First collisions at the LHC with unprecedented Energy! (Ask a particle physisicist)

[JuliaL]

Vell, ve can't all be der virst violinists in der orkestra.
Some ov us gots to push der vind tru der tuba!

After 6 years of medical practice, I thought it might be amusing to take a course in ethics as distribution credits towards an engineering degree.
It was fun, but I wasn't impressed with the rigor.
Math isn't as flexible.  But when it's right it's right.

BTW, is there a 'Particle physics math for dummies?"
I did well in the engineering math courses, though it's been a while.

I strongly disagree with the idea that math isn't poetic. I find the crystalline elegance with which it describes many things, to be among the most poetic things I know.


Concerning particle maths for dummies, when my field theory text book comes out this fall (which is aimed at advanced undergrad and beginning grad students) I have actually considered doing something like that - kind of a popular science book with extra maths sections.

I think, if you check carefully, that I wrote, not that math wasn't poetic, but that it wasn't as flexible.
(don't you love quick editing?)

In your writing, please do address the greater audience.
I'm sure you'll have no lack of volunteers to check for comprehensibility (raises and waves hand with enthusiasm.)

[JuliaL]

Higher number body systems can sometimes be treated in perturbation theory, i.e. a systematic approximation. Newton did not understand this, but Laplace and colleagues did, and this is how they finally were able to fully describe the solar system including the effects planets have on each other.

It is very easy to find scenarios where all analytic description fails and all we can do is try and run a computer simulation, which is also always an approximation.

The equations of motion of the standard model have not been solved exactly analytically either, and need to be treated e.g. with such a perturbation theory.
In fact, Feynman diagrams are exactly that - a graphic representation of a systematic approximation taking more and morr virtual particle effects into account.

I remember, way back in the previous century, when I was taking fluid mechanics, the navier stokes equation was the thing only it couldn't be solved for real bodies and so was sort of a lovely theory with no real applications.
Then came computational fluid dynamics which was nothing but approximations but which could be implemented and now we've got things like spaceship one where really complex dynamics can be simulated and prototyping is minimized if not eliminated.

Sounds like your perturbation methodologies are something like that.

But Julia, here's a follow up question to your idea, how do you measure the accuracy of a theory? How accurate is newtonian physics? I can contemplate situations where it fails with arbitrary severity - just go close enough to the speed of light.

I'm going to take that as a rhetorical (answer optional) question. Otherwise you're really asking the wrong person.
I get stuck on figuring out whether or not motion exists.
How about 'accurate enough?'

[Pyrrho]

Higher number body systems can sometimes be treated in perturbation theory, i.e. a systematic approximation. Newton did not understand this, but Laplace and colleagues did, and this is how they finally were able to fully describe the solar system including the effects planets have on each other.

It is very easy to find scenarios where all analytic description fails and all we can do is try and run a computer simulation, which is also always an approximation.

The equations of motion of the standard model have not been solved exactly analytically either, and need to be treated e.g. with such a perturbation theory.
In fact, Feynman diagrams are exactly that - a graphic representation of a systematic approximation taking more and morr virtual particle effects into account.

But Julia, here's a follow up question to your idea, how do you measure the accuracy of a theory? How accurate is newtonian physics? I can contemplate situations where it fails with arbitrary severity - just go close enough to the speed of light.

Isn't Newtonian physics "good enough," as long as one stays away from very fast things and very tiny things?  Or in other words, isn't Newtonian physics adequate for anything a regular person is going to need?

[Pyrrho]

[Alex K]

[JuliaL]

[Alex K]

You are correct. And it would mean that quantum phenomena that involve very very little energy transfer can have long duration. Bose Einstein condensates come to mind. This is just arguing from very general principles without having thought about the detailed examples too much.

[Alex K]

What I say above is just my standard opinion which I have voiced many times IRL

I .do have a question:  What would finish the sentence you started at the end of your post, which is quoted in full above?

Generally, I think that good philosophy of physics is important, because we do want more from our science than a black box of equations which reproduces certain experiments - because as David Deutsch rightly asks in "fabric of reality" (*), what would we have gained in understanding over someone who merely executes the experiment, if we did limit ourselves to such a concept of science as a predictive black box. We want more from our science - we want it to provide intuitions, explanations, we have a natural urge to see truth in our theories. To what extent we can have this and what it means, those are, in my opinion, questions of philosophy, not science, and questions one would not want to do without.

(*) I may be paraphrasing...

[JuliaL]

[pocaracas]