All Questions
321
questions
167
votes
9
answers
25k
views
Could Legolas actually see that far?
The video “How Far Can Legolas See?” by MinutePhysics recently went viral. The video states that although Legolas would in principle be able to count $105$ horsemen $24\text{ km}$ away, he shouldn't ...
- 6,004
98
votes
4
answers
18k
views
Seeing something from only one angle means you have only seen (what?)% of its surface area at most?
Is there a logical/mathematical way to derive what the very maximum percentage of surface area you can see from one angle of any physical object?
For instance, if I look at the broad side of a piece ...
- 1,149
68
votes
12
answers
34k
views
Is it possible that there is a color our human eye can't see?
Is it possible that there's a color that our eye couldn't see? Like all of us are color blind to it.
If there is, is it possible to detect/identify it?
- 839
68
votes
6
answers
15k
views
How does light combine to make new colours?
In computer science, we reference colours using the RGB system and TVs have pixels which consist of groups of red, green and blue lines which turn on and off to create colours.
But how does this work?...
- 1,945
55
votes
7
answers
12k
views
How many atoms does it take for us to perceive colour?
Atoms individually have no colors, but when there is a large collection of atoms we see objects colorful, which leads to a question: at least how many atoms are required for us to see the color?
- 917
51
votes
2
answers
32k
views
Why do I see better under water using swimming goggles? [duplicate]
I am myopic (I don't really know if this is relevant or not) and I usually swim without contact lenses. My vision is clearly better underwater when I am using swimming goggles.
I have tried to ...
- 1,563
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
38
votes
1
answer
17k
views
Why can you see virtual images?
In optics it is widely mentioned real images are projectable onto screens whereas virtual ones can only be seen by a person. Isn't that contradictory? I mean in order to see the virtual image it has ...
- 1,297
35
votes
9
answers
17k
views
Is it possible to blur an image in such way that a person with sight problems could see it sharp?
If someone has short or long sight, is it possible to tune image on a computer monitor in such way, that a person could see it sharp as if they were wearing glasses? If not, will 3d monitor make it ...
- 1,445
34
votes
11
answers
10k
views
Why can't the human eye focus to make blurry photos/video clear?
The human eye focuses by flexing the lens, changing its focal length. When we switch from looking at a near object to a far object, our lens flexes, moving the focal length such that the near object ...
- 880
32
votes
5
answers
46k
views
Why do nearsighted people see better with their glasses *rotated*?
If you are nearsighted (like me), you may have noticed that if you tilt your glasses, you can see distant objects more clear than with normally-positioned glasses. If you already see completely clear, ...
- 4,004
28
votes
3
answers
6k
views
How do photons get into the eyes?
I hope you will understand me correctly because there are some things that I translated.
It is known that we see the world around us thanks to photons that
are reflected from the surfaces of objects, ...
- 431
27
votes
3
answers
22k
views
Why am I able to see objects within 25 cm?
My book defines:
The closest distance for which the lens can focus light on the retina is called the least distance of distinct vision or the near point. The standard value (for normal vision) ...
- 821
27
votes
6
answers
11k
views
How do we see? Where do the photons disappear?
I know that the light is reflected from a object to my eyes, but I don't understand exactly how. The photons appear from the light source and disappear in my eye! Can someone explain the phenomenon of ...
- 608
27
votes
9
answers
8k
views
What determines whether colors you can't see are visible or not?
So, when someone is red-green colorblind, the colors appear the same to them, like this:
Source: https://iristech.co/what-do-colorblind-people-see/
And if you're totally colorblind, then things ...
- 397