All Questions
13
questions
1
vote
1
answer
45
views
Why do we see objects with a given color?
I'm currently studying Electromagnetic Optics, and I don't quite understand the (classical) process through which we perceive an object with a given color. From my understanding, I'd make a ...
- 1,616
7
votes
6
answers
4k
views
Why does white light appear white?
When I think of white light, I'm imagining a combination of all 7 colors of light but I believe that since light has wave nature I can say that at some point that the probability density of red light ...
- 93
3
votes
2
answers
120
views
Is “imperfect black”, (anything other than a black hole or vacuum), actually a color?
Is “imperfect black”, (anything other than a black hole or vacuum), actually a color?
Nothing absorbs all light except for a black whole, or a vacuum which doesn’t reflect light. If we consider black ...
- 31
1
vote
2
answers
144
views
Why rays of light from different points don't form an image?
I'm asking a clarification about this questions:
Why does an image only form where light rays coming from a single point get reflected or refracted and converge to a common point?
I want to know if ...
- 338
-1
votes
1
answer
259
views
How do we know that the peak of human eye sensitivity is at 555 nm? [closed]
How do we know that the human eye is most sensitive to a light of wavelength of $555$ $nm$ and power of $1/683$ watt? How are experiments performed for obtaining this result? What's so special about ...
- 163
0
votes
2
answers
575
views
Can Human Eye differentiate between High amplitude and Low amplitude visible spectrum i.e. colours?
Every electromagnetic radiation contains particular frequency(f), Wavelength(l) and Amplitude (a). Frequency and Wavelength categories the wave (Infrared , Radio etc) and will be constant. But ...
0
votes
4
answers
788
views
Objects and light reflection
We know that we can see objects because of the light reflected by them. But if an object reflects light of wavelengths undetectable by our eyes, will it be invisible?
- 1,648
2
votes
1
answer
394
views
Why do I see discrete images when moving an object in front of a screen? [closed]
I observed this while doing my homework. I have a habit of shaking my pen between my fingers vigorously while thinking something. My PC's screen is right in front of me (on my study table itself).
...
- 95
1
vote
1
answer
133
views
Can visible light be composed of invisible electromagnetic frequencies?
I know that when we see red light (via electromagnetic frequencies in the red range) and blue light (via electromagnetic frequencies in the blue range) at the same time, we perceive it as magenta ...
- 175
45
votes
6
answers
10k
views
Does pure yellow exist in variations we can't discern? [duplicate]
If you add red light (~440 THz) and green light (~560 THz), you get what we perceive as yellow light (~520 THz). But I assume what you really get is a mixed waveform that we perceive as yellow? ...
- 579
2
votes
2
answers
2k
views
Can you use infra-red goggles (or similar principle) to see through mist and fog?
As per title really... fog is obviously quite opaque to visible light yet transparent to radio waves. What is the range of frequencies at which fog is opaque, and is either end of this range at a ...
- 1,006
5
votes
3
answers
4k
views
Why electric field has a major role in vision?
Although the electromagnetic wave is made op of both electric and magnetic fields the electric field contributes much in vision and is thus, called the light vector. But, why is it that the electric ...
- 3,905
5
votes
4
answers
567
views
Why can we 'make' new colors simply by adding wavelengths?
White light is always said to contain all the different wavelengths of light. Why, then, can we 'make' new colors simply by adding wavelengths? Is it just a matter of our perception, that, when two ...
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