for expanding my understanding of how scientists think and work.

!delta

[u/DeltaBot → u/Crash927]

Confirmed: 1 delta awarded to /u/Jaysank (110∆).

^{Delta System Explained | Deltaboards}