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When reading about various quantum experiments the apparatus often includes things like "semitransparent mirrors", "regular mirrors", "polarization filters" and others. Usually a photon or an electron is emitted, bounces around in the device, and is measured at the other end.

And in all the experiments, all these in-between steps are considered to be "magically perfect". Nobody pays them any more attention except to mention that they're there. All mirrors reflect all photons perfectly. Polarization filters just "know" which photons to pass through and which not, etc.

But that's not how it works in real life, is it? All these parts are big, macroscopic chunks of matter with many, many atoms in them. A particle doesn't just seamlessly pass through/reflect—it bounces around in there, gets absorbed and reemitted, and entangled with god only knows how many other particles on the way.

The final particle that arrives at the detector at the end is almost certainly not the same particle that was emitted. And even if it by some miracle is, its quantum state is now hopelessly altered by all the obstacles it met on the way.

Yet nobody seems to care about this and just assumes that it's the same particle and tries to measure it and draw conclusions from that.

What am I missing here?

When reading about various quantum experiments the apparatus often includes things like "semitransparent mirrors", "regular mirrors", "polarization filters" and others. Usually a photon or an electron is emitted, bounces around in the device, and is measured at the other end.

And in all the experiments, all these in-between steps are considered to be "magically perfect". Nobody pays them any more attention except to mention that they're there. All mirrors reflect all photons perfectly. Polarization filters just "know" which photons to pass through and which not, etc.

But that's not how it works in real life, is it? All these parts are big, macroscopic chunks of matter with many, many atoms in them. A particle doesn't just seamlessly pass through/reflect—it bounces around in there, gets absorbed and reemitted, and entangled with God only knows how many other particles on the way.

The final particle that arrives at the detector at the end is almost certainly not the same particle that was emitted. And even if it by some miracle is, its quantum state is now hopelessly altered by all the obstacles it met on the way.

Yet nobody seems to care about this and just assumes that it's the same particle and tries to measure it and draw conclusions from that.

What am I missing here?

When reading about various quantum experiments the apparatus often includes things like "semi transparent mirrors", "regular mirrors", "polarization filters" and others. Usually a photon or an electron is emitted, bounces around in the device, and is measured at the other end.

And in all the experiments all these in-between steps are considered to be "magically perfect". Nobody pays them any more attention except to mention that they're there. All mirrors reflect all photons perfectly. Polarization filters just "know" which photons to pass through and which not, etc.

But that's not how it works in real life, is it? All these parts are big, macroscopic chunks of matter with many, many atoms in them. A particle doesn't just seamlessly pass through/reflect - it bounces around in there, gets absorbed and re-emitted, and entangled with god only knows how many other particles on the way.

The final particle that arrives at the detector at the end is almost certainly not the same particle that was emitted. And even if it by some miracle is, it's quantum state is now hopelessly altered by all the obstacles it met on the way.

Yet nobody seems to care about this and just assumes that it's the same particle and tries to measure it and draw conclusions from that.

What am I missing here?

When reading about various quantum experiments the apparatus often includes things like "semitransparent mirrors", "regular mirrors", "polarization filters" and others. Usually a photon or an electron is emitted, bounces around in the device, and is measured at the other end.

And in all the experiments, all these in-between steps are considered to be "magically perfect". Nobody pays them any more attention except to mention that they're there. All mirrors reflect all photons perfectly. Polarization filters just "know" which photons to pass through and which not, etc.

But that's not how it works in real life, is it? All these parts are big, macroscopic chunks of matter with many, many atoms in them. A particle doesn't just seamlessly pass through/reflect—it bounces around in there, gets absorbed and reemitted, and entangled with god only knows how many other particles on the way.

The final particle that arrives at the detector at the end is almost certainly not the same particle that was emitted. And even if it by some miracle is, its quantum state is now hopelessly altered by all the obstacles it met on the way.

Yet nobody seems to care about this and just assumes that it's the same particle and tries to measure it and draw conclusions from that.

What am I missing here?

Layman here, sorry if my question is silly. :)

When reading about various quantum experiments the apparatus often includes things like "semi transparent mirrors", "regular mirrors", "polarization filters" and others. Usually a photon or an electron is emitted, bounces around in the device, and is measured at the other end.

And in all the experiments all these in-between steps are considered to be "magically perfect". Nobody pays them any more attention except to mention that they're there. All mirrors reflect all photons perfectly. Polarization filters just "know" which photons to pass through and which not, etc.

But that's not how it works in real life, is it? All these parts are big, macroscopic chunks of matter with many, many atoms in them. A particle doesn't just seamlessly pass through/reflect - it bounces around in there, gets absorbed and re-emitted, and entangled with god only knows how many other particles on the way.

The final particle that arrives at the detector at the end is almost certainly not the same particle that was emitted. And even if it by some miracle is, it's quantum state is now hopelessly altered by all the obstacles it met on the way.

Yet nobody seems to care about this and just assumes that it's the same particle and tries to measure it and draw conclusions from that.

What am I missing here?

When reading about various quantum experiments the apparatus often includes things like "semi transparent mirrors", "regular mirrors", "polarization filters" and others. Usually a photon or an electron is emitted, bounces around in the device, and is measured at the other end.

And in all the experiments all these in-between steps are considered to be "magically perfect". Nobody pays them any more attention except to mention that they're there. All mirrors reflect all photons perfectly. Polarization filters just "know" which photons to pass through and which not, etc.

But that's not how it works in real life, is it? All these parts are big, macroscopic chunks of matter with many, many atoms in them. A particle doesn't just seamlessly pass through/reflect - it bounces around in there, gets absorbed and re-emitted, and entangled with god only knows how many other particles on the way.

The final particle that arrives at the detector at the end is almost certainly not the same particle that was emitted. And even if it by some miracle is, it's quantum state is now hopelessly altered by all the obstacles it met on the way.

Yet nobody seems to care about this and just assumes that it's the same particle and tries to measure it and draw conclusions from that.

What am I missing here?