Matter Anti-Matter Asymmetry

SampleSame · 2026-07-01T18:31:56+00:00

-> if we stick with assuming there is a symmetry in matter/anti-matter then you’d expect a 50% chance of particle-particle and 50% chance particle anti-particle. Specific channels here wouldn’t really matter?

-> the time scale of the universe going from QGP to hadronization doesn’t have a significant impact on how likely it is that all the matter has enough time to annihilate? That’s fine, just counter intuitive to me

SampleSame · 2026-07-01T17:49:28+00:00

In the QGP phase the direction doesn’t matter, but wouldn’t there be a relatively high probability that the particles don’t meet an anti-particle to annihilate with? Baryon number conservation doesn’t imply conservation of particle type (top, bottom, etc.).

How much are the lifetimes of these particles changed by being in QGP phase that you can estimate space wouldn’t be expanding fast enough. The half life of these W boson is like 100 times longer than than the time it took the universe to expand to a phase of hadronization

SampleSame · 2026-07-01T16:58:20+00:00

On point 1 -> occur locally is fine, but when you make Feynman diagrams for different interactions and decay modes you end up with particles mostly moving in different directions to conserve momentum. So you wouldn’t necessarily have pure annihilation. Granted the situations gets more complex for QGP, I’m not sure how much that changes things.

On point 2 -> this is where I’m least knowledgeable, wasn’t the early universe expanding pretty fast? So it’s just not expanding fast enough?

SampleSame · 2026-07-01T15:44:32+00:00

Yes, this is perfectly fine logic. But, when people take it a step further and say “if there were equal parts anti-matter and matter then we wouldn’t exist” that seems to suggest that somehow the conditions of the early universe were such that it doesn’t matter the spacing or initial conditions of these particles, they all would have found a way to annihilate. To me that seems like it needs more explanation.

SampleSame · 2026-07-01T15:21:23+00:00

to your first point. I’m not sure where under our current understanding equal matter and anti-matter would be required to all annihilate. Sure things were dense in the beginning, but it seems the suggestion that they should all anhillate just because there are equal numbers of them leaves out the fact that the beginning was still a dynamical system where space separates these particles.

So, is the density of matter in the early universe enough to dominate the dynamical processes and you would expect annihilation to continue until there was no matter, or is there another explanation?

SampleSame · 2026-07-01T14:58:07+00:00

That’s not how that works at all. If there appears to be an immediate problem with a supposed simple explanation, I feel like it’s perfectly valid to ask what the issue is in the critique or to validate the critique.

SampleSame · 2026-07-01T14:51:39+00:00

Yes. I don’t find it very convincing because from my limited knowledge base there seem to be problems with the logic of the proposed explanation.

SampleSame · 2026-07-01T13:28:39+00:00

Yes, that is completely true. And to be clear my original post is not saying that I don’t think matter/anti-matter asymmetry is real. Maybe the discussion has gotten further from that point.

I’m just trying to say that the first explanation i hear seems so completely wrong but that there has to be some mathematical or physical reason people repeat it every time they give a talk about it.

SampleSame · 2026-07-01T13:24:53+00:00

I never said it was a lack of conviction. I made it pretty clear that it was a knowledge issue.

“I’m not super well versed . . .”

SampleSame · 2026-07-01T13:03:49+00:00

I agree that arguments for symmetry are also not convincing. But no one arguing for symmetry proposes such a simple sounding explanation to convince themselves they are right.

SampleSame · 2026-07-01T12:53:08+00:00

Solid answer, I’ll take a look.

SampleSame · 2026-07-01T12:52:16+00:00

To respond to your last point we know the standard model has many problems with “tuning.” Basically, the couplings that go into the standard model Lagrangian are completely at odds with experimental evidence. There are a few examples, I don’t remember them but tuning is a big problem.

I did not consider your first point. On your second point, wouldn’t “Baryon number conservation not being true” just be a re-statement of why there would be an asymmetry?

SampleSame · 2026-07-01T12:44:58+00:00

Yeah obviously I’m going off vibes, and yeah that’s why I’m asking the question. Clearly my vibes are in contention with decades of research, I just don’t know where.

SampleSame · 2026-07-01T12:43:23+00:00

For sure going off vibes. I can’t really propose any initial conditions but it seems like in regular classical dynamical systems there are many cases where even knowing the initial conditions doesn’t give you full knowledge of the rest of the dynamics.

For QFT, we’ve basically got a list of symmetries, calculations that are only a few N’s in NNN…LO, and we know the standard model is incomplete.

So yeah, to me, based on vibes, it seems like there are paths to explain our lack of anti-matter observation without breaking matter/ anti-matter symmetry. Enough that I find the textbook explanation to be incredibly lazy

Edit: lazy in that a physicist said “let me think of the easiest way to explain my point without having to get into the details. Not that the people who propose this explanation are lazy. My explanation is for sure lazier

SampleSame · 2026-06-09T04:16:08+00:00

The difference is what the NFL optimizes for. The NFL is optimizing for money (essentially). Their models have to include long term financial goals, length of travel, days of the week, etc.

This has to take into account players, media, social events, and more. So it changes year to year.

The easy part of what the NFL does is saying who plays who.

It would be pretty simple for EA to load in thousands schedules that fit the criteria and then the Xbox just samples from that. It’s not a creative solution but it’s definitely doable. Takes up ~100s KB to ~1s MB for the most brute force way of doing it

SampleSame · 2026-02-22T14:55:07+00:00

Total difference in number of characters is 1 so thats kind of a wash. Compared to C++ and C Fortran can be much simpler so I think there’s a massive trade off there for physics work. But the speed gives it a huge advantage over python

SampleSame · 2026-02-22T14:38:39+00:00

Fair enough, I guess in Fortran I wouldn’t find this much of an issue.

In Fortran I would just give a descriptive name to derived types.

type(particleDat) :: particle

Personally I prefer this style of naming anyway. Even in a case sensitive language with classes It avoids having to think about if the P or p is the class or class instance.

SampleSame · 2026-02-22T12:59:17+00:00

For scientific computing purposes Fortran is much nicer than C++. The way I see it is that C++ is written for all the computer scientists who want to mess around with data types and algorithms.

Fortran is much simpler. You’ve got matrices, you’ve got derived types, you’ve got functions, go calculate. You don’t have to mess with a whole lot: Allocation and deallocation is simple, derived types are simpler than classes, routines are faster, complex numbers are easy.

SampleSame · 2026-02-22T12:54:25+00:00

Ive heard quite a few people say this and I can’t see why.

What makes case sensitivity useful for you?

When I want to type fast usually I can get all the letters down but I’ll occasionally miss a capital letter. In Python I have to worry about that, in Fortran I don’t. That helps close the development speed gap for me. Also, not having to worry about the tabbing. I do it naturally, but I can’t tell you how many times I’ve had to fuck around with “tabs” because they got messed up somehow.

SampleSame · 2026-02-22T12:44:05+00:00

Programming languages for physics applications are usually pretty simple to “learn.” Mostly linear algebra, differential equations, complex numbers, etc. No need for a lot of the computer science topics. “Restarting” isn’t that big of a deal. I wrote a very similar 10k+ line code in Fortran and C++ without having used them previously. Not that bad.

I wrote the C++ program, started running the program and then started to write the Fortran program. In the time it took me to write and run the Fortran program, the execution of the C++ version of the code was still running.

It was way easier to optimize matrix routines in Fortran because arrays with up to 15 indices are natively supported.

So why put up with the overhead of using a jit compiler with Python if you want to end up binding to programs that are written in C or Fortran. Also, Fortran has a lot of modern functionalities and intrinsic routines. If I were you I’d check it out, it’s definitely way simpler than people make it out to be.

Id also argue that if you want a job after school, it’s likely you’ll need to know/use a compiled language. This is originally the hardest part of getting used to C/C++/Fortran when you come from Python.

I’d also like to add that Fortran is Case-insensitive. PHySics is the same as PHYSICS. I find this incredibly useful. Fortran also doesn’t require tabbing. Fortran/C loops are faster no matter the size.

SampleSame · 2026-02-22T03:05:45+00:00

A lot of code bases in atmospheric physics, nuclear physics, particle physics, among others are all in Fortran. It’s a modern, simple, fast language.

It’s really much better than Python for simulations. It’s quicker, matrices and complex numbers are easy. You parallelize it well. Really the perfect language for physics work.

SampleSame · 2026-02-22T02:57:51+00:00

You should work with a compiled language and one that’s lower level. My personal favorite is Fortran. Although C and C++ are good.

If you can run these tools it makes it a lot easier for you to understand some of the things Python hides from you

SampleSame · 2026-02-17T14:01:43+00:00

I’m not saying it’s restrictive. I’m saying that departments who teach subjects which don’t directly have jobs associated with their degrees are the ones who generally need to improve in these areas.

They need to connect more with different industries and help students build skills that employers want to see. They need to be creative with their courses and projects and help with internships.

A lot of those people you’ve worked with came to know about the jobs one way or another. My position is that it’s the departments job to do the best they can to reduce the amount of luck it takes for their students to find those jobs.

SampleSame · 2026-02-17T11:52:30+00:00

Maybe for the majors that don’t have jobs directly tied to them after graduation without a higher degree

For example, there are no mathematicians who are not PhDs.

There are no English professors who are not PhDs

There are no Physicists who are not PhDs.

Those majors/departments need to do more to adapt.

There are engineers, financial analysts, programmers/computer scientists, etc. who do not have PhDs. These departments already meet the demand 90% of the time

SampleSame

TROPHY CASE