EXPLANATION FOUR: UNIVERSALITY IN MANY-WORLDS: PROLOGUE (IMPOSSIBLE BUT TRUE)
20th Jul 2014, 1:56 PM
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20th Jul 2014, 3:47 PM
Al,
Excellent summary of the double slit experiment. The results of this experiment changed the way we interpret reality. That such an elegantly simple experiment has done this is just amazing.
Good job emphasizing that the mere act of trying to see which path the particles take by putting detectors at the slits causes the inteference pattern to vanish. This also happens if only one detector is placed at one slit to see "did a particle go this way?". Or, my favorite, putting the detectors after the slit but before the screen to see which path the particle HAD taken. (The interference pattern collapses even though the particle has already interacted with the interfering slits),
Other particles besides massless photons have been used. Firing electrons through a double slit apparatus will give the same wave / particle results.
It's even been done using buckyballs. 60 carbon atoms in a spherical molecule, even fired at the double slit screen one at a time, present themselves as waves by the interference pattern on the recording screen. Until the experimenter tries in any way to determine which slit they passed through; then the image formed on the screen is consistant with an accumulation of particles.
I don't believe it's been done with a potato gun yet. It should.
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Excellent summary of the double slit experiment. The results of this experiment changed the way we interpret reality. That such an elegantly simple experiment has done this is just amazing.
Good job emphasizing that the mere act of trying to see which path the particles take by putting detectors at the slits causes the inteference pattern to vanish. This also happens if only one detector is placed at one slit to see "did a particle go this way?". Or, my favorite, putting the detectors after the slit but before the screen to see which path the particle HAD taken. (The interference pattern collapses even though the particle has already interacted with the interfering slits),
Other particles besides massless photons have been used. Firing electrons through a double slit apparatus will give the same wave / particle results.
It's even been done using buckyballs. 60 carbon atoms in a spherical molecule, even fired at the double slit screen one at a time, present themselves as waves by the interference pattern on the recording screen. Until the experimenter tries in any way to determine which slit they passed through; then the image formed on the screen is consistant with an accumulation of particles.
I don't believe it's been done with a potato gun yet. It should.
To many of you this is old hat, of course. But I have to assume many of you don't know of this-- and I suspect many of you who DO know of this have lived with this so long that you've lost your sense of wonder about it. Unless you understand this, you'll not understand why many-worlds, to many scientists, seemed a reasonable interpretation.
Next time: INTERPRETING THE IMPOSSIBLE.