“If you tell me, I’ll know less”
Posted Tuesday, September 20th, 2005 by
Dave |
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Three scientists have confirmed a suspicion many of us have had for years: information can be negative. If I give you negative information, you’ll know less. So pick your words carefully!
The discovery, by Horodecki, Oppenheim, and Winter, appears in the August 2005 edition of the leading journal Nature.
An introduction to their discovery can be found on Oppenheim’s homepage:
Even the most ignorant cannot know less than nothing. After all, negative information makes no sense. But, although this may be true in the everyday world we are accustomed to, negative information does exist in the quantum world. Small objects such as atoms, molecules and electrons behave radically different than larger objects — they obey the laws of quantum mechanics.
What could negative information possibly mean? In short, after I send you negative information, you will know less. Such strange situations can occur because what it means to know something is very different in the quantum world. In the quantum world, we can know too much, and it is in these situations where one finds negative information. Negative information turns out to be precisely the right amount to cancel the fact that we know too much.
A free version of their article can be found in the arxiv for people without subscriptions to Nature.
