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2 votes

How can the magnetic $B$-field of a photon or light wave be directly compared to the electric $E$-field if the units are different? (Tesla vs. V/m)

Neither Teslas nor Volts are SI base units. In terms of base SI units, $1{\ \rm T} = 1\ {\rm kg \cdot s^{-2} \cdot A^{-1}}$. See wikipedia. You can also verify this equation relatively quickly using $...
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1 vote
Accepted

Does any colour appear white to our eyes if its emitted power is extremely large?

Wikipedia says, "The HSL [hue, saturation, lightness] representation models the way different paints mix together to create color in the real world." (https://en.wikipedia.org/wiki/...
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0 votes

Why are shadows sharp close to the object, but blurry farther?

I think it is a matter of type of source: point-like and huge/extended sources. In the case of the sun, experimentally if you get the object away from the screen its shadow gets blurry and if you get ...
1 vote

What happens when light of two different colours interfere destructively?

Perfect destructive interference/darkness only occurs when the two colors are exactly the same, but completely out of phase. Blue light + Blue light (out of phase) = Black darkness In order for ...
0 votes

How does interference move energy from destructive to constructive regions?

In physics, destructive interference occurs when two waves, one normal and and one inverted, meet each other and cancel each other out. Physics of destructive interference: Light + Out of phase light →...
1 vote

How much energy holds the full visible light spectrum? Same to heat absorbed by back color?

This is an excellent question related to atmospheric science and applications in the earth sciences, physics, and engineering. By inference, the questioner desires the total visible-light solar ...
0 votes

How to approximate a light source as a point source of light?

A “point source” of light is a source whose angular size is smaller than the resolving power of your optical system. Exactly what this means depends on what sort of system you are using and what you ...
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2 votes

How to approximate a light source as a point source of light?

In general, you can consider a source to be point-like if the error this would introduce is significantly smaller than other sources of error or uncertainty that would affect your result, or if the ...
0 votes

How to approximate a light source as a point source of light?

I think you would need to calculate what the error would be between the theoretical result you would get if the light source were actually a point light source, and the result you will get from the ...
0 votes

Which is the real reason for why we don't see light interference patterns?

There is an example of an interference effect that can be elicited with daylight. This optical phenomenon is called 'Newton's rings'. (I'm not going to describe the Newton's rings setup here, please ...
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1 vote

Which is the real reason for why we don't see light interference patterns?

If the pattern moves (so that bright regions become dark, and dark become bright) on a timescale small compared to human eye response time, then we won't see the interference pattern (it will be ...
0 votes
Accepted

How do lasers work if the phase shift from reflection is 180 degrees?

if I have a hollow tube that is reflective to RF that has a reflective cap on one end and an RF source on the other, and I put a strictly receiving antenna in the center (or as far as I can tell, ...
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0 votes

How do lasers work if the phase shift from reflection is 180 degrees?

Not only that but that technique you described is the idea behind the so-called slot line. You take a homogeneous waveguide, be it coaxial or simple, rectangular, circular, and you cut a narrow slot ...
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1 vote

How do photons carry information?

A photon hits a receptor. It's direction is NOT detected. It's speed and frequency are fixed. Spin is not detected. It gives no information about where it has been to the receptor. Behind the eye en ...
0 votes

Why is it that you can see transparent or translucent objects and see what is behind them at the same time?

First of all you can see, that the image is distorted. Secondly there are angles, where the light gets totally reflected by the outer surface, so you can see the contours of the glass as also some ...
1 vote

How do we determine the color of heated glass?

The spectral emissivity, $e_{\lambda}$, of a surface is the power it emits in a narrow band of wavelengths centred on $\lambda$, expressed as a fraction of the power emitted by a black body of the ...
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1 vote

How does RGB really work with subpixels?

The luminance that sensed by your eye is the brightness Y = 0.2126 R + 0.7152 G + 0.0722 B. It is actually the yellow color. Similarly the white balance (the proportion of R,G,B ) for a peak white ...
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3 votes
Accepted

How does RGB really work with subpixels?

If I use a testing website and set the value of red to 200 for example(0,0 for green and blue), the color is darker. (I assume you mean darker than 255,0,0.) Not just less bright, but the red is ...
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1 vote

Scattering Of Light- How does it happen with Sun and Earth?

It isn't the distance from the Sun to the Earth that matters. The Earth's orbit isn't circular. Distance varies over the year. Yet sunsets are red all year long, and noon isn't. Instead, it is the ...
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5 votes
Accepted

What do we actually mean when we say "light"?

Most of the time, light means electromagnetic waves in the visible part of the spectrum. But sometimes people talk about all electromagnetic waves as light. If there is doubt, visible light is a ...
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0 votes

Can anyone explain this peculiar optical phenomina?

The simple answer is diffraction. If you've never heard of that before - it's basically light passing through a tiny slit and creating interference patterns on the other side of that hole (see this: ...
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0 votes

Can anyone explain this peculiar optical phenomina?

My first guess was that it looks like a linear diffraction grating caused by micro defects inside glass, however in that case we should see a wavelength dispersion,- color deviations like in a rainbow....
0 votes

Can anyone explain this peculiar optical phenomina?

That is caused by your windshield having some type of obstacle or distortion on it perpendicular to the lines of light. If you have light diffract around an obstacle (rather than be blocked by it), it ...
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