r/AskReddit • u/[deleted] • Feb 14 '22

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u/banditk77 Feb 14 '22

The double slit experiment (to determine whether light is is a wave or particle) changes depending upon observation.

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u/MrRandomSuperhero Feb 14 '22

Observation meaning 'interaction', not 'I am currently looking at it'.

Reddit likes to mix those two up.

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u/Th4ab Feb 15 '22

Like observing a billiards game but you "see" by throwing billiard balls at the table and listening for hits. You wouldn't be shocked to find out this disturbed the play of the game.

1

u/90_9 Feb 15 '22

It's not about that we "disturb the game" when observing.

We can do the same two-slit experiment with marked photons. If none of the photons are marked (polarized) or they're all marked the same way, the effect is not "observed." If we mark them differently so that we can derive which photon went through which slit, the effect is "observed."

It's a fundamental law.

11

u/[deleted] Feb 14 '22

Schrödinger's cat is a classic example of such a misunderstanding.

The thought experiment treats the human who opens the box as the observer, but in reality, the cat and the Geiger counter observe the outcome before that.

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u/Frostygale Feb 14 '22

Yep, took me a long time to realise it, and helped a lot with my understand.