Quotes About Decoherence

So, whereas Bohr argued away by fiat all but one outcome in a measurement, the Many Worlds approach, combined with decoherence, ensures that within each universe it appears as though the other outcomes have vanished. Within each universe, that is, it's as if the probability wave has collapsed. But, compared with the Copenhagen approach, the as if provides for a very different picture of the expanse of reality. In the Many Worlds view, all outcomes, not just one, are realized.

Here is the answer to Einstein's question about the moon. Yes, it is there when no one observes it – because the environment is already, and without cease, 'measuring' it. All of the photons of sunlight that bounce off the moon are agents of decoherence, and more than adequate to fix its position in space and give it a sharp outline. The universe is always looking.

Decoherence – entanglement with the environment – is the very process by which information passes from the quantum system to its environment. It's what makes this information accessible: what makes the pointer move. Thanks to einselection, the information gets filtered in the process so that only the pointer states survive.