Ray Definition and 517 Threads

Using equation, Vm=(Vo+Vi)/2; 2= (4+Vi)/2 =>Vi=0. I.e, image velocity is zero. I can't understand how it is possible that the image is at rest wrt ground. If the object moves with more velocity than the mirror, wouldn't it collide with the mirror at some point? And plus the object is moving 2m/s...

This is what I have for my solution thus far: "For gold to transition to mercury, it must exchange one of it's neutrons for a proton via ##\beta##-decay. In order to find the energy of the emitted gamma rays, we must first find the excess rest energy ##Q## present after the ##\beta##-decay. The...

For this problem, The solution is, I don't understand how if ## \gamma < 0## then there will be multiple reflections? I don't understand how ##\gamma## can be negative. Many thanks!

The 1st photo is a Google image of a Gamma ray Burst in space, the image in the other photo is being emitted from a device I am playing around with. I am just wondering what is the cause of or what dictates the behavior of actual Gamma Ray Bursts in space vs whatever light patters are in the...

Per the description given in the book, one can trace rays FROM the physical aperture stop into object space to find the size and location of the entrance pupil (EP). Also, one can trace rays FROM the physical aperture stop into image space to find the size and location of the exit pupil (XP). In...

In recent coursework, I was taught that one locates the image and identifies the image height using the marginal and chief rays. These descriptions are: Marginal ray: that ray traced from [top or bottom] of the object, through the outermost edge of the stop. The place where that ray crosses the...

I recently performed an experiment that involved using a cylindrical scintillator to detect cosmic ray muons by observing the amount of particles that decayed within 20 microseconds over a long period of time. I'd like to use this to find the flux of muons at my scintillator so that I can...

I read in the following book A history of the sciences by Stephen F. Mason. About the discovery of the electron the write what I attached in the picture. I wonder what do these positive rays traveling in the opposite direction they talk about consist of? Some ions or what? I understand that the...

Hello! Is there any good free ray tracing simulator? I just want to simulate the behavior of a Gaussian beam in a simple bow tie cavity. Thank you!

A book on optics which is less mathematical maybe a similar one to physics for poets or gamow gravity classics

It just occurred to me while watching some old X ray images , what is the reason behind why modern X ray images have so much more detail than older ones especially really old ones from the beginning of the technology at the start of 20th century? I ask this because (unlike in a CT scanner which...

The ##I_i## are the intensity of the rays, in other words energy per surface units per radians by seconds. The d##\Omega## are the solid angles The equation p75 isis what I don't understand. I suppose that each side represent the energy going and out of the surface dS but I don't understand...

I was reading Einstein's 1911 paper named "On the Influence of Gravitation on the Propagation of Light" when stated the formula for frequencies measured by observers at different fixed positions (heights) on Earth surface. One observer is at the origin of some coordinate system and measures a...

I'm given an ultra-high energy cosmic ray with energy 10^20 eV. It is coming from a source 10 Mpc away with an extragalactic magnetic field with strength B = 10^-9 G. I am to determine the maximum angular deflection of this cosmic ray, so it hits Earth. I don't have an attempt of the solution...

https://arxiv.org/abs/1502.03808 They are using Boyer-Lindquist coordinates for the Kerr metric. As far as I understand they also introduced a camera-fixed basis defining spherical coordinates ##\theta_{cs}## and ##\phi_{cs}## to keep track of the directions of the light rays relative to the...

I tried to use complementary angles and the law of reflection but I still have no idea how to find the angle.

I am unable to see how a sensor where the receiving and emitting instruments are next to one another deal with wave interference between the emitted and reflected wave.

I was reading the Exotic baryons page on Wikipedia and a cited source said that Ray Kurzweil, renowned Futurist said that at the end of the 21st century, we could use femtotechnology to create new chemical elements from exotic baryons that could create a new periodic table of elements. Here is...

I've created an excel spreadsheet with the given model in addition to calculating radius of the layer by subtracting depth from 6371. I've calculated Zf. I've also found what I think is vs by doing alpha * (radius column/6371), but that could be wrong. I know I need to find where 20/6371 =...

Hello, I wanted to confirm a suspicion with how the Aimpoint optics work, but to do that I need to do some ray diagrams. I only ever did them with simple convex, concave, and spherical systems while at college. From what I already know of how reflex sights work, the LED is placed at the focal...

Summary: This is a hobbyist project I am working on. I am building an instrument to measure radiance from the sun at 500 nm, using optically filtered photodetector with bandwidth ± 10 nm. This type of science can be called Sun Photometry, so let's get to it! Geometry for Optics: The sun has an...

So far all I can work out is that the angle of incidence of the outer two and inner two rays is zero degrees, however, I can't work out how to get started on the problem. I feel like I need to use vertical slowness rather than the normal snell's law since I'm working with a dZ rather than a dX...

I'm watching an episode of "How the universe works" and they explained the nightmare scenario where a star supernovas and turns into a black hole, emitting such a powerful burst of gamma rays, that if it were any closer than 6000 light years then it would be capable of stripping the entire Earth...

I have never seen ray model of light being considered for radio waves, or waves of larger wavelengths. I have a feeling that this model does not apply to them. Am I right?

I've attached a picture from the problem, the given equations, and my work so far. I knew I had a problem when My units wouldn't check out. This should just be simple algebra but It's not working. Please help me to understand what I am doing wrong.

Today I read about a seemingly new way of using Xrays that results in images that can be colored and more detailed. https://www.marsbioimaging.com/mars/ See this link for example. I do wonder what would be the major differences or benefits from such technology given modern MRI also has very...

This is an example from a textbook. They show the following: ∫nds = ∫r-2*ds = ∫r-2*√((dr)2+r2*(dθ)2) How do you obtain the expression for ds?

Good Day, I would like to obtain cathode-ray tubes for deflecting electrons with a magnet. However, I don't want to deal with X-rays, and would prefer to obtain cathode tubes that cannot produce X-rays at all. I haven't had much luck on the internet finding such cathode ray tubes or I don't...

Can an everyday magnet disturb a ray of light. I have seen many answers online saying no, and some saying yes, but only if the magnetic field is large enough.

If we want to show whether or not a specific Cosmic Ray particle is confined to our galaxy we must use the Larmor radius (relativistic version), r = γmc / qB Considering a 10^14 eV proton and assuming the galactic magnetic field strength is 10^−11 T, show that the particle is confined to the...

Let there be a sphere whose inner surface consists of a perfectly reflecting surface. It has a hole on it which allows a ray of light to enter. Give the angle made with the normal of the hole when the ray of light enters such that the probability that the ray comes out is the least?Assuming the...

I am planning a physical experiement under vacuum conditions. In this experiement, I want to detect ionizing rays, especially as broad band as possible, for instance including alpha radiation. Typically geiger tubes are filled with a certain gas, that gets ionized by the radiation to measure...

I can't see how the textbook produces the following relationships between angles: $$ \theta = \phi + \alpha \qquad (1)$$ $$ 2\theta = \alpha + \alpha ' \qquad (2)$$ My thinking is that the exterior angle theorem for triangles was used to create expression ##(1)##, but I am unsure as to how...

Here are two ray diagrams for compound microscope, the first one proposed by the book, and the second one recommended by the teacher: In the first image, the light rays form a real image A'B', which becomes the virtual object for the eyepiece. See, the original rays are carried forward to...

Homework Statement I read that the magnification for a point object is undefined, but when we draw ray diagrams we consider the rays to be emanating from a point source and also define magnification for it- what am I missing? Homework Equations -- The Attempt at a Solution (conceptual query)

Homework Statement Homework Equations Minimum/Maximum occurs when the first derivative=0 GM≤AM: ##~\sqrt{xy}\leq\frac{x+y}{2}## The Attempt at a Solution [/B] If the sum of squares of the distances (setup 2) in an arbitrary point is bigger than the sum of the squares of the shortest...

Homework Statement The accelerating voltage in a cathode ray tube is ##1000 V##, the electron current density is ##150 \mu A##. a) How many electrons arrive at the screen in a second? b) What's the magnitude of the force exerted on the screen by the electrons if they stop on collision? (Sorry...

Let's say I have an apparatus that's set up like this Let's also say that the mirror is infinitely long. If the mirror starts moving at subluminal speeds in the x axis, what would happen to the path of the ray of light? Would the dot made by the ray of light on the wall go up?

Homework Statement If the electrons hit the tungsten target with an energy of 75 keV, find the potential difference. Homework EquationsThe Attempt at a Solution I tried this: (W=eV) V=W/Q V=eV/Q V=75,000/1.6*10-19 V= 4.6*1023 V, This seems wrong because all examples in my...

With FIXED SOURCE AND RECEIVER, I have a light incident from fluid 1 with velocity v1 into fluid 2 with velocity v2. Obviously, according to Snell's law, v1/v2=sin(alpha1)/sin(alpha2), where alpha1 and alpha2 are the angles with regard to the vertical line. My question is: how to calculate...

I found out that high dose gamma ray exposure is actually easier for the body to repair than low dose gamma ray exposure. At first this made 0 sense to me as higher dose means you are exposed to more gamma rays per second and thus more damage is done. But now that I think about it, I think that...

Homework Statement [/B] Consider the line whose shortest distance to the origin is 5 and that is perpendicular to the ray ##\theta= \frac {5*\pi}{7}## for r>0 Find its polar equation ##r=r(\theta)## and ##\theta_1<\theta_2## in the interval ##[0, 2\pi]## such that ##r(\theta)\geq 0## for all...

with regards to this https://arxiv.org/abs/1103.5626 "Gamma ray burst delay times probe the geometry of momentum space" May we have updates of the latest experiment results along the line of Smolin 2011 idea concerning gamma ray burst delay times that can test if momentum space is curved?

Hi. When we see a laser ray, it seems that part of the ray are brighter than the other parts and they seem like they’re vibrating and moving. It also seems there are fractures in its path. I want to know why do we see like this? For example see this picture (it is from wikipedia). I circled...

Hello everyone, while reading about the X ray tube, I came across this: https://radiopaedia.org/articles/kilovoltage-peak In the second paragraph, it is stated that: "The radiation dose to the patient is directly proportional to the square of kV." I understand that by accelerating the...

Hi, When U-235 captures a neutron, it may end up with a fission reaction or an excited U-236 isotope. This U-236 emits gamma rays as it goes to its ground state. What I want to learn is that how much is the contribution of these gamma rays' energy to overall fission energy. I checked the...

I wondered if anyone might have something to say about how a 'Ray Transformation' should be defined and also point out what Weinberg means by his 'ray transformations T', see Weinberg, Reference 1, pg 91. Should a ray transformation be an equivalence class of operators? I have started to try to...

Hi everyone, I have this question about POP. Assume a patient separation of 20cm. Using data for 6MV , FS 10x10 cm, plot the depth dose for one beam at 2 cm intervals. Include on your plot the dose at dmax and the dose at 20-dmax. On the same graph repeat this for the opposed beam. Now plot the...

Homework Statement I needed help to undestand some concepts in Ray Optics for my assignment. The topics which U am concerned are: Part 1: Mirror Equation, Refraction at singly curved surface, lens maker's equation, combination of thin lenses in contact. Part 2: Magnification Power of simple...