Nobody in the world does not understand what quantum mechanics. This is perhaps the most important thing you need to know about it. Of course, many physicists have learned to use the laws, and even predict phenomena based on quantum computation. But it is still unclear why the experiment, the observer determines the behavior of the system and causes it to take one of the two states.
Here are some examples of experiments with results that inevitably will change under the influence of the observer. They show that quantum mechanics deals with virtually the intervention of conscious thought into material reality.
Today there are many interpretations of quantum mechanics, but the Copenhagen interpretation, perhaps, is the most famous. In 1920 its general postulates were formulated by Niels Bohr and Werner Heisenberg.
The basis of the Copenhagen interpretation has laid down the wave function. This is a mathematical function that contains information about all possible states of a quantum system in which it exists at the same time. According to the Copenhagen interpretation, the state of the system and its position relative to other states can only be determined by observation (the wave function is only used to mathematically calculate the probability of finding the system in one or another state).
We can say that after seeing the quantum system is classical and immediately cease to exist in other states, moreover, which has been seen. This conclusion found its opponents (remember the famous Einstein "God does not play dice"), but the accuracy of the calculations and predictions still had their.
Nevertheless, the number of supporters of the Copenhagen interpretation is reduced, and the main reason for this is the mysterious instant collapse of the wave function in the course of the experiment. The famous thought experiment by Erwin Schrödinger poor SEAL must demonstrate the absurdity of this phenomenon. Let us recall the details.
Inside the black box sits a black cat, and with him a bottle of poison and a mechanism that can release the poison at random. For example, the radioactive atom during the collapse of the bubble can break. The exact time is not known decay of the atom. Known only half the period during which decay occurs with a probability of 50%.
Obviously, for an external observer cat inside the box it is in two states: it went well or alive, if all, or dead, if the decay has occurred and a bottle crashed. Both of these states are described by the wave function of the cat, which varies over time.
The more time passed, the more likely it is that radioactive decay occurred. But as soon as we open the box, the wave function collapses, and we immediately see the results of this inhuman experiment.
In fact, until the observer opens the box, the cat is infinitely balance between life and death, or to be simultaneously alive and dead. His fate may be determined only by the action of the observer. This is absurd and have Schrodinger.
Electron diffraction...
According to a survey of famous physicists conducted by The New York Times, the experiment of electron diffraction is one of the most exciting research in the history of science. What is its nature? There is a source that emits a beam of electrons on a photosensitive screen. And there is an obstacle in the path of the electrons, the copper plate with two slits.
What kind of picture can be expected on the screen, if the electrons are usually seem to us small charged balls? Two lanes in front of the copper plate slots. But in fact, the screen displays a much more complex pattern of alternating black and white stripes. This is due to the fact that the electrons passing through the slit begin to behave not only as a particle but as a wave (also behave light photons or other particles that may be a wave at the same time).
These waves interact in space, colliding and reinforce each other, and the result is a complex pattern of alternating light and dark bands appear on the screen. At the same time, the result of this experiment is not changed, even if the electrons pass one by one - not even one particle can be simultaneously a wave and pass through the two slits. This postulate was a major in the Copenhagen interpretation of quantum mechanics, where particles can simultaneously display their 'ordinary' physical properties and exotic features like a wave.
But what about the observer? That he makes this complicated story even more confusing. When physicists during these experiments sought to determine with the tools through which slit the electron actually goes, the picture on the screen changed dramatically, and became a "classic": with two illuminated sections directly opposite the slots, without any alternating bands.
Electrons did not seem to want to open their wave nature watchful eye of observers. It seems a mystery. But there is a simpler explanation: the observation of the system can not be carried out without a physical effect on her. This will be discussed later.
Heated fullerenes...
Particle diffraction experiments were carried out not only by electrons but also by other, much larger objects. For example, the fullerenes used in large and closed molecules consisting of several dozen carbon atoms. Recently, a group of scientists from the University of Vienna under Prof. Zeilinger tried to incorporate an element of observation in these experiments. To do this, they irradiated fullerene molecules moving laser beams. Then, heated by an external source, the molecule began to glow and will inevitably show its presence to observer.
With this innovation changed the behavior of molecules. Prior to such a comprehensive surveillance fullerenes quite successfully avoid obstacles (showing the wave properties), similar to the previous example with electrons, onto the screen. But with the presence of the observer fullerenes began to behave like a completely law-abiding physical particles.
The cooling Measurement...
One of the most famous laws in the world of quantum physics is Heisenberg's uncertainty principle, according to which it is impossible to determine the velocity and position of a quantum object at a time. The more accurately we measure the momentum of a particle, the less accurately we can measure its position. However, in our real world, macroscopic quantum validity of the laws in force at the tiny particles, usually goes unnoticed.
Recent experiments by Professor Schwab of the US are making a valuable contribution in this area. Quantum effects in these experiments were not demonstrated the level of electrons or the fullerene molecule (approximate diameter of 1 nm), and the larger objects, tiny aluminum tape. This tape was recorded on both sides so that its midpoint is in limbo and could vibrate under external influence. In addition, a number was placed a device that can accurately record the position of the tape. The experiment revealed some interesting things. First, any measure related to the position of the object, and for the surveillance tape to influence it, after each measurement position of the tape change.
Experimenters coordinates determined tape with high accuracy, and thus, according to the Heisenberg principle, have changed its speed, and hence the subsequent position. Secondly, it was quite unexpected, some measurements have led to a cooling belt. Thus, the observer can change the physical characteristics of objects by their presence.
Freezing particles...
As is known, unstable radioactive decay particles, not only in experiments with cats, but also to themselves. Each particle has an average life span, which, as it turns out, may increase under the watchful eye of the observer. This quantum effect was predicted as early as the 60s, and his brilliant experimental proof appeared in an article published by a group led by Nobel laureate in Physics Wolfgang Ketterle of the Massachusetts Institute of Technology.
In this work it was studied the disintegration of the unstable excited rubidium atoms. Immediately after the preparation of a system of atoms excited by a laser beam. Monitoring was held in two modes: continuous (the system is constantly exposed to low light pulse) and the pulse (the system from time to time was exposed to more powerful pulses).
The results are completely consistent with the theoretical predictions. External lighting effects slow decay of particles, returning them to their original state, which is far from the state of decay. The magnitude of this effect also coincided with forecasts. The maximum duration of the existence of unstable excited rubidium atoms was increased 30 times.
Quantum mechanics and consciousness...
Electrons and fullerenes cease to show its wave properties, the aluminum plates cool and unstable particles slow down its decay. Watchful eye of the observer is literally changing the world. Why it can not be evidence of the involvement of our minds in the world work? Perhaps Carl Jung and Wolfgang Pauli (Austrian physicist and Nobel laureate, pioneer of quantum mechanics) were right in the end, when he said that the laws of physics and consciousness should be seen as complementary to one another?
We are one step away from the recognition that the world around us - just an illusory product of our mind. The idea of a terrible and attractive. Let's try again appeal to physicists. Especially in recent years, as fewer and fewer people believe the Copenhagen interpretation of quantum mechanics with its mysterious collapse of the wave function, referring to the more mundane and reliable decoherence.
The fact that all these experiments, the experimenters with observations inevitably affect the system. They lit it with a laser and measuring instruments installed. They are united by an important principle: you can not watch the system or to measure its properties, without interacting with it. Every interaction is a modification of the properties of the process. Especially when a tiny quantum system is exposed to huge quantum objects. A certain Buddhist eternally neutral observer is impossible in principle. And here comes into play the term "decoherence", which is irreversible in terms of thermodynamics: the quantum properties of the system change in the interaction with other major systems.
During this interaction, the quantum system loses its original properties and become a classic like "obeying" a large system. This explains the paradox of Schrodinger's cat: a cat - a very large system, so it can not be isolated from the rest of the world. The very design of this thought experiment is not entirely correct.
In any case, if we admit the reality of the act of creation consciousness, decoherence is much more convenient approach. Perhaps even too comfortable. With this approach, the entire classical world becomes one big consequence of decoherence. And as stated by the author of one of the most famous books in the field, this approach logically leads to statements such as "the world no particles" or "do not have time on a fundamental level."
What is the truth: in the creator of the observer or a powerful decoherence? We have to choose between two evils. However, scientists are increasingly convinced that quantum effects - a manifestation of our mental processes. And then, where it ends and begins monitoring a reality, it depends on each of us.
