Recent content by llamascience

This gives you the distribution of energy and momentum i.e. your planet

As far as I understand, the only three types of geometry with constant curvature are elliptical, Euclidean and hyperbolic geometries. So starting with the metric tensor for each of these, if you went through and worked out the respective Einstein tensors, then by the EFE's find the...

If all you want is a means of solving the equations, then unless you have a nice computer package, GOOD LUCK! However, for a good explanation of the theoretical underpinning, check out Leonard Susskind's lectures on GR at YouTube or iTunes

Be careful, you must be precise with your definitions or you will run into problems. Energy is more appropriately defined as the functional composition of the Hamiltonian with the coordinates/momenta of the system as a function of time i.e. E(t)=H(q(t),p(t)). This is, by conservation laws...

Solving the time-independent Schrödinger equation gives the wavefunction for an energy eigenstate i.e. definite energy, so by the E, t uncertainty principle the uncertainty in time would be in a way "infinite". Is this what gives it the time independence? If so, how is this state physically...

what sort of topics should i be expecting in a basic first year uni physics course? the university websites are too general and don't usually give too much detail when desribing the topics covered

By this I meant that I believed the Runge-Lenz Vector would have to be defined in terms of \vec{r}, given that it is conserved in all force fields with the inverse square property and as you said; not inverse cube. A: How do you determine the magnitude of this vector? (I'm assuming we still...

actually, is it the constant vector of integration we produced?

well, it must have something to do with \vec{r}, being conserved only for inverse square fields it might come to me after a while, but please enlighten me

ill just go through each bit you said to do myself and show you my working. if you see anywhere i can improve in efficiency, please tell :) the magnitude of e is constant so: 0 = \frac{d}{dt}\left|\vec{e}\right| = \frac{d}{dt}\sqrt{\vec{e}.\vec{e}} =...

also, please explain why the partial derivative and total derivative with respect to time should be any different when r is dependent only on the one variable: t. i know that in the general case this could create confusion with solving a PDE, but how will the choice of differential affect the...

actually, for the sake of my picking up something new here, could both of you explain your methods simultaneously? dont worry about my being just out of high school (australia btw, just to avoid confusion). i don't mean to sound over-confident, but like i say; I've read a lot of university...

aahhh, gotcha. i knew id seen a similar form before, just couldn't put my finger on it we never covered angular mechanics to any significant detail in TEE physics and for some reason vectors were practically left out of the course. still, i understand the basics from outside reading...

yer, the vector product of the position vector and the velocity is conserved and as this is always perpendicular to the velocity, the motion must be in plane

i'd hope so, or i did not deserve a 97% in my calc course :P if you don't mind doing so, id like a detailed explanation of how to go about this. its been haunting my mind for the past year and all the replies I've been given have been helpful, but unsatisfactory