# Search results

1. ### Quantifying Significance In Re-ordering Of a Set

Hi folks, I have what I think is quite a basic question, but I'm looking for options. So, I have data that consists of a set of numbers (this is not a set theory question) - each number can be ascribed to one of two groups (the source of the number). Now, I have knowledge of the source...
2. ### A Sad Day for British Television

http://www.destructoid.com/watch-some-hypocrites-attack-videogames-on-british-tv-168784.phtml For those that can't be bothered watching(!) - the video is a clip from The Alan Titchmarsh show about video-games. The discussion is about the impact violent video games have on children. The critics...
3. ### Unwinding because It's SaTuRdAy NiGhT

Unwinding because It's SaTuRdAy NiGhT!! Well, actually, it's friday. And yeah, just in case: http://xkcd.com/238/ What is everyone up to this weekend? Have your own relaxing routine? I'm doing my usual rounds on the forum before having some food and hitting the games consoles - nothing...
4. ### Engineering Bioengineering as a field for a PhD

Good Evening and Happy New Year to all. I haven't posted in a little while but have been discussing an idea a friend of mine has had recently. She's a Physics Bsc graduate in the UK and is taking a look at Bioengineering as a field for a PhD - one of the department she's in contact with...
5. ### Components of metric perturbation in TT gauge

Homework Statement I'm just working through a text book and there's a line in which I'm clearly missing something. What I want to do is show that from: [tex] \bar{h^{TT}_{\mu \nu}} = A^{TT}_{\mu \nu} cos(\omega (t-z)) [\tex] to [tex] h^{TT}_{\mu \nu} = B^{TT}_{\mu \nu} cos(\omega (t-z))...
6. ### Programs Another medical physics thread. PhD.

Hello, [aside] So i've seen a lot of medical physics related posts on this forum recently, as well as some good answers to questions (thanks go out in particular to Choppy!) and would like to get out-of-the-way my support for a medical physics subforum. Anyway, on to the point. [\aside]...
7. ### Physics Medical Physics.

Hello again folks. I'm starting a thread (obviously.) for a couple of purposes, I guess. I'm looking for a bit of advice, but also think I just need to have a little bit of a rant and get some thoughts out of my head. I'm a final year student at a UK university, and will be graduating with...
8. ### Coordinates query, positional

Hi folks, Have a query that should be simple were it not for my lack of positional understanding - if I have a location for an object, say a star, in a celestial coordinate system (equatorial coordinates is my partciular interest) - what are the transforms to a geographic system? Obviously...

Ok so i'm in a bit of a muddle- i'll give a bit of background just so you can better understand my questions. I've just received my exam results for my fourth year (i'm studying an undergraduate masters 5 year-degree, joint in astrophysics+physics) and whilst I'm pleased to be at the top end for...
10. ### Image Processing

OK, so this isn't anything I've ever done before and would like some input on feasibility, and whatever else you can throw at me. I'm examining images (of atmosphere with a storm structure building up) but unfortunately the data that is available (i.e. the data i've got to use) has quite...
11. ### Questions regarding VSL vs LCDM

A couple of things to start with. I'm going to put forward some questions I need help understanding surrounding VSL. I'm not anti-LCDM or against inflation/etc. I'm just interested in the mechanisms of setting up a 'new' theory (I'm aware Einstein delved into VSL, and subsequently disregarded...
12. ### MATLAB So I have another matlab problem

Should be a simple one, just can't get it to work. Basically, I have two sets of data that I want to compare. One set of data was observed at set intervals of time, and the second set of data is calculated - the problem is that the theoretical data has entries for non-integer values of t - when...
13. ### Decent IDL beginner tutorial

Really just looking for a link to a decent IDL beginner tutorial (I have plenty of Matlab etc experience, still, I'd like to make sure I'm starting the best way from scratch) or recommend a good book on the subject? thanks.
14. ### Equations of motion for an orbit

Only reason I'm posting here is that i'll get more views than in the cosmology thread, I'm afraid.. (Basically, I'm working through a couple of different models and after some work I'm a bit stuck: http://trond.hjorteland.com/thesis/node21.html I'm basically trying to integrate equation 3.33...

mm k. So. As lots of other students are at the moment, I am currently preparing for a presentation. My chosen topic: alternatives to the FRLW model. What I'd appreciate from you guys is simple; I've been coming here long enough to notice that everyone has their own little deviations and...
16. ### It's that time of year[summer project work]

mm, k. Now, I know I can get some of these types of information via wild-googling - I would, however, prefer to hold the contribution of people i know above. Anyway, my post is about the fact that I'm (a 3rd (of 5) year physics student applying for a scholarship in the summer to fund some...
17. ### MATLAB Matlab problem.

Ok, so semi-irrelevant information out of the way first - i'm writing a program that will give a basic model of the solar system - taking into account interactions from the planets on each other. I can get my program running when containing the individual starting points of each of the...
18. ### Some subspace questions

I'm preparing for an end of year linear algebra test which briefly covers things about subsets of Matnxn and their relations to subspaces of Matnxn; I found the following question: Which of the following subsets of Matn×n are subspaces of Matn×n? (i) Symmetric matrices (i.e. matrices A...
19. ### Quick question

the following post probably isn't going to be so cohesive, bear with me anyway: I'm completing a report and need to combine several sets of results for the same experiment and combine their errors to give a best value - can't for the life of me remember the formulae, i know roughly what it is -...
20. ### We all love to prove things [spectral broadening/relativity]

Well, hopefully this is going to be my last help-thread for a while, i'd like to start repaying the members. You may have noticed i've posted a few threads asking for help tonight, and I thank the members who have read my threads very much. I've narrowed down points of my course that I remain...
21. ### Undergrad: General Astronomy Questions.

I've been reading over my astronomy coursework and trying some questions, and i'm coming across a few things I'm not sure about, i'd be grateful if you could provide the answers. 1/ Give three possible astrophysical reasons for periodic variations in the observed photometric signal from a...
22. ### Basic relativity.

Right. Some simple questions, I want to make sure I'm not making stupid mistakes before moving on. I have the questions and my answers, If you tell me that I got them incorrect, i'll run through my working or something (if there could be any..). 1/ How fast must you travel towards a red...
23. ### Test Tips.

Basically, we found out today that my course coordinator wants to try something new this year; making out class tests open-book. Predictably, at first everyone seemed to think this can only be a good thing for us, as students. I, however, think that it's a bad thing. Not only are class...

I'm mid-way through my second year (I'm in UK) in physics (not that this stuff makes a whole lot of difference, but it's background) and i'm about to apply for a sponsorship for a short work-placement in the department of a local University over the summer. To apply, I need to hand a CV in and...
25. ### Inflation/Higgs fields

Whilst this is possibly not in the correct forum, I figure the people looking here will be the best to ask anyway. Basically, I'm writing a few thousand word 'report' on cosmological inflation, or subtopics thereof, it's quite loose. (its to be mostly wordy, and since I'm pre-UGdegree...
26. ### Probability Distributions

Basically, I'm having some difficulty grasping some of the concepts in probability. ..At first I was writing details of what my lecturer has given me, but really I can't make much sense of it and it'd be foolish to type it all out here. The jist of work is really just as follows; we've...
27. ### Physics/Astronomy power spectrum from waveforms

phi(t)=A_o*e^(2*pi*i*mu_0*t) (label:1) Calculate the power spectra of the following waveforms (using 1): 1) for all t 2) a pulse duration of two tau for |t|<tau, and for phi(t)=0 --- 3)an exponentially decaying sinusoid: phi(t)=A_0*(e^(-t/(2*tau)))*e^(2*pi*i*mu_0*t) for t>0 and...
28. ### Bulk modulus, water density

An incerase of pressure of one atmosphere, causes a reduction of 49*10^-^6m^3 in a volume of 1m^3 Give the value of the bulk-modulus of water. Calculate the denisty of the water of a lake, at a depth of 200 metres, assuming that the density of water is 1000kgm^-^3 at the surface...
29. ### Time evolution of temperature help

First year astronomy question, goes as follows: "A closely exact description of the cooling described above is to consider the differential equation which says that rate of charge of thermal energy equals the rate of radiative output. That is: \frac{d}{dt} \frac{\left(3MkT\right)}{m_p} =...
30. ### Magnetic Effects of Currents

1] Two long straight parallel conductors each carrying a current of 24 amps flowing in the same direction are fixed at a distance of 40mm from each other. A third parallel conductor is placed equidistant from the other two and carries a current of 30 amps. Show that the force on the third...