Title: Collapse of the Wave Function
Headings: Collapse of the Wave Function
Collapse of the Wave Function
What is the Wave Function?
Animation of a wave function collapsing - click to restart
Information Physics Explains the Two-Slit Experiment

Content: Although the collapse is historically thought to be caused by a measurement, and thus dependent on the role of the observer in preparing the experiment, collapses can occur whenever quantum systems interact (e.g., collisions between particles) or even spontaneously (radioactive decay). The claim that an observer is needed to collapse the wave function has injected a severely anthropomorphic element into quantum theory, suggesting that nothing happens in the universe except when physicists are making measurements. An extreme example is Hugh Everett ’s Many Worlds theory, which says that the universe splits into two nearly identical universes whenever a measurement is made. What is the Wave Function? Perhaps the best illustration of the wave function is to show it passing though the famous slits in a two-slit experiment. It has been known for centuries that water waves passsing through a small opening creates circular waves radiating outward from that opening. If there are two openings, the waves from each opening interfere with those from the other, producing waves twice as tall at the crests (or deep in the troughs) and cancelling perfectly where a crest from one meets a trough from the other. When we send light waves through tiny slits, we see the same phenomenon. Most of the light that reaches light detectors at the back lands right behind the barrier between the slits. At some places, no light appears in the interference pattern.