How the Quantum Eraser Rewrites the Past | Space Time | PBS Digital Studios

Dammit i told you the universe wasn't ready for offical release yet.

When you are not looking at it, this comment describes the answer to the quantum eraser problem.

This is the most absurd thing I've ever tried to wrap my head around in my entire life. Thank you

You are 100% right about that one - quote: "Physicists DO LOVE a good MYSTERY!" ...even more than answers! PS. ...maybe that's why each answer they provide us with discloses a 100 new questions...

...yeah. I'll be watching this one a few more times.

I remember opening and closing a fridge and every time wondering if the light was always on..then i found the button switch and the magic died forever.

I really like the transactional interpretation for explaining this. In it particles only appear after a three part process where an emitter sends out an offer wave (psi), then receives confirmation waves (psi*) from every possible future absorber and non deterministically "chooses" a single confirmation wave, which then creates something almost like a standing wave in spacetime that transfers energy, spin, momentum, etc from emitter to absorber. Which we perceive as a particle at a timelike interval. The mutual atemporal interaction between both emitter and detector is required for a particle to exist in the first place. So when you have entangled wave packets moving through the delayed choice experiment, as a single offer wave, the potential properties of "future" particles stemming from that offer wave are basically doled out to suitable absorbers in the system as you measure. Which explains all the seemingly retrocausal weirdness. Which is also why when you measure the spin of an entangled particle the spin of the other instantly changes. The possibility of it being one or the other became finalized as soon as it was measured since measuring itself is what caused potential properties to manifest from possible ones into actual events at timelike intervals.

I love how the presenter, with his facials expression, is also like "What?? This doesn't make any sense", lol

"Could it get any weirder? This is quantum mechanics. So, yeah." That made my day.

You kinda represented the data in the study wrong. The pattern that is created by the double slit experiment doesn't change when you turn any of the detectors on or off. The reason why they talked about the pattern changing was they used the detectors to create a list of which photons went through which slit. They were able to get an interference pattern when they only looked at the data of photons which went through one slit. When the data from both slits is put together the pattern disappears.

It took a while but after seeing it multiple times and really thinking about it , It breaks your mind!

Here’s some food for thought: Perhaps the central illusion here is the passage of time (in the before-during-after sense). Einstein and others have posited the notion of “block time” or “block universe” in which past, present, and future are concurrent. To this I would add that, rather than “parallel” universes/realities, such a block universe might contain all possible trajectories and events in superposition — in other words, the firing/ slit passage/ measurement is all just one unitary event. Moreover, the detection display also exists in both wave and particle (and other?) format concurrently — the one emerging trajectory being the one that is observed/attended to (sort of in the way that a sculptor “attends” to particular molecules in a block of granite to reveal a statue). In this scenario, there need be no wave function collapse (physical alteration). It would simply be the “collapse” or focus of attention by the observer on one possible trajectory. An interesting/challenging implication of this would be that the appearance of cause-and-effect is also illusory — simply being events and phenomena that co-emerge when one particular world line is attended to. The above might also illuminate the perennial question “do people have free will?” Along any particular world-line set, the opportunity-choice-outcome is one concurrent, co-emergent phenomenon. Yet the fact that we have a double-slit “paradox” suggests that choice is involved in regard to which world-line set the observer attends to.

"Physicists hate being outsmarted by the universe." 😂

Proof that universe has a parental control," You're are not that evolved to take this yet".

I'm both profoundly shocked, and in wonderland. This is fascinating and provoking. Everything I love in life, thank you for uploading all those videos

Mindblowing. This looks to be the most complex problem to root cause. This is where rational understanding has to be leveled up.

This is by far...the most important program you have ever done.

Alright then, keep your secrets.

I love this so much; in throwing out the Copenhagen Interpretation in favor of Everett's MW Interpretation this seems a much simpler effect - when we effectively entangle with this system determines whether or not we see a double-slit pattern or an interference pattern recorded. If we entangle with the system at the point of the two slits then our later measurement will absolutely be one where photons moved through one slit or the other. We've already opened Schrödinger's box and it's state is now defined because we've entangled with it. However if we don't open Schrödinger's box, we don't entangle with the system until after the double-slit filter, then it's state won't be defined until it's measured at the detector - causing the box to open and it's state finally defined as our interference pattern. Both results are absolutely the result of entanglement. It just depends on when we become entangled with it. If you measure the pattern after we entangle at the point of the double-slit you'll get a double slit pattern; if measuring the pattern is your point of entanglement you'll get the interference pattern. The absolute hidden beauty of this experiment is that it proves that WE entangle with this experiment's system and will do so for every other experiment we devise.

Two thoughts today. 1) I wish my mom was still alive so I could share this stuff with her. She'd love it. 2) If a particle is just a wobble in its field, some mixture of pilot wave theory and the Copenhagen interpretation is easier to intuit. The wave isn't propagating through time - it just _is_. Time is just another dimension, after all. What the 'measurement' does is tap the wave-function so that it bursts all at once like a bubble. What looks like causality propagating through time is an illusion caused by our perception of time. It's no weirder for the collapse to propagate backward in time than it is for it to propagate sideways in space. I don't know if I'm explaining it very well, but it makes more sense to me now than it did 6 years ago when I watched this the first time.