Wave function

Schrödinger developed what is known as Schrödinger equation. This equation states that there is a wave associated with any particle (like the electron), and it is called the wavefunction and it is spread out to fill the whole universe.

The wave function is stronger in one region, which corresponds to the position of the particle and gets weaker farther away from this region but still exists even far away from the “position�? of the particle.

What does all of that mean in plain English?

It means:

There is a fortune teller lady called Schrödinger equation who can predict and describe precisely and deterministically the quantum state of the particle.

However, if you doubt in her ability and decide to check on her by making a “measurement�?, somehow she knows that you want to check on her. She gets really mad and wild even before you or her knows the outcome of the “measurement�?. At that time lady Schrödinger equation transforms herself into a “probabilistic fortune teller�?, and all what she can tell you are probabilities of various outcomes of your “measurements�?.

When you “know�? the result of your “measurements�?, the weird lady Schrödinger equation gets really crazy and “collapses�? or “jumps�?. But does she collapse and disappear or jump to a very far place? No, she jumps to the new quantum state which was revealed by your “measurement�?, as she is very keen to stay with you so you can ask her again to predict the quantum state until you make the next “measurement�?, and so on.

So actually collapse of the wave function is equivalent to saying that we can know where things are, only when we are actually looking at them. Blink and they are gone!

Lady “ Schrödinger equation�? tells us too that particles are like shy people. Their behavior depends on whether or not we are looking at them.


 * http://library.thinkquest.org/C005775/Theory/newtheory_section3.html


 * http://www.chemistry.ohio-state.edu/betha/qm/

Wavefunction_collapse

Schrödingers Cat