Ray Definition and 517 Threads

I have a 3D graphics book, which gives the formula for absorption of radiance along a ray. I am trying to derive the details and would like to see if my derivation is correct. Let o(p) be the probability density that light is absorbed per unit length at point p. They give the formula as...

Homework Statement I have a concave lens where f < do < R. I have to provide a ray tracing diagram. The Attempt at a Solution I drew the focal ray through the focus and parallel to the principal axis. I drew the principal ray parallel to the principal axis then through the focus. I...

I am looking for freeware which enable the simulation of a system with 3 mirrors, a laser, and a detector. So far I've only managed to find software for lenses on the internet. Would anyone lend a hand? :D

Homework Statement Paralel light rays travel from air to a glass hemisphere with radius R and index of refraction n_{g}that is greater than n_{air}. A top view is shown in the attached image. (a) Where do the rays focus relative to the point P? (b) The index of refraction of the...

Homework Statement A 2.0--cm tall object is placed in front of a mirror. A 1.0--cm tall upright image is formed behind the mirror, 165 cm from the object. What is the focal length of the mirror? Homework Equations The Attempt at a Solution I tried 37 cm, it was incorrect

Homework Statement An object is 12 cm in front of a concave mirror with a focal length of 21 cm . Locate the image in s' Is the image upright or inverted? Homework Equations willl get back with it The Attempt at a Solution Im not sure where to start, this should be a simple...

Homework Statement If the focal length of the concave lens is -7.50 cm, at what distance d_o from the lens should an object be placed so that its image is formed 3.70 cm from the lens? What is the magnification m produced by the concave lens described in above? Where should the object be...

Hello. I have a concern in relation to ray diagrams. So I read that the first incidence ray I draw must be parallel to the principle axis and be reflected such that it passes through the principle axis. Ok so this part isn't too much of a worry. However it states that the second ray must be...

Homework Statement I have done the light ray through a glass block experiment at different angles. I've taken the measurement for i1 which is from the incident ray. and i2 which is from the emergent ray. Then I have to take the average of i1 and i2 and then plot a graph using the average...

Is there a video of that kind of scenario floating around youtube? Have not had any luck finding a video of such a scenario.

Hi, For my experiment, i need the gamma ray energy spectrum of Cd-109 and Sn-113 with NaI detector. would anyone help me please? thanks everyone.

Hi guys I wonder if you can explain this to me. In http://en.wikipedia.org/wiki/Ray_transfer_matrix_analysis#Table_of_ray_transfer_matrices it says under "Thin lens" that the ray matrix is given by \left( {\begin{array}{*{20}c} {r_{final} } \\ {r_{final}^' } \\ \end{array}} \right) =...

Sorry if I sound crazy, but I just heard about this and would like a reliable fact check before I worry. So I recently heard about this binary star system known as WR104. I read that it was pointed right at us and, at some point in the future, it will release a gamma ray burst that will wipe...

I'm currently in the process of building a new muon detector using PMTs and Scintillators http://www.hardhack.org.au/scintillator_detector for testing the validity of my other cheaper detector projects. But I was also thinking of building another detector for logging average Cosmic Ray levels...

I've two questions here:- 1) Sound reflects it is said using laws of reflection of light.So,it means we hear max. sound when angle of incidence is equal to angle of reflection,right?& if not equal then what do we hear or not? I guess we hear lesser than max.sound when the angles are not equal...

Homework Statement If you were given 4 cookies, each emitter different ray 1)Alpha, 2)Beta,3) Gamma , 4)neutron You have to make decision of the following: a)eat one of the cookies b)dispose one of the cookies at storage facility called WHIP c)put one of the cookies in your pocket...

the unit of cosmic ray flux is expressed as flux /(m^2.sr.s.GeV), so what does sr stand for? Thanks.

Homework Statement The ‘half-thickness’ tells us the thickness of a given material needed to absorb half the incident photons from a particular source. Find the average distance of a gamma ray in lead before its first collision. I have a value for the half thickness (and equivalent half...

Homework Statement One of the thermonuclear or fusion reactions that takes place inside a star such as our Sun is the production of helium-3 (3He, with two protons and one neutron) and a gamma ray (high-energy photon, denoted by the lowercase Greek letter gamma, ) in a collision between a...

Homework Statement In an old TV cathode ray tube, electrons are accelerated by a potential of 15 kV between the gun and screen. Find: a) Kinetic energy of the electrons when they reach the screen b) Its respective wavelength c) Wavelength of the photons with maximum energy that are...

I'm not sure if this thread fits into this particular forum, but about how many megatons would be equal to the explosive power of a gamma ray burst?

hey there, I'm interested in (eventually) simulating light ray paths near black holes, starting with schwarzschild black holes and working my way to kerr-newman black holes. I have a good understanding of the nature of black holes but have trouble when it comes to the equations. My background...

Homework Statement A CRT is placed in a uniform magnetic field B, with the axis of the tube parallel to the lines of force. If electrons emerging from the gun with a velocity v make an angle θ as they pass through the origin O so that their trajectory is a helix, show that a) they will touch...

A) In a cathode ray tube, electrons are accelerated from rest by a constant electric force of magnitude 6.22 x 10−17 N during the first 2.00 cm of tube's length; then they move at essentially constant velocity another 46.5 cm before hitting the screen. Find the speed of the electrons when they...

"When a wavefront of X-rays strikes an atom, the electrons in that atom interact with the X-rays and immediately re-emit the X-radiation, normally without change of wavelength, and the X-radiation that is emitted by the atom is emitted as a spherical wavefront " Now my question is : visible...

When I look at a nuclear level scheme, there are many gamma ray transitions from energy levels of say, spin 4 to spin 2. However, my understanding was that photons carry spin 1, and so conservation of angular momentum would say that you can only change the spin of a level by 1. What am I missing...

I learned from a website that cathode ray tubes fire electrons from an "electron gun" at the cathode towards the anode, hitting a piece of metal and produce cathode rays in the process. My question is; how do cathode tubes "shoot" electrons? Apparently it's due to a high potential difference...

Hi.I wonder is it possible to create a home made muon or gamma ray detector? And if it is possible would you mind to show me some way? Thanks...

I don't want to hijack another thread, so I'm moving the discussion here... A point about Archimedes Death Ray came up. The question is whether it failed for practical or theoretical reasons. I am of the opinion that it failed for practical reasons due to the inability of a bunch of...

Homework Statement If the apex angle of a prism is f = 74.3° (see figure below), http://i32.photobucket.com/albums/d2/NikkiNik88/apex.gif what is the minimum incident angle for a ray if it is to emerge from the opposite side (i.e., not be totally internally reflected), given n = 1.55...

Could someone please check my work and provide insight on what I may be missing to complete the problem. The question's from Ray Serway's Physics For Scientists & Engineers 4th Ed. Vol. 1. Chapter 4. Review Problem #1. Page 95. Homework Statement A ball is thrown with an initial...

Homework Statement An object is 6.0 cm in front of a converging lens with a focal length of 10 cm. Use ray tracing to determine the location of the image. Is the image upright or inverted? Is it real or virtual? The Attempt at a Solution According to my ray tracing...there is no...

Homework Statement A light ray enters the atmosphere of a planet where it descends to the surface 15.2 km below. The index of refraction where the light enters the atmosphere is 1.2 and it increases uniformly to the surface where it has a value of 1.55. I) How long does it take the ray...

I just can't comprehend that gamma ray can come out of a black hole. Gamma rays are electromagnetism which contain photons, but photons have no mass. And we all know that a black hole swoops up light as well. And what recaton has the gamma ray on the mass around the black hole? I know It's true...

Hey everyone, I need to be able to be able to explain how a gamma spectrometer (NaI scintillator) can determine the energy of a given gamma ray (or more particularly, determines the effective dose rate, but that shouldn't be to hard once I figure out how to get the energy). The problem, as far...

From what i have read the gamma ray frequency cap ranges from 3×10^19 to 3×10^24. I want to know what you guys have heard it is. Are the highest measured gamma ray from a supernova calculated with any time dialated effects? Also what is the thoertical cap of something higher than a gamma ray...

I found two different descriptions about ray transfer martix of interface in two textbook. I am confused about this. which one is correct? I hope someone can help me. _________________________________________________________________ A:Lasers, A.E.Siegman,pp586 B:Laser Resonators and Beam...

Homework Statement The figure from the link below shows a cross section of a cathode ray tube. An electron in the tube initially moves horizontally in the plane of the cross section at a speed of 2.0 x 107 meters per second. The electron is deflected upward by a magnetic field that has a...

Homework Statement When an object is located very far away from a convex mirror, the image of the object is 18 cm behind the mirror. Using a ray diagram drawn to scale determine where the image is located when the object is placed 9.0 cm in front of this mirror. Note that the mirror must be...

Hi all, Does the antenna gain depend on the angle of the emerging ray? or It can be a single number for all ray emerging in all directions? I know the gain is the amount of power an antenna has relative to an isotropic antenna. Sometimes it means the maximum power an antenna can have relative...

Hello, I'm attempting to analyse the data recovered from an experiment that I performed in lab, but I'm having some problems understanding how to properly apply the statistical methods learned to this specific problem. Essentially, the experiment consisted of placing a source of gamma rays...

¿Why one cannot push light but just in the normal direction to the ray? NAIVE QUESTION: I understand I cannot push a light ray (I mean, to sum speed vectors) in its propagation path, but ¿why I can certainly push it in the normal direction to the light ray? Is there some info on this...

Homework Statement A 4.0m wide swimming pool is filled to the top. The bottom of the pool becomes completely shaded in the afternoon when the sun is 20 degrees above the horizon. How deep is the pool? Homework Equations \theta = arcsin(n2/n1) n1sin\theta1= n2sin\theta2 The...

Homework Statement A light ray leaves point A in the figure, reflects from the mirror, and reaches point B. (Intro 1 figure) figure attached How far below the top edge does the ray strike the mirror? Homework Equations The Attempt at a Solution im not sure exactly where it...

Is anyone familiar with the "y n u" ray trace method for optical systems, using paraxial rays where Snell's law is approximated using: n1sinx1 ≈ n1tanx1 ≈ n1u1 = n2u2 If anyone is familiar with this, I'd be interested to discuss the finer points of "a-ray" and "b-ray" tracing, as well...

Homework Statement The figure shows a meter stick lying on the bottom of a 100-cm-long tank with its zero mark against the left edge. You look into the tank at a 30^\circ angle, with your line of sight just grazing the upper left edge of the tank. 1)What mark do you see on the meter stick...

How do the photons actually interact with the atoms to make them diffract. is it related to de broglies equation some how? Also with High energy electron diffraction, are the electrons being diffracted because they are attracted and repelled electrostatically from the nucleus and orbiting...

Homework Statement A primary cosmic ray (which comes from elsewhere in our Galaxy) hits the nucleus of an atom in our atmosphere 38 km above the ground and creates an unstable secondary particle, which then travels straight down toward the ground at a speed of 0.99400c. (The altitude and the...

Homework Statement A ray of light strikes the midpoint of one face of an equiangular (60◦, 60◦, 60◦) glass prism (n = 1.3) at an angle of incidence of 33◦. a.Trace the path of the light ray through the glass, and find the angle of refraction at the first surface. b.Find the angle of...

Okay, I'm writing a short response of about one page right now. Here's the question: Regarding soft gamma ray repeaters, 1. Is there any connection between the electromagnetic radiation and gravitational radiation? (specify: luminosity of the source? Thresholds?) and 2. How much...