In the current campaign against illiteracy, we factor out the brain ordinary humanist theme that has long been interested in it, but any attempt to read a scientific and educational literature ends hang over the first formula. Now we will ask all physicists close their eyes and ears and tell the others what quanta. Surely, you constantly encounter the word in literature, TV, Internet, offices and nanotehnolohotronah sharazhkinyh. It is time to bridge the gap and a little kerf in the subject.
1. The easiest way to explain what the rays - this analogy.
Take the distance between your eyes and the monitor. Purely mathematically, this distance can be divided into several segments. Half, another four, into eight parts. So, for example, to infinity. And it may seem that if you want to poke a finger in the monitor, you can not do it, because it divides the distance to infinity. But you know that physically you do it without a problem, because there is the smallest unit of distance, below which there is nothing there.
Previously we believed that the smallest size is the atom, but now scientists have dug right up quarks and superstrings. But the question of determining the smallest distance will leave physicists - sooner or later we present a standard. The fact that our experience shows that the division of the segment in reality is not infinite.
These arguments are similar well-known paradox of Achilles and the tortoise. The ancients also wondered about the infinity of space division. So what!
2. Now take another example from the life. Energy as it is. You fried skewers, and it, therefore, is now hot. Radiate heat that, in general, is what we call energy, and physics - electromagnetic waves. Life experience tells us that energy exists in the form of continuous waves (remember the lessons of the sinusoid incomprehensible algebra). That is the energy, we believe, is emitted continuously. Until the beginning of XX century, all scientists of the world think so too.
And here and there. It was found that there is a finite piece of energy. The smallest amount of energy, it is no less. As is the case with the distance power transmission can be divided into pieces (or packages, if you web programmer and you more understandable). The tiniest bit of energy called quanta.
3. Actually this is possible and finish. But you're probably wondering how it was discovered and why of such a trifle born a science - quantum physics.
The fact that photons exist, no one knew. While physics purely out of interest not decided to practice all sorts of calculations on ideal situations. They confuse the so-called absolutely black body. It's a fictional figovina, such as the oven, which is heated, and it does not lose (does not reflect) not a bit of energy.
This hypothetical oven after heating, of course, also begins to radiate heat. Physicists began to consider how much heat (energy) will emit such an oven. And like it or not, but they came out infinite energy. It was an ambush - Practice shows that in reality there is no such infinite anywhere else and even more in the oven. And this whole nonsense classical physics went to the forest.
4. The first something worthwhile expressed the Max Planck - grandfather of quantum physics. He drove purely the result of inventing a formula from which it followed that the energy radiated portions. That is, each electromagnetic wave carries a certain amount of energy, proportional to the frequency of the wave. Proportionality coefficient called Planck's constant, which later turned out to be not just some random number, and the fundamental physical quantity.
A good analogy is when we play the violin, and gradually turn up the volume, it actually increases the volume is not continuous, but irregular, but so small that we do not notice it.
5. Planck himself did not understand what was opened - until the end of his life he was an opponent of quantum physics. The quantization of energy was very offensive to the classics. One well-known scientist joker explain the quantization of energy this way: it's like nature has allowed or drink a liter of beer at once, or do not drink anything, avoiding intermediate doses.
Planck's formula with respect to blackbody radiation issued without adequate result of infinity. Because the pieces of energy as opposed to infinitesimal quantities can be counted.
6. Finally finished off the classical physics, Einstein. His first discovery was not the theory of relativity. The explanation of the photoelectric effect.
The photoelectric effect is when the light falls on the plate and knocks electrons out of it. But that's the energy of the ejected electrons is independent of the power increase (brightness) of light increases only the number, not the speed. The energy of electrons ejected from the plate increases if you increase the frequency of light: that is, not to shine in red, and, for example, violet light. A light with a low frequency, such as a very red, generally has no effect.
Here is a general phenomenon no one could explain in terms of classical physics.
7. No one could but Einstein. To explain why the color of the incident light beam and not its energy, determines the speed of the ejected electrons, Einstein decided to move little idea about the amount of energy bracket light wave. After Planck applied his theory only to the thermal radiation.
To begin with Einstein first announced the idea that light can and should be viewed not as a wave and as a particle (later it would be called a photon, as Einstein called it a light quantum). For the curious: in ordinary light bulb emits 100 watts per second, about a hundred billion billion photons (10 is 20 degrees).
When the photoelectric effect by virtue of the size of the battle between the electron and photon goes one on one. For a photon with an electron in a collision tore the last of the metal plate, it must have to do a sufficient amount of energy. And if you apply the formula of Planck is light, it turns out that the energy of each photon is proportional to the frequency of the light wave, that is, taken separately photon has a definite energy, which depends on the natural frequency. It turns out that the frequency of light (its color) determines the speed of the emitted electrons and the intensity of light affects only the amount of the ejected electrons.
Thus, Einstein showed that the electromagnetic wave (light) consists of small particles - photons which in turn represent smaller portions or light quanta.
8. After that, the world was never the same. Physicists have faced incredible to macrocosm phenomenon that the matter can be both a particle and a wave, that energy can not be divided endlessly, and is even a multiple of a certain value (Planck's constant) that these same rays possess the properties that you tell someone in polite company - they will not believe and will cause nurses.
Einstein was a malicious enemy of quantum physics. He was until his death kept the defense, considering that quantum effects can somehow be explained properly. But there are different Bora Nielsen, Heisenberg, Landau discovered more and more new properties of photons. And in the 50s, after the death of Einstein's quantum things were confirmed experimentally and definitively.
Maybe in the future of our educational program, we look at the paradoxes of quantum physics, if we have enough of words and the ability to explain their humanitarian human language.