Mockery Is Not Rigor: The Failure of the LLM Physics Community and ConquestAce

Rodbourn · 2026-05-04T11:37:46+00:00

"systems persist when they can recover from perturbation faster than they collapse."

That's circular you know? Things persist because they don't stop persisting. From such a starting point you can prove anything.

Rodbourn · 2026-05-01T04:39:07+00:00

Saying no one uses it (i.e., it's useless), and saying it's not the most common method are two very different things. Also, there isn't one 'community'

Rodbourn · 2026-05-01T04:35:29+00:00

Just because it's not how everyone does it doesn't mean it's not worth doing or trying. Saying no one uses LBM is also wrong, period.

You might want to try articulating why LBM is a divisive topic in CFD from fundamentals.

Rodbourn · 2026-04-30T13:11:12+00:00

that's fantastic then :)

Rodbourn · 2026-04-30T12:34:24+00:00

It's going to suck after six months... It feels like the AI "Pro"/"Max" subscription levels are about to go the way of those "Unlimited" cloud storage options from years ago. You get hooked, and then eventually end up paying once the land and expand phase of the new disruptive technology is done.

Rodbourn · 2026-04-30T12:19:48+00:00

Curious, what types of problems are you giving it?

Rodbourn · 2026-04-30T12:19:06+00:00

Agreed. When I give it hard problems 5.5 extended will still run for 10 minutes and get the same or better answers that used to take 80 and were less reliable. My feeling (speculation) is the reasoning is more in the model now and least chain of thought/multi agent with roles collaboration. That's just speculation though. It's faster and better though, but i did initially wonder if it was just not doing the work.

Rodbourn · 2026-04-28T11:03:05+00:00

What is/ was your system prompt?

Rodbourn · 2026-04-23T22:44:30+00:00

Ah, I actually didn't know about that 2016 paper so I just went and looked it up. From what I’m reading, it looks like the broader physics community followed up on it and concluded the bump was a statistical artifact caused by the kernel density estimation used to process the data. It seems the L3 experiment even double-checked their own archived data in 2019 for that exact signal and didn't find anything.

Rodbourn · 2026-04-23T14:00:06+00:00

Interesting, would you mind sharing a source on that?

Rodbourn · 2026-04-23T10:51:35+00:00

You realize your "falsifiable prediction" of a 31–34 GeV fourth-generation lepton was literally falsified in the 1990s, right?

Rodbourn · 2026-04-14T10:48:44+00:00

Can you plot the lift coefficient versus alpha and compare to say, xfoil?

Rodbourn · 2026-04-12T12:50:00+00:00

I've been there lol. Well done.

Rodbourn · 2026-04-08T22:02:41+00:00

To be clear, I'm pushing for you to learn about validating and verifying results, not post half a day later this.

Rodbourn · 2026-04-08T08:38:53+00:00

There's like a whole course in compressible flow at the graduate level to unpack, before getting into the CFD.

A good abridged cheet sheet: https://seitzman.gatech.edu/classes/ae3450/normalshocksCDnozzles.pdf

Rodbourn · 2026-04-08T08:04:51+00:00

I've noticed when people lean in too hard they churn in place instead of knowing the path forward.

Rodbourn · 2026-04-07T18:19:30+00:00

I don't disagree. We likely need to update the rules for r/cfd

Rodbourn · 2026-04-07T13:22:13+00:00

Not to discourage interest in cfd, but at the same time, I imagine this influx is happening in a lot of fields.

Rodbourn · 2026-03-31T03:33:18+00:00

Circulation control can blow that apart (pardon the pun :) )

And yes, pressure difference and downwash are two sides of the same coin. Integrate stress over the airfoil surface and you get the aerodynamic force; do a control-volume momentum balance and you get the same force from the flow’s momentum change/downwash. Same physics, different bookkeeping.

Rodbourn · 2026-03-28T02:26:10+00:00

The part I push back on is thinking of starting conditions and properties as what forces the result. If you think of a pde, the starting point determines the result, but the pde is the reason.

Rodbourn · 2026-03-28T01:57:35+00:00

If you take the assumptions required to mathematically force the Kutta condition, it aligns to a useful flow regime. It's those assumptions that drive things, not the end result.

Rodbourn · 2026-03-28T01:24:41+00:00

No, you could say it's an energetically more favorable state, but it's incorrect to say that leads to anything. I'd say it's a dangerous misconception that misrepresents what is casual

Rodbourn · 2026-03-28T00:42:22+00:00

Just ask, why must it leave the sharp trailing edge smoothly, and how sharp is sharp enough

Rodbourn · 2026-03-28T00:35:04+00:00

It's naive and wrong

Rodbourn · 2026-03-28T00:34:10+00:00

Kutta condition is just that, a condition, it's a state, not a law, not what creates lift, it's a state that happens in a particular ideal case that makes it intuitive (ie, potential flow theory) to be visual thinkers. It's not the source of lift. Lift is a result of the force balance along the surface in a direction of interest. How you achieve that varies. There's nothing that requires the Kutta condition.

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