The Weird Experiment that Changes When Observed 

*What do you think the implications of the double-slit experiment are for our understanding of reality?* Try brilliant.org/Newsthink/ for FREE for 30 days, and the first 200 people will get 20% off their annual premium subscription

I can relate. I behave differently when I'm being watched, too.

It's important to note that "observing" a particle is much more involved than what the word would imply. It's not a passive act, in order to observe a particle you have to hit it with another. In such a sense, every single particle in existence isn't "observed" until it interacts with another, so for nearly the entire life span of a particle it doesn't actually exist, it's simply a solitary wave.

Measurement, rather than observation. This is very important. Changes the idea of consciousness being involved.

I just wanted to take a moment to say how amazing your video was! I was really impressed with the quality of the footage, the editing, and the overall presentation. You did a great job of explaining the topic in a clear and concise way, and I learned a lot from watching your video. I also really appreciated the way you made the video engaging and entertaining. You kept my attention throughout the entire video, and I never felt bored or lost. I would definitely recommend your video to anyone who is interested in learning more about the video. Thanks again for making such a great video! I look forward to watching more of your content in the future. PS: I outsourced this feedback to AI.

Albert Einstein saying "God does not play dice" was not for the double slit experiment. It was actually for another Quantum phenomenon which he termed "Spooky action at a distance" (Quantum Entanglement).

It is impressive that these physicists managed to isolate a single photon

If physical reality manifests out of consciousness rather than the other way around then this makes complete sense. Everything is in a state of infinite possibility until the light of awareness shines on it at which point it manifests into existence

What effect does the "measuring device" have on the photon? 1:29 What has been demonstrated is that this measurement device affects the photons, not that the photon knows it is being observed.

This sounds exactly like Heisenberg’s uncertainty principle, in which a particle’s momentum and location in space cannot be determined at the same time, leading it to have multiple positions at once until observed. The same can be said about Schrödinger’s cat. In this thought experiment, a cat is in a black box with some poison. Next to the poison is a radioactive source. When the source reaches a certain count rate, the poison is released; the thing is the decay of the radioactive source is unpredictable, so cat at any point in time is both dead and alive until observed. Another analogy is if a tree falls and no one was there to hear or see it fall, did it really fall? Both theories have been used to question the possibility of a multiverse where every possible outcome generates a new universe. The idea of life being a “computer” program is logical, as almost all aspects of nature have mathematical attributes that are perfectly related to one another. Every possibility follows certain “coded” rules/axioms to carry out. In that case mathematics and physics is just the study of reverse engineering the program of the simulation. But when you reverse engineer a program and come across something that shouldn’t run, like photons arranging themselves when observed, you question whether this is intentional or an undefined natural error. It breaks the algorithm that we have documented for centuries.

Very nice and concise video on the subject, with clear explanations and just enough mystery left for viewers to be curious. I've been exploring this and related phenomenon for over a decade, and still your presentation captures my interest - makes me remember how I felt when I knew about it the first time. I might follow.

we are living in a simulation. the properties are built into the building blocks of our simulation. so when we start observing, it loads in like how we load in the rendered assets in a video game

Thanks Cindy for always doing very interesting subjects that include a mixture of scientific theories explained in a easy-to-understand way. It's a great Channel keep it up!

so what does observing/watching actually mean? to see something you need a photon to reflect from a thing you want to observe and land on the observing device (i.e. eye) so when you are watching photons, you are hitting the observed photons with another photons - and that just changes the observable photons directions

This actually makes sense if the particle is in a different dimension than us, and when we measure it we are taking a slice of that dimension and basically assigning only that slice to the particle.

I recently spent some time with a certain tribal, farming, backwoods community in India. Lovely, friendly people. And at a communal dinner one evening, I explained the double-slit experiment to the tribal elders. I was astonished at how quickly they grasped and understood the physics and the nature of the experiment and the baffling question that scientists faced. And these were people who had never attended school nor knew the English language. And within an hour, they were discussing among themselves the dual wave and particle properties of photons. They were drawing the diagrams in the dirt! Since that day, I've had a deeper respect for the remote, isolated tribal people of the world.

Very informative and makes us curious about physics

Interesting....thanks for this. There is also the water experiment which consistently shows an interaction between the water molecules and the mind of the observer.

Hi! For a long time I have wondered what exactly we mean by saying "when the photons are observed" and I encountered this video when I tried to look it up. I'm a chemist and have learned from analytical chemistry that we can't measure anything without it interacting with the material of the detector. I was of course curious in how we exactly can "observe" something halfway through an experiment without fundamentally changing the experiment and therefore likely the result. So when I heard that "scientists used a measuring device to observe the slit that each photon passed through" it obviously peaked my interest. From my understanding, and please correct me if I'm wrong or misinterprets the experiment, the so-called measuring device or slit-detector is actually polarizing filters which do not perform any kind of measurement or detection themselves. By only filtrating forth polarized light from each slit (which I think are perpendicular to each other), it would presumably be possible to identify which photons passed through each slit later on. If this is the case, I think it is an extreme stretch of the definition detector or measuring device if no observations, measurements or analysis were performed by this so-called device. I realise that this is likely an extreme simplification made in order to illustrate other points, and while it is false (at least from my interpretation of what a measuring device is), there might be a valid argument that "we might as well view it as a detector for the sake of simplicity". So there is no magical detector. Darn it, another childhood dream squashed. I still have some issues with general statements I've encountered such as "the photons change their behaviour because we observe them", which likely are simplifications of "in an experiment in which we tried to observe the path of the photons, they behaved like particles instead of waves". While I don't think either statements are necessarily false, they both seems a bit misleading if left on their own. From my perspective, the experiment when using the filters is, at least to some degree, fundamentally different from the one without filters. We can observe "that perpendicular polarized light behaves like particles instead of waves when passing through the slits", and don't get me wrong, it is definitely a interesting and wierd result that clearly illustrates the wave-partical duality of photons. However, to draw the conclusion/interpretation that "they behave differently **because** we try to observe their paths" sounds rather backwards to me. While it is true that we set up the experiment in order to determine their path, a less misleading way to express the result could be "they behave differently because we fundamentally changed the experimental conditions, i.e. we removed all photons that didn't exhibit certain properties (i.e. a certain polarization)". While this might be obvious for physicists and chemists alike (that we can't measure anything without interacting with it), I don't think it is as obvious to people with other backgrounds. The slit-detector is often breezed over in explanations of the experiment and is therefore more or less implied to be a passive observer. A reasonable explanation for this is that we can't explain everything in a 6 minute video. We would need to explain what polarized light is and why that is significant. Easily understood explanations are without a doubt important, and can be justified even if they oversimplify things (such as the slit-detector). However, when doing an over-simplification and just saying "we just observe the photons" it would be easy, and I think very reasonable, to add a large shining caveat saying "the detector is not a passive observer and that it by its very nature may influence the outcome of the experiment". While this likely would result in some confusion, it would more importantly raise questions which are the bread-and-butter of curiosity. I genuinely think that Newsthink and physicists in general only have the best intentions in mind, but I find this sort of explanation (without any caveats) unnecessarily misleading nonetheless. While interpretations such as "photons change their behaviours/properties **because** we observe them" are alright to make, I personally find them missing the mark of what the actual experiment was about and what the results really showed (i.e. if I understand things correctly). Is it possible that the photons behaviour changed **because** we tried to observe their path? Yes anything is possible, but I find it rather speculative (to put it mildly) if this is the only data that they base it on. In general, while it is easy to say "You should stay sceptical even when experts explain something" or "Of course the experiment is more complex than it seems, we're talking about physics and the video is 6 minutes long", I don't think that's something we should expect people from outside the scientific community to always take into consideration. And that is why i wrote this post (also because I wanted to know if I've misunderstood something). I would also be very interested for any information regarding other real experiments (i.e. not thought experiments) that deal with "whether photons behave differently if "observed"". Have a nice day!

Our world is amazing! The concept that the particles could change when being observed seems like a small change in variables but the consciousness awareness effects it in such a way that had plenty of people stunned! Even to this day people are amazed by this experiment!

The best explanation and animation of the double slit experiment that I've ever seen! Kudos!

Was hoping for a bit more in-depth explanation; Does the method of observation interfere with the light photons? How was the picture taken? Does the slits themselves have an effect on the photons? AT what frequency is the photons fired? What was that about time having an effect on the experiment ? I'm no physicist, but I think by now we should have more experiments where the variables are changed to have a better understanding.

Can you imagine how confused they were trying to figure this out?

By far the best explanation on Double Slit Experiment ❤

When Einstein said his famous quote that "God does not play dice with the universe" Bohr replied by telling Einstein "Stop telling God what to do" This on the surface, may seem to have somewhat supernatural undertones but I think it shows just how perplexing quantum mechanics really is even to two of the most brilliant and influential minds that humanity has ever produced, and we have produced many over the years. Sadly, I'm not one of them... Not even close...

First time I've heard a source mention the similarity to zone-loading in video games explicitly. I've long thought of that when considering this subject. It's a good analogy, with so many gamers out there these days.

One of the best explanations of this ive seen, great visuals

I've been aware of the double slit experiment for some time but I have not studied it in depth. So, I'm unsure if it was variated between pre and post slit observation. I wonder if that makes a difference?

What if the universe doesn’t exist unless consciousness exists? Like how in a video game, nothing exists until you, the character you’re playing, observe the environment around you. Our brains are processors. Without a processor, a video game can’t exist. It’s just a bunch of information waiting to be interpreted

My theory: There's a good chance that we haven't discovered an unknown energy that is Emmitted from every partical and so does from a camera sensor and from electrons So the camera tries to observe Electrons and camera sensor's energy entangle and lead the electrons to behave like a partical

What is the max distance between the 2 slits that we can observe this dual nature

We must flip on/off the observer camera like a strobe light and do it faster than the speed of light so that the light particles cannot keep up with the observer camera and be able to react fast enough, then we can see what up. However this might cause the light partical to go backwards as if time is being reveresed. We need mirrors to bounce it back the right direction as the camera is now observing light going backwards in time, i think. lol

From how many angles can the head of a pin be observed? Then, from how many angles could our own milky way be observed? And does a mirror reflect a finite or infinate number of reflections at all times? I love this stuff.

The thing that gets me is how the photons create an interference pattern even when shot one at a time.

Evolution of the Eye Ball begins in the translucent environment , before it discovered the transparent environment. Atmosphere obviously plays on light density and refraction. The slits are shown on a flat stencil against a flat wall representing a stop in space time continuum. I think results would be different if the stencil was curved against an opposite curved wall . Using black paper against black paper is different from using transparent or translucent emulsion against a solid wall .

This truly is one of the experiments of all time.

Undestand that the term "observe" in this video means "interfer". To "observe" the eletron they must use a photon. Thats why its change from waves to particles

What was the rationale for conducting the double slit experiment in the first place? I mean, did someone correctly hypothesize the results of the double-slit experiment?

Could the observation device be emitting energy that interferes with how the paritcles behave?

A possible reason is the way that light bounces off an object into our eyes if some sort of thing is reversed or bounces back, it could be interfering with the particle, hence changing its state this would have to be something to do with new set of physics laws, which we currently have no way to prove

How are we still proliferating this misconception? The behavior of particles change when we "observe" them because "observing" something so small means we have to bump something else into it (like the way electron microscopes work). The trippy part is the superposition of particles (which allows for the photons to interact with themselves).

What is the device used to "see" which slit the electron passed through? It seems that device is what is interfering with the interference pattern - not us, as implied by this clip.

So, if you did the experiment with 3 slits, would the outer 2 slits cancel the inner slit and make just 2 bright bands? The wave pattern should cancel the inner line.

When you send an individual particle it will act like an individual particle, when you send many particles it will act like a wave. They interact with each other. Particles interact with each other. When does the interference pattern appear only when sent single file? Send it as many Particles with no camera or observations. Is there a way to do so. Make a wall that leaves a special imprint after experiment. ??

A non-living photon changing behaviour when observed is more horrifying than horror movies.

Server admin: oooh they are observing, yo zuckerberg, change the code!

True, that is a hypothesis that it could mean. Something is observing us in controlling the trajectory, or it could mean that we are emanating ionic force with our eyes, and with our concentration, and that we can change the direction of ionic movement with a thought think about that.

That's why time slows down for an observer who approaches the speed of light or is near an extremely massive object (i.e., high gravity)...the universe needs time to process all the information.

Bro!!! 😮😮😮 I'm loving Physics.

I’ve seen a lot of people saying it’s the physical interaction of the observing device that interferes with the photon, by “bumping” into the photon and causing it to change. To reiterate, if the device is turned off, the photons return to being waves. So once turned on the observing device must be emitting waves or particles that interferes with the photons and causes it to act like a particle. This makes the most logical sense to me as well. A photon behaving like it “knows” or has “consciousness” seems less likely to me. So my question is, what if we put more than one observing device in the experiment? For example, one device pointed down (eagle view), another pointed to a horizontal view, and one behind the photon machine. All devices turned on. Would this change the outcome of the pattern the photons make? Would different amount of devices and angles yield different results? I’m not sure if this experiment has been done. I’d love to do it myself but I figure it’ll be difficult to get your hands on a photon shooting machine. Thoughts?

One explanation for ordinary light and lightspeed is that light is prismed from a higher dimension. This means where light is can only be measured using probability, explaining why it never follows patterns like a hard, precise object yet is one.

Isn’t a simulation considered to be a designed creation? (: The Developer really knocked it out of the park with the whole perfect ratio and the Higgs Boson.

no matter how often i watch this experiment i will always be stunned be the result. this is so awesome. also it shows that all choices that we make is one out of endless possibilities.

What Observation methods are we using, because clearly just watching it or recording it does not interfere. I’m sure people try different ways of observing it, but could it just be observation the waves? Obvious stupid question but I need answers

How do you, or a detector, 'observe' a tiny particle without some way interacting with it, and impacting its behavior. In our macro world, we can see a baseball without interfering with it. But when you are trying to detect a single photon or electron, how do you do that without interfering with it in some way?

I bet this is somehow related to the physical interaction between the observing device and the photon. As a rough example, imagine there is a bowling ball moving on the bowling path, and you throw another bowling ball that should hit the first bowling ball, bounce from it and go back to you to tell you that there was a moving bowling ball, from which your bowling ball bounced. And of course, after the hit not only your bowling ball bounced, but also the initial ball changed it's course. Something like that could be happening on a level of particles, in my assumption. The current explanation that the photons change their abilities because of some conscious spectator sounds like magical thinking, similar to that lightning is being thrown by Zeus etc.

When we observe, the observing machine interferes

for me this is proof we live in a symulation as a gamer its just like a game engine

.....finally at the end of the experiment, the photon sued the creepy scientists for invasion of privacy, anxiety , mental trauma and character assassination 😄

This confirms that the universe is against me

This is such a good video explaining a lot of

Why wouldn't it be the case that spacetime is oscillating, or twitching back and forth while the photon is traveling a more straight path, and it's the location of the slit and the capturing surface that are moving, causing it to appear as if light acts like a wave?

This isn't proof that we're in a simulation. This is proof of consciousness and that it is far more important than what we think we know.

I think it's more obvious that there's an error in their equipment than there is in a reality

Wait..if photons changed states as they're observed, then how do we know they are in "wave form" if we can't observe them without them being in particle form? Can someone help me understand this?

I wonder how far away you can watch it till looling at it doesnt matter or does distance not make a difference? Should at least lag at the speed of light

Simulation is not the word. Synthesis is. If it were simulated, it would be violating physics. It doesn't. A synthesis doesn't violate physics. It's too perfect to be real, and it's highly statistically improbable, but it doesn't break laws. The double slit experiment describes the nature of consciousness as an input. As an input, it changes experimental outcomes and directs our actions. It does, in fact, suggest that there is a God.

I am absolutely sure there are some weird invisible ( to our eyes ) beings all around us laughing at us and causing endless misery for their enjoyment. Everything being recorded as if in some alternate reality. Well maybe not that basic, it's hard to express in words, but I get the impression that most humans get a feeling at one time or another/ or many times, that you are being watched by something unknown. One time when in Europe I accidentally took a large amount of a unknown psychedelic ( long story ) it keep me up for 4 days and I had thought I went mad. During this time a weird world revealed itself to me, there were these red balls like eyes everywhere constantly watching and monitoring every movements we humans make, you know the red eyes in the matrix sentinels, well I was seeing those things literally everywhere all around us, you moved and it followed your movements like a lens in a camera. There were millions of these things everywhere I looked. I hadn't seen the Matrix film back then as this was in 1993 and the Matrix wasn't released until 1999. You have no idea how terrified I was when I saw the film for the first time and those red eyed sentinels were in the film. Its not a coincidence that most people feel weird when looking into camera and asked questions or told to say something..

By watching this video I have understood what I was told a long time ago about life when they tell you you choose your path before you come here

In that picture, Leonardo's gears would've turned both the front set and rear set of wheels inwards towards each other or both sets of wheels outward away from each other causing the tank to remain motionless. Edit: I swear I didn't see the explanation before writing this.

The problem begins with thinking of particles.

This is ridiculous. It's not the "mere act of observation" that causes the superposition of a quantum particle to collapse. You cannot "merely" observe a quantum particle. You can't just whip out a microscope and have a look. To observe a quantum particle, it must interact with another particle, and it is the interaction, not the observation, that causes the collapse of quantum superpositions.

Thank you for this excellent presentation. The double slit experiment seems to echo Schrodinger's Cat thought experiment.

interesting interpretation, who knows, could be the right one. my analogy was always the path of a spitball comprises all possible paths until it hits the blackboard...

This test needs to be conducted with several animal observers. If this effect is only observed whether or not a person views it, or whether a person has the potential to view it via a camera. This would prove that humanity is of a higher priority in existence and would suggest that there is a deeper meaning behind this experiment.

Could the speed of light limit be the result of the “clock speed” of the simulation for updating the position of particles in addition to determining their observed state?

Does the information have to be observed or can it just hit air?

I'll never interfere with myself again after watching this

The real mystery is left out: if the observation is made AFTER the light passed through the slits, ie if observed in the future, the future event changes the behavior of the particles as they go through the slit in the past. Thus, a future event becomes the cause of the past.

What I'm yet to understand is how the experiment measures the interference pattern without counting as 'observing' it.

It would be so crazy to find theyre actually sentient beings

I have a theory that this is what Stanly Kubrick was basing his movie on Space Odyssey 2001. The light sequence at the very end as being observed by the pilot (Boman i think) traveling through space after entering a monolith which looks exactly like a slit. The slit is solid black but after he enters he then observes a light show of colors that couldnt have been seen before. Also , everyone knows how perfect kubrick directed his movie shots are, theres never an error meaning the continuation of the story is never out of sequence, except for 1 time i noticed and this could refer to the delay and observation of a particle correcting itself. The jacket appearing on a chair then disappearing in the next shot was thought to be an error which is unlikely, theres a lost and found alert is being said in the following screenshots, meaning that it corrected itself after the viewers observation. A majority of the movie is presented with black and white backgrounds (duality) for example the ceiling is made of white light in the U.S. Spaceship just as the floor in Bowmans room is lit up in white light. We see this again in the meeting room ,black ceilings and corners with white light walls. The white light is also in the center of the ship thats rotating with Hal. Im suggesting theres an inside world and an outside world that exist simultaneously but not observable , its seperated by the light. The absense of light is the the monolith, solid black darkness and going through it brings you to the other side. Bowman went through it twice. 1st time as a pilot and 2nd time at his death bed where he becomes a star child made of light. I cant explain all of it here but i think you can see where im going with this, im very interested to here what you guys think of this.

Particles change their behavior when observed because of consciousness. When the consciousness of an observer connects to the consciousness of a particle there is an energetic and magnetic-like reaction. Much like blowing wind on a leaf, although that is still more random. Many of the big brains out there still have a problem with grasping the concept of consciousness related impact.

The bigger question is if there was no person or thing in the forest to see or hear the tree fall did it fall?

You guys are so smart lol I have such admiration for people who can get this stuff because there’s me the whole time 🦗🦗

The biggest problem I have with the description of this experiment, is that "observed" is just our way of describing the process. If you just LOOK at the double slit experiment, nothing changes or happens. Instead, you are using a measuring device that sends out a wave of some kind to bounce off of the "flung" electrons, to measure what is happening. Its an over simplification to consider measuring and observing one process. The machine measures. We observe the measurement. Turn the machine off, the measurement goes away, and so does the particle pattern. OUR observation has nothing to do with it. I also picture the experiment in reverse. Its not a case of the measurement affecting the electron. Its a case of the measuring devices putting out a wave that distorts space time. And then the flung electron has to traverse those distortions. When an airplane rises, its because of aerodynamics. The airplane wings move into the air so much that the air starts to push the wings downward and upward. The airplane fights the resistance of the air, and then rises. Now imagine that you shoot an election similarly into a an area where the waves coming from the sensor push against the electron particles enough to move them from one course, to a new course. One wave won't do it, but if a few thousand to a few million waves push against the electron from the moment it leaves the slit till it hits the screen...well, maybe that's why the interference pattern condenses back to a particle pattern. My biggest question, to qualify that is, do the particle patterns on the side most opposite to sensor move back toward the sensor, stay in the same place, or mover further away from the sensor. If they move back toward the sensor, maybe they are hitting the back of the sensor waves, and get pushed backward as a result. If they stay in the same spot, then maybe its hitting the valley in those waves, and shooting right at the screen. If they move away from the sensor, then they are hitting the front of the sensor waves. It becomes a game of spacetime Plinko.

The double slit experiment doesn't say as much about light as it does about consciousness being a physical thing.

I think Arvin explained it perfectly in one video.

Instead of observing (and interacting with ) the particles as they move through the slits, let them impact the screen and observe the strike pattern...That will give the true result...It obvious that when trying to observe the particles we interfer with them in ways we don't yet under stand....

I think if that experiment would be replaced with a canon sand( not laser canon) would happen the same thing. It means : the experiment doesn't show anything because sand is particle, that( same thing ) would happen with all things as : sugar grain,salt grain, sand grain etc...

This is why I think a person won't take much computing energy if we are in a simulation, because I don't think everything, I don't know everything, we have little range of eyes to observe things.

I thought electrons were fired at the double slit (or crystals that accomplish the same diffraction phenomenon) and what was crazy was that the electrons (which were particles) actually created the interference pattern. And furthermore, firing one electron at a time, instead of one photon at a time, still created the interference pattern. An illustration of this was done awhile back with a cartoon character named Dr. Quantum: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-NvzSLByrw4Q.html. I might be totally wrong here, but I thought the it was electrons that went back to behaving like particles when they were being observed, not photons. Regardless, this video is great for visualizing the interference pattern created by waves and particles. I enjoy Cindy Pom's Newsthink videos!

i cant stop watching this

What does the double experiment look like with sounds? That will be interesting too

What about an experiment where the media is observed up to x picoseconds prior to passing through the slits, and similarly on the opposite side after the slits, and not viewing the output at the time of the experiment. So the point at which the collapse would occur it’s not observed. If it still produces the two slits, as it’s observed at a point during its travel, then does this not show deterministic behaviour?

To be Honest the Title of the video is quite misleading

I've always wondered if there is some interference from the device "watching" that is altering the behavior and it's not so much that it seems to be aware that it's being observed. I always like to fall back on Occam's Razor for things like this - the easiest answer tends to be the right one. You changed the conditions of the experiment by adding an observation element and as soon as you changed the conditions, you got different results. So look for what was changed. The observation apparatus. Surely there has to be some interference that is being created causing the change in behavior. I have no reason to believe that these particles reacted differently because they were being watched. There has to be a simpler and more logical reason for the behavior.

does anyone pun another slit after the light is watched? it interfere or not in the 2nd double slit? to watch a photon you throw something at it to bounce back at you, so you interact with that photon and that transform it a particle from a wave, but in the next slit will it be still a particle or back to wave?!?

We just have the art watching and storing things and how our brain reacts to light

This is the first time I’m hearing about this experiment. And my mind is literally thinking this has to be a conspiracy. But how do you explain the electrons behaving that way!? 😂