Recent content by Umaxo

Thanks guys. Yes, i am sure not being able to commit on projects that the groups actually want to do is a problem. But i thought there could be some projects that are perhaps interesting or would be nice to do, but not really worth the effort for profesional scientists or inapropriate for...

Hello, I would like to ask you opinions on working in reasearch in physics as hobbiest in my spare time. Right know i am just looking around for options, so any opinion would be appreciated. I have masters degree in theoretical physics. After finishing the study i started working and - long...

Ok i thought about it and this question is no longer relevant for me. However, another quetion arose in me. Sadly i don't have a lot of time right now. but i will be back soon:)

Make sense... But in the book, they assume to be in frame of reference in which space and time are homogeneous and isotropic. Doesnt this have any influence on your discussion?

So much bad experiences in here:(... Just to balance, i add my: I don't know about some random physics degree from noname village university, but at least one physics degree from one particular university in my country i studied at has very high worth (and the university is for free, anyone can...

Thanks for the links. I recently grabbed a book on mechanics from Goldstein, Poole and Safko as suplement for Landau-Lifshitz and it seems that indeed there are even mechanical systems that cannot be modeled using variational principle. Goldstein starts with Newtons force law which he wants to...

Hi, I got curious on the limits of variatonal principle. As far as i know all of the theories can be reformulated as problem of finding extremum of some action. Not only that, but it seems to be most convenient method for looking for new theories in a lot of cases. So my question is, what are...

Hi, I am reading Landau-Lifshitz course in theoretical physics 1. volume, mechanics. The mechanics is derived using variatonal principle from the start. At first they start with point particles, that do not interact with each other. Thus the equations of motions must be independent for the...

Okay, i realized median doesn't disect vertex angle in half. Silly me:)

<Moderator's note: Moved from a technical forum and thus no template.> Hi, i am quite embarrassed to ask this question, but i am really stuck. i want to derive length of median of triangle from cosine law and i am getting wrong results. I cannot spot the mistake. So let's have a triange with...

P.S. what helped me personally with understanding of STR is to get rid of trying this mental gymnastics to come up with some absolute world-view using frame-dependent language. There is geometrical language in which you don't use frames and you have certain absolute world-view, but you must...

Yes, but they would tick at the same rate. All you would see is that the clocks (and all events too) at different places become shifted relative to each other, but they would still show the same rate of time. Also, you would still see that when clocks A sounds noon it is the middle of the day...

Well yes, but this expression leads to proper time only in minkowsky spacetime and for timelike separations. Proper time, to the best of my knowledge, is defined as time measured by the clocks in objects rest frame. This definition is as good in Newtonian as in minkowski spacetime, even though...

I don't get this. How can you derive LT from invarience of proper time? Proper time is invariant even in Newtonian physics or in any other imaginable physics that allows definition of proper time.

I would like to add something to the discussion if i may. Its very strange sentence. It suggests to me, that there is some time outside of time so that you can say all time happened in single moment of some another time. I would just say spacetime is some kind of block that puts time and...