Title: Observing The Universe Really Does Change The Outcome, And This Experiment Shows How
Headings: Observing The Universe Really Does Change The Outcome, And This Experiment Shows How
Observing The Universe Really Does Change The Outcome, And This Experiment Shows How
Content: And now, at the end, when we look at our screen, this is what we see. If you measure which slit an electron goes through when performing a one-at-a-time double slit ... [+]
experiment, you don't get an interference pattern on the screen behind it. Instead, the electrons behave not as waves, but as classical particles. Wikimedia Commons user Inductiveload
That interference pattern? It's gone. Instead, it's replaced by just two piles of electrons: the paths you'd expect each electron to take if there were no interference at all. What's going on here? It's as though the electrons "know" whether you're watching them or not. The very act of observing this setup — of asking "which slit did each electron pass through?" —