Islamic theories of inertia

Several Muslim scientists from the medieval Islamic world wrote Arabic treatises on theories of motion. In the early 11th century, the Islamic scientist Ibn al-Haytham (Arabic: ابن الهيثم) (Latinized as Alhacen) hypothesized that an object will move perpetually unless a force causes it to stop or change direction. Alhacen's model of motion thus bears resemblance to the law of inertia (now known as Newton's first law of motion) later stated by Galileo Galilei in the 16th century.
Abū Rayhān al-Bīrūnī (973-1048) was the first physicist to realize that acceleration is connected with non-uniform motion. The first scientist to reject Aristotle's idea that a constant force produces uniform motion was the Arabic Muslim physicist and philosopher Hibat Allah Abu'l-Barakat al-Baghdaadi in the early 12th century. He was the first to argue that a force applied continuously produces acceleration, which is considered "the fundamental law of classical mechanics", and vaguely foreshadows Newton's second law of motion.
In the early 16th century, al-Birjandi, in his analysis on the Earth's rotation, developed a hypothesis similar to Galileo's notion of "circular inertia", which he described in the following observational test:

"The small or large rock will fall to the Earth along the path of a line that is perpendicular to the plane (sath) of the horizon; this is witnessed by experience (tajriba). And this perpendicular is away from the tangent point of the Earth’s sphere and the plane of the perceived (hissi) horizon. This point moves with the motion of the Earth and thus there will be no difference in place of fall of the two rocks."

* Abdus Salam (1984), "Islam and Science". In C. H. Lai (1987), Ideals and Realities: Selected Essays of Abdus Salam, 2nd ed., World Scientific, Singapore, p. 179-213.
* Fernando Espinoza (2005). "An analysis of the historical development of ideas about motion and its implications for teaching", Physics Education 40 (2), p. 141.
* Aydin Sayili (1987), "Ibn Sīnā and Buridan on the Motion of the Projectile", Annals of the New York Academy of Sciences 500 (1), p. 477–482
* O'Connor, John J.; Robertson, Edmund F., "Al-Biruni", MacTutor History of Mathematics archive.
* Pines, Shlomo (1970). "Abu'l-Barakāt al-Baghdādī , Hibat Allah". Dictionary of Scientific Biography. 1. New York: Charles Scribner's Sons. pp. 26–28. ISBN 0684101149.

Fibonacci numbers

Fibonacci number is a sequence where each remaining number is the sum of the previous two.
1,1,2,3,5,8,13,21,34,55,89,144,233,377,610,987,...

Vitamin or Antibiotic. Which one?

Our body has a defensive mechanism - immune system. What's that?

Immunity is a biological term that describes a state of having sufficient biological defences to avoid infection, disease, or other unwanted biological invasion.

It's a feedback of our organism for some un-usual conditions, like cold or hot weather, finger cut, virus, and so on.
Vitamins increase the power of our immune system, antibiotics - decrease.

Let's imagine that immune system is an ambulance of our organism: little cars, which go to the hotspot, problem zone.
First case, virus damage one of our cells, in the result, it doesn't do its usual tasks. In this case, our "ambulances" come to solve the problem. And when our immune system is not able to fix the problem, it needs more power. That is a vitamin.
Second case, virus damage only surface of the cell, it continues its usual tasks, but our immune system cannot respond that cell. Immune system "thinks" that this is some kind of virus. And try to "kill" it. In this case we need something to calm down our immune system, because it is trying to kill an important cell in our body. It's an antibiotic.

Of course don't use them without doctors receipt.

Virus is going to a Coke factory and having them make Pepsi

The viruses are amazing… They go into a cell… It's barely a life form on its own. But when it goes into a cell, it completely takes over the machinery and turns it to its own uses. And it's a hostile takeover. «Your cell, under new management»… It would be like going to a Coke factory and having them make Pepsi.

And if you think about this kind of stuff too hard, here's the kind of joke you come up with.

A virus walks into a bar. The bartender says: «We don't serve viruses in this bar». The virus replaces the bartender and says: «Now we do».

An infectious disease walks into a bar. The bartender says: «We don't serve infectious diseases in this bar». The infectious disease says: «Well, you are not a very good host».

A few bacteria walk into a bar. The bartender says: «We don't serve bacteria in this bar». The bacteria say: «But we work here, we're staff!»

A room-temperature superconductor walks into a bar. The bartender says: «We don't serve any superconductors in this bar». The room-temperature superconductor leaves without putting up any resistance.

An infrared photon walks into a bar and says: «Is it hot in here, or is it just me?»

A neutrino walks into a bar. The bartender says: «We don't serve neutrinos in this bar». The neutrino says: «Hey, I was just passing through».

http://www.youtube.com/watch?v=e7DkeQ0roAM

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