I am a PhD Student working on Molecular Dynamics and I deal with Quantum mechanics on a day to day basis, I have attended so many lectures on Quantum physics, quantum mechanics, statistical dynamics etc. But I have to tell you this mate , you explained Heisenberg's uncertainty principle better than anyone else I have heard it from. And believe me when i say this, I have heard explanation for it from at least 20 different professors, lol. Veritasium Good job mate, Keep it up
@SteveLPDNB
3 жыл бұрын
How did your PhD go? Also what UK uni were you at?
@tanmaykarde
3 жыл бұрын
@@SteveLPDNB It's been 7 years
@harishthethird
3 жыл бұрын
@@tanmaykarde oooof
@roshanthapamagar1318
3 жыл бұрын
You doc yet? ;/
@parvashah2671
3 жыл бұрын
I beg to differ. Slit experiments were supposed to show that the light has a wave nature. Here he is showing that light has a particle nature. Wth is going on?
@veritasium
10 жыл бұрын
On this day in 1927, Werner Heisenberg first proposed his famous uncertainty principle. Though the date of this discovery is known with precision, Heisenberg's whereabouts at the time remain a matter of speculation. ;) Check out my video on a counter-intuitive demonstration of the uncertainty principle. Heisenberg's Uncertainty Principle Explained
@hxhxhgfd
9 жыл бұрын
***** The short answer is that physicists don't currently know why they follow these rules. They just know that that's how the world operates.
@daviddennetiere9217
9 жыл бұрын
Veritasium Seems like a nice demonstration, but by looking at the equations, i got a 4pi factor hanging around suggestion Heisenberg is only responsible for less than 10% of the broadening... In deed, diffraction says the first zero happens for d*pi/lambda*sin(theta_z) = pi => theta_z = arcsin(lambda/d) But Heisenberg only suggest that d*h*sin(theta_z)>= h/(4*pi) => theta_z = arcsin(lambda/(d*4*pi)) (at the limit) given, the micronic width of the slit, we could linearize the arcsin which leaves Heisenberg width twelve times smaller than the width of the spot as predicted by diffraction... Don't mistake me though, I like your work ^^
@rich1051414
9 жыл бұрын
***** It's an intrinsic attribute, not a flaw in our ability to measure. Look into quantum mechanics.
@MrProgrampro
9 жыл бұрын
***** With regards to knowing precise position at the same time as velocity and vice versa: It's not "unknowable" in the sense that we think we can't know it, it's "unknowable" in the sense that there's nothing to know: a precisely-bound-in-position particle has a 'blurry', ill-defined momentum (ie. wide probability distribution function in v) and a precise-momentum particle has a blurry position. I'm not a physicist, but I have heard it has to do with the fact that each of these quantities is the fourier transform of the other. Tall, precise peaks get fourier transformed into wide, imprecise hills, and vice versa.
@MrProgrampro
9 жыл бұрын
Well that's a great question :) After all, empirical observation is the most important thing when it comes to understanding our universe. Frankly, I don't know much about this, but I'd suspect based on things like the phenomenon shown in the above video that when scientists try to restrict a particle's position, its momentum goes all over the place in a probability distribution, and similarly for restricting its momentum.
@Paguyuban_tepa_selira
5 жыл бұрын
Are you a particle or a wave? Photon: *yes*
@UjjwalKumar-wg4wu
4 жыл бұрын
I am a particle and travel in wavy direction
@PasajeroDelToro
4 жыл бұрын
It's a candlestick, like in the stockmarket. Lookup Leonard Troland. imgur.com/a/xQbuukM archive.is/0I6Rp
@nazarissa9494
3 жыл бұрын
Same for human😁
@michaelcarrasquillo4781
3 жыл бұрын
Yes but no.
@thorny8013
3 жыл бұрын
When Light reflects/refracts with a large object, it acts as particle When light reflects/refracts with objects smaller than a certain limit, it acts as a wave
@zi-tong9302
3 жыл бұрын
This was the moment when Walter White truly became a photon.
@vinayakzzz5934
2 жыл бұрын
waltuh waltuh
@Joshua-dl3ns
Жыл бұрын
Bravo Vince, he did it again
@UnkownUnkown01
Жыл бұрын
Photonberg
@nomanaziz804
8 ай бұрын
Done and dusted
@blink1747
7 жыл бұрын
The background music, the passionate energy of this guy and the instrumentation are what I believe the keys that the video is awarded with so much views. Keep the good vibes going Veritasium!
@mrlawilliamsukwarmachine4904
10 ай бұрын
It’s because of Breaking Bad!
@austinhigby2157
Жыл бұрын
I want you to know how timeless your videos are! This randomly came up in my feed since I have seen some of your videos before, and I was just as entertained and intrigued as any newer videos you’ve made!! Truly amazing thing not many can accomplish. GREAT work, and thank you for all you do!!!!!!!
@3snoW_
10 жыл бұрын
A physicist went for a drive and got stopped by a traffic cop. - "Do you know how fast you were going?" - "No, but I know where I am." xD
@EnellGmz
10 жыл бұрын
***** Watch the video again.
@elmohead
10 жыл бұрын
***** You can either determine the speed of an electron or its position, but not both.
@TosiakiS
7 жыл бұрын
Though you still need to have a bit of uncertainty in one of them, otherwise the product of the uncertainty of position and uncertainty of velocity would be 0 since anything multiplied with 0 would be 0.
@kevkasim
7 жыл бұрын
+elmohead It's not speed its momentum. The symbol for speed is v but the equation uses p wich stands for momentum.
@rubiks6
7 жыл бұрын
it's a joke that you didn't get, kevka.
@zachgilbert3815
10 жыл бұрын
I tried defying Heisenberg's principles once. ...I ended up in a barrel buried in a New Mexican desert.
@mickelodiansurname9578
7 жыл бұрын
Zach Gilbert well lucky that was in the past.. if it were a few years from now you'd need to also climb a wall to get back into the US.
@oreole9608
7 жыл бұрын
You are really lucky you didn't end up on the Moon or something.
@fandomguy8025
6 жыл бұрын
@Mickelodian Surname, He said *new mexican* as in the state "new mexico".
@badhombre4942
5 жыл бұрын
Ha, rookie mistake. You have only yourself to blame for your position and lack of momentum.
@namanpal123
5 жыл бұрын
For any one of you who didn't understand what the op meant : It was a reference to breaking bad show .
@bautistakeithcharles3302
7 жыл бұрын
I really have the most appreciation of this channel now than ever before. Showing these experiment and clearly explaining the principles behind the physical laws is awesome!
@jpheitman
11 жыл бұрын
The problem I have with this video is that it does not explain Heisenberg's uncertainty principle; it merely demenstrates it. I want a video showing WHY Heisenberg's observation is correct; what is it about the universe that makes these subatomic particles disinclined to be observed precisely in regards to position and momentum?
@jpheitman
11 жыл бұрын
God dammit, *demonstrate.
@REDSHIFTEDuk
10 жыл бұрын
Very late reply but if your still curious Brian Cox explains it very well in his book. He also proves using a few equations. The book is "our quantum universe-everything that can happen does happen"
@ivorclark2523
10 жыл бұрын
My understanding is that it is an instrumentation problem. If we use photons to observe photons they will interact with each other, changing the properties of the target photon. So use lower energy photons, but then the target becomes dimmer to observe. So use something smaller like electrons, which are even harder to see, but they still interact with photons and change their properties. Basically you cannot " observe" a target photon or electron with other photons or electrons without changing its very nature, defined in terms of where it is and how it is moving. To me this experiment illustrates simple diffraction, not the difficulty in determining a quantum particles position or momentum....
@fandomguy8025
6 жыл бұрын
@jpheitman Very very late but here you go: kzitem.info/news/bejne/rnik1IyYiH9mhmk&vl=en
@fandomguy8025
6 жыл бұрын
@Ivor Clark, hope you know better in the 4 years that have passed but if you do not. No, it's not. It's due to the wave nature of matter. kzitem.info/news/bejne/rnik1IyYiH9mhmk&vl=en
@panda-bm4de
9 жыл бұрын
02:30 - "now photons must veer of to the left or right to ensure we don't break Heisenberg's relation" well, this is not the line of thought I like. The laws of physics are not like laws of men. The particles do not behave the way they do in order not to break some law. They do behave the way they do because and the laws and equations just describe that. Derek, kindly tell us why exactly do the particles change their momentum when going through the narrow hole.
@mohammadtausifrafi8277
9 жыл бұрын
+panda4247 The photons do not do so consciously, of course, it happens as the uncertainty cannot decrease too much due to the laws of physics in our universe.
@esp1344
8 жыл бұрын
+panda4247 well that's the issue aint it. you do all these fancy experiments to answer the question why and you get this fascinating law that says that the certainty to which one can measure both the position and momentum of something cannot exceed this limit. why? well who the hell knows >.
@AntiTekk
8 жыл бұрын
EXACTLY I really missed that in this video
@Plumjelly
8 жыл бұрын
+panda4247 Photons are fined very large amounts of money, and are given community service if they don't follow physical laws properly. If we want them to behave differently we just need to change the laws, and they'll act according to the new laws, because they're such diligent and obedient citizens.
@Stijning
8 жыл бұрын
+panda4247 Well we don't really know that
@djcofficial870
2 жыл бұрын
imagine being a renound scientist, dedicating a huge amount of time to researching and developing a breakthrough principle, only to have a guy who cooks meth in an AMC tv series named after you who like ten years later gets memed on by the internet
@MK-rn1mg
2 жыл бұрын
Imagine a man watching that TV series and laughing at memes, then looking up who Heisenberg is, who Gödel is, getting hooked on physics, discussing physics and science with son at young age and that son now pursuing scientist career. Imagine - what if the character had a different name in the TV series…
@mentilly_all
Ай бұрын
@@MK-rn1mg if someone is not inspired to look into how reality works until they watch breaking bad, something is already wrong there
@IELTS_with_Anfisa
8 жыл бұрын
It's a shame the video isn't translated to more languages. I made a translation into Russian to spread your word wider =) Thanks for your work!
@jpmorgan187
5 жыл бұрын
Everyone should learn English
@erezsolomon3838
3 жыл бұрын
@@jpmorgan187 but don't count on it
@shannonmoraes6282
3 жыл бұрын
@@jpmorgan187 nope
@COVID--kf3tx
3 жыл бұрын
@@jpmorgan187 They really shouldn't. Science has no language
@nostalji93
3 жыл бұрын
@@COVID--kf3tx id argue it does. Actually all languages "serve" science, since they are tools to express our thinking. We are limited by their limitations. The most useful language for science would be math. I consider math a language wich is designed for science.
@hughjasse4047
9 жыл бұрын
this explains why people who wear tighter and tighter pants tend to look fatter
@cyberschn1tzel997
9 жыл бұрын
Verirektium
@f00zh
8 жыл бұрын
+Hugh Jass good answer , hugh jASS
@faxrialiyev3711
8 жыл бұрын
+Hugh Jass genius!
@jas672
8 жыл бұрын
Brilliant! 😂
@emp3202
8 жыл бұрын
hahahaa
@MrNathanParrott
7 жыл бұрын
Hey Derek, love you work. Fellow aussie engineer/backyard physicist here. Wait a minute, there are some things that don't make sense here: 1) If the light is effectively bending outwards (similar to what happens in dispersion) what is going on here, what causes the light to bend and change direction? In dispersion, it is that different wavelengths have different apparent speed in the glass prism and thus refract at greater degrees, what is causing it to happen here? 2) Do the photons change direction because classically (p=mv) relativistic mass of light cannot change? only the velocity made up of c and direction can. Since everything else is constant, only the direction can change? 3) But the momentum of light according to de-broglies relation (p=h/λ) for p to increase the wavelength must be decreasing (i.e frequency increases). Is this occurring? If we were to put a detector on the other sided of the slit would we notice higher frequency photons being emitted? 4)When I created my own single and double slit experiments I always thought this was occurring due to diffraction as the light bent around the edges of the slit?
@vladnovetschi
8 жыл бұрын
jesse we have to cook
@medhawinikapoor4735
7 жыл бұрын
ok
@lightnox8388
3 жыл бұрын
@Dinesh Pandey valar morghulis
@justsomeguy892
3 жыл бұрын
jesse were is the cocainer
@abhikchakraborty5616
3 жыл бұрын
OP... . Only breaking bad fans can get this....!! 🤣🤣🤣🤣🔥🔥🔥🔥
@malavpatel1135
3 жыл бұрын
Methamphetamine
@1SoulonFire
7 жыл бұрын
Great stuff! I spent all evening looking for some good resources to show students on this, and this is by far and away the best thing I have found.
@mahdibakkar7446
4 жыл бұрын
Amazing experience Sir . When we reach the limit where delta x decreases delta p needs to increase to be always greater or equal to h bar divided by 2 . h bar equals plank's constant divided by 2 Pi . This principle is really important . Not only it is important in physics but it expanded to many other domains .
@yashpalsaraswat
4 жыл бұрын
kzitem.info/news/bejne/2WqQmnecemdqoHo
@ricardomiranda7737
7 жыл бұрын
Honestly, I thought that the Heisenberg uncertainty principle had to do with not knowing if the batch was going to produce 99.98 or 99.99 percent purity....
@horsenuggets1018
4 жыл бұрын
I thought it was about the speed and position of a fly
@tiko4621
4 жыл бұрын
shut up, SHUT UP SHUT UP SHUT UP SHUT UP
@bladenmartin
7 жыл бұрын
Isn't this just an example of single slit diffraction ??
@MikeSmith-vb8ul
4 жыл бұрын
Veritasium's videos are sometimes incomplete. Of course there is diffraction, and the smaller the slit and less photons we have coming through the more obvious the diffraction patterns appear
@khayyamaurelius912
3 жыл бұрын
Yes, but if you think about it, the uncertainity principle is a natural consequence of the wave particle duality. If you tried this with electrons, you would get a similiar result because of that.
@suediem9315
3 жыл бұрын
It absolutely is. Somebody need a principle, that's all.
@alextroll3400
3 жыл бұрын
@@MikeSmith-vb8ul It‘s not incomplete. He explains at the end of the video that this phenomena was caused by diffraction.
@MikeSmith-vb8ul
3 жыл бұрын
@@alextroll3400 No -- for full completeness, he would also talk about diffraction more fully and explain all the properties and understanding behind what diffraction is. Obviously, not just only merely slapping a "oh this also could've just been just...'diffraction'. Alright now this video is over!!"
@Am_Photography13709
7 ай бұрын
I cant believe 11 years are over since this video was published, time just flew
@GlorifiedTruth
10 жыл бұрын
I have always struggled with the uncertainty principle, and this is the most awesome thing I've ever seen.
@shinji906
5 жыл бұрын
Hi, doesn't the image actually gets wider because of the diffraction ? Because we did a very similar experience in science class by calculating the wavelength of the laser using the length of the image on the wall and some formulas... But our teacher says it has nothing to do with Heisenberg uncertainty principle and only illustrates the diffraction of light. We used 160nm wide holes and green lasers with a wavelength of 532nm
@kripashankarshukla4073
7 жыл бұрын
Light behave like both particles and waves that is why widening of the beam is caused by both diffraction and uncertainty in momentum. Diffraction because light behaves as wave and uncertainty in momentum because light is a particle.
@aaronsmith6632
5 жыл бұрын
Yes exactly, they are just two different perspectives which result in the same conclusion.
@TheBreakbattle
10 жыл бұрын
Wow! I'm studying quantum mechanics at the moment, and this video made Heisenberg's uncertainty principle a lot more understandable.
@Name-ps9fx
2 жыл бұрын
Fascinating that with a simple mechanical device one can alter quantum probabilities...I would not expect that! Thanks for showing it!
@Drteslacoiler
5 ай бұрын
HANDS DOWN THIS IS THE BEST EXPLANATION VIDEO FROM VERITASIUM SO FAR! BRAVO!
@ordeloliveros5999
9 жыл бұрын
Say my uncertainty principle. You're goddamned right.
@abkh9039
9 жыл бұрын
This is also known as the diffraction of light (that proves the wave caracter of light). The lenght of the spot is equal to the wavelenght multiplie by the distance between the slit and the screen divided by the size of the slit. If the slit goes narrower, the lenght of the spot goes wider ! :)
@abdelrahmangamalmahdy
8 жыл бұрын
if you do it mathematically, you'd find it's not about uncertainty, it really is diffraction.
@lochvids108
8 жыл бұрын
Truth Seeker exactly. its just more 20th century mumbo jumbo. What the fk were the scientists on at this time? was einstein to good for us dod we need some wackos to turn science back to the controlling arms of the churches !
@abdelrahmangamalmahdy
8 жыл бұрын
Light as an EM wave is supposed to be diffracted when the slit size reaches the wavelength of the wave. I(theta) = I(0).sinc^2[bi.d/lamda.sin(theta)] where I(theta) is the intensity of light for a given angle. It is called "single slit diffraction".
@ChrisJaesun
8 жыл бұрын
He mentions that at the very end of the video (3:24)
@abdelrahmangamalmahdy
8 жыл бұрын
oh yeah, thanks for the hint.. I didn't watch the end of the video
@abdelrahmangamalmahdy
8 жыл бұрын
Vinay N.K did you model light as a wave ?
@flyingllama87
5 жыл бұрын
Isn't this just the diffraction you get when you send light through a small aperture? Also, how does changing the momentum result in the widening light projection if the light is from a laser (therefore straight)? I thought an increased uncertainty in position would result in this pattern. Please help me understand.
@dhichicpop2531
2 жыл бұрын
Basically momentum is a vector quantity = mv. Here the mass of the photons cannot change. Their speed in a medium( air) also cannot change. So the only thing that can change such that momentum changes is the direction of the vector
@TylerUchiha
2 жыл бұрын
You're correct, it is the same diffraction you get from placing a laser beam through a small aperture. When the beam of light spreads due to diffraction, it loses coherence - it becomes less focused. The aperture would be the distance between the two slits - this distance is what influences the uncertainty of the position of the photons. The smaller the aperture, the less uncertainty we'd have in knowing the position of the photons because the light beam has to fit into a smaller slit. This is where it becomes very unintuitive. The calculation you saw in the video, (deltaX)(deltaP) >/= h/u X Pi is the uncertainty relation - it's compendiously a constant of the universe in a mathematical expression, think of it like balancing colours of paint to produce a certain colour. You may have to decrease the intensity of one colour to make another colour more apparent. Also, changing the momentum results in a wider and more diffracted light beam because the momentum is tied to the direction of the light beam photons. Momentum is a vector quantity - it has direction and magnitude. The momentum would change and in turn the direction, so as to balance Heisenberg's uncertainty relation. Don't forget that the uncertainty/focus of the momentum increases when the uncertainty of the position decreases. The shape of the light on the walls is related more to the momentum as the momentum determines the destination of the light beam, remember what I mentioned about direction.
@GR8119
10 жыл бұрын
Say my name... "You're Heisenberg..." YOU'RE GODDAMNED RIGHT.
@seraphthrone
7 жыл бұрын
Is the following understanding correct? Momentum is a characteristic that is more like an event whereas, position is a characteristic that is more like an object. For example, take the sentence "a truck is going from Los Angeles to New York over a period of a week", if we consider the sentence's main focus as "going from Los Angeles to New York over a period of a week", it has well defined direction and speed. But if we consider the sentence's main focus as "a truck", it has a well defined location. As we shift our focus more from where truck is going towards where the truck is located, we begin to lose the overall direction and speed accuracy. The truck driver might stop to go to the restroom in the middle of his trip, and we observe the truck has zero speed and no direction at that particular moment, even he's still on his week long trip to New York. And as we shift our focus more from where the truck is located at towards where the truck is going, we begin to lose the overall location accuracy. For example, when we say the truck is on its way out of Utah on the 2nd day, we are not really sure where exactly it is at. And of course if we say it's on its way to New York, it's even more vague. And the uncertainty between these two, is the difference between how we define a particle and a wave. The more we describe an item as a particle, the less it looks like a wave, and the more we describe an item as a wave, the less it looks like a particle.
@ianturley502
Жыл бұрын
By my guesses and partially calculated thoughts,. I believe the hiesenburg uncertainty principle can be directly related and compared to many things in life, for example, human thoughts on a given situation.. or the amount of traffic at a given junction when driving at a certain time of day, the estimated amount of fish in a river and countless other situations and circumstances.. I consider it to be a basic fact of life now.. along with the law of un-intended consequences..
@watamatafoyu
Жыл бұрын
Macro objects don't work that way.
@yashkesari
10 жыл бұрын
If people accepted Heisenberg uncertainty principle based on this experiment, then people were/are weird. Let me explain, before making the slit narrower, a lot of photons were going straight but a lot of them were already going to the right and left.But this was not very clear initially. Now when the slit was made narrower and narrower, the photons which were going to the right and left started bouncing of the sides of the slit and changed their momentum and started moving to the center. This increased the brightness at the center . This is why we see many more bright lines and spots appearing at the center when the slit was narrowing down. When the slit was even more narrowed down ,less number of photons passed through the slit and so the brightness decreased.Also , the photons that are now capable of passing through the slit had more chances of hitting the sides of the slit because the slits were very close enough. So now more photons were hitting the sides and changing their momentum , almost 90% of them. So they were spreading out more and so the brightness at the center decreases more and more. Of course the bouncing to such a degree that the particles bouncing from the left side are interacting with the particles bouncing from the right side and creating crest and troughs pretty far away from the center. Its particle physics ..not an uncertainty principle. Stupid for all the people who can't think in the right way and believe everything blindly.
@NickPershyn
10 жыл бұрын
Wow, man. You are actually really really wrong. Let me explain why: 1) The same thing happens when "sides" are sharp, and there just no place for photons to bounce. 2) The material of the slit could be black, so photons just get absorbed instead of bouncing. 3) How would you explain experiments with black disk that creates white spot behind it? You can't! 4) What do you think happens whet you reflect a laser beam from diffraction grating? Just go and check you yourself!!! 5) What pattern would monochromatic light create if it goes through a long waveguide? Make a prediction and see for yourself what happens in OUR world! Do you really think your primitive hypothesizes haven't been checked and disproved already??? You'd better checked yourself before calling someone stupid! Current physics theory not only explains everything ordinary human can encounter, it is also so simple and easy that even you can understand it if you want to. P.S. I as a physicist have rechecked every single thing while was studying, trust me, the current theory we have IS the most logical, simple and intuitive explanation! There were so much different experiments with different quantities, materials, shapes, details, so I am pretty sure I can name an experiment that can prove you wrong in any way, if your theory is simpler that quantum mechanics. Did you heard about tunneling effect? How would you think reflectionless surfaces work? With this primitive concept of bouncing photon particles so many things in this world shouldn't work, so I can't even imagine how in this universe you could come up with such an absurd idea...
@yashkesari
10 жыл бұрын
Nick Pershyn 1) No matter how sharp the sides are , photon are just too small and for them the sides will mostly remain big enough. 2) Who says that all the photons are absorbed by black color. Light can only be absorbed completely in a black hole, not in a black sheet , or anything which is painted black or any material which is black. 3) Same reason as above. 4)I will check and come back 5) I will check and come back. And yes I am talking about OUR world.....where all black colors are not black holes.
@yashkesari
10 жыл бұрын
Nick Pershyn Try this experiment.Take a glass of water and keep a board on the floor with a narrow slit in it.Then slowly throw the water towards the slit. The water will come out from the other side and spread itself. It will not move in a narrow straight line after coming out from the other side. Also, if the same experiment is done with a tunnel the same result will be seen... and water is seriously a group of particle , not wave... light behaves in the same way.
@iNotFound
10 жыл бұрын
yash kesari water is not the same as electromagnetic waves.
@yashkesari
10 жыл бұрын
Heisenberg's uncertainty Principle is applicable to both particles and waves.
@Galileosays
2 ай бұрын
The interference pattern is only visible with coherent light (laser). Since photons do not know Heidenberg's relation, the path change must have a physical cause. So what is happening in the slit ? As soon as the slit narrows to the nm range, the electrons at the left and right side start to repel and create a fluctuating EM-field. This weak field deflects the photon. The narrower the slit, the more electrons start to 'see' electrons at the other side of the gap, this strengthens the fluctuating field in the gap, and thereby the photons will be deflected wider. It might be interesting to find out, whether this field is material related. Is there a difference between the transition metals? Or between carbon, silicon and metals? Is the interference width related to the material, i.e. electrons in the outer shell?
@lifeofphyraprun7601
5 жыл бұрын
I love the way how u represent light quanta as packets of grouped waves.Like in 2:04.Its actually how they are.
@moncef2466
7 жыл бұрын
"I've gotta say a big thank you to professor Walter...White"
@MrigankaRoy
Жыл бұрын
this is by far the most practical way to convey the concept
@sigmabond1289
7 жыл бұрын
this experiment seems so perfect and easy but I'm afraid every other person on this planet would have been a physicist if physics and nature were that simple...... what I mean is...nature doesn't work the way it does to NOT break OUR laws...instead we make laws to describe nature's nature! so what you said wasn't convincing enough.... I really like your videos and expect the RIGHT explanation for this so very complicated phenomenon soon....thnx! :)
@mansonjoselito
9 жыл бұрын
"It's the way the world works" Best line ever.
@rampalsingla2862
7 жыл бұрын
Sir I want to know is Hiesenberg's uncertainty principle valid for stationary electron. As taught by teachers to me that Hiesenberg's uncertainty principle is not valid for stationary objects. But if we think of the principle it is valid for microscopic particles and it is due to fact that we don't have length measuring device whose least count is less than that of microscopic particles and also to determine the position we need watch it using a microscope and a light beam will fall on it exciting it and thus changing its momentum. Now if electron is stationary then to determine its position we watch it with microscope a light beam falls on it this it's momentum changes. So Hiesenberg's uncertainty principle is valid.
@HarshRajAlwaysfree
5 жыл бұрын
I am so glad i clicked on the video , i never thought of diffraction in this manner
@ajayrawat3262
7 жыл бұрын
hey Dr. Muller, I'm working on a project o Quantum Physics? i have one question. How can we find the width of slit (uncertainty in x) when uncertainty in momentum increses?
@mfundomabona70
Жыл бұрын
Answering your question on the demonstration, that is incredible bro!🙌
@gauravkar4805
7 жыл бұрын
It's a single slit experiment much like youngs double slit experiment. All you need is a coherent beam of light which is Laser.
@MinecraftxFan1995
10 жыл бұрын
What's the *cause* of the principle, though? That's something I really wanna know...
@adamwilkinson4264
10 жыл бұрын
There is no cause. It's simply how the world works, in the same way that gravity pulls you down, and electrons are negatively charged
@MinecraftxFan1995
10 жыл бұрын
Adam Wilkinson I'm sorry... Forgive me or feeling that's not good enough. Cause and Effect is a big part of science. Why should some principles get exceptions just because we can't explain them yet?
@adamwilkinson4264
10 жыл бұрын
something Because the Uncertainty principle IS the cause
@MinecraftxFan1995
10 жыл бұрын
the Heisenberg uncertainty principle is the cause of the Heisenberg uncertainty principle. Is that what you're saying?
@adamwilkinson4264
10 жыл бұрын
something Kind of, I'm saying that it simply is one of the fundamental things that makes the universe work, it doesn't have a cause, in the same way that magnetic forces/attractions have no real cause when you get down to it, and as well as why you can't walk through walls.
@PhilMoskowitz
2 жыл бұрын
This isn't the same as the double slit experiment. What's happening here is that when the photon is made up of various frequencies it has a well define position (particle behavior). As you narrow the slit you mask off the longer wavelengths. This has two immediate effects. One the photon is less defined in position and two, it's momentum is more defined and the photon acts like a wave. At that point it's just wave diffraction at the slit.
@TomHendricksMusea
8 жыл бұрын
The Heisenberg Uncertainty principle says we can't know both the position and the momentum of a quantum particle. My question is this, if you know that a photon is going the speed of light, the momentum, then does that mean you can never know the position of the photon?
@erikdk321
8 жыл бұрын
No, you can't know what direction a particle is going, you can know the momentum.
@TomHendricksMusea
8 жыл бұрын
Strange, so when it comes to photons, we don't know anything about direction - even in the two slit experiment. How do we know they are going through the slit instead of around it or coming from behind?
@erikdk321
8 жыл бұрын
Tom Hendricks We know they are going through the slit because we can see it and because there would be no reason for them to just suddenly go in another direction, until they passed the slit.
@TomHendricksMusea
8 жыл бұрын
But they are outside of time, so they have forever to get back there. That seems logical, and mine seems silly, but they both fit the facts. And when you see, you change the outcome too don't you?
@erikdk321
8 жыл бұрын
Tom Hendricks wut?
@wxh2018
8 жыл бұрын
hi what is the difference between this and diffraction. are they both the same?
@SkizzlePiano
8 жыл бұрын
the uncertainty principle causes diffraction, it also applies to other things tho
@wxh2018
8 жыл бұрын
SkizzlePiano oh i see thank you
@mikaeljensen4399
7 жыл бұрын
In no way does the uncertainty principle cause diffraction. Diffraction is a wave behaviour. Uncertainty is just uncertainty and in quantum mechanics it is about the failure of operator to commute; or more precisely about the fact that no quantum mechanical state can have shared eigenstates (of definite value for some operator) for two operators which do not commute. So the lower limit of the uncertainty is proportional to the expectation value of the commutator.
@fandomguy8025
6 жыл бұрын
Mikael Jensen, No it's that particles have wave behavior. And it's simply due to Fourier transforming a matter wave.
@KarthikKBDevadiga
4 жыл бұрын
∆x is change in position ∆p is change in momentum So if you limit the change in position. Momentum would change right? But why you suggesting the change in angle to form diffraction? Momentum is mass times velocity. So mass stays same so velocity increases. But in same direction forming no diffraction. According to me uncertainty principle suggest that. At a given time either we can know the position or momentum at one time. We can not know both at same time. This experiment is single split experiment. Anyone PLEASE explain. I'm lost here.
@MatheusLB2009
8 жыл бұрын
Where are the Breaking Bad jokes?
@nischay4719
7 жыл бұрын
terrysarmy2695 but i am watching this as a infotainment :p
@mickelodiansurname9578
7 жыл бұрын
terrysarmy2695 ahh... its 5 months later now... so did you get a pass?
@rentacowisgoogle
7 жыл бұрын
Cop: "Sir, I pulled you over for speeding. Do you know how fast you were going?" Citizen: "No officer, but I do know exactly where I am."
@sc-ek6qz
7 жыл бұрын
Walks in front of cop car with hands together like a monk and walks on by... ..
@jay-tbl
6 жыл бұрын
You stole this from top comment lol
@AmmoBops
5 жыл бұрын
rentacow this joke makes no sense Or maybe I don’t obtain the knowledge to Find the humor in this puzzle
@officialspock
5 жыл бұрын
@@AmmoBops same, lmk when you get this joke
@AmmoBops
5 жыл бұрын
spock still don’t get the joke 😂 it’s all good tho
@parthsarathidixit5648
3 жыл бұрын
This phenomena is actually Diffraction which is explained on the basis of wave nature of light and not particle nature. But this guy gave a whole new aspect to thinking about it . Good !!!
@finlaymcewan
8 жыл бұрын
I came here to find breaking bad jokes and was not disappointed
@gamerN77
9 жыл бұрын
When you stop down your apature on your DSLR (f.ex) to something like f/22, you'll get less sharp images because of "diffraction" (as photography-tutorials always say). But is this also because of Heisenberg's uncertainty principle?
@amanganeju7904
6 жыл бұрын
No, it isnot. increasing the f value rather increses the sharpness.
@JimCullen
6 жыл бұрын
Increasing the f value doesn't increase "sharpness", it increases depth of field, which means a larger portion of the photo is in focus. But what +overTIMe is talking about is something different. When you stop down really far you start to get diffraction which can reduce the sharpness of your image somewhat. The effect is fairly minor though, and even at extreme crops it can be difficult to notice.
@lolPantsProductions
7 жыл бұрын
So reducing the gap the photons can pass through enables us to know where they are, which in turn causes their momentum to go up? And momentum is mass X velocity so either of these needs to increase? Which is it? And why does the light spread out?
@Daiin0
10 жыл бұрын
You're Goddamn Right!
@mattrex8
10 жыл бұрын
I thought we were going to see how to cook meth.
@ManyThings26
10 жыл бұрын
that's quite the same thing to physicians !
@Tesla_Death_Ray
10 жыл бұрын
David Lecaille You mean physicists, but should have said chemists
@makaimesa3893
10 жыл бұрын
why.
@Tesla_Death_Ray
10 жыл бұрын
Makai Mesa Heisenberg is the alias of a character on a popular tv show about methamphetamine production
@NickPershyn
10 жыл бұрын
butterflycaught900 And he was teaching chemistry.
@cptblueblitz
3 ай бұрын
Hello ! I'm still not convinced about your video ! I'm not "surprised" to see the wider spectrum light because I can explain myself the spread due to the interference we are adding trough the filter. The object used in our case is metallic which produce reflection To our view the filter is perfectly square, in reality it has rounded angles which are able to spread light. So as light would hit the angles and is cut-off, i can imagine fragments being redirected on the opposites parts of the "filter", bouncing off until it reaches the out-opening. I'm kind of challenging you there ; I wonder what would happen with a filter composed of absorbing light or one that could prove it's non-interference with the light as it passes trough it ; (doing what we think it do) - especially for very small interaction ; i feel like a small filter width (not the gape but the the tube size trough which light passes trough) would still be able to make significant changes ; Now i'm not a photon-scientist / engineer and i'm writing this trying to "playing the scientific game" without much more knowledge of the actual realities. Very fond of your videos and I hope to see more ! I could guess that there are some papers that have already worked on this idea with much more sophisticated filters ?
@RodrigoIdiomas
4 жыл бұрын
Good video!
@Drowzye
8 жыл бұрын
Not really an 'explanation', an explanation would be telling us why this is the case, you've only told us that this is the case with reference to an equation which is the result of observing this phenomenon.
@garfieldthomas8118
8 жыл бұрын
+Dan Rowe That is the state of physics as we know it. Many members of QM have even said that they do not fully understand it...no explanations why.
@valeriobertoncello1809
8 жыл бұрын
Consider this experiment as pushing a baloon under water and observe how both the part above and under water grow when the other gets smaller and vice-versa. There's no magic going on neither you think of asking why it happens, because the question wouldn't make sense.
@valeriobertoncello1809
8 жыл бұрын
*narrowing the slit is li ke pushing the baloon down
@Phabiussss
8 жыл бұрын
Heisenberg's relation is not empirical: it can be derived without too much difficulty once you know some Fourier analysis, but that would require a much longer video :) I think the point was to explain what it is, rather than why it is.
@mickelodiansurname9578
7 жыл бұрын
Dan Rowe the equation is predictive... it works before you set up any test... and no math is a result of observation... but I'd be amazed if you could show us how to make that work... it'd save a lot if time.
@ascobal
5 жыл бұрын
so youre telling me that i just watched a 20 minute video and didnt understand a word, and i find this 2 minute explanation and now i completely understand the concept. veritasium is the best!
@earthuser4245
8 жыл бұрын
So Heisenberg is driving one evening and he gets pulled over by a policeman. The policeman says 'Do you know how fast you were going?' Heisenberg says 'No, but I know where I am.'
@vibodhj349
6 жыл бұрын
So Heisenberg was driving a vehicle..., Yeah, Yeah I know the joke.
@taewookim6368
3 жыл бұрын
this dude does not explain the reason
@Д.Түвшинбаяр
2 ай бұрын
Why do universe need maximum cosmic speed limit (speed of light/causality)? Why it has to be finite speed? Why is that mass and energy related to each other? Why matter is not infinitely divisible? 🤔
@lok1506
2 ай бұрын
@@Д.Түвшинбаяр Regarding instantaneous speed..... check out quantum entanglement and quantum eraser topics
@gueduo
Ай бұрын
Yeah he don't, Imma look another video for that, cool explanation though
@shrirangbondale2263
Ай бұрын
It's because we can't explain reason....
@mentilly_all
Ай бұрын
👏 thank you
@KingJAB_
Жыл бұрын
Thank you so much for making an accurate description of the effect, i hate it when well known channels confuse it with the observer effect
@SuperZarrabal
11 жыл бұрын
Yes, but..., how do i make meth?
@jlann8243
8 жыл бұрын
So basically it's like water through a hose the smaller the hole the more it's sprays/mists because it's being forced through a smaller space.
@lochvids108
8 жыл бұрын
J Lann exactly.
@wildedibleplantsofthemedit8676
6 жыл бұрын
Nothing like that :p
@vibodhj349
6 жыл бұрын
I was thinking about this same analogy. But then, how can it relate to the uncertainty principle in which the h value is very small 1 divided by 1 followed by 34 zeros?
@ViliamF.
2 жыл бұрын
0:50 That's just the light rejecting the oppression, while the song "We're Not Gonna Take It" silently plays.
@alkreddy9285
10 жыл бұрын
this may be explained through diffraction also
@pathikghugare
4 жыл бұрын
??
@nauka7565
4 жыл бұрын
Yeah
@khayyamaurelius912
3 жыл бұрын
Because it IS diffraction. This happens because particles have a wave-particle duality. When the slit becomes smaller than the particle's wavelength, you decrease the uncertainity in position, but the uncertainity in momentum goes up.
@yamansanghavi
8 жыл бұрын
yeah it was an excellent explanation but wait.... photons are not conscious , it seems like they saw the decreasing slit width and they discussed among themselves that yes now its time to split....
@hridaykulshrestha5833
6 жыл бұрын
Yaman Sanghavi that's where the wave nature of light comes into play sir. A strong suggestion from my side would be to watch a good video regarding single slit diffraction. You'll enjoy this video much more. Cheers!
@robertrogers7938
7 жыл бұрын
I love this demonstration and explanation. What it never answers is WHY this must be so? The math clearly explains how this occurs and helps make a lot of predictions. I just really want to dive into the WHY of the matter. Why must the momentum change when the change in x approaches 0? I understand that it must change to make the equation work but WHY must the equation be this? Why does nature force this to occur?
@metadragon7500
5 жыл бұрын
Scientist: Do you understand? Me: Well yes, but actually no
@watamatafoyu
Жыл бұрын
This didn't explain why the uncertainties exist.
@manjurana297
3 ай бұрын
Uncertainty exists,becuz everything in our universe have properties of both wave,and particle. Simplest explanation.
@effectingcause5484
Жыл бұрын
0:36 Please explain the physics of what the light is doing in this pattern?? Also moments later, I begin to notice the blob breaks up into a bright spot center, then after some shade, a crescent shape on the left and right sides, almost appearing to be an interference pattern! Why would this happen with only one slit??? Then at 0:58, take notice that the light begins to smear into a stepped pattern on the left and right sides of the blob. Also notice moments later, the stepped pattern grows across the blob to form horizontally oriented fringes. Why are there horizontally orientation fringes in the blob even though the source is a vertical slit? Why are all these things I mention be happening?
@TheAdriyaman
9 жыл бұрын
WATCH THE WHOLE DAMN VIDEO BEFORE YOU COMMENT THAT IT IS DIFFRACTION.
@issanesheiwat1396
8 жыл бұрын
Isnt this just diffraction?
@valeriobertoncello1809
8 жыл бұрын
No, diffraction decomposes white light into Its components.
@Phabiussss
8 жыл бұрын
Actually the decomposition of white light into colors is due to refraction being different for the different colors, something completely different from diffraction. Diffraction is very closely related to Heinsenberg's uncertainty principle, but it also adds the concept of interference.
@junichik762
5 жыл бұрын
I have a weird doubt but at the same time interesting(If you got those crazy minds please feel free to answer). Consider the electrons. To make calculations easy let's assume it's mass to be 1e-30.Multiply it with the speed of light (say 1e+8) and you get it's momentum : 1e-22. Now, let's assume 4*pi to be 10. So, dividing plancks's constant by 4*pi would give 1e-35 . Since the product of deltaX and deltaP should give a value greater than 1e-35, so let's put the value at 1e-34(planck's constant itself (somewhat)). Now since the momentum is 1e-22 and the required value is 1e-34, so deltaX must be somewhere around 1e-12m. This is a very small length(smaller than the radius of a hydrogen atom) But the slit can be seen way tooooooo bigger for this. So, how could the splitting of the laser beam start at such a 'huge' length?
@ShashankRaghunath93
9 жыл бұрын
you are merely showing diffraction of light.. what has uncertainty principle got to do with it?
@swng314
9 жыл бұрын
shashank raghunath It's more than just light. Any particle small enough to be noticeably influenced by this will be. We see this same effect when firing alpha particles as well. So I guess this means all small particles travel in waves?
@ptyamin6976
9 жыл бұрын
+Steven Wang that's the conclusion debroigle reached: what if all particles have a wavelegth, because symmetry. it's a really beautiful conclusion in my opinion
@PeterWalkerHP16c
9 жыл бұрын
+shashank raghunath The is *no* change in medium (eg: air to glass prism) to cause refraction. Also refraction moves the refracted frequency in one direction. The result here was in *both* directions.
@Kaepsele337
9 жыл бұрын
+shashank raghunath The diffraction of light is a special case of the uncertainty principle. You can explain the effect purely classical, but it's a good example where we see that the HUP isn't violated. It's the same as if I'd make a video how milk diffuses in coffee and say it's a demonstration of the second law of thermodynamics, and you'd comment "you are merely showing random motion of molecules in liquid ... what has entropy got to do with it?"
@chrisallen9509
9 жыл бұрын
Say my name
@saransh85
4 жыл бұрын
Exactly at the start of video I was thinking that why doesn't he take account of diffraction.Thanks for clarifying at the end
@Aldurnamiyanrandvora
9 жыл бұрын
it's like a conservation of probability...
@mickelodiansurname9578
7 жыл бұрын
Aldurnamiyanrandvora that's a pretty good analogy... and if we looked on probability as a property of the universe, a thing, then its valid... but is probability a property of the universe?... or would it work in all conceivable universes everywhere... ? how would you determine this? nit knocking your analogy... just asking.
@Aldurnamiyanrandvora
7 жыл бұрын
No idea. It was more me trying to wrap my head around it. I'm an English major and so this is a very foreign field for me. If I were to try and defend my analogy, I would guess that probability is a very fundamental part of this universe. I don't have the knowledge to think about other universes though.
@plysmeister
11 жыл бұрын
i came here to learn to cook blue meth damn it
@loukasvenetikidis2267
Жыл бұрын
As a non physicists , observing the mark becoming wider I'm thinking maybe it's caused due to the light bouncing ( I don't know if refracting is the right word here ) from the edges of the slit towards different directions other than straight ahead , is this logic wrong ?
@Talazorn
10 жыл бұрын
Heizenberg's uncertainy principle is stupid and wrong. If i almost close my eyes I don't have a wider plane of vision. (just kidding)
@yashkesari
10 жыл бұрын
i think u have a point
@yashkesari
10 жыл бұрын
Try one experiment. close one eye and look at your laptop screen with the other eye. Now slowly close this eye as well.. What do you observe... when are eyes are quenched , the light coming from the laptop screen expands in the top and bottom direction. Do this in a dark room...I guess Heisenberg works here as well
@baresto3753
2 жыл бұрын
BREAKING BAD REFRENCE IN KZitemR
@ashwinmandan5
2 жыл бұрын
Derek, I don't think a photon cares about a stupid equation, all ithink is that instead of relying on a simple equation, we can prove this by saying that the diffraction phenomenon becomes more significant at the smaller levels, as the light passes closer to the slit's limits at the atomislc levels, the light diffracts more, that's it
@Slarti
9 жыл бұрын
I came here hoping to find out how to make meth and all I get is a physics video!
@yannidamianos443
5 жыл бұрын
Wrong example. Nothing to do with Heisenberg's uncertainty principle. All we see is the wave function coming into being. No momentum uncertainty..
@paradoya1706
2 жыл бұрын
Wait, is this a breaking bad reference?
@anteconfig5391
7 жыл бұрын
I was thinking that it looks like some of the light is reflecting off of the edges making it look spread out, but the spot it the middle actually gets thinner as well :48 so reflection by itself doesn't make sense. So the light is traveling perpendicular to the slit, lets call that x. And the blackboard and the slit are parallel to each other lets say they're aligned on the z axis. At first the light hits the blackboard making a circle. So the light is equally distant from the center of the circle on the y axis and z axis. As soon as he narrows the slit, which is only narrowing along the z axis, the light expands along the z axis and shortens along the y axis. That wouldn't make sense if it was a mere reflection off the edge of the slit. It must therefore mean that light interacts with itself and does so as a wave.
@pykapuka
10 жыл бұрын
sorry but i wouldnt call that an explanation... (that doesnt mean i dont like the video)
@ivelsoup
5 жыл бұрын
I hate Veritasium. His videos are usually pompous and uninformative. I feel like he just wants to show off because I never get anything, really, out of his videos. I know, unpopular opinion, but that's how I feel.
@ozymandias3617
5 жыл бұрын
Heisenberg *"you're goddamn right"*, especially if you are looking for the essence of the problem
@ivelsoup
5 жыл бұрын
@@ozymandias3617 Are you agreeing with me? Is this some kind of a joke? I don't get it, sorry...
@ozymandias3617
5 жыл бұрын
@@ivelsoup Fully agree with you
@alexandertownsend3291
4 жыл бұрын
I see your point. Quantum mechanic is a difficult subject. I will not pretend that I understand it beyond the most basic of basics. In general though if you are trying to learn a concept you are better off reading it from a well known published paper or some sort of academic text like a journal or textbook. The information is more likely to be accurate and less likely to include unnecessary metaphors and oversimplifications.
@Maduar95
10 жыл бұрын
i only clicked because of breaking bad lol
@James-fe7wd
9 жыл бұрын
Well now you know the premise of quantum physics. Nerd.
@Maduar95
9 жыл бұрын
ok?
@James-fe7wd
9 жыл бұрын
It was a light hearted joke ;)
@redcoat4348
8 жыл бұрын
Wendover?
@tamircohen1512
8 жыл бұрын
lol yep
@gregturkington6330
8 жыл бұрын
yes still didnt get it
@Votrae
5 жыл бұрын
I really enjoyed the polite discourse at the end! Well done and well presented throughout. Cheers
@phantom21ize
5 ай бұрын
I am a physicist specializing in optics. The problem with the Heisenberg Uncertainty Principle is that it is so robust that it can be used improperly and you'll still get a good qualitative/quantitative estimate for a phenomena. The effect he's showing is the single-slit experiment which has to do with interference effects of the wavefront of the light. The Uncertainty Principle basically says that a wavepacket constructed using Fourier optics has some intrinsic width, dx, with some distribution of wavevectors with an estimated FWHM of dp. As dx goes to infinity, you have no knowledge of when the wave started or where, but you do know its wavevector with absolute certainty. As dx gets smaller and smaller, the FWHM of the wavectors that construct it gets broader and broader based purely on how Fourier transform properties work. The absolute limit of how sharp you can get dp for a given dx is given by \hbar/2. Interestingly, creation and annihilation operators in quantum mechanics are constructed using this principle. The combination of creation and annihilation operators are responsible for the addition or subtraction of quanta of energy from waves. This is where we get the "particle" nature of light from. So, in reality, the particle nature of light is a direct manifestation of the wave properties of light. It seems a bit paradoxical until you consider that all beams of light must be finite and you need to consider what happens at the boundaries of the beam.
@joshuascorca550
Жыл бұрын
I have a question. The momentum becomes less certain as the position becomes more certain. Can we simplify this since the experiment uses light? Momentum is Mass*Velocity...but light doesn't have mass, so is it ok to just use velocity? Velocity is Speed and Direction, but lights speed is constant...so without a change in mass, and without a change in speed, does this mean that the direction of the light is becoming less certain as the position of the light becomes more certain?
@qwerty_1_2_3
Жыл бұрын
light technically in quantum mechanics does have linear momentum = H/lambda it is the same H as in the video used for Planck's constant and with this formula you use the uncertainty principle and yes over here what is represent is change in direction but i am not sure if this is the Heisenberg uncertainty principle i was under a completely different interpretation which i was taught and made much much more sense whereas this video didnt give an explanation about how that is the uncertainty principle so i am not sure if this is it or some other principle
@raminagrobis6112
5 жыл бұрын
Soon I'm gonna receive a video where Derek hasn't started walking. As time goes, I receive his videos in my recommended views further and further away from today: it started with 1, 2 yrs ago. This is 6 yrs old. It's all right with me. Except for the irritating "ain't I great?" coolness factor, those are amazingly well -prepared shows.
@RonBenjaminBFT
2 жыл бұрын
I'm a visual learner, so I liked the video graphics you have, much better way for me to learn. Dr. Dorian Canelas at Duke Univ has a link to you from the Intro to Chem course on Coursera. Glad she gave us student this link!
@victorpisarev7768
4 жыл бұрын
Does п in the denominator equal 3.14? Then the right part would be a certain number everytime...
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