The Quantum Past
In this talk about quantum physics and the possibilities of a retrievable past, the language and ideas are so abstract that although the technical information is beyond any but extreme-specialists, the subject itself is somewhat understandable.
Much of the credit goes to the lecturer, Charlie Bennett, who indicates that there is no way to retrieve the past via some quantum magic (entanglement). Since the universe conserves energy it might seem that if a clever machine could be built, that energy could be reverse engineered to figure out what existed say 30 years ago. Exactly as it was configured — the sand at the beach in 1953 was the example.
This sounds odd, but quantum physics is not exactly intuitive. Bennett indicates that memory (in the physical sense) is retrievable only if fossilized, but if not copied to a medium that can last a long long time, the dissipation of any physical manifestation drains into the sink of the universe itself, at the speed of light.
The 45 minute lecture was fascinating, not only because the ideas are sci-fi fascinating, but because Bennett is an unassuming, clear, humorous and warm individual, which can make all the difference in your efforts to grok his points. In addition, the audience, all experts apparently, give you a feeling for the community involved in one form of serious thinking about reality. Listen to it yourself.
