Thomas Young's Double Slit Experiment
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- Опубліковано 9 лип 2024
- Seeing light in a different way. Ever wonder what happens to light when it gets in its own way?
License: Creative Commons BY-NC-SA
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Thank you for shedding light on this subject. It is articulate and well explained. 🙏🙏
I see what you did there
i skipped a 1000 videos for this MIT explanation.
worth it
Have you used coherent light sources in this experiment? I am not able to understand why the intensities of the maxima keep decreasing... could someone please help!
The pinhole-pair itself is not covered, but it is really small in the center of
the disk. The tape (and tinfoil below it) is to keep stray light out of the
tube. To see the image you have to look through the tube, through the pinholes,
at a light source. My best results were from streetlights and stoplights at
night. To avoid damage to your eyes you do NOT want to use this type of system
to observe laser light or light from the sun.
I was looking for something like this.
Thanks !
Thanks i needed this for my science fair project!!
For the best explanation I'd probably go to the Feynman videos, but the thrust
of the result is that photons are particles and can be observed as such. The
wavelength and wave properties all relate to the probability of finding any one
photon in some region, and the interference pattern we calculate classically
describes how we expect the photons to be distributed on the screen.
cont...
I'm sad I didn't get to see a single photon emitter with results from it being observed vs not being observed. Thank you for the demonstration.
This was very interesting and accurate ....thanx for such grate explanation
Great videos. Thanks. Theorist here trying to remind myself of what doing optics actually looks like.
Please can someone explain, in simple terms, the reason why the wave is transformed in a solid particle when observed? Thanks for the answer.
@NothingMatters1991: At the laser power levels used in the video there are a significant number of
photons traveling through the system at once and we can't distinguish by eye
the impact individual photons, and we're not observing if the photons passed
through one slit or the other.
cont...
What happens to the particles that hit the barrier? They whould be bouncing and making another patter somewere else. A patter that is not being observed. And if the pattern is not being observed , will it be afected when the experiment IS OBSERVED?
Hey! This was the best video I found about Young's experiment, but I am still not satisfied with how the corpuscular nature of light is explained.
How could we launch one electron at a time against the fends?
This 1970s experiment, how was it done???
I love how the light pew-pews from a candle.
It's pretty cool because in that video
you clearly see the impact of individual photons as discrete points, but the
resulting pattern is what you would expect from wave-like behavior.
Yes, thank you, a very neutral and unbiased Presentation.
Why did you not mention what happens when the photons are observed or not? Seems this is the heart of the experiment.
Because it was never done. The whole thing about observation part is a big myth. That's why you will not find any video footage of such experiment done.
@@innerbytesno i have seen such footage before
Nice video Bill. Why is there a wave pattern on the back wall when the beam is going through 2 slits when we, or you, are observing the beam? Doesn’t the wave pattern cease, and instead shows up directly only behind the 2 slits, when an observer observes the particle in the original DSE? Isn’t that the main reason for the popularity of this experiment “the act of observation changes things”?
Why would he not discuss the most important part? The knowledge of the data and how it changes the results.
Please can you explain to me how we are able to isolate a single electron , is it just such a weak source of light only 1 photon or electron is emitted?
Thanks, tou saved my physics Fair about light duality
Linear superposition means that light never gets in its own way. The physical conditions for gamma-gamma scattering and vacuum polarization are nowhere near met for visible light at the kinds of intensities that we are talking about here.
I haven't seen yet if these double slit experiments are done in a total vaccumm or if the air moved rapidly during test Albert Harvey Rotary Engines
It is possible to do the experiment with a small number of photons so that only
one photon at a time passes through the system, and with the right detector you
can observe the impact of individual photons on the screen. I think the
University of Leiden has UA-cam video of the photon by photon buildup of an
interference pattern on a CCD camera.
cont...
link?
At 6:00 i thought you will say "Warning you might see a parallel world", still cool though
Maged EWilliam lol
It looks like you cover the pin hole with the tape.. Is that true? Also where does the image appear? Do you see it as you look through the pin hole?
No fullscreen?
IMO, a "quantum vibrational wave/ripple" is set off at the point where the electron is fired. A quantum aerodynamics of sorts. The wave precedes the electron. It is this wave that is responsible for the distribution pattern as each electron, even though fired 1 at a time, is carried on it. It explains the "probability" of where each would land.
When you try to measure the electron, it is not the "conscious" act of doing it that causes the electrons to behave as particles, but it's because you break the wave. Thus, as there is no wave for the electron to ride on, it will come through the slit as an independent particle.
i think you are talking about pilot wave theory.
Hey, isn't it also the case that you can change the way the photon behaves (wave or particle) depending on whether or not you measure which slit the photon goes through? And, is this pattern seen with larger particles also?
That's what I've always heard, but from this explanation it seems like you only get that pattern if you go 1 photon at a time in order to get it through only 1 of the holes. Kinda makes me doubt whether the observation is what causes collapse of the wave function.
Show the detection method
I think its fascinating. We have much to learn about this universe...thats about all i can say
Helpful
nice job. I'm wondering if no one's tried to slow the thing being tested down. Perhaps making it pass through a medium or a very very cold vacuum? Also, Sean Carroll speaks of everything being a field and I'm imagining a wave or disruption in a field. It's certainly an odd thing this dual nature of stuff. The peaks in the waves being seen as particles or probabilities for particles etc. Light passing through a vacuum without a medium to carry the wave is another strange one that brought us back to particles and corpuscles didn't it? I'm still not seeing how it can be both forms, it's especially strange when you're talking about one atom or photo at a time. I hope this is resolved in my lifetime. Excellent thought provoking video presentation.
vaccum cant be cold dummy!!
interesting he only gave you half the experiment..I wonder why?
Well, he WOULD have, but the detector......um....... was....um.... sent out for service....yeah.... that's right! And he had to finish the video that night! Besides, how many times do you need the experiment demonstrated? This ultimate perplexing experiment been done twice in the last 110 years. I don't have any video of it, but isn't the word of a thousand scientists swearing by somebody's notes good enough for you? He didn't have to do it, and how dare you question it? ;-)
@@imgonnagogetthepapersgetth8347 It is normal in physics that only the first experiment that shows a specific effect is credited. It is also normal that it is repeated many times to verify whether the original paper had it right. This experiment has been repeated many times, and always shows the same results as the original experiment did. See for example physicsworld.com/a/feynmans-double-slit-experiment-gets-a-makeover/ for one from 2013. If you search the internet you will find many similar experiments. Even the double-slit wiki-page mentions at least 5 of them.
This video seems to lack the fact that if you attempt to observe each slit to see which slit a photon is travelling through you no longer get an interference pattern. Instead light reverts back to acting like a particle instead of a wave.
Tzimnewman3 Even if one slit is closed, you still get an interference pattern, which is usually called single slit diffraction.
What is the actual geometrical shape of the fringes?(Y.D.S.E.)
I think it's hyperbolic.... with the slits acting as the focii
I watched this video several times, but I couldn't figure out how the pipe is supposed to work. Because the other end is taped completely. There is no opening for the eye.
By shining
a very large number of photons at the double slit we repeating the single photon
experiment millions of times a second, and the interference pattern we observe
is the result.
cont...
This is also the same guy who translated the Rosetta Stone
so its a wave, but when measured it collapses to a particle.
The problem with these vids is that it fails to captivate the audience.
How annoying, the subtitles are exactly over the interference pattern. So I was really confused the first time.
What if the observer were a rabbit? Does it matter or make a difference?
What if we perform young's double slit experiment with magnetic or current carrying slit
With photons? Absolutely nothing will happen.
I have done this experiment showing light interference not on a screen or wall but airborne.
Whenever I am giving a lecture on quantum physics, I feel as if I am talking about Vedas. (Spiritual and scientific books of Hindus written down in 5000 BC and an oral tradition before that). I studied matter for 35 yrs only to find that it does not exist- exactly what Adishankara said (a Hindu sage -2000 BC) long back from the upanishads.
" All that you see does not exist"
- Hans Peter Durr (German Quantum and Nuclear Physicist)
Kashsoldier truelly u got the main source..After all doing the experiment u find the same thing at end what the vedas told earlier ...
Yes, as einstein, bohr, heisenberg, planck, schrodiger, max born, dürr, buddha, jesus, the Yogis, and lots of others said: this Plane here is an Illusion, albeit a persistant one.
Is it even possible to measure light in an experiment with a device that uses electricity as its propulsion. In that I mean to say, how are you using something that is not as fast as light AKA electricity , to account for particles that move faster than the electricity and therefore cannot account for every possible particle. What kind of detectors have the ability to identify a single particle or wave of light?
A quantum is simply an amount of energy. If your detector can resolve the amount of energy in the quantum, then it will be a single quantum detector. Some detectors take longer to achieve that resolution and some can do it quickly, but the time resolution of the detector is a completely independent question of the speed at which electromagnetic energy propagates.
The most simple detector for single quanta is called a photomultiplier tube. A small one costs a couple hundred dollars new and you might be able to pick a used one up in working condition for a fraction of that.
Is there a possibility of making a real photon experiment where there are not enough photons to make a solid line?
Are there ways of seeing photons through a prism and make the different wavelength go trough different slits?
Yes and yes.
@@schmetterling4477 Thx, and do you know if their is any video of that?
@@JonasUllenius You can do it at home. Close the curtains at night in a room without windows. That should do it to get you very few photons. :-)
@@schmetterling4477 "curtains at night in a room without windows", what does the curtains do in a room without windows?
@@JonasUllenius That is what physicists do to make "very few photons". We put things in a box clad with black fabric inside a room without windows that has the doors covered with thick curtains. Regular doors have very wide gaps between the frame and the door. If you don't cover them your photomultiplier tubes will be screaming.
thought the double slit experiment required photons to be shot one at a time.
Could it be possible that by measuring at one slit, energy is being absorbed, effectively creating two different light sources that aren't in phase and don't interact.
Here (2:30) the h in the sinc-function is wrong! Watch the Wikipedia-article on this:
en.wikipedia.org/wiki/Double-slit_experiment
No laser in 1801
I'm coming to understand physics lesson 🤓👩🏻⚕️❤
So has anyone found the answer?? Does anyone think consciousness has anything to do with it?? If that’s the case that would open up a huge ballgame? And tell us a lot about ourselves. IMO, help I need answers/ opinions???
Yes, Young found the correct answer in 1801. :-)
You can make it using an empty card box and a candle...:)
Holy Quran Chapter 24 The Light verse 40 looks like hinted at Young's double slit experiment from 1801.
Or ˹their deeds are˺ like the darkness in a deep sea, covered by waves upon waves, topped by clouds. Darkness upon darkness! If one stretches out their hand, they can hardly see it. And whoever Allah does not bless with light will have no light!
This verse talks about Internal Waves but why waves used in the context of darkness and light. Why twice these words (darkness, waves, light) used in this verse together ?
Old Interference Interpretation had a Gap #InterferenceGap explained by Ion Murgu Ohio
At 6:42 he says, "The top half of the screen is showing the photon impacts at each stage." I see nothing but a black screen. Where is there an experiment showing the famously predicted "two bands" when the detection apparatus is turned off???
Oh wait, I looked more closely at the top screen and could see the light "snow" on the top screen. My original question still remains however: Where is there an experiment showing the famously predicted "two bands" when the detection apparatus is turned off???
I see quite a few people here and elsewhere are asking the same question, and not getting any answers.
+McAllister Pulswaithe Have you gotten the info you wanted? I'd be interested to know also.
+John Batibasaga Yes, I did, but it was quite a steep learning curve. Here's the upshot: if you fire single electrons at two tiny slits in a screen, what you will get is an interference pattern - very paradoxical, since you have particles acting like waves. But if you use a detector on the other side of the screen to determine which slit the electron has passed through, you will get two bands. The electrons are now behaving like particles. Why? Because by detecting, or taking measurements of the electrons, you are actually taking information from them, and they go from probabilities (waves) to discrete trajectories (particles). This is called a Wave Function Collapse.
It's important to distinguish between "observing" and "measuring." Merely observing the double-slit experiment with your naked eye isn't going to make the interference pattern collapse. This is a very widespread and misleading misconception. You have to take actual measurements of the particles (photons or electrons, or atoms) after they have passed through one slit or the other to cause them to collapse into two discrete bands .
my god, for someone explaining how light works u would expect a better image quality
Stand back further you don't see the particle nature of images :)
Nice video....shame about the end..yet again someone else who can’t provide the exact proof of these photons..I’m starting to agree with ken wheeler!!!!!!
I’m not convinced anyone is sending one photon or electron, wish I could be
Most sources are emitting single electrons or photons, the question is merely how quickly. One can make sources that emit multiple quanta at once, but that's much harder.
@@schmetterling4477 all sources emit a beam, wave of light. that is experimentally verified. photons, quanta, electrons have never been experimentally verified. they are an imaginative mathematical construct.
@@whatsappvideos9665 We have religious freedom. You can believe whatever you like.
@@schmetterling4477 ah! so this is about making faith in God look like stupidity? is that why you are doing it?
@@whatsappvideos9665 I can do that in addition, if you want me to. Do you want me to?
I thought light travels as waves of particles.
this experiment is to prove the dual nature of light. light can act as both a wave and a particle.
That's not uncommon.
I do understand that the scientific community has pretty much accepted particle/wave duality, but I believe there is a simpler answer that makes more sense. The double slit experiment makes perfect sense if light is a waveform because of the interference patterns. The reason people believe its a particle and wave could be partially due to the assumption that what they are emitting is light. If an electron is emitted, it will create an electromagnetic field around it much like a wake from a boat or when it impacts other matter. The electron itself is not light. This theory is very testable. perform the double slit experiment in a total vacuum, there should be no interference pattern.
Another reason why people believe light as it's particle form is because of the way it behaves in space. For example, how could light travel through space if its a vacuum, or why does a black hole or massive objects cause light to change direction.
This could be answered the same with sound waves. Does sound travel in space? No. Does Light travel in space? Actually no. Electrons striking the atmosphere impact create the electromagnetic wave which we see as light. If you were to put a camera in space, the electrons would contact the CCD on the camera and create the electromagnetic wave directly on the camera. But technically by this theory the light doesn't exist in space until it contacts matter. This makes perfect concerning black holes. black holes have a lot of mass, electrons have mass. The same could be said about sound in space, an object traveling in space hits your space helmet, you would hear it as the object would create the wave when it contacts you. So the sound doesn't travel in space, but you will hear it when it hits you. black holes effect the trajectory of electrons, problem solved. According to common scientific belief, "photons" have no mass. How does gravity effect the path of light then?
My theory has huge consequences on the way everyone views the universe. Speed of light is not constant, just like sound. Sound travels slower or faster depending on the propagation medium just like light. In fiber optics, this concept is known as refractive index, because light waves travel 1/3 slower through fiber optics. This would mean that there may be some errors in the way which people theorize the distance of the stars using the speed of light, although the actual light waves do not travel through space.
If it's not travelling, how can it hit you? Also has anyone tried the experiment with an electron in a vacuum?
light is an electromagnetic wave, it only propagates through mass. electrons can travel through free space though because they have mass. Elections or subatomic particles striking other mass create the electromagnetic wave which we know as light.
Think of sound for example. Sound is not a particle-wave like a "phot-on", there is no such thing as a "sound-on" nor a photon. Sound cannot travel through space, neither can light. If we were in space and I threw a rock at your space helmet you WOULD hear it though, because the rock impacting your helmet would create sound waves internal to your space helmet. It's the same thing with light, light doesn't travel through space but an electron impacting your eye or camera lense would create a light wave on impact.
jakeflow27 I'm confused, what do you mean there's no such thing as a photon? Are you saying light can only travel through space via the medium of an electron? I thought light travelled through space in the form of a photon? When you shine a torch, you're not firing electrons out of it, the electrons in the element were excited and then the equivalent energy released as the electrons return to its natural state is what we see as light. So if light is energy, are photons just energy? How could it then exhibit some aspects of a particle wave as energy cant have matter... I think I need to research what exactly photons are
zedooncadhz in school people are taught about photons. im telling you my opinion that to me it makes more sense that light is ONLY an electromagnetic wave, like microwaves or radiowaves. nobody believes in micro-tons or radio-tons but they are known to travel through space. waves need a medium to propagate, that medium is matter, light propegates differently in different mediums just like sound. light travels slower in water and fiber optic lines. sound travels slower in water as well. the fastest speed of light is in a vacuum which is the speed of what the particles (electron or other charged particle) travels. light is effected by gravity in space, thats a known fact, but im saying thats not light, its the particles which are going to create the EM wave on impact
jakeflow27 ok I get that but can you differentiate light from the particles it uses as a medium? Light in transit is light in a potential form and so isn't saying that light itself isn't bent verging on semantics?
What do you all think about the idea of this double slit light experiment? Would be cool to see it done and the outcome! ua-cam.com/video/faSQnk_SoFA/v-deo.html
I believe QM is wrong in their assumptions. There are no mythical photons as particles or photons as waves. There is only a probability field. Move the back wall so that it is directly behind and touching the double slits. Do the experiment (I imagine you'll get two bands). Then move the back wall far enough away to get multiple bands. Then move the back wall in 12 incremental steps towards the double slits and pay attention to the pattern created as the wall is moved to new locations and changes. My contention is that just like in music you are proving there is a frequency that is being affected, the frequency of the probability field, proving QM to be utter nonsense. Imagine a guitar playing an open note. This is the state without an observer. Moving the back wall towards the slits would be like fretting a note and moving your thumb towards the bridge of the guitar, wherein you increase the FREQUENCY of the note. Adding an observer could be like muting the frequency. Physicists get confused because they SEE things in visual terms or in mathematics. But what if a physicist is a musician and HEARS a conclusion to a puzzle using music theory, that otherwise wouldn't be considered?
+Ken D. Webber Well thought of! I'm keen to attempt this experiment. I assume when you say "Adding an observer...' that you're referring to the effect of the measuring device on the pattern of light? How is the frequency muted in your guitar analogy (which I think is intuitive)?
John Batibasaga In muting on a guitar you pluck the note but your hand is resting on the strings so it cannot freely vibrate. I think an observer is like that in that it reduces the frequency, the vibration of what we call light.
The video itself is an interference pattern
I got this link from the Khan Academy. This video is as interesting as watching a turd turn into compost... in real time. No wonder why most kids hate sciences.
+fahadkelantan Actually most kids enjoy science, atleast the well educated ones, because it helps explain the ways in which the world works.
Ebere Aladi
- "Actually most kids enjoy science" no they don't.
- "atleast the well educated ones" you just negated your first statement, as mist aren't well educated. Hence my argument that this video is poor at educating. Plus "atleast" is "at least". If you came to argue, don't trip on your toes.
- "because it helps explain the ways in which the world works." so does any other subject. Grammar teaches how language and thus thinking works, history teaches how things became as they are, and even physical education forces athletes to learn sciences through practice. Man most subjects are relevant.
This video sucked. And I posted my comment more than 6 months ago. Way to go in reviving a dead thread.
+E Aladdin actually you should go fuck yourself
Just cause you ain't smart enough to understand such stuff doesn't mean the video sucks.
Besides, if you don't like science why watch this video?
Interesting experiment, terrible video.
@1.56...false.. After 7 years after Newton death .. Thomas Young came..newton died 1726..but Thomas Young born on 1773...what a fool statement without knowing these basics
+MITK12Videos
Young had a laser or flashlight in 1805? Sorry, but I very much doubt that.
However, the interesting bit of Young's experiment is the moment of the collapse of the wave function. Why did you omit that, using young's original set up?
Funny, that everybody just shows animations and NEVER the real thing, very suspicious and very unscientific. This sloppy video here casts shame on the MIT.
Are you an idiot?
Well, the title of the video is quite clearly "Thomas Young's Double Slit Experiment",
not "One Of My Experiments, That I Always Wanted To Do With Other Peoples' Money".
I say: UA-cam Heroes are GO!
The point of Thomas Young's experiment was to determine if light is a wave or a particle. That's it. In 1805 the whole topic of Quantum Theory was still almost 100 years in the future.
The question at the timie Thomas Young lived was: particle or wave, which one?
Newton had good reasons to think it was a wave. Young's experiment (in the context of knowledge of his time) showed without a doubt, that Newton was wrong. Light was a wave. And it was treated as such nearly 1 hundred years, until some doubts showed up in the form of additional experimental results and the idea was born, that there must be more to it.
That is why the experiment is called "Young's double slit". Its only purpose is to show that light behaves as a wave. Nothing more, nothing less.
Nice story but all these truth about cosmos came out only after the discovery of Vedas (5000 BC and an oral tradition before that) by the British/German looters in India in the 17th and 18th century. We all know that Pythagoras, Plato and socrates studied in India.
Hindu Vedic book Rig veda (5000 BC) clearly says that Energy and matter are Inter-convertible. It also talks about electromagnetic field
According to Advaita philosophy of Hinduism by Adi-Shankaracharya (2000 BC)
"All that you see does not exist"..which is validated by the so called double slit experiment.
West thought that earth was the center of the universe (Geocentric) until 300 to 400 yrs ago but brilliant hindu mathematician and astronomer Aryabhatta (2750 BC) was the first to say from vedas that Sun is the center of the universe (Heliocentric).
Smart people of the west sent Galileo to exile for repeating Vedas by saying that Earth rotated around the sun. LOL
Earth goes around the sun - Rg Veda 10. 22. 14. and Yajur Veda 3. 6.
Sun and whole universe are round - Yajur Veda 20. 23
Shape of Earth is like an Oblate Spheroid. (Rig VedaXXX. IV.V)
Moon is enlightened by the sun - Yajur Veda 18, 20.
‘Earth is flattened at the poles’ (Markandeya Purana 54.12)
Blue Sky is Nothing but scattered sunlight (Markandeya Purana 78.8)
There are many suns - Rg Veda 9. 114. 3.
Seven colours in the sun - Atharva Veda 7. 107. 1.
Electromagnetic field, conversion of mass and energy - Rg 10. 72.
The gravitational effect of solar system makes the earth stable (R.V.1-103-2, 1-115-4 and 5-81-2).
The axle of the earth does not get rusted and the earth continues to revolve on its axle (R.V. 1-164-29)
The Sun never sets or rises and it is the earth, which rotates (Sama-Ved 121).
The gravitational effect of solar system makes the earth stable (R.V.1-103-2, 1-115-4 and 5-81-2).
Blue Sky is Nothing but scattered sunlight (Markandeya Purana 78.8)
The science of Time and its subtle nature is described in (R.V.1-92-12 and 1-95-8)
Source: Ajith Vadakayil blog
Ppl please dont believe anything on the internet, include a random guy with infomation from a random blog.
Gia Hy Le Pham Ignorance is bliss, isnt it?
kashsoldier I am trying to verify what you posted. I find it interesting. For example "The Sun never sets or rises and it is the earth, which rotates (Sama-Ved 121)."
Sama Veda has two books- book 1 has 6 parts and book 2 has 9 parts. What does 121 mean in reference to what book and what part?
Go and verify in Vedas instead of grudging against kashsoldier. What all he has written is correct. If it appears on many videos, it will not become bullshit. Have guts, verify and then comment. I have verified myself.
India has great scientist in past but we ran towards Western culture adopting bull shits...Left the virtue of life...
This is such bullshit. The reason individual photons of light exhibit the interference pattern is because of time dilation. Photons are already traveling the speed of light, so for them time has completely stopped. Thus it doesn't matter how long the interval between each photon; as far as the photons can tell they have all been fired together.
What? That doesn't make any sense.
too complicated to understand..... plus you throw that HAIRY sinc cos@ ..... n all containing expression in ... that would TURN off ANY inquisitive person... Please make these MORE clear and LESS Complicated......