Recent content by masteralien

You would have to solve for v_y

Also is my solution physically sound like is the setup logical physically

Also v_x would never truly reach 0 just get very close and its best to express the solution a bit differently. Also I have plugged in my equation the first into desmos to check and as you decrease v_x it goes to -V/2 but never set v_x=0 $$v_y=v_x\sinh(\ln(\frac{v_x}{V}))$$ Taking x to 0 =$$V...

No my steps are right below I subtracted v_y and squared both sides then divided by v_x^2 then took the limit. You need to take the limit as it approaches as this for long times its a bit like terminal velocity.

The steps are right below. I even checked with a graphing calculator that as v_x approaches 0 v_y approaches -V/2

Its right below the algebra

TL;DR Summary: In Morin 3.7 sliding sideways on a plane I used a completely different method than he did and got the correct answer is my method right The problem statement is as follows I split up the friction force into x and y components derived a diff eq for v_y in terms of v_x then took...

But when you have an electron and positron collide they can either annihilate or scatter which one happens then. How would this initial quantum state evolve if its not in a superposition and could you elaborate a bit more on why superpositions are not possible.

In QFT one important calculation is the Scattering amplitude the overlap between an initial state and a final state due to an interaction. For example the S Matrix element for electron electron scattering is the overlap between an initial 2 electron state in the far past and a 2 electron state...

Also one more question can the Propagator G_2(x1-x2) be thought of as the Probability amplitude for a Particle to be found at spacetime point x1 created by a delta function source at spacetime point x2

What about expectation values for states which aren’t the vacuum like particle states can all those be computed with the n point functions

I see also is it true in principle any expectation value can be computed with the n point functions

In QFT the objects of interest are the n point Correlation functions which contain all the information about the theory and can be used to compute any expectation value in principle. However I cant figure out how to compute the vacuum energy from the correlation functions alone and cant find any...

What do you mean QFT is still a work in progress I thought we have the Standard Model and QED all sorted out? Could you elaborate a bit on why and how QFT is a work in progress I thought we had it figured out?

I understand its silly just was curious to see, as QFT has the Bethe Salpeter Equation for Hydrogen Bound States does String Theory have something similar. Also even if its inappropriate it can maybe be an interesting exercise. Also you say we dont have a complete String Theory how comes I...