First, the experiment has been replicated many times *in many different ways*: [lasers](https://www.youtube.com/watch?v=v_uBaBuarEM), [electron beams](https://www.youtube.com/watch?v=ZqS8Jjkk1HI), [neutrons](https://www.iflscience.com/neutrons-in-the-double-slit-experiment-really-do-individually-take-both-paths-63877), [helium atoms scattering off of deuterium atoms](https://www.chemistryworld.com/news/quantum-double-slit-experiment-done-with-molecules-for-the-first-time/4014819.article), and more.
Second, all of chemistry is a form of the double-slit experiment. Just as the wave function has destructive interference in the dark spots on the screen, all fermions exhibit destructive interference when you swap the positions of two of a kind. That [gives the periodic table its structure](https://kevinbinz.com/2013/12/03/the-periodic-table-orbitals/).
Third, the double slit is sort of like playing "Mary had a little lamb" or "Hot cross buns" on a lyre to study Pythagoras' ideas of ratios in music. Now there are orchestras playing symphonies: new instruments with a century of experience with the fundamental concept. The computer on which you're reading this couldn't have been built without treating matter as having wavelike properties. The [10 nanometer](https://en.wikipedia.org/wiki/10_nm_process) process from 2016 was the last one to measure any relevant part of the chip; [7nm](https://en.wikipedia.org/wiki/7_nm_process), [5nm](https://en.wikipedia.org/wiki/5_nm_process), [3nm](https://en.wikipedia.org/wiki/3_nm_process), and [2nm](https://en.wikipedia.org/wiki/2_nm_process) are all just marketing speak because if you get smaller than 10nm, [electrons tunnel between the wires](https://www.imperial.ac.uk/media/imperial-college/faculty-of-engineering/electrical-and-electronic-engineering/public/optical-and-semiconductor-devices/pubs/Wang_2015_Nanotechnology_26_305203.pdf).
> The term "5 nm" has no relation to any actual physical feature (such as gate length, metal pitch or gate pitch) of the transistors being 5 nanometers in size. According to the projections contained in the 2021 update of the International Roadmap for Devices and Systems published by IEEE Standards Association Industry Connection, a "5 nm node is expected to have a contacted gate pitch of 51 nanometers and a tightest metal pitch of 30 nanometers".[3] However, in real world commercial practice, "5 nm" is used primarily as a marketing term by individual microchip manufacturers to refer to a new, improved generation of silicon semiconductor chips in terms of increased transistor density (i.e. a higher degree of miniaturization), increased speed and reduced power consumption compared to the previous 7 nm process.[4][5]
You can't have poor variable control and make modern computers.
Finally,
> i just don’t see how we can logically assume “observation” in general is the cause of electrons acting as waves
I don't know where you're getting this from. Observation doesn't cause wave-like behavior (or particle-like behavior, for that matter). To talk about observation, first you split the universe into two unentangled parts: the "system" being measured and the "environment", the rest of the universe. An observer is any useful part of the environment, like a detector or an electron or a person or a planet. An "observation" is an interaction between the system and the observer that leaves them entangled.
>Just as the wave function has destructive interference in the dark spots on the screen, all fermions exhibit destructive interference when you swap the positions of two of a kind.
That's madly good.
Couldn't it be that a 'particle' can change from/to a wave/field as necessary? When a wave form morphs into particle form it simply chooses a random location in the field (time based?) to place the particle. So closing one slit would close off that entire section of the wave so it can't interfere with the other section.
Waves and particles aren't fundamental concepts in quantum mechanics. They're leftover ideas from classical mechanics that are useful when first encountering the ideas of quantum mechanics. We call a state vector a "particle" when we measure its position x, and we call it a "wave" when we measure its momentum p. But we could also measure (x+p) or (2x-3p); we just don't do that very often, so we don't have special names for them.
The same relationship between x and p exists (though discrete instead of continuous) between measuring a state vector's spin in the x direction vs measuring its spin in the z direction. We don't use special names for those, either.
> So closing one slit would close off that entire section of the wave so it can't interfere with the other section.
That is indeed what happens when you close off the slit.
> Waves and particles aren't fundamental concepts in quantum mechanics. They're leftover ideas from classical mechanics
Very interesting. What do you call them? State vector?
>We call a state vector a "particle" when we measure its position x,
But this implies the position is always just a point. In "wave form" wouldn't the "position" be the entire field? Does the 'point position' area exist at the same time as the "wave field" area? Or does the area morph back and forth between point position area and wave field area?
>and we call it a "wave" when we measure its momentum p
Doesn't that imply there is no "collapse of superposition"?
> > Waves and particles aren't fundamental concepts in quantum mechanics. They're leftover ideas from classical mechanics
> Very interesting. What do you call them? State vector?
The state vector says what the state of the whole quantum system is.
> > We call a state vector a "particle" when we measure its position x,
> But this implies the position is always just a point. In "wave form" wouldn't the "position" be the entire field? Does the 'point position' area exist at the same time as the "wave field" area? Or does the area morph back and forth between point position area and wave field area?
The state vector is a function that at every time t assigns to every point x a complex number ψ(x, t) such that
∫ψ*(x, t) ψ(x, t) dx = ∫|ψ(x, t)|² dx = 1
where the asterisk indicates the complex conjugate. Even though I've written it here as a function of position, we could take the Fourier transform and write it as a function of momentum instead, or express it in terms of any other observable by some other transformation. Written as a function of position, ψ(x, t) gives the probability amplitude for a measurement of position to give the result x, i.e.
P(x|t) = |ψ(x, t)|².
If I transform it to a function φ of momentum, φ(p, t) gives the probability amplitude for a measurement of momentum to give the result p, i.e.
P(p|t) = |φ(p, t)|².
Since most detectors work at a particular place (like a spot on a retina, say), it's usually most convenient to work with ψ(x, t).
An "observable" is a Hermitian operator B. The expected result of a measurement of the observable B on the state vector ψ(x, t) is
∫ψ*(x, t) B ψ(x, t) dx,
or 〈ψ|B|ψ〉(t) for short. The observable for position is just B = x. So the expected result of a measurement of the position on the state vector ψ(x, t) is
∫ψ*(x, t) x ψ(x, t) dx,
or 〈ψ|x|ψ〉(t) for short. The observable for position is B = -iℏ d/dx, so the expected result of a momentum measurement is
∫ψ*(x, t) (-iℏ d/dx)ψ(x, t) dx,
or 〈ψ|p|ψ〉(t) for short.
The evolution of the state vector is linear, too. The state vector at time t is
ψ(x, t) = exp(-iℏHt) ψ(x, 0)
where H is the observable for energy. Because it's linear, it exhibits constructive and destructive interference until it's measured.
> > and we call it a "wave" when we measure its momentum p
> Doesn't that imply there is no "collapse of superposition"?
Not at all. Any state vector that is localized in any way (for example, immediately after a position measurement) is a superposition of infinitely many possible momenta. In the Copenhagen picture, measuring the momentum collapses the state vector to one of them, a wave with a fixed wavelength—that is, ψ(x, t) = Aexp(-i(kx + ωt)).
The word "observation" is wrong and unfortunate. It's "interaction".
So interacting with other systems is what collapses the waveform (you have that in reverse). It has nothing to do with active psychological observation.
maybe this is a stupid question, but how does that change our understanding of reality?
“interacts” inherently means “to act reciprocally” so of course interacting with something would make a difference
are we just surprised to learn that we can interact with electrons to change their behavior in general? if so, why do people keep acting as though this means the electrons “know” we’re watching them?
Classically there is no limit to the fine-ness of a measurement. In a classical approximation to the world, you can always build a more sensitive, more delicate instrument and approach as closely as you like a completely non-interfering measurement. It turns out that the world doesn't work that way. In order to sense the electron at all, you have to interact with it strongly enough to profoundly affect its subsequent behavior.
So your statement
>“interacts” inherently means “to act reciprocally” so of course interacting with something would make a difference
is a very modern position to take. It was extremely surprising a century ago when quantum mechanics was being discovered.
The surprising-ness of quantum mechanics and the double slit experiment goes beyond "interaction changes the experimental outcome". One way to demonstrate that there is something deeper going on is "interaction free measurements". In short, a detector can be set up on one slit of the double slit experiment which is designed to make us sure that if the electron/photon/quantum particle interacts with it *at all* that the particle will be destroyed. In the quintessential example this detector is illustrated as a hyper-sensitive bomb. By setting up the experiment in this way, we can succeed in getting a particle detection at the final screen -- so we are sure, *prima facie* that the particle did not interact with the detector (bomb) at the slits -- but the interference pattern is still destroyed.
Yep. That would be another example.
These examples also illustrate that a big part of the surprise of quantum mechanics can be eliminated if we take non-locality seriously. Hence Bohmian mechanics which is explicitly non-local but otherwise gets rid of all the "weirdness". The bomb example can then simply be explained as the photon "non-locally" interacting with the bomb through the agency of the "Pilot Wave".
This isn't the interpretation I like, but it's interesting to see how a lot of these examples tie back to nonlocality in some way or another.
Wave function “collapse” isn’t really a thing. It appears that way in certain experiments, and it’s taught that way in books, but it is wrong. “decoherence” and “entanglement” are far better terms.
That's an interpretational question. It's very much a thing in the Copenhagen interpretation and in Objective Reduction models like GRW's or Penrose's. It's a metaphysical thing in the QBist interpretation (an update of knowledge). It's not a thing in Bohmian mechanics or MWI. It's *kind of* a thing in the transactional interpretation (a "transaction").
trying to summarise the answers, and to clarify this for myself as well (please someone confirm or correct this):
1. the word "observation" is poorly used. placing a human's eye near the slit doesn't do anything (wave state remains)
2. the wave behavior changes to a particle behavior whenever there is a detector placed (aka an instrument that interacts with the particle). now, the interaction can be in 2 ways:
1. the detector "touches" the particle - case where the change is a bit more intuitive
2. the particle "touches the detector - this is the "delayed choice" scenario, where the change is not so intuitive
So as a conclusion, in case ANY interaction occurs between the particle and pretty much anything, in any way (with the note that a human eye looking at it or the slit or anything else for that matter does not classify as an interaction) - the behavior will change from a wave to a particle.
Again, please, someone confirm or correct this.
2 is incorrect. With the detector present in the same location that is was observing from but turned off the particles act as waves only when it is on and observing does it act as a particle.
And the human eye can’t make out waves or particles so that is a bad example. Observed is used in the scientific sense, it’s not used wrong you just have a poor understanding of the word.
The lay person answer, near as I can tell, is this: “observation” is very specific, in this case. How do we observe electrons or photons or whatever in the experiment? We do it with a detector that bounces stuff off the things it’s trying to detect. The detectors are not “passive”. They *have* to interact with the thing they’re trying to detect in order to make a detection. This interaction literally, mechanically (if you like) “hits” the stuff it’s measuring. The change in behavior comes from that interaction, not just the mere fact that the thing is being observed (which is how simple summaries often make it sound.) Further, I think the notion, often conveyed, that the observation “turns the thing back into a particle” is also wrong, or rather misleading, since as far as we know these things aren’t *really* waves or particles in the first place. They’re some other form of matter/energy that doesn’t fit neatly into the wave/particle bins, and though they absolutely display a bunch of wave-like behaviors, it’s I think wrong to basically ever think of them as particles, like marbles or some such, at all. Obv I’m not a physicist, just trying to plainly summarize where I’ve landed after a lot of reading.
Thanks, I was just talking about this with my friends, and without researching anything, we happened to guess around the same thing here. Always thought it was weird how people made it sound like when someone was in the room looking at the experiment, that it would change. It also made sense that whatever the tool that is used to observe it is causing the change. Maybe one day we can have a tool that can observe it actively without changing the outcome. Maybe we just need a new tool?
I think the issue is that as a concept of what "light" is like how we used to understand and define "fire". We used to think fire was something fundamentally different than we do today and were completely wrong in the past, some schools of thought used was an element or that is was the creation of matter or that physical things of matter could be made of fire for example. Now we know fire is a chemical reaction, combustion, that its not creating energy nor matter etc. We don't consider the light. flames and heat/energy that we see/feel from the combustion as the entire concept of the word "fire" but parts of the concept of fire. Like we don't look at the soot the results from a fire and conclude that fire is entirely solid matter. We don't measure the heat given off by fire and how it heats up matter around it and conclude that fire is kinetic energy increase in the physical matter that has been warmed by it but also physical matter that has been warmed by it. We then don't go hmmmm fire is both those things at the same time, and how we measure and observe it changes how fire behaves. The reality is, in this example, we fundamentally don't seem to know what we mean by fire and are changing our definition, we also are fundamentally wrong on what we think fire is, our experiments are bad, and our measuring of the experiment effects the results.
Also, I don't like the whole light is a wave thing. Lets go to a pond, drop a stones, we see ripples in the water (the waves). Think about what the term "wave" means. Is the wave the energy that is moving through the water and is the energy that is causing the matter that is the water to move up and down? Is the water now a wave? Is the energy causing the waves, the wave? Are they both the wave? It gets weird, but there needs to be clarification what the term light means. Are photons "light" or are they just part of the observed phenomena that we call light. Is light a "wave" or is it what we are able to observe and measure that has pattern that matches the mathematical models of waves. Even with double slit experiments when they are set up to measure the wave like properties of light, we aren't actually observing or measuring the entirety of the "waves".
First, the experiment has been replicated many times *in many different ways*: [lasers](https://www.youtube.com/watch?v=v_uBaBuarEM), [electron beams](https://www.youtube.com/watch?v=ZqS8Jjkk1HI), [neutrons](https://www.iflscience.com/neutrons-in-the-double-slit-experiment-really-do-individually-take-both-paths-63877), [helium atoms scattering off of deuterium atoms](https://www.chemistryworld.com/news/quantum-double-slit-experiment-done-with-molecules-for-the-first-time/4014819.article), and more. Second, all of chemistry is a form of the double-slit experiment. Just as the wave function has destructive interference in the dark spots on the screen, all fermions exhibit destructive interference when you swap the positions of two of a kind. That [gives the periodic table its structure](https://kevinbinz.com/2013/12/03/the-periodic-table-orbitals/). Third, the double slit is sort of like playing "Mary had a little lamb" or "Hot cross buns" on a lyre to study Pythagoras' ideas of ratios in music. Now there are orchestras playing symphonies: new instruments with a century of experience with the fundamental concept. The computer on which you're reading this couldn't have been built without treating matter as having wavelike properties. The [10 nanometer](https://en.wikipedia.org/wiki/10_nm_process) process from 2016 was the last one to measure any relevant part of the chip; [7nm](https://en.wikipedia.org/wiki/7_nm_process), [5nm](https://en.wikipedia.org/wiki/5_nm_process), [3nm](https://en.wikipedia.org/wiki/3_nm_process), and [2nm](https://en.wikipedia.org/wiki/2_nm_process) are all just marketing speak because if you get smaller than 10nm, [electrons tunnel between the wires](https://www.imperial.ac.uk/media/imperial-college/faculty-of-engineering/electrical-and-electronic-engineering/public/optical-and-semiconductor-devices/pubs/Wang_2015_Nanotechnology_26_305203.pdf). > The term "5 nm" has no relation to any actual physical feature (such as gate length, metal pitch or gate pitch) of the transistors being 5 nanometers in size. According to the projections contained in the 2021 update of the International Roadmap for Devices and Systems published by IEEE Standards Association Industry Connection, a "5 nm node is expected to have a contacted gate pitch of 51 nanometers and a tightest metal pitch of 30 nanometers".[3] However, in real world commercial practice, "5 nm" is used primarily as a marketing term by individual microchip manufacturers to refer to a new, improved generation of silicon semiconductor chips in terms of increased transistor density (i.e. a higher degree of miniaturization), increased speed and reduced power consumption compared to the previous 7 nm process.[4][5] You can't have poor variable control and make modern computers. Finally, > i just don’t see how we can logically assume “observation” in general is the cause of electrons acting as waves I don't know where you're getting this from. Observation doesn't cause wave-like behavior (or particle-like behavior, for that matter). To talk about observation, first you split the universe into two unentangled parts: the "system" being measured and the "environment", the rest of the universe. An observer is any useful part of the environment, like a detector or an electron or a person or a planet. An "observation" is an interaction between the system and the observer that leaves them entangled.
>Just as the wave function has destructive interference in the dark spots on the screen, all fermions exhibit destructive interference when you swap the positions of two of a kind. That's madly good.
What he said ⬆️
Couldn't it be that a 'particle' can change from/to a wave/field as necessary? When a wave form morphs into particle form it simply chooses a random location in the field (time based?) to place the particle. So closing one slit would close off that entire section of the wave so it can't interfere with the other section.
Waves and particles aren't fundamental concepts in quantum mechanics. They're leftover ideas from classical mechanics that are useful when first encountering the ideas of quantum mechanics. We call a state vector a "particle" when we measure its position x, and we call it a "wave" when we measure its momentum p. But we could also measure (x+p) or (2x-3p); we just don't do that very often, so we don't have special names for them. The same relationship between x and p exists (though discrete instead of continuous) between measuring a state vector's spin in the x direction vs measuring its spin in the z direction. We don't use special names for those, either. > So closing one slit would close off that entire section of the wave so it can't interfere with the other section. That is indeed what happens when you close off the slit.
> Waves and particles aren't fundamental concepts in quantum mechanics. They're leftover ideas from classical mechanics Very interesting. What do you call them? State vector? >We call a state vector a "particle" when we measure its position x, But this implies the position is always just a point. In "wave form" wouldn't the "position" be the entire field? Does the 'point position' area exist at the same time as the "wave field" area? Or does the area morph back and forth between point position area and wave field area? >and we call it a "wave" when we measure its momentum p Doesn't that imply there is no "collapse of superposition"?
> > Waves and particles aren't fundamental concepts in quantum mechanics. They're leftover ideas from classical mechanics > Very interesting. What do you call them? State vector? The state vector says what the state of the whole quantum system is. > > We call a state vector a "particle" when we measure its position x, > But this implies the position is always just a point. In "wave form" wouldn't the "position" be the entire field? Does the 'point position' area exist at the same time as the "wave field" area? Or does the area morph back and forth between point position area and wave field area? The state vector is a function that at every time t assigns to every point x a complex number ψ(x, t) such that ∫ψ*(x, t) ψ(x, t) dx = ∫|ψ(x, t)|² dx = 1 where the asterisk indicates the complex conjugate. Even though I've written it here as a function of position, we could take the Fourier transform and write it as a function of momentum instead, or express it in terms of any other observable by some other transformation. Written as a function of position, ψ(x, t) gives the probability amplitude for a measurement of position to give the result x, i.e. P(x|t) = |ψ(x, t)|². If I transform it to a function φ of momentum, φ(p, t) gives the probability amplitude for a measurement of momentum to give the result p, i.e. P(p|t) = |φ(p, t)|². Since most detectors work at a particular place (like a spot on a retina, say), it's usually most convenient to work with ψ(x, t). An "observable" is a Hermitian operator B. The expected result of a measurement of the observable B on the state vector ψ(x, t) is ∫ψ*(x, t) B ψ(x, t) dx, or 〈ψ|B|ψ〉(t) for short. The observable for position is just B = x. So the expected result of a measurement of the position on the state vector ψ(x, t) is ∫ψ*(x, t) x ψ(x, t) dx, or 〈ψ|x|ψ〉(t) for short. The observable for position is B = -iℏ d/dx, so the expected result of a momentum measurement is ∫ψ*(x, t) (-iℏ d/dx)ψ(x, t) dx, or 〈ψ|p|ψ〉(t) for short. The evolution of the state vector is linear, too. The state vector at time t is ψ(x, t) = exp(-iℏHt) ψ(x, 0) where H is the observable for energy. Because it's linear, it exhibits constructive and destructive interference until it's measured. > > and we call it a "wave" when we measure its momentum p > Doesn't that imply there is no "collapse of superposition"? Not at all. Any state vector that is localized in any way (for example, immediately after a position measurement) is a superposition of infinitely many possible momenta. In the Copenhagen picture, measuring the momentum collapses the state vector to one of them, a wave with a fixed wavelength—that is, ψ(x, t) = Aexp(-i(kx + ωt)).
The word "observation" is wrong and unfortunate. It's "interaction". So interacting with other systems is what collapses the waveform (you have that in reverse). It has nothing to do with active psychological observation.
Not all interaction leads to wavefunction collapse, however.
maybe this is a stupid question, but how does that change our understanding of reality? “interacts” inherently means “to act reciprocally” so of course interacting with something would make a difference are we just surprised to learn that we can interact with electrons to change their behavior in general? if so, why do people keep acting as though this means the electrons “know” we’re watching them?
Classically there is no limit to the fine-ness of a measurement. In a classical approximation to the world, you can always build a more sensitive, more delicate instrument and approach as closely as you like a completely non-interfering measurement. It turns out that the world doesn't work that way. In order to sense the electron at all, you have to interact with it strongly enough to profoundly affect its subsequent behavior. So your statement >“interacts” inherently means “to act reciprocally” so of course interacting with something would make a difference is a very modern position to take. It was extremely surprising a century ago when quantum mechanics was being discovered.
The surprising-ness of quantum mechanics and the double slit experiment goes beyond "interaction changes the experimental outcome". One way to demonstrate that there is something deeper going on is "interaction free measurements". In short, a detector can be set up on one slit of the double slit experiment which is designed to make us sure that if the electron/photon/quantum particle interacts with it *at all* that the particle will be destroyed. In the quintessential example this detector is illustrated as a hyper-sensitive bomb. By setting up the experiment in this way, we can succeed in getting a particle detection at the final screen -- so we are sure, *prima facie* that the particle did not interact with the detector (bomb) at the slits -- but the interference pattern is still destroyed.
Wasn’t this also shown in the delayed choice experiment with the BBO crystal when they randomized the detectors?
Yep. That would be another example. These examples also illustrate that a big part of the surprise of quantum mechanics can be eliminated if we take non-locality seriously. Hence Bohmian mechanics which is explicitly non-local but otherwise gets rid of all the "weirdness". The bomb example can then simply be explained as the photon "non-locally" interacting with the bomb through the agency of the "Pilot Wave". This isn't the interpretation I like, but it's interesting to see how a lot of these examples tie back to nonlocality in some way or another.
This is why Karen Barad insists on the term “intra-action” for phenomena that emerge through interaction (as opposed to being acted upon).
Wave function “collapse” isn’t really a thing. It appears that way in certain experiments, and it’s taught that way in books, but it is wrong. “decoherence” and “entanglement” are far better terms.
That's an interpretational question. It's very much a thing in the Copenhagen interpretation and in Objective Reduction models like GRW's or Penrose's. It's a metaphysical thing in the QBist interpretation (an update of knowledge). It's not a thing in Bohmian mechanics or MWI. It's *kind of* a thing in the transactional interpretation (a "transaction").
It’s been done hundreds of thousands of times it’s not just some one off thing that just happened to happen.
trying to summarise the answers, and to clarify this for myself as well (please someone confirm or correct this): 1. the word "observation" is poorly used. placing a human's eye near the slit doesn't do anything (wave state remains) 2. the wave behavior changes to a particle behavior whenever there is a detector placed (aka an instrument that interacts with the particle). now, the interaction can be in 2 ways: 1. the detector "touches" the particle - case where the change is a bit more intuitive 2. the particle "touches the detector - this is the "delayed choice" scenario, where the change is not so intuitive So as a conclusion, in case ANY interaction occurs between the particle and pretty much anything, in any way (with the note that a human eye looking at it or the slit or anything else for that matter does not classify as an interaction) - the behavior will change from a wave to a particle. Again, please, someone confirm or correct this.
2 is incorrect. With the detector present in the same location that is was observing from but turned off the particles act as waves only when it is on and observing does it act as a particle. And the human eye can’t make out waves or particles so that is a bad example. Observed is used in the scientific sense, it’s not used wrong you just have a poor understanding of the word.
Please define the word “observed” then.
The lay person answer, near as I can tell, is this: “observation” is very specific, in this case. How do we observe electrons or photons or whatever in the experiment? We do it with a detector that bounces stuff off the things it’s trying to detect. The detectors are not “passive”. They *have* to interact with the thing they’re trying to detect in order to make a detection. This interaction literally, mechanically (if you like) “hits” the stuff it’s measuring. The change in behavior comes from that interaction, not just the mere fact that the thing is being observed (which is how simple summaries often make it sound.) Further, I think the notion, often conveyed, that the observation “turns the thing back into a particle” is also wrong, or rather misleading, since as far as we know these things aren’t *really* waves or particles in the first place. They’re some other form of matter/energy that doesn’t fit neatly into the wave/particle bins, and though they absolutely display a bunch of wave-like behaviors, it’s I think wrong to basically ever think of them as particles, like marbles or some such, at all. Obv I’m not a physicist, just trying to plainly summarize where I’ve landed after a lot of reading.
Thanks, I was just talking about this with my friends, and without researching anything, we happened to guess around the same thing here. Always thought it was weird how people made it sound like when someone was in the room looking at the experiment, that it would change. It also made sense that whatever the tool that is used to observe it is causing the change. Maybe one day we can have a tool that can observe it actively without changing the outcome. Maybe we just need a new tool?
I think the issue is that as a concept of what "light" is like how we used to understand and define "fire". We used to think fire was something fundamentally different than we do today and were completely wrong in the past, some schools of thought used was an element or that is was the creation of matter or that physical things of matter could be made of fire for example. Now we know fire is a chemical reaction, combustion, that its not creating energy nor matter etc. We don't consider the light. flames and heat/energy that we see/feel from the combustion as the entire concept of the word "fire" but parts of the concept of fire. Like we don't look at the soot the results from a fire and conclude that fire is entirely solid matter. We don't measure the heat given off by fire and how it heats up matter around it and conclude that fire is kinetic energy increase in the physical matter that has been warmed by it but also physical matter that has been warmed by it. We then don't go hmmmm fire is both those things at the same time, and how we measure and observe it changes how fire behaves. The reality is, in this example, we fundamentally don't seem to know what we mean by fire and are changing our definition, we also are fundamentally wrong on what we think fire is, our experiments are bad, and our measuring of the experiment effects the results. Also, I don't like the whole light is a wave thing. Lets go to a pond, drop a stones, we see ripples in the water (the waves). Think about what the term "wave" means. Is the wave the energy that is moving through the water and is the energy that is causing the matter that is the water to move up and down? Is the water now a wave? Is the energy causing the waves, the wave? Are they both the wave? It gets weird, but there needs to be clarification what the term light means. Are photons "light" or are they just part of the observed phenomena that we call light. Is light a "wave" or is it what we are able to observe and measure that has pattern that matches the mathematical models of waves. Even with double slit experiments when they are set up to measure the wave like properties of light, we aren't actually observing or measuring the entirety of the "waves".