Light Definition and 1000 Threads

Phase difference is $\phi=\frac{2pi}{\lambda}* \Delta+\pi$ Phase difference, max: $\Delta \phi=2pim=\frac{2pi}{\lamda_{max}}*2nd$ Phase difference, max: $\Delta \phi=2pim=\frac{2pi}{\lamda_{min}}*2nd+pi$ Flim thickness: $d=100nm$ Set the equations equal to each other i got a d=-100nm which...

Hello, I am looking for something a bit out of my wheelhouse today, gamma light sources (10 MeV or higher on the max energy threshold). Does anyone here have experience or more information on these machines? Are they typically electron accelerators utilizing a tungsten or tantalum target? I am...

In special relativity I can get ## \gamma ## , ## \frac {T_B}{T_A}=\gamma ## Why do I not go ##{T_B} - {T_A} = \gamma## ? ##T_B = \frac {2H} {c^2 - v^2}## . ## T_B ## is the moving light clock. ## T_A = \frac {2H} {c^2} ## . ##T_A ## is the stationary light clockI assume LaTeX doesn't work...

My book says: I don't understand why the bottom eye only sees the horizontal red arrow and not the other angles (black arrows)

I found that I had an inaccurate understanding of their relationship earlier. After rethinking, I try to express their relationship in a simple and understandable way Nuclear reactions convert energy from form of mass to form of light, and both energy and momentum are conserved during the...

https://www.linkedin.com/in/hellandhansen/ CMO at an ophthalmological tech company; Bulbitech. Now initiated an industrial PhD at the University of Oslo, supported by a Norwegian Research Council grant, where I will work on one of our tests (retinal adaptation speed to different lighting...

In doing a project on phototransistors I am using my smartphone as illumination source. In order to find the responsivity of the induced current from the light, I need to know the surface power density, which I could estimate, if I knew the effective optical power of the light from the...

I'm quite aware that according to Einstein light is a particle and a wave at the same time. However, I try to imagine how exactly would light expand. A photon must likely have a certain timing for expansion. I mean, after a photon is originated it immedialy multiplies itself into many other...

i think that the light sphere will go up higher(will have bigger acceleration) because there has to be a balance between the mass and the acceleration as long as the force is the same, for example if you push a heavy object and with the same force pushed another light object the light object...

Hello, Is there a mirror that will reflect light in parallel trajectories ? If yes, is the reflected light in sync, and will all beams hit a flat surface simultaneously ? Thank you

Intuitively, the Rindler wedge is timelike in Minkowski coordinates and an object crossing the horizon enters a spacelike region. This seems at odds with my understanding of the light cone where the 2 regions are reversed. I think this may be related to the signature of the metric but I'm not...

More or less all ICF schemes seem to be similar to the first artificial fusion method (also inertial) of the secondary of the hydrogen bomb. Before I present the question let me show just another ICF approach recently done. The company is called "first light fusion", Their method is essentially...

I am 74yo and love Physics. If my basic knowledge of physics is correct, light is a photon. My question is: 1. Is the reason we cannot see infrared light because the spectrum travels at a wave link our eyes cannot see? 2. Does the light from the sun have all the different waves combined, and we...

The question constantly arises how the speed of light is measured and what does it mean that the speed is constant, including at remote points for the observer, including at points beyond the local frame of reference, as you understand it in general relativity (GR). First of all, it should be...

I realize turn into probably isn't the correct term. Also I know gravity can bend light but can gravity cause light to turn into other particles? I am layman so can someone explain this in layman's term? Also I am not even sure the quantum section is the correct section.

(edit.. not the red light, that's my emergency power outage light in every frame, I'm referring to 3:57am and exactly 15 seconds, blink and you will miss it) turn up the volume Strange white/yellow flash appeared in my room and the sound it made when the light hit my security camera sounded...

Homework Statement:: Einsteins Theorie Relevant Equations:: Theorie Hi. My name is Sven Dahlhaus. I'm from Germany and just got my high school diploma. Nevertheless, I am a big fan of theoretical physics. There is a question that bothers me a lot. According to Einstein's theory, nothing can...

I know that red light has a lower index of refraction than blue light, but that’s not what I’m seeing. The blue light is where the red light should be. I can’t afford to join CHEGG. Any chance that someone would help me out for free? I’d really appreciate it. [Link to chegg removed by the Mentors]

The idea is to have 2 clocks at position A and B. The clocks are synchronized by sending a light pulse from position S over 2 equal distances x. The receiver is at position R at a distance y rectangular to the direction AB and exactly in the middle between A and B and right below S. for proofing...

ρ_kdk = k^2/π^2 dk is the density of field modes (what we are trying to solve for here), and as ρ_kdk = ρ_λdλ, and k=2π/λ, we can rearrange this to get ρ_λdλ = 8π/λ^4dλ This is where my confusion lies. I am not sure what to do next. I know this equation physically means the number of modes per...

Could I please ask for help in how to do this question. Is it in fact well formed, can it be solved as it is or do I need more information? Q. Find the external forces and the force in each rod in the following framework of light rods which is supported and A and C: So, I need to find Fa...

Been thinking about this since I was 12. Suppose you had a 1 lightyear long pole, and on the other end was a button 1 inch away that activates a light. The light is powerful enough for you to see it 1 lightyear away. You push the pole 1 inch forward. How long does it take for the light to reach...

Please bear with me I am trying to get a grip with underlying principles. Starting to try and understand Einstein’s second postulate and distinguish that the speed of light is independent of the speed of the source – v - of objects, other than light with travel initiated independent of the...

Can I understand that light energy contains heat energy? or Do I have to separate between two concepts? because light energy from the sun makes heat energy after absorption of molecular?

if someone want to explain to me what is an upright image ? , and what are the other adjectives to define an image in geometric optics and their meaning , Thanks .

If you're in a relativistic starship, approaching the speed of light, then if you get too close to it, do you end up becoming a black hole? Relativistic length decreases as you get closer to light speed. Relativistic mass increases as you do the same. Will your relativistic mass and relativistic...

Hi everyone! Hope your day is going well. I’m an ex-physics student who recently wanted to go back to studying the subject (as a hobby, mostly). So I picked up Zee’s GR book since GR is the thing I’m the most interested in. I expected to hit a wall on some basic things since I’m rusty, and did...

Hello, I built myself a spectroscope with a CD (where I removed the coating), similar to this one: With this I now want to look at light sources. However, some interesting lamps are a bit too bright to comfortably look directly into (through the spectroscope). Does anyone have an idea how to...

I know that in order for the two lights to be distinguishable from one another they have to be separated by an angle of at least theta = 1.22(wavelength)/(width of aperture). I tried drawing the given picture below and then using trig to find L in terms of d/2 and theta/2. However, this ended up...

One of the reasons to suggest that light might be bent by gravity is the assumption that light is behaving as the other objects that bend their trajectories by gravity. On a similar ground, we could suggest that as the objects are experiencing Gravity Assist, then the light could be also...

As we all know, light itself is the fastest thing in the universe, and the cosmic speed limit, basically. That said, it is said to go at 299,792,458 meters per second in a vacuum. That is pretty fast. However, I have a question I want to ask... Does light really go that fast in a vacuum? I ask...

Source: https://bigthink.com/starts-with-a-bang/fast-space-expanding/ I need help with the part in red. What does it mean when it says light is redshifted by 70 km/s? When the redshift occurs the wavelength increases which is measured in meters or kilometers. I don't understand the "per second"...

I understand the relativistic effects at high speeds, what accounts for the constant speed of light at low speeds? Example... If I travel towards a beam of light at 25 MPH, I will still measure the light as traveling towards me at the speed of light and not the speed of light plus 25 MPH.

Case 1 worked out great, I found it to be linearly polarized light at an angle ##\alpha = \frac{\pi}{4}##, but Case 2 is giving me trouble. As best I can tell, ##\alpha## is undefined in case 2. How do I solve case 2?

Good evening all, I had a question on how the standard for the meter is defined. A simple Google search tells us that since 1983, the meter has been internationally defined as the length of the path traveled by light in vacuum during a time interval of 1 / 299, 792, 458 of a second. Many other...

We know that as speed increases, time slows, and at the speed of light time apparently ceases. Imagine a hypothetical hitch-hiker sitting on a photon and speeding through the universe at -- well, the speed of light. If time has stopped for him (her?), what is his experience of his journey? Are...

Originally Answered: If light reaches the Earth from the sun, why is the space between the sun and the Earth dark? Because light illuminates surfaces, objects. Space is not an object, is the lack of matter. If you turn on a flashlight in a dark room you will illuminate the floors and the walls...

Hi all, as we all know EM waves are made up of magnetic and electric waves in a plane perpendicular to the direction of propagation. Given this, why don't I see conductors being affected when I shine light at them? Woulnt the magnetism cause a force? Is is that the force is too small? What am i...

I’m getting confused somewhere, and I’d be obliged if someone could pinpoint my error. 1. At or near the Big Bang, everything was so close as to be within each other’s light cones. 2. All parts of the cosmos are now outside of some other parts’ light cones. Therefore, 3. Something traveled...

To keep things "simple", the black hole is 1E30 kilograms. The statite (stationary satellite, blue) hovers above the hole at a fixed location (twice the Schwarzschild radius from the singularity) by tremendous acceleration. The statite drops a probe (green) that begins to fall toward the hole at...

I may be way off, but at some point in the past I understand there was super expansion where the universe expanded faster than the speed of light. If matter expanded with it it's an example of matter in separate areas moving apart faster than the speed of light. If it didn't the universe has...

Waves are energy moving. Light is moving packets of fixed amounts of energy. Why must we invoke particles to understand light? How is a wave (energy moving) antithetical to packets of energy?

Being a neophyte to physics, I try to visualize a light cone as it travels about. I try to put myself in it and use my car to talk of it. When I ride in my my car, I note that when I corner, one wheel will speed up as compared to the other side. A light cone does the same, and given that the...

I just watched this episode of Star Trek the Next Generation; The Inner Light. One of my favorites. edit: I just found this from a google search

Summary:: I have a fibre coupled LED light and an achromatic doublet lens, I know by placing the collimating lens at a distance equal to the focal length of the lens, the light will get collimated. But is the a simulation software available where I can input the parameters I can so as to...

Recently I have seen a number of General Relativity visualisations that show spacetime flowing towards any mass, similar to water flowing into a sink hole. ScienceClic's video is an example. That model is also used in the "waterfall model" to explain the event horizon of a black hole, as the...

I think infinite speed is unimaginable. If something is moving at infinite speed, we can't find it at all because it has moved to infinity. Furthermore, when the maximum speed is limited, a reasonable inference should be that observers in different reference frames should find the same one speed...

The question is of what does it depend on? We take it for a constant still how do we know that its the exactly the same as in a vacuum in a center or closer to the center of our galaxy for example. Why is the number what it is?

I used the equation for the refraction on a spherical surface: ##\frac{n_1}{p}+\frac{n_2}{q}=\frac{n_2-n_1}{R}##, where ##n_1=1## is the index of refraction of air, ##n_2## the index of refraction of the sphere, ##R## is the radius of the glass sphere, ##p## is the object distance which, since...

Let there be a track 450,000 km long and a rocket 300,000 km long with a laser attached to the bottom of it's back end with a clock beside it, and a second synchronized clock attached to bottom of its front end. Both clocks were also synchronized with a track clock while the rocket was parked...