In the famous double slit experiment, setting up a measurement device that watches which slit an electron passes through changes the eventual outcome on the screen, causing the wave function to collapse.
If the measurement device were a light year away and were precise enough to “zoom in” and see which slit the electrons went through, what would happen on the final screen?
Surely, if the measurement device were off, then the electrons would behave like waves and not particles. An interference pattern would appear on the final screen as there is no observer. On the other hand, if someone a light year away turned on the measurement device, this far-away person (and the measurement device) wouldn’t know which slit the electrons went through until a year later. And, the electrons going through the slits wouldn’t “know” they are being observed because no information (ie the measurement device turning on) can travel faster than the speed of light.
The “observation” doesn’t occur when a person sees the result, but rather when the electron or photon interacts with the device (in this case the wall). The wall is making the observation. In this situation “observation” doesn’t have the traditional meaning, but rather refers to an interaction event.
So the same average result will happen no matter where the device is, the only thing that changes is its proximity to you.
When you say zoom in, what you are actually asking is what if the wall was a light year away, and you’re building the delayed choice version of the experiment, details here https://en.m.wikipedia.org/wiki/Delayed-choice_quantum_eraser
But basically, the universe knows, and you can’t worm your way around it.if you detect which slit the photons flow through, then you lose the interference pattern.
A measurement device is necessarily local: if it’s “zooming in” from a light year away, it’s using transmitted particles to observe—and those particles are traveling (and entangled) with the particles you’re trying to observe.
If the measurement device were a light year away and were precise enough to “zoom in” and see which slit the electrons went through, what would happen on the final screen?
That level of precision implies technological advancement, that would result with far better equipment to perform the test and measure the results, providing they would be still needed.
I know it sounds like an attempt to brush the question off, but it’s Spherical Cow and/or Newton’s Flaming Laser Sword territory. 😉
The results of the double slit experiment and the uncertainty principle will not change with our level of technology. They are fundamental laws of nature.
The quality of the camera to observe the result of the double slit experiment (meaning the pattern on the wall) has no effect on the results.
I disagree.
The hardware, software, money involved and other variables required to conduct an experiment from a lightyear away definitely elevate the project to different level on Kardashev’s scale.
