Fyi, there's a lot of
woo woo(edit: apparently racist term) crap out there that tries to make you believe that somehow the photons can feel that a human is watching them and they choose to behave differently as a result. This is not true. It just means that when you use a detector or some sort of probe that physically interacts with the photons they change their behavior. It's not magic.The way some of such experiments are done is by creating entangled photons and observing (or not observing) the second photon. No interaction with the first photon, except mysterious instantaneous wave function collapse. Also known as Magic.
So, it's fine that you don't understand the experiment, it's really confusing and not intuitive. It's not that the photons change their behavior when measured. It's that they pass through two different slits as a probability field, and the field collapses as soon as it is measured in any way. It's not just that the behavior changes, the nature of the photon changes. It doesn't exist as a single point in spacetime until it is measured.
One of the key points that the "it's just mechanical interactions, bro" crowd should be more aware of though are the quantum eraser variations (not the delayed choice quantum eraser).
There is still something rather bizarre about mechanical interactions that measure which path information being sufficient to collapse on their own but suddenly insufficient when something like polarization which erases which path information is added back in later in the chain.
Also, it's worth declaring when giving an answer like this that you are operating under the assumptions of QFT, and that this isn't necessarily for sure what's going on. For example, I'd imagine there's Bohemian mechanics adherents still around somewhere that would take issue with your "it doesn't exist as a single point in spacetime until it's measured."
So you’re telling me that the double slit experiment has reached a sufficient saturation point in modern culture so as to have a conspiracy around it?
It's not a conspiracy.
It's straight up some of the ways in which various accredited physicists were explaining how and why it does the weird things it does.
Von Neuman arguably started it by correctly pointing out that the collapse could be taking place anywhere between the measurement device to the subjective perception of that measurement.
The latter boundary was favored at the time by people like Fritz London, a five times Nobel nominee.
Eugene Wigner further doubled down on the theory, and has the rare distinction of being one of the few people whose gedankenexperiment eventually ended up realizing the very counterintuitive result it was proposed to explore.
These weren't conspiracy theorists.
They were physicists.
Thinking outside the box and from all different angles to try and understand counterintuitive experimental results.
Some of those theories have since been extrapolated from by popsci and new age circles to claim ridiculous things, but the existence of "quantum stickers" to cure your ills doesn't mean Dirac and Schrodinger were crackpots, and so neither does someone claiming "The Secret" like powers based on quantum theory mean that folks like Wigner or Penrose are conspiracy theorists.
It's a legitimate interpretation with a number of very experienced physicists in favor of it over the years, even if not a popular one.
Considering it was one of the basic labs I did in college physics that pretty much every student has to take, and a significant portion of the classes just do the experiments wrong until they get helped, there's probably just enough familiarity to kinda know what's happening but with major misconceptions.
Thank you. I had someone sit for about 30 minutes trying to convince me our eyes, without any level of interaction, changed the behavior of photons and quantum particles simply by the fact we were gazing at them. I could not understand how but kept being reassured it was the case.
People take the word "observe" at face value (no pun intended) a bit too often
There's actually no way to prove or disprove consciousness collapse theories, as even if an unmonitored detector causes collapse, you only know about it when a consciousness is reviewing the data. So at best it can be said that direct consciousness collapse theories aren't true, but AFAIK the ones still around are all indirect (i.e. collapse occurs at the point you are reviewing the data).
We could similarly talk about the "woo woo" of multiverse theories and how there's no proof for Everett's interpretation (despite being one of the few popular theories not to need an invalidation of an assumption in the Frauchiger-Renner paradox).
But no proof doesn't equal "not true."
All QM interpretations are up in the air, and an appeal to Copenhagen interpretation is probably one of the most nonsensical given a specific interpretation doesn't even exist for that one and it's effectively just become euphemistic for "shut up and calculate."
Wheeler's delayed-choice experiments demonstrate that extracting "which path" information after a particle passes through the slits can seem to retroactively alter its previous behavior at the slits.
from the Wikipedia article on the double-slit experiment
If you read through Wheeler's delayed choice experiments, all the variations he went through to try to pin this down, well... it's hard to avoid the conclusion that the waveform doesn't collapse until the moment that someone looks at the data. In fact, it's hard to avoid the conclusion that the universe is laughing at us every time we try to get a specific answer. This statement from the conclusion is absolutely bonkers if you think about it:
The fact that it is possible to decide whether a wave or particle feature manifests itself long after—and even space-like separated from—the measurement teaches us that we should not have any naive realistic picture for interpreting quantum phenomena.
The method of observation determines whether the photon behaved as a wave or a particle, after the measurement is done.
Our results demonstrate that the viewpoint that the system photon behaves either definitely as a wave or definitely as a particle would require faster-than-light communication. Because this would be in strong tension with the special theory of relativity, we believe that such a viewpoint should be given up entirely.
The photon behavior as recorded changes depending on how you examine the record, even "long after" the record is made and the interpretation should be fixed. It quite literally depends on how you look at it.
There's a video about how the delayed choice experiment is compatible with existing quantum physics and doesn't require further weirdness like retrocausality to explain.
I mean, magic is just weird shit that isn't fully understood yet.
That being said, you might as well look at it as branches.
Each state is a possibility, thus both exist.
The "magic" isn't that the probabilities of either state being in effect suddenly collapsed and became reality. The magic is that by observing the result, we collapse our own probability and are suddenly aware of the branch that we exist in. But we also exist in that other branch, suddenly aware that we exist in it. But "both" of us are incapable of viewing that other branch.
Which is all mumbo-jumbo, but I'm a fiction writer, so I don't have to be rigorous :)
As far as I know, the detectors need to be able to interact with the photons, which redirected(or consumed) the outer "branches" that were landing in the outer slits. This left the only two slits untouched. It shows the fallacy of using detection equipment without considering their impact on the environment or experiment, especially when the extremes of our physical world are being tested. In the experiment, the detection equipment, or sensors, were placed in the two slits.
What is an eye and the brain if not organic cameras and computers? This is actually an issue in science philosophy.
There is no material difference between observation through tools and through “the bare senses”. Observation is what matters.
Observing quantum phenomena changes it. The tool does not matter.
Yes, but eyes and other sensory organs are passive observers. You can only see photons if they've already been reflected in your direction, and whether you're looking has no impact on if they are reflected or not.
Feels like a kind of "if a tree falls in a forest" scenario. Whether your eyes were in the way or not makes no difference.
It's not even "observing" in that sense. It's just an interaction that forces the waveform to collapse. Basically, if anything requires a result, then it collapses. It doesn't need to record anything or anything like that. It just needs to be effected by (or apply an effect to) the photons.
Actually not correct, words in a lab can mean different things from the popular usage. With Theory being the most popular misconception, as so many people believe that it just means I guess, when in reality it is closer to something we can't test, but if it weren't true so many other things that we can test couldn't possibly be true.
Typically a theory is never proven nor disproven, it is however replaced with a more accurate Theory.
Inside of a laboratory, observation means something less like you saw it, and something more like you measured it. All the observation changing it proves, is that we don't have a method of measuring it that will not interact with it. Which is to be expected given that Quantum phenomenon is legitimately so small that even a microscopic bacterium would say it's tiny.
Even the dictionary says woo-woo refers to the sounds ghosts are supposed to make. Don’t trust randos on lemmy.
I agree but please don't say woo woo, the term is considered offensive against Asians, plus James Randi, the guy who came up with it, was literally a climate denying pedophile who was the primary science advisor on the thoroughly debunked false memory Foundation.
The term, like this man's legacy, needs to die.
It is a shame really, I used to be so convinced that magic had to be real, that men of science just didn't want to hear it because it conflicted with their worldview. God I would give anything for that to be true.
James Randi, the guy who came up with it, was literally a climate denying pedophile
I'm unsurprised that someone born in the twenties with an identity built heavily around being skeptical of anything without a lot of concrete evidence, a stage magician whose whole thing was being angry about psychics, mediums and the like defrauding people would require extraordinary evidence to believe in climate change.
Especially given we've been 10 years out from irreversible catastrophe since the 70s, according to various high ranking UN officials with positions related to the environment/climate. When that time passes, releasing a new statement claiming it's another ten years out and pretending the previous one never happened. For someone like Randi, that's got to set off the same bullshit detectors that religious leaders predicting apocalypse do.
I'd never heard the claim he was a pedophile before though, at least not outside the same circles accusing him in hushed tones of theft, tax evasion and being a Communist. Got a decent source on that one?
The amount of times I've seen people misunderstanding this...
When you blast something with a high powered laser it behaves differently, who knew?
So how do you explain the quantum eraser experiment (note for those who might be excited to respond with recent YouTube physics videos, this is not the delayed choice quantum eraser, and has nothing to do with retrocausality claims)?
NO FAIR! You changed the outcome by measuring it!
This actually reminds me of latest Futurama episode :)
Fucking brilliant! And all of the upvotes assure me that I'm hanging out with the right bunch of nerds on the internet!
Shit. That maybe the most clever meme I've ever seen.
fascinating
That's the best use of that meme I've seen.
That's the best use of this meme I've ever seen. Bravo.
Can someone who understands science explain this to me (what im getting at is its a pregnancy test)
The double slit expiriment demonstrates the duality of the nature of a photon: that it's both a wave and a particle.
When a photon is "observed" (or detected) it has the properties of a particle. However when it's travelling it acts like a wave and can demonstrate interference patterns with other photons.
So when you pass photos through two tiny slits, instead of them just passing right through like a particle, they interfere with each other and when the wave pattern collapses when it is observed on the wall, you see the interference.
That being said, I don't think this cartoon makes sense. I get what they are driving at, as they are saying it acts differently when not observed, but this is not what happens. Also this isn't a ln experiment that deals with observation forcing an outcome, but as I noted it's about the duality. Additionally, the wave pattern on the top is what you would you observe when looking at, so I'm not sure why that is what it would be like if you were looking away.
But maybe I'm missing something.
The double slit experiment is about observation.
When you fire photons through the double slits, one photon at a time, they cause wave interference patterns with themselves as if each photon travelled through both slits.
Yet if you set something up to measure which slit each photon passed through, they no longer interfere with themselves, and give you the two straight lines pattern, rather than the interference pattern.
So how long until someone comes in here and claims that this it disproves materialism?
"But but the Double Slit!" Is my favorite pseudoscience argument
Very clever, made me laugh
https://www.youtube.com/watch?v=A9tKncAdlHQ - 9 minutes of explaining of how this evolved.
Can someone post a search term or some other clue so we can learn?
The double slit experiment demonstrates the wave-particle duality of light.
You shoot photons at a barrier that has two slits in it. The pattern on the backstop appears as in the top right panel: an interference pattern, because light is behaving as a wave.
Next, you set up a detector at the slits, so that you can determine which slit each photon passed through, one photon at a time. Now the pattern on the backstop appears as the lower right panel, not an interference pattern, because each photon is acting as a particle.
Not looking: wave. Looking: particle.
TLDR the goddamn universe makes no fucking sense if you really look at it.
Not looking at it only introduces more uncertainty.
Just start believing the conspiracy theories. Looking or not looking just changes the lighting system from ambient to raytracing, simple. Why spend so many resources rendering what no
playeris there to observe? Low level simulation on unloaded chunks.
Young's double slit experiment.
When which slit a photon goes through is unobserved, it behaves like a wave and self interferes so many photons create an interference pattern with stripes where self-interactions prevented any photons from appearing.
When the photon is interacted with in a way which leaves permanent information about which slit it went through, it behaves like a particle and the pattern from many photons looks 'ballistic' like you were shooting tiny balls through each slit.
So in the meme when he's not looking at the slits, there's stripes, and when he's looking it's a ballistic pattern.
Double-slit experiment
If particles act as waves, but are not directly observed then those waves will interfere with each other and make the first image (this is correct). If it is observed directly, the wave collapses and you get the second one. Note that you would effectively only ever see the first one.
TL;DR: quantum mechanics is freaky. In the double-slit experiment, it was shown that un-observed photons behaved like a wave, interfering with itself (top pic), while observed photons acted like particles (bottom pic). The phenomenon is known as wave function collapse.
Nothin' like learning in 240p
For those watching, just ignore the stupid conclusions of it. This movie tries to use quantum physics to explain their insane beliefs.
Ok that’s pretty good lol
Brilliant. Do you call this quantum consciousness, quantum mind or something? At least in German its Quantenbewusstsein. After all these years i remember that photons notice you observe them and behave differently, because it's ducking interesting.
Actually scam artist call this Quantum Consciousness and believe that it proves that quantum physics is just the old magic under a new name.
Everyone else just calls this the Dual slit experiment
I mean it is quantum awareness at least, artful phrasing just makes it a bit misleading.
Do you call this quantum consciousness, quantum mind or something?
Nope, we call it wave-function collapse.
More like double-slut lmao
