Recent content by Physicsphysics

I'm reading once again through Landau-Lifchitz and I am stuck on the first page! I can't wrap my head around why we only need to define the coordinates and velocities to determine the acceleration? Surely if we only know those two in a single point in time, that's not enough to determine an...

Ok then, I'll assume it's wrong. Thank you for your reply.

After some discussion, this was the conclusion... Is this correct?

This is a task set by my professor and we're meant to show the quarks explicitly. We've been taught the basic rules with Feynman diagrams but honestly not much of the maths so this is almost entirely guesswork. It is quite frustrating with the hilariously superficial "understanding" I have atm 😅

Right. Where the lines cross, I assumed another interaction happens? I found this while on a googling rampage from https://physics.stackexchange.com/questions/235366/feynman-diagram-pi0-pi0-rightarrow-pi-pi If this person is right (I am far too inexperienced to tell that as is clear!) then by...

Um, so far I have this? Is this what you mean?

Yes, the pi plus is an up and an anti down, and anti up and down for the minus. The only way I can think to draw that is with the down and anti down annihilating into a photon and same for the up and anti up? I'm not sure if there's a way to do it as one diagram?

π+ + π- → γ + γ How do you represent this in a Feynman diagram showing the individual quark? I am very confused please help! [Moderator's note: Moved from a technical forum and thus no template. Own effort below.]

I tried finding a.a (four vector inner product) and I got to γ4{(v.a)2(1-γ4v.v - 2γ2) - a.a}, where again a and v are three vectors on the rhs (sorry to be confusing). a.a = g2 since it's a constant. I have no idea where to go from here to find the time and position. Please help!

That's just it though. I don't know what the pros and cons of each are! I have no clue where to find them either...

At this point I have no idea how to look at this situation, so I'm really hoping I can get a little help here. I have an offer for Mathematical and Theoretical Physics which leads to an MMath, and eliminates all lab. I also have an offer for straight Physics, leading to MPhys with no extra...

I've come across countless equations in which i and j are written as either subscript or superscript or both. I am an AS level student (16 - 17 yrs old), and all I know is that i, j and k are unit vectors, but I've never seen them written as subscript or superscript and I'd like to understand...

My teacher said we might get funding from the school, so if we don't have one already maybe we'd get one? but yeah, that sounds good, I'd love to hear it!

Thank you for your reply! Those are some really helpful ideas. (Not that it's extremely important but just to clarify I am also a 16 year old, just much nerdier than average. Also by college I meant sixth form college which I think is american high school. I guess I should've specified that...

I'm pretty much in charge of a physics club that I pretty much started at my college. It's 16 to 18 year olds, and I need to keep them occupied for an hour. I will look up things to teach them but the things I find fascinating might be boring to them so it could be tough. If anyone has any...