Border between a light and a shadow is YOU

As I wrote before, We see objects only because they all reflect light.
After beam of light starts its way from a light source, it touches objects, reflects and reaches our eye.
sometimes these reflected beams of light cannot reach our eye, because of other objects between the object and our eye. and we don't see a part of that object.
what exactly happens when the light cannot reach our eyes?
Imagine that we are watching at a wall, in a dark room, with one lamp...
light which comes from a light source, a lamp, reaches the wall, reflects from it, and reaches our eye.
If
1. we put our hand between the wall and our eye, we will not be able to see a part of the wall, because "the reflected" light cannot reach our eye. But we will see our hand, because a light, reflected from, our hand reachs our eye.
2. we put our hand between the wall and a lamp, the light from the lamp, will not reach the wall, and instead we will see a dark spot. why? because there is an obstacle, our hand. that's why that spot will have a shape of our hand.
Border between a light and a shadow is YOU! (Stanislav Yezhi Lec, "Good and Evil")
Aziz Shahhuseynov. special thanks to Franz

Objects in mirror are closer than they appear

Objects in mirror are closer than they appear

Have you ever seen this phrase?
If you have a car, then 90% that you have seen it!
But why? Why objects in the mirror ACTUALLY are closer than they appear?

The warning is used because passenger side mirrors must be convex to have a useful field of view. This makes objects smaller than they would appear if the driver viewed them in a flat mirror, or turned and looked at them directly. Since smaller objects appear farther away, the objects seen in the mirror look further away than they really are

wikipedia

But, there is something else!
When you look in a mirror, mirror shows exact reflection of you and everything around you.
The distance between you and a mirror is, for example 3 meters.
But between that guy in the mirror and the mirror distance is also 3 meters.
So, you see a distance between YOU and a mirror, and between mirror and your reflection.
That’s why, in the mirror you will see not 3 meters, but 6 meters.
Be careful, while parking your car :-)

Aziz Shahhuseynov

What is colour? Where does it come from?

We see objects only because they all reflect light.

As you know things consist of molecules, and molecules - of atoms...

Each atom consists of a nucleus (made of protons and neutrons) and then there are the electrons orbiting around it.

For example let's take the simplest atom, the atom of Hydrogen (H). It consists of one proton and one electron spinning around it. This electron can spin on 6 levels over the nucleus. In static position it spins on the closest first level.

As soon as it gets energy – any energy - heat, power, light, it moves on to the next second level. Then it progresses to the third, fourth, fifth and to the sixth levels. On the sixth level it stays for 8 to 10 s. and then “goes back”.

At this moment, when the electron moves from the higher level to the lower one, it gets rid of the energy it got earlier.

When it reaches our eyes we see this radiation of energy like a beam of light.

Do you see this? It’s only ONE atom, with only one electron, with only 6 orbits. Imagine how much beams of light other molecules radiate, the molecules with more than one electron: 2, 3, 5, 8, 13, 21 and so on.

As you can see, "colour" (beam of light) reflected by any object depends on the structure of the atoms and molecules it consists of.

by Aziz Shahhuseynov, special thanks to Marieke and Lyubov