Light Definition and 1000 Threads

I would like to know whether my thought is right or wrong about time dilation example. Let's say, A person is standing at a starting point so his velocity is 0 ms'1. A car runs from that point in the velocity of 3 ms'1. A photon from a light source at that point is also emitted at the same...

As I understand it, light is an electromagnetic wave consisting of an oscillating electric and magnetic fields perpendicular to each other. Are there experiments that will demonstrate (a) there is an electric field present? Stark effect? (b) a magnetic field, (c) that they are perpendicular to...

I'm puzzled that the stretching of space by a gravitational wave stretches the LIGO arm but not the light within it. Because we are told that the red shift of a distant galaxy is caused by light being stretched by the expansion of space (the universe).

I may have a fundamental misunderstanding of the concept, but I was wondering, how does the accelerating expansion of the universe calculate for the time dilation in light travel? From my understanding, we know that the universe expansion is accelerating because the farthest galaxies that we...

Homework Statement I have an equation to solve. See the attach pichture. I(r,φ,λ) = I0.sin(2πr/R).sin2(φ).(1/λ) where I0 , R are constants r,φ are cylindrical coordinates 0≤r≤R/2 : the cut is laterally limited λa ≤ λ ≤ λb : the beam contains a limited frequency spektrum where the shortcut for...

Hello from Belgium. Bruxelles. In 1815, Fresnel made, with Arago, the experience of Poisson spot. (or Arago spot, or Fresnel bright spot). A bright point that appears at the center of a circular object's shadow due to Fresnel diffraction. Arago and Fresnel glue a round opaque screen on a glass...

Dear all, I am currently doing a project about the light trajectory near Schwarzschild black hole. I wrote down a couple of differential equation and I have created a C++ program hoping to solve the orbit of light. However, the program results turn out to be quite weird. The differential...

Hi, Can someone please explain as to why light beams attract or repel each other even when they don't have charge. Seems like it behaves like two current carrying parallel wires. There is very little material about this which goes completely above the head. Thanks

A) Can the light of a laser be trapped by a spherical mirror. B) would it help to have a liquid in the sphere so as to distribute this light equally throughout the volume of the sphere. Assume laser is shown in the internally spherical constantly. The key is that we want this light to remain in...

Homework Statement Homework Equations Weight = Tension in y direction?? The Attempt at a Solution I thought that W = the tension in the y direction of the two cables so that T2y and T1y are both 20 N each. Thus, i calculated that the tension in AC is 33 N ( cos(53.1) = 20/T1 --> T1 = 20/...

Hi, Can someone please anlayse the visual effects for light travel in the documentary 'Journey to edge of the universe' Especially around the 43:12 and the 1:02:20 mark. Can you also tell me if it is or is not an accurate depiction of what we should be seeing theoretically?

I'm Timo Moilanen , physics my hobby chemistry mytrade BsC English third language or worse .

Hey :) I am currently doing a project on university in cooperation with CERN where I have to find new business fields for light sensitive sensors (CMOS) which every camera contains. The special feature is the radiation hardness. So you can use it for example for detecting x-rays or you can use...

What is exactly happening when the light hit a surface of a mirror? I know it is not same as a bounce of ball from the wall, because of constant speed of light for example. So I suppose the light is absorbed by electron of reflecting material. This probably define the materials who are...

Homework Statement A system comprising blocks, a light frictionless pulley, and connecting ropes is shown. The 9-kg block is on a smooth horizontal table (μ = 0). The surfaces of the 12-kg block are rough, with μ = 0.30. In Fig. 5.7, the mass M is set so that it descends at constant velocity...

https://www.dropbox.com/s/t5lv4nlunn35ok8/phy1.PNG?dl=0 https://www.dropbox.com/s/ktc9pj7qmqhejrv/phy2.PNG?dl=0 https://www.dropbox.com/s/qbjz1p1gokvsgj2/Capture3.PNG?dl=0 I googled "polarizer film diagram" and "malu's law" and "polarizer physics" to obtain the pictures in this thread. I...

IMAGINE an infinitely large space where there exists no particles or energy fields at all. If we introduce a single photon or a single ray of light, will it be visible from all angles?

Hi I can't see the error in this can someone please explain where I went wrong? A man is in a spaceship traveling at a constant velocity He makes 2 identical tubes of length L with a mirror at one end, tube a and tube b He has a single light bulb. Next to the bulb is a detector. He carefully...

What types of light are able to pass through the human body without causing damage to tissue or individual cells? Are there any truly safe alternatives to x-rays that could allow doctors to see internal body parts but not cause damage from extended exposure?

Hello first time posting anything like this to people that have a better grasp on these ideas. Please pardon the lack of proper language structure. So to my understanding that light travels on photons. The light from a source comes out in waves and particles. As it travels redshift will happen...

is anyone looking for what might be the effect of something going into or coming out of the speed of light?

So I understand that scientists have been able to slow light to extremely low speeds using Bose-Einstein Condensates and even without them (https://physics.aps.org/story/v3/st37) and if I understand this correctly they slow light the same way water or air does; atoms absorb the photons and...

What will happen if something traveling faster than light is found?What effect will it have on modern physics?

GW170817 showed that gamma rays came 2 seconds after gravitational waves. (after 130M years) Are these two seconds uncertainty at determination of difference of these speeds? Or is it possible to explain, why 2 seconds of difference, or is it possible to explain, at least, a part of this...

If we need light speed to travel in time and light already have it , so is light traveling in time

Suppose at the instant a gravitational wave passes through an interferometer, one of the interferometer's arm get stretched by 1%. Would the wavelength of the photon traveling in the arm also get stretched by 1%? If so, then would the frequency of the photon remain the same and hence increasing...

Is it possible to get a laser tube with the ends unmirrored, designed such that a photon being sent through will have a good chance of stimulating another photon to be emitted? If this is possible, then a beam of light going into the tube would be roughly doubled in intensity. When stimulated...

I was just wondering as it seems pretty counter intuitive that there is a really defined horizon where light can't escape from a black hole. It would make more sense to me if light gradually curved into one. Or does it do this? Please enlighten me ;)!

Hi! I just had some questions. Is there any jobs or careers that directly relate with the interference of light waves. I know that an optical engineer would be one but they would create lenses for telescopes and stuff. I don't understand how that would relate to the interference of light, are...

Help with the question of the concept of the stability of the speed of light. I gather that current atomic clocks are based upon the speed of the electron around their nucleus, which is a function of the speed of light. Measurements of the speed of light that depend upon atomic clocks therefore...

1. We have a moving platform traveling 700 miles per hour to the Right-Direction. 2. In the middle of the platform, we have a gun which fires a laser both at the front and back of the platform at the same time. 3. We have at both the front and back of the platform, a mechanical device. These...

We know interference of waves play a role in causing "colors" on soap bubbles. But does light refraction play a role in bubble iridescence? When the light wave travels into the soap bubble surface, won't it refract since the wave is into a different matter (what matter the soap bubble surface...

Homework Statement I've linked my data table down below. My problem is the relative intensity column. From the table, the units of relative intensity are w/m/s. I'm assuming this is power/velocity, where velocity is the speed of light. However, nowhere in the lab manual did it mention the...

Homework Statement How to demonstrate that we see colour of an object due to reflection of light? Homework EquationsThe Attempt at a Solution We see an object because photons from that object come to our eyes. The photons from the object comes to us due to radiation or reflection. If the...

Hey guys, I'm itching to find out what you know or theories about gravity and light... My first question that I pose to you is this.. If the cosmic speed limit is set by light.. then why can gravity affect it? Consider this. Light is traveling away from a black hole.. gravity is so...

I know that light is always at constant speed but does it ever accelerate when changing direction, if you put light through lots of different densities it curves into the Brachistochrone curve, would that be an instance of light acceleration.

I am a physics "layman", so please forgive me if these questions seem basic. Let's say we can travel at light speed, we send a crew to Proxima Centauri, & it's exactly 4 light years away. They explore for exactly one day, then return. 1. Since it takes 4 years for light to reach it & 4 years...

Can you help me figure out how this light-based phenomenon works? Please explain with an intuitive answer using the simplest principles possible. Note how the location and width of the dark horizontal bands is constant with respect to the edge of the video frame. The LED light looks normal...

In a physics investigation we were required to use a Photo-Electric Effect Instrument (Shown in the attached pdf file), which was able to measure the current produced via the photoelectric effect. One of the objectives of the investigation was to alter the aperture size, and hence intensity of...

I recently read this article from Science Alert regarding Light by Light Scattering (http://www.sciencealert.com/light-continues-to-behave-really-weirdly-in-the-large-hadron-collider). They seemed to be astonished to witness light actually bouncing off each other, as they state that photons pass...

How would polarized light behave after being reflected by a diffuse surface, such as a white wall? Would it still be completely polarized or would it be more randomly polarized? Would whatever effect takes place vary significantly with different diffuse materials? What about a mirror? Surely...

In an elevator "vertically" accelerated at g in outer space, the equivalence principle says a "horizontal" light ray in the elevator looks like a parabola. I completely understand that the light ray is curved but don't understand why the deflected light ray is an exactly parabola. Almost all...

I have a tube light at my home which produces this sound: The sound can be heard for a long time every time the light is switched on, but it stops after about half an hour of switching on the light. What is the cause of this sound?

I've seen a little bit about the gravity light. I think it works in a simple way, a weight at a certain height has gravitational potential energy depending on how far the weight will fall, this quantity represents the total energy we have at our disposal to power a light. Now we normally think...

I don't uderstand how, using special relativity theory (time dilatation and length contraction), one can explain why in the Michelson interferometer there is no delay between the two rays in the reference frame where the interferometer is moving. Consider the picture ##2.## Setting...

Are mosquitoes attracted to UV light? This PF thread isn't very clear on whether it does or not- some of it suggests that it does... So, I looked it up and found this article on Wikipedia: The American Mosquito Control association also http://www.mosquito.org/page/faq: Is the information...

The mainstream interpretation of GRT equations is, that additional double amount of angle of bending of light (Newton vs GRT) is caused by gravity (which is interpreted as curvature of spacetime). But when looking on the equations, it seems that this additional amount of bending is caused by...

I'm likely going to have a ton of questions in the following weeks about a wide range of particle physics etc. If (electricity X mercury vapor) = light, then multiplication being transitive, (light X mercury vapor) = electricity. Can someone inform? I've found only mercury vapor as a metallic...

When the water waves go through one wide slit (slit wider than wave length), there's no fringes, the water waves spread all over the sides, like in this pic: http://electron6.phys.utk.edu/light/images1-3/misc3b.jpg or in this pic...

Hi. I am willing to make an experiment with light. The idea is to have a light source (specifically a led light) and a photodiode to detect the light and make some spectroscopy. The photodiode has to detect the light in the same frequency that is emitted by the led. I'm not an expert in...