Ray Definition and 493 Threads

I noticed that the ray diagram for the "how the compound microscope works" and "how the telescope works" is wrong in my government sanctioned physics textbook(and countless other books and websites!) The diagram printed was this- Name: Physics Standard XI Printed by: Maharastra State Board of...

Homework Statement B) Using the mirror equation, find the image distance. Homework Equations 1/do + 1/di = 1/f The Attempt at a Solution [/B] B) do = 2cm f = 4cm 1/do + 1/di = 1/f 1/di = 1/f - 1/do 1/di = do/f(do) - f/f(do) 1/di = (do-f)/(f*do) di = (f*do)/(do-f) = (4cm * 2cm)/(2cm - 4cm)...

Homework Statement [/B] B) Is the image real or virtual? Explain. C) Using the lens equation, find the image distance. 2. Homework Equations 1/di + 1/do = 1/f The Attempt at a Solution A) B) The image is real because it is on the opposite side of the lens as the source of light. C) do =...

Hi, my question is that would it be possible to reduce the energy and frequency of gamma rays to visible light then maintain it at that level?

1. I figured out the first few, I just can't get the last one! -The refractive index of a transparent material can be determined by measuring the critical angle when the solid is in air. If θc= 40.4° what is the index of refraction of the material? 1.54 -A light ray strikes this material...

Hi folks Please bear with me, I'm new here and this may not be the correct forum to ask this question. If this is the case, I'll of course remove my question and ask it the appropriate place instead. However, here it goes: I need to be able to calculate how much a given intensity of gamma...

I would like to simulate a light ray hitting and refracting through a transparent freeform shape. Any advice on software which will do this easily? I want to just draw the shape, point the light at it, and see where the beam goes. Tom

Homework Statement The net deviation of ray A(Figure(i))) in counter clockwise direction after one reflection and emergence is 180+2i-4r (True False) Homework Equations The Attempt at a Solution I don't know how to begin to solve this problem, so there is no attempt at a solution.

Hi! I've been watching this video http://ocw.mit.edu/courses/chemistry/5-111-principles-of-chemical-science-fall-2008/video-lectures/lecture-2/ on the discovery of electrons , and I have some doubts about it. The lecturer explains the cathode ray experiment performed by J.J Thomson. This is...

Skin Effect: . where = resistivity of the conductor = angular frequency of current = 2π × frequency = relative magnetic permeability of the conductor = the permeability of free space ------------------------------ From Wiki According to Skin Effect, the higher the frequency, the less...

Say we have a one dimensional chain of N mass points separated by springs of spring constant k. This system can be quantized? Let the quantized system above be at rest and let one of the end mass points emit a photon of energy E along the crystal axis. Will we get physics similar to he...

Gammaray bursts (GRB) may affect the prevalence of life in various different regions of the galaxy. http://arxiv.org/abs/1409.2506 On the role of GRBs on life extinction in the Universe Tsvi Piran, Raul Jimenez (Submitted on 8 Sep 2014) As a copious source of gamma-rays, a nearby Galactic...

Homework Statement for part a , in order to produce first minima from the central bright ray , the path differenece between 2 ray should be equal to λ/2 or 180 degree am i right? why the notes give the path differenece = λ ...If path differenece = λ , the two light ray are in phase right...

Homework Statement according to the notes in the photo, the light ray undergo of phase change of 0.5 λ when it strike and reflected from glass surface (denser) at point A . so the OPD of ray 1 &2 = 2nt-0.5λ.. but in the 2nd photo , the OPD of ray 1 & 2 is given by 2nt+0.5λ . i am not sure...

Why do alpha ray tear out neutron in Be, but don't do such thing in Au?

I was looking at this problem. Does the problem assume that the focal point of the divergent lens is right next to it? The answer is c, saying that the focus point will be further away: but that assumes that the focal point is not RIGHT NEXT to the divergent lens. If it were RIGHT NEXT (VERY...

So, here's the deal: I'm trying to complete the publishing of a paper dealing with my thesis from almost two years ago, and I finally wrote a program that I believe will tell me how different geometries will influence the outcome. Here's the setup, I am modeling the radiation that goes through...

Hi, I'm curious about J.J thomsons Catode ray, and i have a few questions: In J.J. Thomsons Catode ray setup he has hydrogen gas in a chamber through which the catode ray is beamed. What is the role of hydrogen gas? What could he use the hydrogen gas for? And how could he make up...

Hi all, I've been reading about biconvex lenses, drawing ray diagrams and real/virtual images. I'm now trying to translate this into how an image is formed in a compound infinity optics microscope. And this has raised some questions: -In an infinity optical system the object is placed at a...

I thought this was an interesting article. I wondered does it create issues for the isotropic homogeneous view of the Universe when 25% of the highest energy cosmic rays come from one spot? http://news.yahoo.com/big-dipper-hotspot-may-help-solve-100-old-135703814.html

I'm learning ray optics and feeling so confused by the definition of "Hamiltonian of light". What I learned was that the "Hamiltonian of light" defined by H = n-|\vec{p}| = 0 indicates the momentum conservation, where n is refractive index and \vec{p} here is the canonical momentum. The...

i understand that heat acts as a wave,it has some variations depending on the frequency i believe.we all know we can build machines to create such waves.my understandings of physics tell me that waves can be nulled out by other inverse wave.my question:can heat be electromagnetically ruled out?

Homework Statement i don't understand why the OPD of ray 1 and ray 2 is as shown in the notes.i don't understand why the equation given is (nt +nt)-(0.5 lambda)... why is nt +nt ? Homework Equations The Attempt at a Solution

i wonder about tesla death ray. is this machine really exist ? or just conspiracy theory ?

Hi guys I am looking for a dataset to use in my thesis. I am working on UNION 2.1 sample of supernovea Ia data. That dataset consist of redshift and distance modulus with uncertainty (sigma) for 590 supernovea. Do you guys know where can i find similar dataset for GRBs?

Can someone please provide me with some research topic ideas for dexa?

Hello my friends I want to collect data for (xpert highscore ) that is a software for xray diffraction information. I need its datas Can you help me? thank you

Hi guys, Could someone refer me to sources which explain and give examples for crystals which absorb xray / gamma ray and emit RF ? Meaning that if I radiate a crystal with xray I get RF so I can theoretically track its movement in the enclosed are. Thanks a lot!

I know that High-energy (hard) X-ray light cannot be focused as easily as visible light by using a burning glass. But why is this? If there was x ray light spread over a normal sized lens with the same intensity as sun light why couldn't it focus? would the material needed for say 50cm^2...

Homework Statement A light ray in air strikes the right-angle prism shown in the figure (Figure 1) (∠B=28.0∘). This ray consists of two different wavelengths. When it emerges at face AB, it has been split into two different rays that diverge from each other by 8.50∘ . Find the index of...

My understanding of ray tracing is that it maps out luminance for a scene. Now with ray tracing (backwards ray tracing that starts from the camera outwards) does each ray have a luminance value associated with it? In the case of a perfectly diffuse surface, can one simply take the mean of all of...

First of all this is my first thread, so I apologize for any mistake. Perhaps this is a stupid question, but i need some help in exercise 21.10 of D'Inverno, to write down geodesic equation for l^a, which is a vector tangent to a congruence of null geodesics and then by a rescaling of l^a...

On page 122 of Born and Wolf's "Principles of Optics" the following equation for the trajectory of a ray of light is glibly derived in association with the eikonal equation. \frac{d}{d \bf s} (n \frac{d \bf r}{d \bf s}) = \nabla n where n is the index of refraction and r is the displacement...

I know it's old-ish news, but I just heard about it in an engineering class recently while we were talking about ethics. Apparently two guys, one a member of the KKK, decided that they would try to hack some medical equipment into a serviceable X-ray "cannon" that would expose those they deemed...

what is program used as attached.thank you!

Consider an oblique circular cone of altitude h, base radius R, with apex directly above a point on the base circumference. What is the mean length (& variance) for the set of all rays from the apex to points on or within the base circumference?

does thermal radiation involve ultraviolet x ray and jamma ray or just heat of light...

I know several raytraycing results for static Schwarzschild black holes, but I have never seen something similar for collapse models like Oppenheimer-Snyder or Vaidya. Are there reliable raytraycing results showing the effect on light rays from far distant light emitters observed by (far...

Homework Statement I am building a CRT for my physics project but have some doubts. I know there will fluorescence effect but my project requires to do an experiment and make observations. So how can I relate this experiment so that I have:- 1. Different cases and experiments with the CRT...

I've been looking to do a physics project, and since particle accelerators are too dangerous, I was thinking about building a cathode ray tube (CRT) I've done some research about building CRTs, and haven't been able to find anything that gives a complete list of how to build a CRT. Could anyone...

As many of you may know, ray tracing was first introduced by Turner Whitted in 1979 in a paper titled "An improved illumination model for shaded display" (can be found on ACM digital library). On the 2nd page, in part 2 (Improved Model) there are a number of fairly simple vector calculations...

Hello All, Guys in my recent lecture I discussed that unlike the focal length of spherical mirrors which is half the radius of curvature, the focal length of lenses depends not only on the geometry of lenses but also on the refractive indices of the media, and that here the relation f=R/2 is...

While thinking about the recent-ish developments in meta materials for 'cloaking' systems, a thought struck me: could a meta material or combination of meta materials (probably of a somewhat more advanced state than they currently are) be used as a form of shielding from cosmic rays of various...

I recently read the following article: It was not very long, and it did not contain much information. However, after a little searching I discovered the article was referring to GRB 130427A. The key features of this GRB are its strength at 94 GeV, and its duration at "better part of a...

Here goes a conceptual question that has been bugging me: Consider the famous eclipse experiment that shows the Sun's gravitational lensing effect, allowing a star that would otherwise be obscured by the Sun to be visible from Earth. Say an observer wanted to travel to the star from Earth and...

http://www.sfgate.com/bayarea/article/Ray-Dolby-pioneering-sound-engineer-dies-at-80-4810882.php Those of us who grew up with audio cassettes remember the Dolby noise-reduction system for reducing tape hiss. It made cassettes capable of "high fidelity" music reproduction, at least by the...

Hi. I hope this is the right place to ask this and I hope it's not that much stupid. In school we have been told that the reason we see objects is rays of light reflected from that object received by our eyes. Now if I look at a specific part of a building from above, below or exactly the...

99% of all marine fossil generating species on Earth that ever existed have gone extinct. There are periods in the fossil record that show massive extinction rates. For example, the K-T (now the K-Pg) boundary marks the extinction of dinosaurs in the fossil record along with marine animals, at...

If a gamma ray is being fired and is in turn colliding with electrons and ionizing the electrons in the gamma ray path, where do the electrons tend to? In what direction is the current most likely to flow for a high powered gamma ray ionization?

Homework Statement A light ray parallel to the x-axis strikes the outer reflecting surface of a sphere at a point (2,2,0). Its center is at the point (0,0,-1). The unit vector along the direction of reflected ray is ##x\hat{i}+y\hat{j}+z\hat{k}##. Find the value of ##yz/x^2##. Homework...