Re: why can't we erase information?

Unitary evolution preserves information. It is only through measurement by an observer that information can be created or destroyed. Usually, the second law is interpreted as the destruction of information (anyone observing a closed system will over time know less information about the system), so

Re: why can't we erase information?

I've heard it said that the conservation of information can be described as "you can always reconstruct the past from the present."  Does this description shed any light on this question?   Another thought is that this question assumes reductionism and a closed system.   Tom   --~--~-

Re: why can't we erase information?

Saibal Mitra wrote: > > >How would an observer know he is living in a universe in which information >is lost? Information loss means that time evolution can map two different >initial states to the same final state. The observer in the final state >thus >cannot know that information really has b

Re: why can't we erase information?

How would an observer know he is living in a universe in which information is lost? Information loss means that time evolution can map two different initial states to the same final state. The observer in the final state thus cannot know that information really has been lost. - Original Mes

Re: why can't we erase information?

Wei Dai wrote: > If we consider our observable universe as a computation, it's rather > atypical in that it doesn't seem to make use of the erase operation (or > other any operation that irreversibly erases information). The second law of > thermodynamics is a consequence of this. In order to f

Re: why can't we erase information?

It does seem a little confusing how to quantify information when the universe itself is regarded as a computation. Some flies buzzing around the horses may make a difference in the horse race. If the flies are "erased," then that issue is settled, which seems to count as a decrease of uncertai

why can't we erase information?

If we consider our observable universe as a computation, it's rather atypical in that it doesn't seem to make use of the erase operation (or other any operation that irreversibly erases information). The second law of thermodynamics is a consequence of this. In order to forget anything (decrea