All Questions
14
questions
0
votes
4
answers
1k
views
How does the mirror know what’s behind the paper?
I found this on social media. Although it was posted for fun, this is a valid question: How does the mirror know what’s behind the paper?
Show me how light reflected from the egg reaches the mirror.
- 5,054
15
votes
1
answer
2k
views
Why is an arrow pointing through a glass of water only flipped vertically but not horizontally?
Look at the bottom picture for example. If I try to imagine the glass of water as a lens, shouldn't it be flipped in both axes? Why does it only flip in one axis?
- 159
1
vote
1
answer
187
views
How does viewing through two eyes give us a sense of depth?
With ONE ray, your eye can never determine where the object is. Note that in your diagram, the eye can deduce the line along which the apparent image is, but to make a point, we need two lines! Who ...
- 7,980
10
votes
3
answers
3k
views
Where does the "water" come from in a mirage?
First, I would like to clarify that I know why a mirage is formed, what I want to know is why is it that when a mirage is formed it appears that a pool of water is present.
Like for a palm tree in a ...
- 113
0
votes
1
answer
156
views
Do all objects we see emit light which then forms an image inside our eye?
Daily life we see so many objects .Often in textbooks the ray diagram for the image formation in eye is shown by showing light rays coming from the object and making an image in inner layer of eye . ...
- 512
1
vote
2
answers
360
views
Why don't I see infinite images with parallel mirrors? [duplicate]
Sitting on the barbershop, watching myself in the mirror which is parallel to another mirror (so that two mirrors are parallel to each other), I was seeing an infinite number of photocopies. After a ...
- 11.9k
0
votes
1
answer
733
views
How to calculate shadow area for objects perpendicular to sunlight?
I'd like to know how it'd be possible to calculate the area of a shadow projected on the ground by an object perpendicular to sunlight and held at different heights.
I'd expect that at height H = 0, ...
- 1
3
votes
1
answer
8k
views
Why do my glasses make the ground look tilted?
I just started wearing glasses to correct my myopia today. I have -0.25 spherical and cylindrical power in my right eye and -0.5 spherical and -0.25 cylindrical in the left eye. Everytime I look at ...
0
votes
1
answer
212
views
What are the conditions for an object to be "invisible"?
So, I came across this YouTube video which shows a couple of men doing push-ups, seemingly without using their arms.
My question is, what could be a logical explanation?
Theorising in the comments:
...
- 422
40
votes
2
answers
3k
views
What is this sort of abstract rainbow?
Today I saw the phenomenon in picture below. It was not raining (at least nearby me). What can that be? What is the technical explanation?
Edit: Just seen today in Southern Brazil another ...
- 17.8k
1
vote
3
answers
3k
views
Can eyeglasses slowly "burn" one's eyes similar to using a magnifier glass?
can eyeglasses (either concave lenses as in near-sight glasses or convex lenses as in far-sight glasses) burn your eyes (maybe even very slowly over the years) the same way a magnifier glass would ...
- 39
2
votes
3
answers
2k
views
Prismatic shaped rear view mirrors
To reduce the intensity of the incident light, prismatically shaped rear view mirrors are used in cars with a day-night switch which changes the angle such that instead of the polished surface ...
- 3,148
7
votes
2
answers
2k
views
Why would the reflection of a lamp by a bowl look like a heart?
I have this bowl roughly the shape of a circular truncated cone, and the lamp shines on the bowl at an angle. The reflected lamp light hit the bottom of the bowl and created a light ring that looks ...
- 1,168
2
votes
3
answers
11k
views
How do contact lenses work?
I understand how telescope, microscope and glasses work.
But how do contact lenses work?
- 5,637