Delayed Choice Quantum Eraser: Does the Future Affect the Present?
Why Physics Stack Exchange recommends it
Physics Stack Exchange askers cite it as the explanation that introduced them to the delayed choice quantum eraser, then ask the community to clarify the retrocausality claims or the setup it shows.
Recommended by 0 people across 0 different months, 2019 to 2020.
What it is
Arvin Ash gives a roughly ten minute animated explanation of Wheeler's delayed choice idea and the delayed choice quantum eraser, an extended double slit experiment that seems to show later measurement choices affecting earlier results. It is aimed at a general audience and walks through the setup with diagrams.
What people said
Cites Eddie Bravo · 2019-07 · Physics Stack Exchange · on “If I know in advance I'm getting an interference pattern, wouldn't I have time to remove the splitter so the which-path information would be know?”
Check the image below, from this excellent explanation of the quantum delayed eraser [this video] . My question, and please forgive me if it is a naive one, is that first the photon reaches detector A , which tells us whether we have an interference pattern or not. With this information in hand, and because the second detection to know the which-path information is delayed for minutes or even millions of years , won't we have enough time to just remove the splitters and always send the entangled particle to detectors 2 and 3, effectively revealing the which-path information and causing a contradiction ? My point is that if I first look to find an interference pattern on detector A and then wait f
Cites BioHazard · 2019-11 · Physics Stack Exchange · on “Modifying "Delayed Choice Quantum Eraser" experiment to send messages in past”
Firstly, I am a science fiction writer --- please do not judge my technical knowledge harshly. (Also, English is not my first language.) I'd like to know whether it is nonsense or not to have the following concept in a novel: In "Delayed Choice Quantum Eraser" experiment it is shown that if you measure in future in which slit particle went through you destroy interference pattern in past ( [this video] ). If this is true then theoretically you can have a device with photon container in which you store the photon for a significant amount of time. Then in future you can measure a photon stored in device or destroy device without measuring. If you measure it you destroy interference pattern in past
Cites brzepkowski · 2019-12 · Physics Stack Exchange · on “Are results of "quantum eraser experiment" same both for particles moving at the speed of light and slower ones?”
Recently I've encountered a video about the quantum eraser experiment [this video] . I was curious, if results of this experiment are the same for entangled particles moving with the speed of light and slower ones?
Cites Pranav K · 2020-09 · Physics Stack Exchange · on “Why doesn't delayed choice quantum eraser experiment imply retrocausality?”
WRT: [this video] [LINK] Now I found a paper "Why Delayed Choice Experiments do NOT imply Retrocausality by David Ellerman" on the internet but as a layman, I couldn't understand the paper but everyone on youtube is saying that this experiment shows retrocausality, can someone explain in simple terms why this experiment does not imply retrocausality?