Anyone who is not shocked by quantum theory has not understood a single word.Niels Bohr
Science News reports on an odd experiement:
There’s no way around it: The nature of light seems different depending on how it’s observed. Light can act like a particle or wave, and all shades of gray in between. Now, physicists have the most dramatic demonstration yet that this range of behaviors between wave and particles really is unavoidable, and that light itself doesn’t know what it is while it’s propagating....
“You can change choices which, common sense says, had to be made at the beginning,” comments Wojciech Zurek of the Los Alamos National Laboratory. “In some sense, you can rewrite the past by what you measure now.”
Read the whole thing.