It doesn't work like this, popular misconception. It is cool in sci-fi though.
The easiest way to understand this is in terms of mutual information.
If we both flip a coin independently of one another, then both coins have a 50%/50% chance of being heads/tails and the distributions are independent of one another and thus uncorrelated, but imagine the two coins are initially attached to one another, flipped, and then we separate them. Now they're both still 50%/50% for heads/tails but are perfectly correlated, so they are guaranteed to have the same value, and so if you know one, you know the other. In this case, the coins are said to have mutual information on one another.
It turns out in the physical world that mutual information, or more specifically quantum mutual information (QMI), plays a very important role. The marginal statistics on the behavior of a system can depend upon whether or not it shares mutual information with something else. You see this in the double-slit experiment because if you record the which-way information of a particle, then necessarily it must have interacted with something to record its state, and thus whatever measured it must possess QMI between itself and the particle, and thus the particle's marginal statistical behavior will change.
This is in no way unique to human observers or human measurement devices. You can introduce just a single other particle into the experiment that interacts with the particle such that they become statistically correlated and it will have the same effect.
QMI is rather counterintuitive because you can establish QMI in ways that you would intuitively think would not impact the system being measured. For example, you can have an entirely passive interaction whereby only the measuring device's state is altered and not the particle in order to establish QMI between them.
You can also establish QMI without an interaction at all, such as, imagine that the measuring device is only placed on 1 of the 2 slits and you only fire a single photon and that photon is not detected. If it's not detected, you still know where it is, because it must have traversed the slit the measuring device was not on. Hence, the non-detection of something can still be a detection and thus can still establish QMI.
Intuitively, you would think a passive measurement, or a measurement that does not even involve an interaction at all, should not alter the system's behavior. But the mathematical structure of quantum mechanics is such that the system's marginal stochastic behavior is genuinely statistically dependent upon the quantity of QMI, and so things you would intuitively believe should not affect the system do, in fact, affect the system.
You can even use this effect to detect the presence or absence of something without ever (locally) interacting with it.
In the Mach-Zehnder interferometer, the photon can take two possible intermediate paths, we'll call them A1 and A2, but both end up at the same place. Then, at the end of the experiment, it can take two possible paths again, B1 and B2, with a detector placed on both paths. You find, in practice, that there is a 100% chance the photon will show up on B1 and 0% on B2, unless you block either A1 or A2 with your hand, then it will have a 25% chance of showing up on B1, 25% chance of showing up on B2, and 50% chance of not showing up at all (because it was blocked by your hand).
The reason this is interesting is because, without your hand blocking an intermediate path, there is a 0% chance it will show up on B2, but with your hand blocking one, it changes to 25%. Thus, if you measure a photon on path B2, you know with certainty that someone's hand must be blocking A1 or A2, yet, clearly the photon did not traverse the path of the hand or else it would have been absorbed by the hand and you would have detected nothing. You thus can deduce the presence/absence of the hand from a particle's behavior that never (locally) interacted with it, and so logically speaking, the hand must be having a non-local influence on the statistical behavior of the particle.
This influence is due to the fact that if the particle interacts with the hand, it will be absorbed into it and slightly will alter the states of the particles in the hand, and if it does not interact with the hand, it will not do this. Thus, you could in principle look very closely at the particles that make up the hand and deduce whether or not the particle took the path the hand is on based on whether or not this alteration occurs, and thus there is QMI between the hand and the particle's path, regardless of whether or not the particle actually interacts with the hand. The mere presence or absence of this QMI changes the particle's behavior.
"Observation" or "measurement" actually means interaction. We literally can't measure anything without interacting with it. If you place something at the slits which is able to detect a photon going through, it can only do so by interacting with it.
The common way seems to be that the passing particle induces a tiny electric current in a wire loop. Obviously, that takes energy away from the particle (that energy is now in the movement of one or more electrons in the wire). And that means, its wave function in that very moment is one locational probability of 1 - it is collapsed.
It only kinda works like this. If you have two slits, looking at it or not, you will see the top one. Now, the really weird thing is that if you fire a single photon at a time, you will still get the top one over time, suggesting that the single photon is somehow going through both slits and interfering with itself to do so. But the even weirder thing is, if you place a detector in one of the two slits to check which slit the photon is going through? You suddenly get the bottom picture.
My understanding is. Every method of measurement influences the results.
I'm in cognitive sciences not physics. But it applies there as well.
The measurement method always interferes in some way with the result.
I have used this example with helping students understand research methods.
Doesn't matter how "non-interfering" you think your method is.
In some way or another, the act of measuring or the device used to measure (or both) changes the thing being measured.
A photon doesn't care if you watch it or not. Unless it goes into one of your eyes and dies there, you can't see a photon.
Anyway, what I wanted to add: https://en.wikipedia.org/wiki/Weak_measurement
What I'm getting from this meme is even less interaction than a weak measurement ... They just look at the result and it's changing... That's not how measurement(-problem) works... I think.
Have I mentioned that I'm German and that btw I'm running arch? ๐
Exactly, I like to imagine it with our senses.
In order to see something lightwaves had to have interacted with the objects we see.
In order to hear something objects had to have moved or interacted in a way to produce changes of air pressure.
In order to smell something an object had to have "lost" some of its molecules into the air.
Well, and touching and tasting are kinda obvious, your body has to directly interact with an object.
Right. Our own sensory and perception system also alters and limits incoming information. Thus it influences measurements.
Right, that's even better. Everything we sense are just changes to our own body structure.
What constitutes "measuring" here? Is it in the wider sense of any quantification of an observation, or are there conditions?
Not a true expert, but I think it comes down to "observing" a particle/phenomenon like this inherently comes down to some sort of interaction, and it can't just be neglected like you could on a macro scale. Even for something like holding a ruler up to an object and seeing what mark lines up, you're relying on a bunch of light bouncing off the object (and the ruler) to be able to judge that. If the thing you're trying to measure is on the order of one particle of light, blasting it with a bunch of anything is gonna affect it pretty severely, and who knows what a "ruler" would even mean in that analogy. So it's less like some idea of sapient knowledge, and more like when you struggle to measure something like a tiny feather or single bead of Styrofoam, like you can't even get near the thing without the wind from moving or some random static or something else moving the thing around uncontrollably, except many orders of magnitude more sensitive.
shy proton theory
uwu ๐๐
Naw. "observing" doesn't mean, a human looks at the data. It means, we force the particle to be in one place on a quantum level. the word "observation" is overloaded in some sense
Until we have a solution to the wave function collapse, it kind of freaks me out.
My understanding is that the tools that are used to observe it cause the wave function to collapse. Like how putting a thermometer into meat to check the temp makes a little hole.
Yep! The only way to "see" a photon is to actually absorb it. You can't just detect it as it goes by, it has to be absorbed and reemitted, and that has an effect on it.
WE ARE WAVE, RESISTANCE IS FUTILE (unless you measure us), your biological distinctiveness will receive energy and transmit it in a periodic fashion
Stealing photons.
intference pattern by light wavelengths, used by many animals to give them those iridescent colors.
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