I get terribly confused to consider which rays for determining image formation via concave and convex lens? Many times examples take 3 rays into consideration - 1) A ray passing through Focus 2) A ray passing Optical Center (center of curvature) and 3)A ray parallel to principal focus. But the...
**For example, drying a surface
--> I know it has an effect on the skin, but if it were contained and blocked from sight, would it still leave any radiation emissions on any hard surface??
I understand that cosmic rays can (and do) propagate through space extremely rapidly. But just how rapid, I wonder? (For reasons I know not, and despite having googled questions like "Speed of cosmic rays" and "How fast do cosmic rays travel?", I keep drawing a blank. I gather that subatomic...
Homework Statement
I am given the following figure:
These are converging rays that appear to be going to a point F convert to a plane wave upon hitting the boundary between n2 and n1, and I am asked to find the equation for the boundary between n1 and n2 that perfectly accomplishes this...
I understand that the fusion of hydrogen to helium in our sun's core generates gamma rays. My question is how are these gamma rays transformed to the full spectrum of photons that we that we observe from earth?
Hi all, so I am working on a presentation. What I have done so far was to calculate the cosmic ray spectrum (so given some data from Voyager 1 and PAMELA, I found the intensity as a function of the energy, in units of m^-2 (sr s MeV)^-1.
Given this function, which is essentially J =...
Hi everyone, I suffer from Delayed Sleep Phase Disorder: https://en.wikipedia.org/wiki/Delayed_sleep_phase_disorder
I've been taking sleeping pills for it for years (without them, I'd never be up in time for work) but have recently become concerned about adverse consequences of long-term use...
Homework Statement
Two rays of light fall on a surface of the prism. Do they remain parallel after they come out from the prism?
Homework Equations
sina/sinb=n2/n1
The Attempt at a Solution
I think they do, as the incidence angles are equal, the refraction angles are equal they become...
Hi there,
We can't use Infrared rays outside for data communication of our home as sun light also contain infrared rays which possible will interfere with it.That's what i read in Data communication book. My Question is , Does sun rays also contain radio wave, microwave ? if yes, then why can't...
I have drawn a diagram of the incident and reflected rays of an object by the concave mirror. Red color shows the incident rays, black color shows the normals drawn from the center of curvature, while green color shows the reflected rays. Shouldn't all the reflected rays meet at one point.
Any...
In the episode Unafraid of the Dark in Neil deGrasse Tyson's series Cosmos, Tyson says the following: "Hess had discovered cosmic rays, showers of subatomic particles that crisscross the universe at nearly the speed of light. Without the shielding effect of the Earth's atmosphere, they would be...
Homework Statement
Consider a telescope composed of two convex lenses, the objective lens and the eyepiece. The objective lens has a focal length of 26cm. Rays parallel to the principle axis enter the telescope through the objective lens and exit the telescope from the eyepiece as parallel...
It is probably a basic question, but here I go.
Suppose a source emit two almost parallel light rays. The rays travel very close to each other so at short distances (the ones in laboratory) they are indistinguishable and any measurement device will detect them as one.
So, the question is...
Asked in 2015 on "Quora," a PhD candidate answered that near-infared wavelengths can penetrate the body more that visible wavelengths, but only by a millimeter or two.
She sums up her answer, "So the question: can NIR light penetrate the human body? The first millimeter, yes, through the chest...
Hi! I'm not studying physics and what I know about light is mostly what I've read on the internet and what I've learn thinking and observing the nature.
I come to realize that the space is full of light. When I look at the black space, I don't see light but I know that is light everywhere up...
When I saw the report of a gamma ray burst associated with the LIGO GW event, my immediate thought was that the obvious explanation is that the compact massive objects were not in fact black holes, and the gamma ray burst was from the energy of the final collision and merger.
This would...
If there are bacteria that can get their energy from gamma rays (thus thriving on nuclear reactors), can multicellular life do it too?
If so, wouldn't that broaden the parts of the universe where life could arise?
If we can not use gamma rays to detect Dark Matter what can we use?
http://www.sciencedaily.com/releases/2016/02/160203110928.htm
Studies by two independent groups from the US and the Netherlands have found that gamma ray signals from the inner galaxy come from a new source rather than from...
The following article is from the January 28, 2016 edition of Spaceweather.com:
INTENSIFYING COSMIC RAYS: For the past year, neutron monitors around the Arctic Circle have sensed an increasing intensity of cosmic rays. Polar latitudes are a good place to make such measurements, because Earth's...
Hello, we routed V-shaped grooves in an acrylic panel using a CNC milling machine and placed the panel in front of my window, with no direct light hitting it.
The pictures below show two cases, in the top picture, the grooves are facing the window and on the bottom one the grooves are facing...
When electrons of high energy fall on metal X rays are produced.What about the metals having large atomic number and showing natural radio activity?Will there be a collision between the electrons and alpha and beta particle? I can not understand this. So please help me.
I am trying to solve a problem my camera exhibits. It has a sensor with 6000x3376 pixels. HD video is 1920x1080. In order to reduce the amount of information to the processor the camera throws away 2 out of 3 pixel lines.
this creates a problem with thin lines tike telephone lines and makes...
There are now more active cell phones than humans. (?) The camera lenses of cell phones can detect cosmic rays. An app has been created that stores such detections in a data base. The app has been used in Iceland, Uzbekistan, and Uganda. There is no apparent practical use, it is for...
Hello, say you are on the unit sphere and you have 2 rays intersecting it from the origin. You know the spherical coordinates of where these 2 rays intersect the sphere ##(\theta_1,\phi_1),(\theta_2,\phi_2)##.
Now, because we know the dot product of two vectors, it is simple to get that the...
Hello, over the past few days I've been looking at glowing ionization tubes on YouTube. there seems to be this innate correlation and association between ionization chambers and noble gasses, like xenon, argon and neon. i was wondering is it possible for oxygen or nitrogen to glow like them ...
MODERATOR'S NOTE: THIS THREAD HAS BEEN MOVED HERE FROM ANOTHER FORUM, SO THERE IS NO TEMPLATE
A ray of white light is incident on a 45o – 90o – 45o prism (ray 1 in the figure on the left). The prism is
constructed from crown glass with a refractive index of n2 = 1.5205 at the wavelength of...
I want to ask something about light, light can be defined as ray, wave, or particle. The group formed because of the wavelength, if the wavelength is less than the dimension of equipment it is grouped into ray, if the wavelength is equal to the dimension of equipment it is grouped into wave, and...
From my understanding gamma rays can damage metal, making it brittle. Fortunaly, this appears to be little, but sill if you have a lot (like in p-D fusion) it becomes a serious hazard. The question is, how much? Specificly I need to know how much damange it does in compairison to Neutron...
This question straddles this forum and the "Beyond the Standard Model" one a bit, so if a mentor thinks it belongs better elsewhere, please feel free to move it.
I've seen references in the "popular science" press about the possibility of indirectly detecting dark matter by looking for gamma...
Hello,
I have a question regarding the density of the LHC vs. Cosmic Rays and why the big difference doesn't matter for particle research? As a reference we look at ultra-high-energy cosmic rays which are perfect for 'one on one' collisions, but isn't 'dosage' also a parameter to consider?
--...
Ive seen similar questions elsewhere and people say that you can consider a ray that comes not from the atom directly beneath, but an atom beneath and to the left. That ray will coincide with some ray. I don't like that interpretation because it seems contrived.
Also that interpretation does...
Hi! I have a question regarding the radiation coming from the sun. It might seem stupid to some people but I would really like to know how this works.
When you see images of the sun's rays reaching the Earth for example on this image from wikipedia (see attached image).
The rays are almost...
Or, more specifically, what determinates the frequency of the photons emitted by a such a collision. I know that the number of photons produced depends on the spin and energy states of the initial particles.
It is a fact that all inertial observers would measure the same area normal to a beam of light rays in relativity. You can prove this by considering the displacement vector connecting a light ray to its neighbouring light rays. But I wondered if there were some intuitive explanation of why this...
Homework Statement
A vertical mirror is placed at the origin. A ray of light coming from A is reflected by the mirror so that it passes through B. How far from the bottom does the ray hit the mirror? The coordinates are A = (11.4, 15.9) and B = (15.9, 4.7), in centimetres.
Homework...
At page 135 of Max Born's "Principles of Optics", he proves the statement that there are two foci on each ray of a rectilinear congruence.
Here a rectilinear congruence of light rays is defined as a collection of straight light rays such that for each point in space there is one ray of the...
Just being curious. I was wondering what kind of material you could use to reflect a cosmic ray like visible light to a mirror. It would probably pass right through it, but I was just wondering. =P
Hi,
I came across a question in an exam which I couldn't really relate to any topic of physics, that I had studied.
It goes like this-
A detector is used to count the number of gamma rays emitted by a radioactive source. If the number of counts recorded in exactly 20 seconds is 10000, the...
How did they derive equation (6)?
I don't like how they say -Φm instead of Φm, but that aside, I get that both rays 1A and 2A' travel the same distance, but AC incurs a phase change due to total internal reflection (-Φm) and it travels AC from there. Meanwhile, A'C is the distance the other...
Hi everyone
I have a question and that question is" are alpha and beta and also gamma rays behavior is similar to a wave ?"
For example if we set up an experiment as same as Young's interference experiment, are these rays acting as same as light in this experiment.
Thanks
A group of researchers from the University of California has published a paper regarding the viability of detecting cosmic rays using an array of 'SmartPhones'. I've read before that the digital sensors (photomultipliers?) in most cameras and cell phones detect infrared and, by design, this is...
Well I just took a introductory course in physics at Udacity.com a while back . In that , I learned about Archimedes attempt at calculating the radius of Earth . According to that , at a place near Syracuse , Greek , the sun rays fall at 90 degrees on the summer solstice . Just wanted if you...
I am wondering how Muons are manufactured.
Wikipedia says they're the decay products of cosmic rays, and that cosmic rays are usually high energy protons.
So a high energy proton (cosmic ray) decays into a muon after colliding with matter on earth.
How is consistent with the fact that...
I know how the canal rays are produced. As I looked from wikipedia;
"The process by which anode rays are formed in a gas discharge anode ray tube is as follows. When the high voltage is applied to the tube, its electric field accelerates the small number of ions (electrically charged atoms)...
I don't know much thing about rays. When I was studying Rutherford experiment, I saw that nucleus scattered the alpha rays with Coulomb forces, and naturally the opposite forces effect the nucleus. So do the nucles of atom moves to the direction of alpha rays' first direction?
Please look at the problem.
The problem is solved for me. However, I don't understand why the angle alpha is considered to stay constant when the rays go through the lens. The ray along the distance s DOES NOT get refracted, which I agree. But the ray along the top point of the circle DOES get...
Hey everyone I'm new here and this is my first thread, although i have great interest in chemistry and physics my knowledge of these fields is very basic( I'm graduated in economics) so don't be surprised if i ask something that may look silly.
so here are my firsts questions.
-Is it...
Hi.
Quantum states are usually represented as vectors, and treated as such, even when distinct states should be represented by rays. Is there any case (in physics) when it is important to take into account this distinction?
Thanks.