Recent content by TheMercury79

What is up with your answer?. It is obvious I just forgot an extra '$' so it is not necessary to ask about my equation. Yes I said 'measure', you're right I should have said 'determine', but you still know what I meant. It depends on two quantitites, their fractional errors add in quadrature...

I understand how to compute and propagate errors but have trouble with conceptualizing all things put together. I have performed an experiment to determine a value for some quantity. This quantity depend on two variables. The first one depend in turn on some other quantities as well but I think...

anyway, thanks for the help

Because I knew the answer is not zero. Why should I check and see if the answer i zero? That's just ridiculous, of course it's not zero.

Now I see it! Pero said the same thing but he threw me off by insisting we should set ##\theta## to zero

But the correct answer is supposed to be ##Q^2=-4\frac{EE'}{c^2}cos^2\frac{\theta}{2}## I just put in it the other form to illustrate the plus and minus difference. And I instead got ##Q^2=-4\frac{EE'}{c^2}sin^2\frac{\theta}{2}##

maybe I formulated it badly but the original statement was"##\theta## is the angle between the outgoing electron and the incoming proton". I figured the collision was head on, so this is the same as what I said "##\theta## is the angle between the electron before and after the collision" I don't...

In a head-on collision between the proton and electron, what is the squared 4-momentum transfer between the two particles. Starting with the difference in momentum of the electron with the 4-vectors before and after the event: $$(P-P')^2=P^2+P'^2-2P\cdot P'$$ The circumstances are such that the...

Thanks. It turned out they are the same. I just ended up with different expressions on the transposes. e.g (3/2)*sqrt(1/2) was transposed with sqrt(1/2)*(1+sqrt(1/2)), but these are equal so there was no problem

But I actually don't get the same matrix. What I get is the transpose of the other when I change the order i.e when I do [A]^2[A] I get the transpose of [A][A]^2 and vice versa What I'm trying to do is find the cube of the expectation value of x in the harmonic oscillator in matrix form. We're...

No it didn't. The text we use showed how if you differentiate the first you get the second. I guess the intstructions threw me off a bit. "Use the second equation directly" it said, it sounded so definite, like that's what you have to work with, nothing else. Anyway thanks. Will try and see what...

If we take a flat universe dominated by radiation, the scale factor is ##a(t)=t^{1/2}## which can be derived from the first Friedmann Equation:$$(\dot a/a)^2 = \frac{8\pi G}{3c^2}\varepsilon(t)-\frac{kc^2}{R_0^2 a(t)^2}$$ But suppose I want to show this using the second Friedmann Equation (Also...

I feel kinda stupid now, The Friedmann equations is in the next chapter. I was under the impression this should be solved with contents of the current chapter. But I see now I've read the curriculum wrong. I have a full time job and taking this course on the side is really stressful. I just knew...

Imagine a Universe where the Hubble parameter is truly a constant, in both space and time. How much smaller would such a Universe be 14 billion years ago compared to today? Using the Hubble parameter in terms of scale factor: ##H(t) = \frac{\dot{a}}{a}## leads to the differential equation...

After further inspection I still come up with nothing. I found that if y=a, then ##bx+x^2=1##, but since this is a quadratic, it yields two possible values for x in terms of b, so there can't be a unique point for the second system. And how to use it with ab>1 is a mystery to me since it seems...