# Search results

1. ### Blogging Software?

I am trying to set up a blog. I was just wondering if anyone had any experience of the different software available out there, like 'Simple PHP Blog', 'Blogsphere' etc. I want to be able to host the blog myself so I am not keen on Blogger and the other free hosted blogging tools out there...
2. ### Parallel Worlds: A Question From Olbers' Paradox

I understand that background radiation that we observe actually dates from the time of the creation of the universe (The Big Bang). I also understand that nothing can travel faster than the speed of light. My question is how did we (the solar system) get here before the radiation did...
3. ### Changing Earth Orbit July 06! Is this for real?

This site has a whole theory about changing the orbit of the earth by having 600 million people jumping at the same time. I am very skeptical about this. I mean it sounds like the violation of the conservation of energy/momentum if you can change the earth's orbit without any mass...
4. ### What are Kernel Times?

I've recently noticed that there is a 'Show Kernel Times' option in Windows XP's Task Manager under the 'Performance' tab. This shows up as a red meter over the green 'CPU Usage' meter. I gathered that the Kernel is a piece of software that allows the operating system to multi-task but what...
5. ### Snakes and Ladders

I want to calculate the average duration of a snakes and ladders game in terms of the number of moves. Does anybody have any idea on how to tackle the problem?
6. ### Simple question on Conservation of Momentum and KE

I am having a bit of a conceptual problem with the conservation laws. Consider a system of two bodies of mass m each. One moving at speed V1 towards the second body which is at rest. For the case of an inelastic collision, I understand that the total kinetic energy of the system is not...
7. ### Specular Reflection from a Reflection Diffraction Grating

I understand that a laser beam shining onto a diffraction grating produces a 0th order, 1st order etc... diffracted beam. My question is: What is the wavelength of the specular reflection [0th order beam] off the grating in regards to the wavelength of the incident beam?
8. ### Gain Curve for a Diode laser

Can someone please explain what exactly the gain curve of a laser is? Is it exactly the same thing as the natural linewidth of the laser [a graph of intensity vs frequency] or am I off track? I found this graphhttp://www.phys.ksu.edu/perg/vqm/laserweb/Ch-5/C5s1p5.htm [Broken] that tries to...
9. ### Simple Question about Photodiodes [Current and Voltage]

Would someone be right in saying that a photodiode produces a current as output and that to be able to make use of this current, you ABSOLUTELY need to convert it into a voltage by using a current to voltage op-amp circuit? I've heard this from someone but to be honest doesn't make much sense...
10. ### Cavity Length of LASER and Interference

I have been working on an experiment that uses double exposure holography to determine sub-micrometer displacements. [see attached picture for details] It turns out that the optical path lengths LRP and LOP do not have to be exactly but roughly equal for the light if you want the light from R...
11. ### Schools Best Physics Graduate Schools in Canada

Does any one know where UBC [University of British Columbia] and the University of Manitoba stand in terms of Physics for graduate studies? :confused: I have heard a fair bit about McGill but any info about good graduate schools around Canada would be much appreciated. :smile: I am...
12. ### Which travels fastest?

[a] a wave on the surface of the sea? [b] a wave on the surface of liquid mercury (dense metal)? [c] a wave on the surface of liquid mercury on the moon?
13. ### Quarks and Leptons: Fundamental or not?

I've been trying to research this area but there doesn't seem to be much out there. Does any one know of any evidence or theory showing that quarks and leptons are or are not fundamental? I have heard of String Theory but does string theory actually suggest that quarks and leptons are made...
14. ### Muon Charge

I'm trying to write a program that would process data from a particle physics experiment and I need to know what the charge of a muon/anti-muon is. It doesn't seem to be easy to find on the web. Does anyone here have a value for it?
15. ### Interesting places to see in Vancouver

I'm heading to Vancouver next week and I'm wondering if any of you have any suggestions as to what to see and where to go ... I'm actually there for 3 whole weeks, so I will have quite a lot of time to spend. Please try to keep off the likes of Art Museums coz I get dead bored :zzz: in such...
16. ### Basic question on Specific Heat Ratio of gases

I have been trying to understand the concept of specific heat ratios. From what I gather, the ratio is defined as the quotient of the Specific heat at constant pressure and the Specific heat ratio at constant volume. Could anybody give me an insight into what leads to gases having different...
17. ### Movie Physics

I found a brilliant site that picks out the bad physics portrayed in many movies. It even has ratings like, GP (good physics), XP (physics from an unknown universe), ... http://www.intuitor.com/moviephysics/ Enjoy!
18. ### Digital Picture Orbs

Does anybody have a logical explanation to what those little white things on digital pictures are? I figured they can't be dust on the camera lens because they come out in a different place of the photo even if 2 photos are taken one after each other. Anybody, any ideas?
19. ### The Universal Human

I've heard from someone that if you superimpose enough pictures human faces (of all races) on top of each other, you get something like a universal human face. I mean like if you have several samples and superimpose all faces from each sample, the end result from each sample would be the same...
20. ### All this superconductor business!

I am new to superconductors and how they work. :confused: Could anybody maybe explain how currents actually arise in a superconductor? Is it just by placing the superconductor in a B-field that causes a current due to the expulsion of the external field (Messiner Effect)? If so, is that...