drossbucket

I’m pretty serious now about becoming a crackpot physicist. I even have an expandable bullet-pointed plan:

Actually I’ve had this list for a while now, but it’s becoming less of a joke. And a couple of weeks ago I went to the most amazing workshop, organised by early-career physicists who are pretty unimpressed with the state of a lot of academic physics themselves, and they were very understanding and welcoming. So now it looks like I have allies on the inside!

The aim is to be a sort of high-class crackpot, rather than the sort who spams mailing lists with EINSTEIN WAS WRONG screeds. I want to engage with the actual physics community, and learn more physics.

Learning is going well already. I have a full time job so have to work around it, but I’ve got fairly disciplined now and have learned that you can do a lot with half-hour focussed blocks of time. In some ways it’s more freeing than the PhD situation, because you never have to worry that you should be working on your stupid thesis instead.

Research will be a harder one to crack. I’m pretty sure it just needs longish stretches of uninterrupted time, and I don’t have many of those. So long term I also need to work out a better employment situation. I’ve punted those decisions to October at the earliest, though, and for now I’ll focus on learning.

This is the plan:

• QFT first pass: focus on scalar phi^4 theory

This is pretty much the simplest option, and I’m sticking to it pedantically in the spirit of ‘examples first’. I’ve had this ‘sort out my embarrassing total lack of QFT background’ plan going for a while now, so I’m already a good way through this one. The aim is just to know roughly how to calculate some shit without getting too hung up on technical details.

I lucked out by buying the book Quantum Field Theory for the Gifted Amateur, by Blundell and Lancaster. It’s a bit of a weird name but turns out to be brilliant – it’s pitched at exactly the level I want, giving a reasonable overview of how to actually calculate things with out being immediately bogged down in the sort of practitioner-level detail that the likes of Peskin and Schroeder need to go into. I’m starting to think I should ask the authors for some kind of sales commission as I keep plugging it to all the physicists I meet. I’ve got a few chapters on renormalisation to go and then I think I’m done with the phi^4 material.

I don’t want to go completely mad on conceptual questions either, but I do want to clear up some of my ‘quantum without quantum’ confusions and figure out what’s actually novel and what’s a bunch of methods that could just as easily be used in classical physics.

I think the key question is still: where are the loops coming from? You don’t get those in classical perturbation theory. I’m suspicious that the weirdo Feynman propagator is part of the issue, and I’m curious what happens when you introduce it in the classical case. I should stop vaguely wondering about this and actually go and do some maths.

• Quantum foundations grab bag

Now I’m a proper crackpot I can think about the foundations of quantum mechanics as much I as want 😀

The main part of this is going through Matt Leifer’s Perimeter course video lectures, which I’d already started on. But now I also have a big old supplementary reading list from the workshop. Also I might get hold of Bell’s Speakable and Unspeakable, which was passed around there like some sort of holy relic.

• QFT second pass: nonzero spin

Not sure of the exact plan as this is some way off, but it may evolve into some giant detour where I learn geometric algebra too.

I always thought that was one of those weird things with the worryingly zealous true believers, but at the workshop a couple of true believers did a good job of convincing me it was worth bothering with. Apparently they find it to be a really useful tool for going up and down the ladder of abstraction, with the same notation helping them both with getting a clean geometric understanding of a problem and with cranking actual numbers out. That’s exactly the kind of thing I’m always looking for! So maybe if I’m going to be messing about with spinors this’ll help.

Also now I’m a crackpot I can learn whatever I like. Being a crackpot is fun!

• Looking for the fine structure constant in the Bible

… or maybe not. I’m not that far gone yet! (Growth mindset?)