[hamdani yusuf]

Except that it doesn't make sense.

Do you think it's Bard's fault, modern physicists' fault, or science media's fault instead?

[alancalverd]

A detector is placed near one of the slits: Now, when a photon triggers the detector, we know which slit it went through. Interestingly, the interference pattern disappears!
The "eraser" comes in: In some versions of the experiment, another measurement is made on the photons after they pass through the slits. This can involve measuring their polarization or phase. Depending on the type of measurement, the interference pattern can reappear, even though we "know" which slit the photons went through!

One photon, all the photons exiting one slit being captured by a detector, or lots of photons, some of which are measured?

The only way a photon can "trigger" a detector is by transferring energy to it, so whatever happens downstream from  the detector doesn't include the original photon, hence no interference, and whatever else you measure isn't related to the photon that triggered the detector!

Whatever the quality or source of its input material, Bard has delivered garbage.

[hamdani yusuf]

The only way a photon can "trigger" a detector is by transferring energy to it, so whatever happens downstream from  the detector doesn't include the original photon, hence no interference, and whatever else you measure isn't related to the photon that triggered the detector!

Do you think that downstream of optical devices like mirror, lens, prism, polarizer, slit, grating, or waveplates  still contains the original photons?

[alancalverd]

Slit, yes. Everything else, no. But beware - when discussing propagation, we need a wave model, not a particle model.

[hamdani yusuf]

Slit, yes. Everything else, no. But beware - when discussing propagation, we need a wave model, not a particle model.

What makes slit different than the others?
Isn't grating just multiple slits?
What about a knife edge, which is basically a half slit?

[alancalverd]

A slit is an absence of stuff to interact with, everything else is a presence.

[hamdani yusuf]

A slit is an absence of stuff to interact with, everything else is a presence.

The edges of the slit are stuff to interact with.

[Zer0]

Instead of four lines, it answers in four paragraphs. I hope you don't mind.

lol

ps - mwaah!@Bard.
: )

[Zer0]

Except that it doesn't make sense.

umm...okay then.

Utube!
I'm Back & i missed U.

ps - huggs@Utube
: )