Double Slit Experiment explained! by Jim Al-Khalili
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- เผยแพร่เมื่อ 31 ม.ค. 2013
- "If you can explain this using common sense and logic, do let me know, because there is a Nobel Prize for you.."
Professor Jim Al-Khalili explains the experiment that reveals the "central mystery of quantum mechanics" - the double slit experiment.
Watch the full lecture here:
• Jim Al-Khalili - Quant...
For more info on all things quantum, you can buy Jim's book "Quantum: A Guide For The Perplexed" now - geni.us/32pvu
Sometimes called the "two-slit" or "Young's" experiment, it demonstrates that matter and energy can display the characteristics of both waves and particles, establishing the principle known as wave-particle duality. Furthermore, it questions the role of the observer in the outcome of events and demonstrates the fundamental limitation of an observer to predict experimental results.
For this reason, Richard Feynman called it "a phenomenon which is impossible ... to explain in any classical way, and which has in it the heart of quantum mechanics. In reality, it contains the only mystery [of quantum mechanics]," (see more at en.wikipedia.org/wiki/Double-s....
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As a game developer, I can tell you its for performance reasons. Why waste processing power rendering particle behavior when there is no observer to output to.
Hahaha maybe so, I suspect upgrades maybe soon forthcoming.
The question is whether these design artifacts & other physical constraints are necessary or intentionally?
Elton Maiyo With the possibility of our physical observations being selectivly simulated depending on if we're physically observing them, it also seems possible that on "the other side" there may be beings living out several lives, each time starting with a new redeveloping consciousness that can't seem to grasp the double slit theory. I wonder if they're then able to remember each and every life when on the other side ("unplugged" from simulated reality). The social implications of your lives lived's quality can then be a factor when it comes to your footing in the community hierarchy on "that side". Not that I believe in this, but it is interesting that the Hindu idea of reincarnation and karma that basically says your life lived determines how you'll return can fit in that far out logic. This can obviously also explain other realms of _being consciousness_, like heaven and scary enough, hell. Hell, if these beings are only nearly as messed up as humans they'll send the oppressed or misbehaving to shitty simulations for possibly an infinite time period. The knowledge a civilization with this capability can produce when the data of many simulations are mined could make them infinitely knowledgeable. Another possibility could be that you are just a learning AI component. So many possibilities opened up by this gap (slit) in our knowledge. kooky
Adriaan Serfontein
Interesting ..observations :) The nature of base reality/"the other side" is an infinitely interesting subject to explore with equally infinite conceivable possibilities. Your theories makes sense.
Well, as a developer your algorithm knows what area should be observable on the screen at any given moment and does the rendering accordingly. How can a 'dumb' particle 'know' when it has been observed?
As a CG artist, what particle system is being used here?
Getting this kind of thing free and recommended for you is definitely a positive of modern life
This comment can't be praised enough
It's also a negative because getting free stuff also means getting distorted facts. Back in the day of dusty roads, horses, and ipads, we had to seek Truth by wagon-based travel and persistence, often going thirsty along the way, due to lack of rain. We never got false info that way. Only facts. It's like digging for gold. You find pure gold if seek it out yourself, in the mountains, and if (instead) it falls into your lap, it's probably false gold. It's just a lure. Someone wants something from you. Look around to see what it might be.
@@LisaBlooper what a load of verbal diarrhea
@@jimmydanger2223 lol no need to feel small and fragile.
unless of course, you are Jimmy :)
The people are laughing but just the mere thought of it runs chills down my spine
exactly
Why?
@@joxyjoxyjoxy1 well maybe we live in a predetermined universe, that's the scariest outcome. or maybe we live within a simulation or a conciseness, but the chances that we live within the universe that is material by nature is probably untrue
@@garrybarry4286 or maybe God just likes messing with us.
@@joxyjoxyjoxy1 A bible god? Zero chance
I’d say one of the Best double-slit-experiment explanations on the internet.
Fills you with awe and curiosity about this wonderful universe we get to experience.
Can you explain how the detector detects? How can it detect the atom without touching it or shooting photons at it, potentially affecting its trajectory?
@@Oscaragious You can with X ray plates in the old days, now we have better detectors that pick up the tiny charge the atom/particle deposits on the screen.
Given that it's a deliberately obfuscatory _non_-explanation, I have to disagree.
The same way we turn on three dimensional box inside out is the same thing that’s happening here we are the 1- looking down at the H2 on the periodic table. THE HUMAN SOUL IS THE FIRST ELEMENT
@@Oscaragious We can’t. At the quantum level to observe is to interact. This video was extremely oversimplified and feeds the popsci crowd (which isn’t bad since it gets people more interested in science). The popsci idea people seem to have is that observing (which means interacting) a photon causing change being the weird part, when its not. The weird part is the multiple questions and experiments that followed and are still continuing to this day.
Seen this experiment described a dozen times,,,, this is about the best one. Bravo for helping my slow brain.
I hear ya!
I'm with you as this is the first time I really "get it" !! wish this guy was my HS teacher back in the day !!!
this professor is amazing. What he is stating is that the atom somehow KNOWS that its being "measured" or sensed. and thus it ALWAYS becomes a "particle". it will NOT interact! but IF you turn the "detector" OFF.. it doesn't know! and thus it just becomes a part of a "wave". yeah how does that atom KNOW about the EXISTENCE or ABSENCE of that detector?? thus if there's only ONE slit present the atom has no choice but to pass through that one slit. thus every atom that does so hits the screen in basically the same place. its ONLY when you open the 2nd slit that things get a bi "hairy". But as long as nobody is measuring the atoms perform as interference waves. BUT if you turn on a detector for just ONE slit NOW ONLY TWO DISTINCT patterns on the screen are formed (one directly behind each of the slits). The atoms are communicating. hey if I go through slot # 1 YOU go through slot #2!
@@leecowell8165 p
@@leecowell8165 The atoms knows its being measured or you know the atom is being measured or not? Im new to this but this observation behaviour seems to be related to knowing or not knowing. I wonder if there was a way to put a detector that beeps in a frequency we cant hear and that no one knows that it beeps for example. What would happen?
I tried the double slit experiment at home. The wife was not impressed.
lolol
great fuckin comment, keep experimenting
Alex G haha i think he meant it in a sexual way
Hahahahah me too goof ball
That was a funny ass comment! I am still cracking up!😅
Even if we forget about thousands of other variations of this experiment with all the timetravel, causality breaking consequences, already the fact that a single atom behaves differently going through a single slit and double slit is enough to blow my mind.
There are no causality breaking consequences or time travel.
@@amihart9269 There have been tests that have resulted in "reverse causality" concerning the double split experiment. This requires entangling two particles, and one travels a further distance than the other. The one that travels the shortest distance is not measured. However, if you measure the particle that travels further, it will be reflected in the interference pattern (or not) of the one that traveled the shortest.
It's as if it knew the other particle was going to be measured, and thus its behavior is altered prior to the actual observation taking place.
@@goldnarms435 Nope.
@@amihart9269 care to elaborate?
No, that's not the major inconsistency. The rub is that the pattern seems to depend on whether the atoms or photos are being "observed". But I think there is an explanation, which is that the device doing the detecting is interacting with the atom. Why didn't he explain how the detector works, to rule this out, if he believes it is not the explanation?
Even though I struggled over this for the last 35 years I never stop to be amazed by this. And this explanation is simply clever AND cheerful. Cheers for that!
What explanation? No explanation for the inconsistent results were given at all. In fact we're told we'll get a Nobel prize if we come up with one. Did you even watch the whole video??
"According to quantum physics, you cannot "just" observe something. That is, quantum physics recognizes that to make a observation, you must interact with the object you are observing " - Stephen Hawking.
Im not sure if this was stated before the delayed choice experiment was done in 2007
That’s not true just because Stephen Hawking says so. There are thousands of experiments on this, delayed choice is a perfect example.
That has more to do with the Heisenberg Uncertainty Principle than it has to do with this experiment.
Observing is interacting
Could you tell me the source of this quote pls?
I hope this analogy helps others to understand.
When people say "observing" changed the result, they do not mean the physical act of watching the experiment - they mean the act of measurement changed the PROPERTY of the thing they were watching.
My analogy; when you take your temperature, the thermometer you use SUCKS heat away from you (consider a metal teaspoon in a cup of tea, the spoon gets hot because heat energy is being transferred from the liquid to the spoon. The tea is actually getting cooler by transferring heat to the spoon) Therefore, the act of using an instrument to measure the temperature of something CHANGES the temperature of that very same thing.
I believe this is the same thing (but of course, probably more complex) but am happy to be corrected. It's a layman's explanation which I feel stands up
But if they are watching only the upper slit, why the atoms that go trough the bottom slit don't still behave like waves since no one interferes with them?
This is actually incredibly helpful, dude. Thank you!!!
@Dirk Knight Almost 100% of people? What's that 99 and half % peeps? or 99 and three quarters% peeps? Be specific man, or don't you know your sums?
@Dirk Knight Were you missing me 100% or only 99.99%.
@Dirk Knight Oh well, that would make it 100%. Well done, there's a good boy.
I'm not a physicist, so most of the time I'm just going about my life. But periodically, every few years, I remember this experiment, and I remember there is something about it that I find eerie. I can never remember exactly what it is, so periodically I review the experiment as I just did with this video. And once again, I'm left with the disturbing feeling that something is very wrong with our reality. It's almost like we are not supposed to be aware of certain things, we aren't supposed to be observing them, and when we do, they are altered to keep us from seeing what's really there. If I was running a simulation and didn't want my simulated agents to discover they are in a simulation and start trying to hack their way out, I would implement something to prevent discovery of the fundamental nature of their reality. Every time they tried to look at the substrate of their existence, I would show them something other than the processor they were running on. I don't know about anyone else, but this experiment has caused me to increase my estimate of the probability that we are living in a simulation.
This experiment isn’t the confusing part. Everything in this video can generally be explained. At least the “relevant” parts. The questions and experiments that followed are what really get whacky. So to relate it to you: if you think we’re living in a simulation, Quantum physics is so whacky the simulation is debating on whether its living in a simulation!
@@adamnguyen4517 this is comforting 😂
@halligalli I'm just saying while quantum physics has some unanswered questions, its also a relatively new science. Just give us a century or two and I bet we'll have it down to a science, literally. Then we'll move on to the next weird phenomena of reality.
@@adamnguyen4517 You didn't mention the real elephant in the room: quantum gravity. The idea that time doesn't exist in the human sense of a sequenced order of life, everything exists simultaneously, and life is the process of sequencing those events into some perceived order. And if that is so, then just why?
@@steviesteve750 Well thats just one train of thought, but if that does turn out to be the case, I'm not sure. Definitely not qualified enough to answer something that complex.
My layman's theory: Photons generate very subtle gravitational waves in which they themselves travel. To prove this, one can try to disturb this wave with another device. The photon detector might actually interfere with this wave, which is why the result of the experiment is surprising.
No, still doesnt make sense, the detector is looking at only ONE slit, still the second slit is affected too. Also the detector is passive. And even if you unplug it, it will receive the energy but dont record it. Also ALL the atoms are shot one after another... The only explanation would be that space has a structure that guides the atoms. And that structure is becoming deactivated by the detector... the question is, WHEN. When WE look at the result or when the detector looks at it... If its about US (way later..) this would mean that the space has somehow temporal determinism or the atoms do... its weird anyway...
You might think that the universal laws of thermodynamics apply here, after all to detect an atom, or "see" it, that requires an interaction with a photon, this changing it's energy level; a bit like using a contacft thermometer, which immediately changes the temperature of the surface once it's in contact, as the thermal energy rebalances locally. The issue is how does this interaction change the slit pattern?
I agree with this and was going to post but was hopeful there was another person who saw it this way. Bravo go collect your nobel prize 🎉
This is absolutely how it works. The observation device disrupts and, therefore collapses the patern. If we could detect a photon or electron without altering its state, we could theoretically have instantaneous communications between devices from one galaxy to another. The atoms do not "know they are being observed," like many experts say or allude to. It's just them witnessing to you about their silly simulation religion.
Nice glitch in the matrix if you ask me. Humans 1 creator 9999999999999😂😂
"Quick, the Sims are becoming self-aware!!!!"
Expect a software patch shortly.
Kurt V haha 😂
They tried patching it last week but I remember this happening last week so looks like the patch update failed
@@grahamyodude I'm from future. What happened last week
It will never be patched, because then we would all realise that we are definitely in a simulation/computer program
The COVID-19-restart-required patch?
I can explain this easily but I don't want youtube people stealing my Nobel Prize
me too
grahamyodude it’s quite simple my good sir 🍷
Tom Campbell has it licked in his video The key to understanding our reality.
watch him say God
American Movement email meee im interested to know
This issue is what sparked my everlasting curiosity in physics and quantum mechanics, just to fall down a rabbithole of hundreds of weird and confusing data from experiments that classical laws of physics just cannot explain. there's just so much unknown, and so much to discover and learn. This specific problem in quantum mechanics not only gives plausibility to an observers universe, but also in certain specific scenarios, it fully implicates direct time travel of photons as a normal working part of the universe
I've heard this explanation: So long as quantum particles do not interact with anything in the universe at all they act as waves. But as soon as they do interact with anything they take on particle like behavior. Every detector necessarily relies on some type of interaction with what is shot through the double slit in order to detect it. So, in this example unplugging turns off that interaction.
Have you heard of "delayed choice quantum eraser double slit experiment"??? If not Please checkout and explain to me with logic..
ppl buy into the "spookiness" of quantum physics so easily.. while there are perfectly reasonable and simple explanations out there.. makes me pretty disappointed on my fellow human beings.. we are smarter than this if we just try a little bit.. come on now.
@@takisk.7698 obviously everyone there know there's an explanation.... the point is with our current knowledge we are so far from understanding it that it ''currently'' is magic for us
@@popcorn2466 there's way too much that we don't know and that's okay but when you get some unexpected results and you default to supernatural nonsense like "the human conscience affects the quantum world?!" instead of going with logical explanations.. it's just disappointing to see.
@@takisk.7698 true
Bruh I started from a physicist reacting to Attack on Titan and now I’m here😂
Hahahaha same! Except it was him reacting to Rick and Morty and also referencing this.
me too but from rick & morty
Ha ha anime working wonders
I started from a tiktok where a woman criticized religion and now I’m here ;-;
@@bro0ke_lyn794 i do not even wanna know what happened in between lol
0:57 - with light
2:08 - with sand
5:48 - without camera
7:34 - with camera
Thanks!
Thanks but TH-cam ads ruined it!
It's the photons of the camera recording them that affects their behaviour. It's not a mysterious effect.
@@ernestamoore4385 lol sure Mr einstein, you should be a scientist. 🤧
@@ernestamoore4385 I thought cameras contained sensors capturing photons rather than projecting them. However, you may be on to something, because it might be true that when the photon hits the material making up the camera sensor it is absorbed and an electron is released. Could these electrons being released from the camera sensor as the detector observes the atoms moving through the slit have an impact on where the atoms travel to as they pass through the slits?
I have watched many of videos with Jim Al-Khalili, and I can say that he is very good at explaining complex things. Very much like Jacob Bronowski, James Burke and Carl Sagan.
he did a great job
And dear Richard Feynman
And Brian Green
He physically resembles Robert Andrews Millikan.
I've read about this experiment tons of times and it still amazes me. The visuals really help. Its F'n nuts
I learned about the double slit experiment in high school and then again in college. I never understood it as well as from your presentation. Thank you.
I was thinking the same thing. High school, then college .... errrr.. ok...huh? Now this video -- Ah I've got it!
I was just remembering doing this experiment at uni, I remember the girl I was doing it with and that's about it lol
Same here i study this in highschool when i was 16 yrs old and now i m 28 a doctor but still haven’t understand this
@@schrodingerscat8391 You covered quantum mechanics and the double split experiment in high school? Some high school you went to. I went to high school in Norway, and when I studied in the US at University, the math class my year at University in the US was high school level in Norway. So color me impressed of your high school.
Also learned the young double slit experiment at highschool. At the time it was only referring the wavelike pattern so no biggie. 10 years after that the same experimet cropt up on my feed and said it was one of the explainations of quantum theory .# My whole life is a lie
How do you detect an atom without interacting with it?
this is an underrated comment
Entanglement.
You don't. If I got it right, nobody has ever really detected these particles in an experiment, it's simply not feasible. It's just a theoretical thing to explain how QF works, based on the Uncertainty Principle stating you cannot measure both wave and particle behaviour. If you detect the particle it will act as a particle (two bands), if you detect the wave it will act as a wave (interference).
@@marin7615 You contradict yourself saying particles can't be detected, and then they do detect particles and waves. We observe particles by measuring their interactions and vectoring. This experiment demonstrates the Observer Effect on the quantum level, the act of quantifying the particles collapses their wave function.
This experiment also demonstrates that particles only exist in waveform when there is no observation, evidenced by the interference pattern that can only occur from waves. Using detection equipment collapses the wave function thereby causing particles to behave like solids.
@@David-bc4rh I fully agree. I just meant the particles cannot be detected both at the screen and in between at the same time. If we were able to do that, we could probably solve the mistery, similarly as we understood the micro-world in biology after the invention of the microscope.
so if anyone ever asks you if supernatural things exist just point them to this experiment.
It’s often given a sort of magical interpretation where just looking at something can alter the outcome. More like coming into contact with anything will always distort it to some degree.
Bingo.. there's no way to "gently observe" as the presenter puts it.
@@takisk.7698 Gently doesn't mean without influence
@@nmarbletoe8210 it's a misleading word to use.. the detector interferes with the result so there's nothing "gentle" about it
@@takisk.7698why would a wave function collapse when it is measured
Eureka! So that's why a watched pot never boils!
I actually debunked this in 6th grade for a science fair. Watching the pot takes the same amount of time, but it generates boredom as a byproduct
I make a point of watching every pot of every liquid change to the boiling state just to feel the satisfaction of putting it to everyone's face who repeats this nonsense.
Boils but very slowly
@@doktormcnasty You're taking too seriously fella, the phrase means that things seem to take longer when you watch it, kinda like how if you watch a clock for 5 minutes it will seem to take much longer than if you just watch a 5 minute video on TH-cam or distract yourself some way
@@manawearblack You know what, if you don't mean it then don't say it. Why not just say "It seems to take water longer to boil when I'm watching it"? Why's that so hard? Why do people feel the need to get all hyperbolic with words like 'never' which are obviously completely untrue to the situation?
I don't know much about science, it wasn't my easiest subject growing up. I am just beginning to learn about quantum physics. Some videos I have watched on this experiment, and I couldn't quite comprehend what was going on. This explains it so very well in an easier to comprehend way. Thank you for this video.
in a way, quantum physics isn't very good at science either - because anyone who thinks they understands it, doesn't understand it. And by definition, quantum physics is very much not classical physics, and therefore not being good at that to start with isn't a barrier. Quantum physics in essence is anything that logically doesn't fit with any everyday knowledge and experience.
@dr_jaymz it's good at stats, but bad at theoretical physics. But everytime i watch the double slit experiment again i just get blown away again and again by it.
Stay curious Simon!! 🙂
This gave me chills!
Thank you. This is the clearest explanation I have come across.
First of all, I would like to thank Jim Al Kapone for making this Nobel prize possible. Second, I would like to thank the atoms for being so confusing. I also have a split personality and thats why I can get in their mind. Its not easy to be an atom. You dont even know if you're a particle or a wave. Sometimes you behave like a particle, but sometimes you behave like a wave.
And last but not least, I would like to thank me for being made of these particles waves.
*Waves at atoms. Atoms wave back.*
Wow...so profound!!
Swing and a miss.
As made as it seems in black and white it’s does make sense
Thank you for the unexpected laugh lol
That's intellectual venom
"Described" rather than "explained".
Both are the same tbh but i agree with you
Because it's a mystery, we can't explain why it happens.
He explained the EXPERIMENT not the phenomenon.. smh..
I think you read it as “the results of the double slit experiment explained” when all the title implies is an explanation of the experiment itself, which it did.
Duh! ....explain it and the Nobel prize is yours!
As commented by some, I think what we perceive as atoms (just like electrons) may exist in a quantum cloud that's governed by higher-dimensional laws than we can detect. However, our detecting equipment may cause some tiny variations in those dimensions that account for this behavior. Figuring that out is obviously non-trivial, but imo that's where the answer lies.
If the tree falls in the woods and no one is there to see it, has it really fallen?
Does the world exist before you Open the Door?
Yes, that seems obvious, so why didn't Kalilli address it??
Excellent video and presentation. Thank you.
Love Jim Al-Khalili. This was a great video, cannot believe I never discovered it before.
"Nothing is exactly as it appears, but everything is exactly as it is.. " - B. Bonzai
Or, as President Eisenhower once observed: "Things are more like they are now than they every have been before."
And God saw the light, that it was good...
Genesis 1:4
Jonah 3
10 Then God saw their works, that they turned from their evil way...
Best explanation out there. Made me finally visualize the two slit experiment. Unplugging the detector boggles the mind. My thoughts. When you take a measurement. You are making a call on energy much like a computer operating system to generate physical reality. When you unplug the measuring device whether you like it or not you have made your intention clear you no longer intend to take a measurement and reality corresponds accordingly.
More boggling for me is that when the detector is plugged in it's only observing the top slit, not both, and atoms are only being fired out one at a time with a gap in between. This means atoms passing the bottom slit are both not being observed and not being influenced by a previous atom - why would these ones not form a wave distribution pattern? In those instances, the act of observing *literally something else and not the atoms in question* is causing a change in behaviour, which is just whacky.
Excellent presentation... thanks.
Thank you Sushant Singh.. Learnt something new today
Hm
An explanation of how the observing apparatus works would be helpful
thank you
it's all very small of course, but it's just an electrode that's tuned to detect the micro current of electrons or photons. There's other ways to get particles to move a needle, but to count single photons passing through a slit, this is all that's needed. old tech.
Does it really need an explanation though? It's based off of emitting a certain frequency that will detect the atom or some individual particles that compose it. I'd like to know what you think about the comment I made recently in this video. Sorry I can't provide you with a specific link though.
@@benitocamela6336 Not everybody understands everything without having scientific background.
Have been avoiding this freak show for 40 odd years --but Mr Al Khalili has a brilliant method of getting this phenomena across to dodos like me --thankyou Jim !
Best double split explanation out there. Bravo.
Explanation: Atoms are actually aliens in tiny spaceships who like to confuse humans. Noble prize please!!
+Avi K LEL
+Avi K You sir have just wrecked this kid hard. I guess you deserve the Nobel prize...
Jaydon Nolan i was just thinking something along these lines! lmfao
or! or! or!... reality is trying to keep us from realizing thr truth, that truth being that all of reality doesn't truly exist, and reality conceals this secret with superposition. ;)
i refuse to believe this isnt the right answer, for me...thats how it is now thank you.
Why so complicated? They are just trolls.
Jim Al khalili is my favourite when it comes to quantum mechanics. I just love how easily he explains such complex things.
Why do you love false explanations?
Technically, he failed to explain something.
@@joxyjoxyjoxy1 Yes, he failed to explain the actual physics of it. ;-)
@@schmetterling4477u dumb , by ur logic explain the physics of God or a lack of God
@@joxyjoxyjoxy1L
This is the BEST!! Explanation ever! I also never thought this would be funny.
This was mindboggling...breaks your understanding
As far as I am concerned, it was difficult to work in the same relaxed way in the office when the boss was standing at the back of my seat and observing what I was doing compared to the moments when no one was observing.
True
That’s because when he was there you were working and when he he was gone you were on the internet watching clips like this.
And God saw the light, that it was good...
Genesis 1:4
Jonah 3
10 Then God saw their works, that they turned from their evil way...
"No fair! You changed the outcome by measuring it!"
1. The behaviour of atoms going through the slits is the same as the behaviour of light, for whatever reason (e.g. maybe something is altering the behaviour of the atoms, or maybe some assumption about the behaviour is incorrect).
2. The detector interferes with the results. E.g. a detector could cause the photons to go through each slit with a 50% chance, whereas the absence of a detector could cause them to go through both(somehow).
3. The detector being activated or deactivated is a determinant in whether or not the results get changed. Even if that doesn't appear to make any sense. Maybe it changes it in a way we just don't know about yet.
To me that's the most rational explanation even if we don't know how or why.
Haven't they done an experiment where they put a filter on one slot as a method of detection and the thickness of the filter effected the result of the spread?
I've heard these mysteries , never took the time to watch in detail very interesting .
It bothers me how when describing the double slit experiment, they nearly always gloss over the inner workings of the detector. Since we're dealing with individual particles, it's kind of important to know what the detection method is so we can know how they are or are not interfered with. In this video, for instance, it is utterly un-awing to me that the interference pattern comes back when you turn off the detector. If it is in any way an active detector rather than a passive one (think bouncing a second ball off of a first ball to figure out where it is, vs looking at the track left behind as it rolls), then turning it off is essentially backtracking to the experimental conditions that produced the prior interference pattern, so of course you get the same result.
ohemgee
That's the problem, isn't it? An instrument effect is the most logical conclusion to draw from the double-slit experiment, but videos like this (and indeed whole communities, including seemingly many physicists) are trying to argue the exact opposite: That it isn't an instrument effect; that the “observer effect” is a separate concept that involves some sort of knowledge transfer rather than an interaction of physical states.
You can see that this is what they are trying to do when they put in the detector and the interference goes away; and then they turn off the detector without removing it and say “Look, the interference comes back! It must not be because of the detector!” If they thought it was an instrument effect, the final round of oohs and awws wouldn't happen. Hence my comment about active vs passive detection; the way videos like this treat the experiment only makes sense if it is a passive detector, since turning off an active detector is effectively removing it. (It becomes even more troublesome when you know that passive detectors at the quantum scale are pretty much impossible.)
I guess I'm less confused about the experiment than I am about people's reactions to it. Why do they think this is impressive, let alone a world-shattering paradox? I feel like I'm missing something by not finding it as baffling as all of these scientists make it out to be.
ohemgee
I think this guy honestly believes that there is something other than instrument interaction going on. I don't have any direct evidence of a large number of physicists thinking that way, but I get an impression of it from the phrasing that goes with this sort of experiment, even if the person talking is otherwise competent.
Badly Drawn Turtle The reason we don't hear scientists refer to the detector is because it had the same effect on the experiment in both cases. Without changing a thing, the experiment was done recording and not recording the information. Believe me, this experiment has been repeated many times and by much smarter people than you and I. Detector interference was the very first thing they tested for. We are beyond that now.
But there is a logical answer. It just doesn't apply to a strictly material world.
Goohuman
Yet, I have yet to find any reliable source that describes such an experiment with adequate attention to the detector. In other words, I don't believe you. Not without sources.
A strictly material world is all we have evidence for. Postulating non-material answers would require a lot more than one type of experiment; it is an extraordinary claim that would need an extraordinary reason to consider it.
Badly Drawn Turtle I get it. You are not willing to consider non-material causes. I put it to you that the results of this test are pretty extraordinary.
If you are seriously questioning the detector, then you owe it to yourself to look into the actual research that was done.
en.wikipedia.org/wiki/Double-slit_experiment
You may also be interested in an even newer version where the observation is made after the photons have passed through one of the slits and before they land. Quite fascinating:
en.wikipedia.org/wiki/Double-slit_experiment#Delayed_choice_and_quantum_eraser_variations
You can now enjoy this mind bender in Spanish, thanks to a kind person who donated their time to provide us with Spanish subtitles. Gracias!
The Royal Institution is it possible that the device used to sense the particles was interfering in some way... magnetically or electrically? and that that caused them to behave differently
Witchcraft.
You are on the right path my friend!
So now The Mental Institution can mislead and confuse Spanish viewers as well!
Watch The Primer Fields Theory 1 - 3 he goes into a great details about why all this is a new age BS. We are not allowed to go into higher energy physics and thanks to above bs is not going to happen any time soon.
Lo siento, no entiendo. ¿Cómo se dice en español?
Please remember that this is not a mind binder. I can give myself the Noble prize if you want but the explanation is so simple. The problem of course here is that scientists still think n term of electricity and magnetism as either wave or particle. They have not yet put feet n the other forms of energies that compose this duality of electricity and magnetism. If only they understood that thoughts are the creators of this duality, they would understand their own experiment. They still fail to understand how consciousness impact its own creations. They still don't understand the two impulses that manage this manifested expression. Time will come. I explained this mind binding illusion in simple terms but look into how consciousness create reality via its 2 impulses and you will understand why the camera impact on this experiment. No need to be a scientist, you see.
It’s perfectly easy to explain:- The contra-di-fabulating trans-denominating upper and lower oodle Flori-murdle-bunds are all explurjigating in an anti-clockwise Oodle Splunge cloud. I thought everyone knew that.
I'm glad to have seen this before the program gets updated.
Atoms are the same as humans, when they know that they are being watched, they act different. :D
No, humans are made of atoms
lol
This is a very good one
The "observer" in quantum physics is not a human being.
But if a human being did observe the particle, it would still behave differently if it was being watched
Love prof. Jim. His 3 part series 'Atom' was life changing for me.
Watching that next, ty for the rec
@@williamdekker enjoy
Same bro. Still gives me goosebumps.
Fantastic video!
It'd be interesting to know more about this. How did the sensor work? Did it emit any waves or particles itself? What different detection methods have been used and what were the results? This was 10 years ago, is it still considered that the atoms somehow change their mind?
I was thinking the same....it could be the detector interacting with the atoms that produces the results seen.
Wouldn’t all these genius researchers also pose that question?
@@Morethanamethod. I'd have thought so, but, I'd also expect them to talk about those questions too and they haven't.
That's a very very good point. Didn't think about it....
I believe that this is stiill the most accepted interpretation. I believe that cameras work by light wave/particles affecting the the recording part of the camera.
The atoms are having a party and we're not invited, so when we call them to see what they're doing they tell us they're just chilling at home. I think we just need to understand that we're not cool enough to hang out with atoms.
Like UFOs. They are more free and open when we are unaware of them but once we prepare the detector equipments they are gone
All future Nobel Laureates in the comment section
Hahaha
But jut what, just imagine, what if one of those commenters is the one capable of solving this mistery, and is dehumanized by ordinary youtube commenters disgusting behavior, and actually never look back at this double slit experiment again.
Yeah we humans deserve to be wiped out of egzistence
Solved it: our thoughts create waves (brain activity can be measured through frequency) therefore when we're observing we're emitting waves and the particles are simply riding them 🏄♂️
@@mudza92 relax dude. your resintment for humans has nothing to do with his briliant comment.
@@0i0l0o That's briliant to you? You are very easily amazed lol
Thank you very much. About a decade ago I read an article on this subject and was baffled. You presented this in such a clear pleb-friendly manner. I almost feel that I understand.
I have one simple explanation for that: The equipment you use to check the behavior of atoms, affects the behavior of atoms.
simply use another method.
There are lot of bad measurement devices that affect the measurement process. for example a bad voltmeter can itself drain current and show less voltage. A bad thermometer can itself changes the temperature of item under examination.
I wish this challenge and admission that "we don't know it all" was written in my text books when I was studying..
My god, that is unbelievable. Stunning explanation
Very good explanation
The double slit experiment is amazing and truly bizarre. That said, I will leave this little nugget: there is no observation without interaction.
What's bizarre about two slits minus one slit makes one slit? That's kindergarten arithmetic. Don't tell me you stopped paying attention in kindergarten. ;-)
Maybe the detector gives out an interference of its own which changes the way that the electrons act?
what about when the electron goes though the bottom slit ? the detector isn't required
***** chill out, i'm just making suggestions xD
I was wondering the same exact thing. This is the only logical explanation. I can only assume this has been ruled out as a possibility, and if so, I'd like to know why.
***** oh soz mate
it actually does seem like that lmao
he's wearing a bowtie which helps me focus more by about 5%
😂😂😂
Yeah but it's also +5 RADS
Well of course, Bow Ties are cool, just ask Matt Smith.
oh God, if you get affected by these small things, then for sure you are distracting freak.... :)
Good try Jim, I love the way you communicate, I keep trying to get it, I’ve watched many descriptions of the double slit experiment, but even your very clear description still leaves me confused.
Time will heal your confusion my friend. Remember, a mere 400 years ago, the Earth was believed to be flat. And it would have been absurd to tell those people that we will go to Mars. What is Mars? would have been the question. Today, we see the same thing happening. The universe is either particle or wave and is matter, they tell us. In 400 years from now, people will have a splitting laugh under the table, with contortions hearing this. How would you feel if someone tells you that the Earth is flat when you know that it's not? That is the same feeling I get when I see the descriptions of our universe in all scientific books at the moment and probably for another 400 years. But I stay away from the contortions and splitting laugh. Instead I give a bit of insights in forums like this one.
I had a old wagon axel hub, really old & weighed about 15 lbs. I knocked out the spoke holes and put a small 110 volt lite in it. the effect was very neat.
'Do you really believe the moon is not there when you are not looking at it?'
- - - Einstein
according to this science its always there just sometimes as an energy wave and sometimes as a solid mass. But when is the moon EVER not looked at with millions of species crawling about the planet?
This is a theory. There is not proofs about it. This theory uses in the games for optimizing the game. Just render where you look at. We do not need to render the back view scene in the game for optimizing the game. The world is not video game and then there could not be such as this theory.
@Fida Muhammad When you asked your friend you effectively transferred the vision to him so you ARE EFFECTIVELY looking at the moon. Now if he is also not looking at the moon and he tells you it's there, then he is lying to you :D
Prove this to yourself, sit quietly,clear your mind, close your eyes, close your mouth, close your nostrils, give it half an hour and then ask your self what really exists. Then try this for 3 hours!!!
I am looking at the moon where it was about a second ago.
This was such a GOOD video. Understanding this experiment was very difficult, & you nailed it in one shot !
You only think that he nailed it in one shot, because you were observing! If you didn’t watch this video, it definitely would’ve been two shots.
So, how does one creat a particle pattern, if I want to do it at home, how would I do that?
Ur comment deserves more love. Very clever
Whenever I hear about this experiment, it reminds me of the rule of "probability". It always gives me a chill that, in South Korea where I live, there are about 8~9 lottery winners every week. The chance you win the lottery is about 1/8,000,000, and the number of winners can be easily calculated with simple math of probability. I mean, isn't it spooky that "probability" works like a rule in this world? Does it really make sense that when you roll the dice so many times, you will get similar numbers of each spot? I never does for me. Maybe there is some hidden connection between how photons work in the double slit experiment and how the probability works in this world.
you should probably look at a video on how rng in video games or technology is calculated. i think youd find it interesting how probability is simulated
probability however is not actually a concept ingrained in reality and is just how human beings perceive things that happen a certain amount of times out of a chosen amount of situations. really, the reason anything happens is due to a reason and not randomness.
I think this is one of the biggest arguments to say we're in a simulated reality - the simulation only does accurate calculations when required to due to observation in order to save resources.
This is so fascinating! I could learn this stuff all day!
What did you learn ?
@@steefv781 quantum mechanics
MIT must be a place for you my friend
Having watched the video again & again I stand by my original statement. If you unplug the detector & the wave pattern goes back to the multi-pattern then you are interfering with the atoms when you have the detector turn on. Exactly how does this detector in this experiment work?
A very good teacher. You describe things in an easy to understand fashion.
Leave the detector turned on, but wear ear blockers so you can't hear the sound it makes. Also block your vision so you can't see the individual spots on the screen, just the aggregated result. Then repeat the experiment but let a (hearing) cat see and hear it as the experiment proceeds. Small bird, octopus (DNA significantly different from human), cockroach, whatever else you can think of. Then, combinations. This would be even more interesting.
Thanks for the explanation. Finally understood what this experiment is. 🙂
2 channels you may like are, 'David Butler' and 'closer to the truth'
Cheers
Yes, and that's about as much as we can really understand haha what the experiment is, what's actually happening is just ridiculous.
I remember 20 years ago my elementary physics teacher mentioned this experiment and said "and this is where our physics ends".
I didn't remember anything about the physics, just that phrase. Now as an older guy i decided to google it and see what that was and if they figured it out. I'm so glad i did, this has to be the coolest bug in the matrix that I've heard so far :D
So you met an idiot with Dunning-Kruger. So what? There are thousands of them in this comment section alone.
@@schmetterling4477 whoa, what does Dunning-Kruger have to do with what I said? You're high or what?
@@aga1nst A physics teacher who says that "this is where our physics ends" is displaying Dunning-Kruger. (S)he doesn't know what (s)he doesn't know.
@@schmetterling4477 you mean she should have said "this is where *our understanding of* physics ends"? That's what she said actually, but it got lost in translation.
Really big deal, if you get triggered by things like that, you have issues.
@@aga1nst No, she should have said "This is where MY understanding of physics ends.". That she didn't is where her Dunning-Kruger starts. You are not very far away from displaying it, either.
Many lovely explanations of the experiment and its importance. However, I have still not found a video of an experiment demonstrating the two bars of photons when the detector is looking at the slit. Anyone has a link?
Also, try a 3 slit experiment with the beam, light or atoms, aimed down after being split into 3 beams to reflect in 3 mirrors to combine and display on 3 different screens. Then try the detector part of the experiment, also with the non-human observers.
It genuinely upsets me when people without much knowledge about physics are trying to explain why this is "bullshit" using their own assumptions. I'm sorry, but do you really think that you can figure out what those with a PhD in physics can't? That's like choosing whether to listen to a meteorologist or a psychic to tell you what the weather will be like tomorrow. Surely you must believe the one who has extensive knowledge and performs tests to find out facts?
KreeZafi that's true but, whats going on in these experiments like with quantum entanglement is foreign to physics. Like for example this guy Jim Al-Khalili has a PhD but does not understand whats going on in this experiment
Aweri Blakely That's what I said. If people with massive knowledge about physics don't get it, how come amateurs without that knowledge believe that they have the answer which professionals can't find?
KreeZafi Because having multiple viewpoints can spark new ideas, which leads to new experiments, which leads to new answers.
I agree we can't let them meteorologists go telling the weather, the rapscallions!
KreeZafi I recommend reading about the Dunning-Kruger effect. Those without skill don't know how little skill they have!
Pity he didn't explain that observing is not passive. In order to detect a particle you have to hit it with another particle. So by observing the atoms you interfere with them
they never do. They always pretend that atoms have some sort of telephatic powers.
Yeah, I was disappointed he did not explain that. I think it's because they think it looks cooler when they don't.
@@nihatnihat8264 it's a lot more entertaining to leave the interaction detail out, makes it seem "spooky" as if the particle/waves can "see" if someone is looking at it.
@Donald Piniach I'm interested, maybe information has something to do with it, information is sort of like QM, it's very hard to understand. Your words require a definition. What is precisely meant by "delayed" and how is the information "sampled"?
@Donald Piniach Very interesting for sure. After looking at the erasure experiment several times over using various sources, it's kind of like a magic trick, where you distract the audience by having them all focus away from the obviousness that exposes how the trick is being performed. The obviousness in the erasure experiment, is that the screen itself is a detector that interacts with and therefore is able to influence the behavior of the entangled photons being detected on the other set of detectors, including the one that supposedly erases the "which way" information. It appears that all that was done, was to make the double slit experiment considerably more complicated without actually doing it any differently, i.e., we've simply relabeled one detector " the screen" for another "the detector".
I do like what you suggested about the "observed" behaviour having something to do with "information", because to this point in time, I've not yet found a satisfactory definition of what information actually is, despite spending a lot of time studying the concept. Usually when it's hard to pin something down, it's because the word that is used is "loaded" where as it relates to multiple things all together ambiguously, the challenge therefore becomes how to identify and separate all of the different things out so that they each can be understood individually.. The reason why I'm looking at QM concepts, is while trying to sort out the concept of information. I actually find QM simpler to understand than the concept of information, that's not saying that I think that QM is not complicated, it instead appears to be better understood at this time than the concept of information.
I am 33, and just showed this to my 67-year-old university-educated, bible-following father. At the end of the video, he was speechless with raised eyebrows. My hope is that he will watch more of these with me in the future.
Dont you think showing your dad things that are beyond his capability to understand is going to make him believe in the Bible even more so
You'd better think a bit more about your own beliefs.
That light is both a wave and a particle mimicks Christian theology: the Trinity is both 3 (which speaks to particles) and yet 1 (which speaks to waves). Commensurately, the bible says that "God is light".
So the material world speaks to spiritual realities. God is light and God is 3 and 1 at the same time. This is an exact parallel of what has been shown here about light's behaviour. Couldn't be more exact.
His comment of unplugging the atom detector? 100% reasonable and very much needed.
Great lecture. Probably the best explaining the Double Slit Experiment..
That sense we get when we feel like someone unseen is watching us is the atoms in our bodies doing what they do best.
... that feeling you'll get when you actually realize, "Lots of unseen, NonPhysical, are watching you/us, all the time" - just keep observing Quantum Physics and *"keep mind fully open, free of predetermined beliefs, theories, opinions" i.e. apply the "Standards of Science and Research" ...*
... *"the info will flow to you in relative time".*
... and, *Keep in mind, the "Universal Law of Attraction" is Absolute.*
Nothing to fear, it is all very Positive.
Consciousness watching the body-mind
my answer is TIME .. the past, present and future exists simultaneously, hence, when carrying out the double-slit experiment at any given moment (without observation) then there is/was enough time passed already for the photons/atoms to form the interference pattern due to deflection, hence the result (notice how the atoms are concentrated in the middle of the pattern and less conentrated at the edges). Once we start observation then the result will be limited to the timeframe of our observation, therefore, we only see two bands of photos/atoms. It is impossible to see the interference pattern through observation as the only way to see the pattern is by starting the observation before the emission of first-ever photon
i used to think that the particles might be accompanied by some kind of electromagnetic field (which acts like waves) and the field goes through both slits and interferes with itself, but the particle only goes through one slit. So the interfered field guides the particle into an interference pattern, even one at a time. But I didnt know that the pattern changed when the device was switched off.
This has to do with the device which is being used. How are we detecting the small particle without interference that's the question.
My kitten behaves in the same way. He stops playing as soon as I start filming him !
Does your cat happen to be a member of Atom Cats?
Show him what happens to schrodinger's cat, and let's see if he still acts that way
This might explain how you can "feel" when someone is looking/staring at you..
It’s a survival instinct
You can't. People start experiencing the "I am being watched"-feeling because - for example - the room becomes awkwardly quiet.
@@aliasanonym9778 not at all man I’ve on many many situations through out my life just for no given reason looked in a particular direction that happened to be exactly where someone was looking at me and I have had the exact same thing happen when looking at someone else. In multiple different loud and busy situations as well like a bus a coffee shop the mall.
@@jesserodgers3759 and there were many more times where you didn't observe the person watching you; you only remember the times where you caught them
@@jesserodgers3759 Yeah, it's amazing that we sometines just have a "knowing" about being observed, as we do with intuition
has there been an experiment set up for the double slit, where there a sensors at each level. And if each sensor (2 gaps, 1 wall) receives a ping over time, could we attribute the wave appearance to the gravitational influence on that photon at time of observation?
I am wondering the same.
I just enjoy that there are still things left unexplainable
can the detector when switched on be causing some sort of involuntary interference with the atoms
I'm certainly not proficient with physics, so I'm probably about to sound really dumb. So a photon is a wave particle, but because it travels at constant velocity, it has a zero resting mass, yeah? But we know atoms do have resting mass. First question is: do researchers get the same effects if they send just one photon at a time through the two slits as they do when they send one atom? Second, can the difference then mass between the two contribute to the differences in the outcomes?
The detectors are actually photo-multipliers, they don't "shoot" light/photons onto the particle.The more sophisticated "delayed" two-slit experiment shows that if you know the path of the photon (by which detector it hits), it will act as a particle. If the path is not known (possible two paths), it behaves like a wave. Really weird.
They've sent everything from photons to Bucky Balls and the results are the same.
Interesting! Truly mind boggling stuff. How do the photo-multipliers work?
ConsciousConversation They are basically multi-stage amplifiers, converting the photon into an electrical signal large enough to be analyzed and processed.
I don't know anything physics and have tried reading up on this experiment but could never really understand it and why it's so famous, but now i have a much better idea!!! Wonderfully explained and thank you so much!! It's so cool and weird😂😂 atoms are sneaky
Veritasium did a much better video.
@@SunShine-kd6td If you think that. you don't understand the problem
Not really sneaky my friend.
The atoms and molecules themselves possess kinds of consciousness impossible for you to analyze, because the scales of your activities are so different. They are information-gathering processes, however, containing codified electromagnetic properties that slip between all of your devices. The atoms and molecules and all of the seemingly smaller "particles" within them are, again, information carrying processes, and upon them depends your entire interpretation of the nature of events.
@@promoteamutube gathering information for reality?
Truly mindblowing
I attempted the question on Young's double slit experiment in my higher school exam in 1995, today I understood it.
And God saw the light, that it was good...
Genesis 1:4
Jonah 3
10 Then God saw their works, that they turned from their evil way...
Every time I hear about this experiment it blows my mind! Every time. This was a good simple explanation of the "mystery"!
but see comment by Jako above with possible explanation
There is no mystery my friend. “the observer is a part of the experiment, and the results will conform to the expectations of the observer”. By viewing the double slit experiment as not just an experiment, but as a reflection of the observer’s own experience, we see how our own expectations and beliefs can influence our reality. The "particle" itself is just information and has nothing solid. If you can find an individual capable of focusing so much as to see the picture of mona lisa in his mind, the "particle" will draw mona lisa on the detecting screen.
@@promoteamutube Perfect! This is what enlightened sages have said too.
Make it 3 slits to confuse them 🤣
block all the slits
turn out the lights
exit lab promptly
@@David-bc4rh Don't forget to lock up the atoms first, you really don't want to leave them loose in the lab, I use a shoe box.
Or remove the slit and place a hair.
@Tanaphar Plus Masks what’s waving? Aether?
I don’t use the same mechanism everyone else’s uses for light. I use another assumption.
@Tanaphar Plus Masks so the question is, why to we see fringe pattern on the wall? We have two hypothesis, on a “wave” two a particle. Can we assume of a third hypothesis that mediates light?
what role does light play on the test with the atoms? is it 100% dark when the atoms are shot through or is light also present during the test? Does the detector use light in a way that cancels out the normal light wave pattern?
could the elecrtical feild in the counter be affecting the atoms?