Monday, August 12, 2013

Who wants to hurt Schrödinger's cat? - Gazeta Wyborcza

This cat physicists have a problem for nearly 80 years.

Let’s start with the fact that the universe is full of things that are hard to find – socks, umbrellas, keys to the car. Some in the end there, others do not, but it seems that they have to be somewhere at some one, though unknown to us, the place.

At least, we think, until we begin to study quantum mechanics. She does not give you assurance that you will find every thing in its place. Maybe it’s strange, but – according to this theory – the keys to the car can be both in the pocket and the newspaper on the desk, and socks – on foot or in a washing machine. At the same time. As they say, physicists, each object can be in superposition (deposit) of two states – either in one or the other, but both.

It’s one of the things that students learn in the early years of physics. – Initially, young people are surprised to say what’s going on? This is contrary to experience. But seeing that the lecturer says the m ost serious, with time getting used to the strange fact – says Roger Penrose of the University of Oxford.

Quants work, but how?

Of course, at the beginning of the quirks are accustomed to scientists. They had no choice – the quantum theory of the beginning of the triumphs of the saints themselves. Thanks to technical revolutions occurred twentieth century – the release of atomic energy, the use of lasers and computers, miniaturization of electronics. However strange conclusions follow from this theory – but it works. For example – so that the electron can simultaneously fly through two adjacent slots, or be in two places at once, I was able to construct an electron microscope.

The problem is only in the fact that quantum mechanics should also apply to the more scale than micro-world. Just how much larger than the electron billiard ball never behaves like an electron crazy? As the quantum laws that lead to a microscopic scale to a lot of weird for us paradoxes emerging normal world that we see around every day?

This question spent their dream with eyes already crea tors of quantum mechanics. “When someone says that he can think about quantum mechanics without dizziness, proves it’s just that it’s still not understood” – used to say, the famous Danish physicist Niels Bohr.

I see, so I’m

Physicists from the Copenhagen school explained that the observer and measuring instruments to evoke the quantum world order. Electrons caught on film does not ever leave the two tracks – he had to decide where he belongs.

However, the interpretation, in which everything depends on the observer, is clear. “The universe does not pay any attention, whether on a small planet evolution has led to the emergence of people who can trace its history. Keeps it in accordance with the laws of quantum matter what they do physicists” – notes Nobel laureate Murray Gell-Mann (discoverer of quarks) in the book “The Quark and the Jaguar”.

Gell-Mann also mentions, as Enrico Fermi, a famous nuclear physicist, asked him if quantum mechanics is correct, why Mars is moving at a certain orbit? According to quantum mechanics, electrons in the atom does not move like a planet – its location is “fuzzy”.

“We both knew the old answer, according to which Mars has a well-defined position, because people are watching it, but it seemed to both of us just stupid “- writes Gell-Mann.

Cat in Wonderland

As one of the first on the paradox pointed out in 1935 by Erwin Schrödinger, who was one of the pioneers of quantum mechanics. From planets prefer cats, so cat plays a major role in his thought experiment, which was published in 1935 in a review article “The present situation in quantum mechanics.”

Schrödinger cat locked in a box with a radioactive atom (closed only in my mind!). If the atom falls apart, it will release a poison that will kill a cat. But the atom – as befits the subject of the microworld – behaves ambiguously. According to the laws of quantum is the superposition of states. One already broke, so activated the poison, and the second – even a whole, and therefore not harmful to the cat.

So – if the cat lives in a box or not?

Quantum theory says that the cat at the same time and lives, and was dead. Nobody, of course, never a cat in this condition is not seen. We can not even imagine such a thing. You can be satisfied with the Copenhagen interpretation of quantum mechanics – only when we make the measurement, ie, look inside the box with the cat, they decide whether to materialize alive or dead. But it smells like bullshit, as the Gell-Mann.

Even worse they sound fantastic ideas “of many parallel universes” that if any superposition of states our universe is divided into two – one happens to be one story, and second – the second. In a world of cat dead, and the second – is dead.

It is known that cats they walk in their own ways, but whether it is essential to create new universes up to kill (or not!) One cat

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