I Misunderstood Heisenberg's Uncertainty Principle... Until Now!

[@Mahesh_Shenoy]

To try everything Brilliant has to offer-free-for a full 30 days, visit brilliant.org/FloatHeadPhysics . You’ll also get 20% off an annual premium subscription. Also FAQ 1) What does it mean to add two waves together? I could have been clearer here. The bottom line is since a wave packet can be mathematically constructed by adding lots of pure sine waves of different wavelengths (Fourier series), a wave packet contains multiple wavelengths. So, an electron can be thought of as a wave packet HAVING multiple wavelengths, and hence HAVING multiple momenta. 2) What's the intuition behind energy time uncertainty? If you hear a tone for a small time, you are unsure about it's frequency. (You don't know if it's a pure sine wave or not). This means you are unsure about it's energy (E = hf). But since the time interval was very small, you are pretty accurate the absolute time value when you made the measurement. On the other hand if you hear a tone for a long time, you become more sure about it's frequency. (You have much better idea about the repeating pattern). This means you are more sure about it's energy. But since the time interval was large, your accuracy about the absolute time when you made the measurement went down!

[@steveclark2205]

Shoehorn Dirac's Equation into this explanation 😊

[@jiannisDimi]

Man you are the biggest badass physics teacher of all times.... realy a genious...

[@danielculver2209]

psi(relief)

[@Starteller]

I have one for you What was the temperature of the film inside the camera while being on the Moon?

[@MahsinTasneem]

Sir Can you please explain how time is related to motion

[@marcievamp]

I love how every time you make a video like this you talk as if you brought the scientists back from the dead and had lunch with them to make this video.

[@c.jishnu378]

Bold of you to assume he didn't.

[@tomcranwell8871]

Yeah at first I found it patronising, but then I realised it is the perfect way to explain things. The conversation is the stepping stones to understanding 👌

[@Mahesh_Shenoy]

Haha, when you read well written books, that's exactly what it feels like. I kid you not! (Try the book, 'surely you are joking mr. Feynman'. It's so nicely written, you feel like Feynman is sitting next to you explaining his life)

[@mlonguin]

You should do one about Feyman’s “why”? It is amazing!

[@cyclestunt.891]

@@Mahesh_Shenoy"Curiosity is the spark that ignites the flame of discovery. Embrace your curiosity, ask questions, seek answers, and never stop wondering about the world around you. For in the pursuit of knowledge, you shall find the secrets of the universe, and the universe shall reveal its secrets to you." Remember, science is a journey, not a destination. It's a mindset, a way of thinking, and a passion for understanding the world. As a scientist, you'll encounter challenges, failures, and setbacks, but also moments of triumph, wonder, and awe. So, cultivate your curiosity, stay curious, and never lose your sense of wonder. The world needs more curious minds like yours, eager to explore, discover, and push the boundaries of human knowledge. Now, go ahead, ask a question, design an experiment, collect data, analyze results, and draw conclusions. The scientific method is your tool, and the universe is your playground. Happy exploring!

[@shreya...007]

Got this in my recommended. Started watching and when I heard your voice, I thought that it sounded familiar. But then when you started just the voice over I immediately knew... You're MY physics teachers.I've been learning physics from your videos on Khan Academy since 8th grade!!! 5 years now, and I NEVER KNEW YOU HAD A KZbin CHANNEL!!! Thank you so much for your videos. I owe all my grades and understanding of physics entirely to you 🙌💛

[@itsoktochoosephysics]

Yes.... This also happened to me...

[@fredfurner]

Now I understand. It's been 30 years of me trying to understand the uncertainty principle. I started as a 14-year-old and a high interest in physics, but no one was ever able to just break it down and explain it to me like this. Thank you, side quest complete.

[@Mahesh_Shenoy]

Wow, feels incredible to hear this. Thank you for sharing :)

[@VertauePhysik]

​@@Mahesh_Shenoy Man... Wormhole video

[@VertauePhysik]

​@@Mahesh_Shenoy wormhole video day 4

[@liamweavers9291]

Still struggling to get my head round that! How can the probability not come from the measurement side? If The electron follows a path in the electron cloud, surely the probability of position comes down to the timing of measurement. How do we know the electron doesn't follow a specific path?

[@wesjohnson6833]

@@liamweavers9291 Now you're back to a double slit type experiment.

[@kinshuksinghania4289]

Almost 20 years ago, I first came across the uncertainty principle in Class XI Chemistry studying the atomic structure. This is the best explanation yet. Indeed intuitive. And over the years, I've realised that it's not that some subjects and some topics are tough, it is the quality of books and quality of the teachers that make a difference!! And if you're not in luck with the teacher's quality, do get good quality books!!

[@chr0ne692]

This is how I feel too! To have a teacher or a book that makes a subject feel easy is a blessing. And it makes you wonder if some subjects aren't intrinsically harder, but are rather just taught poorly.

[@mohamedzafir8566]

I am currently studying atomic structure, which is why I came to this video

[@Bildgesmythe]

The sign of a great genius is to be able to explain a complex subject to an idiot, like me, in a way I can understand! Thank you so much!

[@EvanOfTheDarkness]

He explained it well. Actually, the formula actually applies to all waves. You would just use the frequency instead of the momentum for non-quantum objects.

[@Starteller]

But be careful Quantum Physics is FICTION. Like many other pseudo-sciences. Like faster than light travel, time travel to the past, and other dimensional universes. Those quack do like he did he explains something true and then switches to his pseudo-science

[@ahmedadil3612]

A sign of a smart person is being able to recognize that they do not understand something. You would be startled by the percentage of people who accept concepts that they misjudged to have understood.

[@DrDeuteron]

@@EvanOfTheDarkness not frequency, but wave number, p~hk. Ofc for time domain signals, like radar, the relationship is with frequency, usually called "the time-bandwidth product" which has a minimum of 1 (since radar uses cycles/s, not radian/s). When that is >>1, it's called "the sophistication" of the signal, so if you have a chirp, or a phase-code, or all that stuff. Thats done to reduce max power..then a matching filter in the Rx compresses the return to get to the minimum. A similar idea applied to lasers won the 2018 Nobel Prize, back when it was still awarded for Physics.

[@journeytotheinfinity440]

Honestly, as an Indian, I never expected some Indian to be this passionate about Physics, a person really wants to understand physics for the sake of Physics, at least until now. It was my friend who first suggested your video about Quantum Spin. I thought it would be just like any other video about physics, a Lecture with a bunch of mathematical relations and claim something to be true just because math does imply so. I know and I agree that Quantum and Relativity are not intuitive in our common sense and it's true because what we say common sense, is just a genre of experiences in the macroscopic world, a classical world. Still, there is always room for improvement we can extend our domain of intuition by asking the right questions and that's what you do best. Really, I always wanted someone to share the same passion for Physics. I have seen all your videos and all I want to say is "Keep on doing"

[@Mahesh_Shenoy]

Wow, that's truly encouraging. Thank you :)

[@jackychan4640]

Hey, did you sent out a message to me. Can you send me again

[@Mr.Nobody-v4l]

​@@Mahesh_Shenoy hi sir ! If you love the physics this way, why didnt you become a theoretical physicist ? Or you are ?

[@solconcordia4315]

There are Indians who are passionate about Physics, too. There are even some Nobel Prize winners among them. You as an Indian just need to dig deeper to uncover your (very ancient as well as up to modern times) civilization's cultural heritage. 😊

[@solconcordia4315]

Bose and Chandrasekhar came to my mind. Ramanujan was a great pure mathematician, though not in physics.

[@Haris-bg4jy]

This is genuinely the best science education channel out there man. Have never left any of your videos without having learned something new or in a better way than I previously understood it.

[@c.jishnu378]

ScienceClic is also one channel, it is unfortunately one of only 3 complete explaining channels I found.

[@Rod-f4u]

Agree

[@alejandrocastellanos7139]

@@c.jishnu378 What are the other ones?

[@c.jishnu378]

@@alejandrocastellanos7139 This, ScienceClic and Eugene Physics, though the last one's animation is a bit old school.

[@ElaineWalker]

Just subscribed! 😃

[@mountainman4774]

I have been trying to understand the uncertainty principle for a long long time. This was, by far, the best explanation I have ever come across.

[@Avomance]

Mahesh… that was exceptional! Thank you… my uncertainty on this is now far more certain while making my certainty more uncertain!!

[@siddharthshivakumar4379]

I didn't expect to find you here, love your videos!

[@Mahesh_Shenoy]

Thanks a lot :)

[@Grecks75]

Same for me. I find the quantum world very strange and confusing, even more the more I learn about it. I'm trying to get accustomed to these explanations but have still a long way to go. I always wonder how these quantum effects add up to the predictable, deterministic macroscopic world we live in!

[@adt007ad]

​@@Mahesh_ShenoyHi! Could you please explain the physical meaning of adding another wave to the electron wave (I mean does it mean shooting another electron to the original electron)

[@solconcordia4315]

​@@Grecks75 If you understand geometric wave optics with its wave interference and superposition, you can understand quantum mechanics quite "intuitively" (intuition is a form of education and according to Albert Einstein, education is the layer of prejudices laid down upon oneself before one's reaching the age of 18).

[@robertmontague5650]

I really love this guy's teaching style, his knowledge, and his excitement for physics. Mahesh is unique.

[@jmcsquared18]

Whenever I tell my students about quantum theory, I always try to highlight how necessary it is. The wave-particle duality is the entire reason we have atoms. If the electron is not a wave, but a particle, then all atomic orbitals decay in about 16 picoseconds. You can use the uncertainty principle alone to back-of-the-envelope estimate the order of magnitude an electron's energy at various distances to a proton. Within nuclear scales, it'd be enough to shoot it clean out of the proton's attractive potential. At the scale of the Bohr radius, it's on the order of a dozen or so electron volts, in agreement with the Schrödinger equation. The uncertainty principle actually implies a repulsive force between the proton and electron at sufficiently short distances, preventing orbital decay. Even though I teach this, it never fails to blow my mind every time I think about it.

[@o_2731]

Ty

[@nanotechnano7193]

no distances electrons don’t move around nucleus!!! They just waving ,and higher energy levels just means a higher electron -wave energies

[@jmcsquared18]

@@nanotechnano7193 true but you can measure the distance the electron is from the nucleus at a given time. The probability distribution for this observable in Hydrogen's ground state peaks at the Bohr radius with a mean at about 1.5 times that distance. Whereas, the probability of measuring the electron to be within nucleon distances to the proton is so small that it's practically zero. So, the qualitative understanding we can derive from the uncertainty principle alone matches what the full theory would predict.

[@solconcordia4315]

​@@jmcsquared18 What's the angular momentum of a single electron in the ground state of protium ?

[@Starteller]

Quantum theory does not exist! We cannot travel faster than the speed of light We cannot physically travel into the past. There is no transdimensional dimension Answer this question my dear pseudo-scientist What was the temperature of the film inside the camera while filming on the Moon? Ask yourself why you can't control your mind to focus on the question and why it triggers feelings. You are in DENIAL. In reality, Everything is Energy Matter is condensed Energy Space is expanded Energy Time is Energy in movement That's it! Everything else is Mombo Jumbo nonsense

[@nerdyscienceofficial]

"Wow, this video is truly inspiring! It's just incredible how 'INTUITIVE ' this lesson was .This is a really underrated channel, u deserve more bro. Big props to Mahesh for simplifying such a genuinely important and" hard to get ur head around " topic!"

[@But_Whyyyy]

Finally, Mahesh is heading towards the intuition of Quantum Physics!!!!!!

[@foodsafari-rj3uq]

Every pop science channel ever wants you to think that such a thing is possible because it drives their views and engagement. The only intuition you can get in that subject is by a good understanding of the math or the data you see from experiments.

[@solconcordia4315]

​@@foodsafari-rj3uq It's indeed possible to make quantum mechanics understood by high-schooler sophomores if we restructure education properly. Geometric Algebra with i = e1e2 and e2e1 = -i, etc. should be taught to condense a lot of mathematics.

[@foodsafari-rj3uq]

@@solconcordia4315 my claim has nothing to do with high schoolers. What are you even replying to?

[@neogetright7542]

I was fortunate enough to have a lecturer who taught me this exact way with as much enthusiasm as you when i was in college. That guy made me love chemistry for life. His name is Murulidhar. I hope kids these days get atleast one lecturer like him in their life.

[@therealist9052]

Bro explained the Heisenberg Uncertainty Principle in the first 1 minute of the video better than I've EVER heard anyone explain it. Makes PERFECT INTUITIVE SENSE now. Thanks so much!! Edit: I watched the rest and yes that's the less accurate version but it ended up still working for me because I didn't assume you could determine velocity by just going to the next slide because I assumed there was no next slide, which ended up working for me. However, the next explanation he gave was even better anyways so ... win win!!

[@hubbletrubble7875]

and that is the LESS accurate version!

[@mosedrogba]

That's why we're here every time he uploads

[@epajarjestys9981]

And then he explains that this intuitive explanation does not really work. Watch the rest.

[@Mahesh_Shenoy]

Haha. Also if you keep the ball at rest on a table, now you know both its position and momentum :D. So in Feynman’s words, I would have cheated you very badly!

[@mickwilson99]

Mahesh, again, good job on a complex topic. As a physics grad from the 80s, the thing I need better intuition is how Schrodinger arrived at his equation after saying "Hold my cat".

[@DrDeuteron]

from the Hamilton Jacobi Equation formulation of classical mechanics.

[@solconcordia4315]

Is there something similar to the Hamilton-Jacobi formulation of Relativistic Mechanics which may lead to something like Dirac's equation for a relativistic electron ?

[@DrDeuteron]

@@solconcordia4315 idk, but relativistic field theories use the Lagrangian formulation, which has S, the action at it's core. But then, Dirac got his equation by brute force declaring time and position to be on the same footing, and linear...in a (particle) Hamiltonian...good question.

[@peteryyz43]

Heisenberg gets pulled over by the cops, and they ask him "Do you know how fast you were going?", Heisenberg says, "No.. but I know exactly where I am".

[@WoutDekeyser]

Heisenberg gets pulled over by a cop. The cop says: Do you know you were going 15 km/h over the speed limit? Heisenberg answers: Great, now I'm lost.

[@JeremyB49503]

How many times have I read about this concept and only now, after years, do I come across an explanation that makes it click. Thank you once again. I think the magic of your lessons is that (a) you trust us to understand, and (b) you've remembered the questions you once had back when you didn't understand either, you remembered what made it click for you, and (c) you wanted to share that joy of discovery. Thank you so much for being you.

[@jessstuart7495]

Time and frequency are also complementary variables. A sinewave extends to -inf to +inf. This gives us a pair of impulse functions (infinitesimally wide, but infinitely tall pulses) in the frequency domain when we take the Fourier transform. When we look at a sinewave for a non-infinite amount of time, we are always chopping off some of the sinewave (Rectangular window function). This causes the frequency spectrum to of the impulses to spread out (convolving with the fourier transform of the window function in the frequency domain). This spreading of the sinewave's spectrum gives us an uncertainty on the actual frequency of the non-chopped sinewave. If you look at the sinewave for a shorter period of time, the spectral spreading of the sinewave, and your uncertainty about the frequency of the sinewave gets worse.

[@DrDeuteron]

100 percent true. It's informal in quantum mechanics, though, since time is not an operator--but it works, where frequency -> energy. And for decays, the energy (read: mass) of the unstable state is not fixed, but has an hbar / half-life "width". The math is exactly the damped simple harmonic oscillator...again it's informal, as the Cauchy aka: Breit-Wigner aka Lorentz distributions has infinite variance, so FWHM is the standard. It also gives atomic lines (Lyman, Balmer, etc) a minimum line-width.

[@oo2542]

You are almost the first person to explain quantum duality in an understandable way. It’s like bringing life to the topic, given the vague understanding and unclear media representation. Is it a wave or a particle? Your explanation honestly helped us a lot.

[@vanshmishra7119]

If only everyone had the chance to learn from the great minds like Feynman & Einstein themselves. Luckily we have YT and someone as passionate as you are. Forever indebted.

[@sharthakghosh970]

These videos can become the backbone for understanding such complex and abstract concepts for the new generation of high school students around the world. I am a software engineer who started exploring quantum computing just for fun and somehow landed up here. Been here the entire day.

[@sankalp_02171]

A similar thing can be observed for signals in time and frequency domains. Signals which are non-zero for low time duration have their spectrum spread apart in frequency and vice versa. For instance, Fourier transform of an impulse (infinitesimally small duration signal) is constant ( i.e. spread over entire frequency spectrum) whereas Fourier transform of a sinusoidal signal (spread in time domain) consists of impulses in the frequency domain.

[@99eigencharu]

That's becuz Heisenberg uncertainty principle is a result of a more general uncertainty that arises due to the wave nature.

[@ajinkyakamat7053]

Yes. I had all sorts of confusion about Heisenberg's uncertainty till I was teaching one of my undergrad EXTC junior about Fourier and then something just clicked. Its been 13 years since but I vividly remember the moment and the insane nerd out we had after figured it out.

[@DrDeuteron]

@@99eigencharu I see what you mean, but I disagree that wave stuff is more general, since the HUP is a formal result from non-commuting canonical operators, of which [x, p] ~ ih is the most famous...but there is massive overlap. I've worked in signal processing and I'd sometimes slip into quantum lingo, since I learned it 1st, and the EE's would be all ??????

[@shaggygoat]

A fun way to get a feel for the phenomenon is to play with a sound editor like Audacity, mix in some beeps of varying lengths and pitches (arranged into chords, even), then show the track in Spectral view mode. You can adjust the vertical (frequency) resolution as much as you like, but doing so smears out the horizontal (time) resolution and visa versa. A note can only have a pure frequency when it is eternal, and a very short note is just a click, composed of many frequencies.

[@DrDeuteron]

remember when the key-pad replaced the dial on phones, and it played tones from a musical scale? A classic intro signal processing homework was "what's the fasted you can dial"...because you need time to even define a recognizable frequency.

[@mikolajtrzeciecki1188]

Many people said they loved your explanations. I love them too. I will add, I love your T-Shirt too.

[@MedlifeCrisis]

Pranav from Science is Dope sent me! Seen a bunch of your videos now, fantastic stuff, I can see why he recommended you so highly. Keep up the great work!

[@Mahesh_Shenoy]

Thanks a lot!! Great to hear that :) :)

[@dipanshu0ag]

Until now I was waiting for a breakthrough that will measure an electron's position and momentum exactly. The minute I saw the "title" of this video, I knew I was wrong and that small (but persistent) itch to understand such a beautiful theory intuitively will finally be satisfied. That's my confidence level in you, and I keep recommending you to fellow physics enthusiasts.

[@dangerahead2108]

are you satisfied, i mean we still know nothing we are just giving theories .

[@avibhagan]

When I was first introduced to the uncertainty principle, I understood it as a simple mathematical problem that resulted from the inaccuracy of our measurement methods. I never understood how uncertainty became some fundamental "property" , of matter . I see the NEED for uncertainty to be accounted for in every Quantum Mechanical equation ! We cannot do QM without it. But I never saw it as a fundamental property. I never understood whey some schools of Physics treated it as such. As far as I'm concerned it is just a parameter required for calculations because of our inability to measure the position or speed of a particle without changing the speed and position of the particle while measuring it.

[@solconcordia4315]

In classical mechanics, a physical property is plotted on a real number line but in quantum mechanics, Hilbert Space is used instead, from which the probability of finding the measured physical property to be a particular real eigenvalue can be computed.

[@DrDeuteron]

@@avibhagan formally, HUP is derived in general by writing down a variance for an operator A: var_A = and it's canonical conjugate B...and you do the algebra (it's on wikipedia) and the fact that [A, B] = ihbar, they don't commute, leaves you with a minimum value. It has nothing to real measurement errors, it's a property of the operator formulation of QM.

[@avibhagan]

@@DrDeuteron lol ! (1) It is a property of the operator formulation of QM . (and therefore not reflected in reality) (2) It IS by design , formulated to handle real inaccuracy and real unknowns in a system. The tool was invented for Statistical mechanic. QM is just an engineering approach. QM is statistical mechanics . QM was designed to allow us to do calculations while compensating for unknows and inaccurate measurements by using statistics.

[@jamesmcgarity2985]

I *literally* said to myself out loud "WHOA ......" at your teacher's explanation of the Heisenberg Uncertainty Principle at the beginning of the video. I've never heard such an intuitive way of thinking about this phenomenon! Amazing!

[@theomommsen6875]

No - this explanation is misleading as he said!

[@clairecelestin8437]

Excellent video! For me, the intuitive understanding of Heisenberg came as a result of developing an intuitive understanding of how Fourier transforms work. We could imagine making a normal 'amplitude over time' graph in a way like a seismograph, where the amplitude changes the vertical position of our pen on a piece of paper that is translating to the side. To do a Fourier transform, we do the same thing, only instead of drawing on an unrolling scroll of paper that translates, we put a piece of paper on a record turntable and draw on that. Normally, this will make a spirograph squiggle that is, on average, centered on the rotational axis. However, if the rotational period of our turntable record matches a frequency component of our signal, the signal will be significantly off-center compared to our usual squiggle. By the time the pen swings to the other side of the turntable, the paper has rotated around to that side as well, and most of our ink ends up on that end. If our frequency is a little wrong, the squiggle will be more spread out, but will still have an offset- it's like our squiggle has a slow precession. The Fourier transform just keeps track of this off-centeredness of the squiggle we have drawn, both in phase and amplitude. Like, imagine that the ink we are drawing with is heavy, and we find the center of mass of the squiggle. How this ties into Heisenberg is that, as we turn the dial to change the speed of our record, there is a smooth transition from being on a totally wrong frequency where our center of mass is close to the turntable's rotational axis, to a nearly right frequency where our center of mass starts to drift away from the axis, to a perfectly correct frequency where our center of mass is a maximum distance from this rotational axis. Because the center of mass makes a gradual transition, therefore there must be a fundamental resolution tradeoff between any two attributes of a system that are Fourier complements of each other. Your videos are so wonderful. It's a joy to watch them, and a joy to share them.

[@applelmao1973]

Ffts for the win!

[@jatinbhatt7826]

I had never understood this principle for like years . I looked for books after books, videos after videos. Now I understand it completely. Thank you so much

[@generationxpvp]

Literally the best science communicator I have watched. Good shit man, love this.

[@abdallanasrelden9886]

This might be the most intuitive and simplistic explanation for the Heisenberg uncertainty principle I've ever came across, Thanks bro.

[@steveclark2205]

Don't forget about Diracs Equation also & Maxwells Equations and the Pauli Exclusion Principle 😊

[@BurningBread-vi4bm]

So far this is the best video I’ve watched about Heisenberg’s principle of uncertainty. Simple and straightforward while keeping the details. Keep up the good work! +1 follower

[@rv6amark]

"...hold my cat!" Cracked me up! 😅🤣😂🙃😊

[@JoseRodriguez-gj7vx]

Where have you been all my life 😭 you’re probably the best explainer I’ve come across. Your ability to break things down to the layman(myself) without washing away at the lessons integrity is elite and absolutely unique. I’m just 1 guy so I know it’s not much but just know you have a full fledged subscriber in me. As I type this idk if you have a patreon page or anywhere that I can contribute to you so I’ll find out after I post, just know if you do I’m def contributing

[@menyasavut3959]

Heisenberg was never a confident man. One of his characteristic personality traits was his tremendous uncertainty - hence Heisenberg's Uncertainty Principle exists.

[@navneetrout8193]

He was not an ignorant man. He was confident in the uncertainty.

[@Rakpasa]

Heisenberg Uncertainty Principal - Head of the Mystery Dept.

[@jumpspoon2762]

Amazing, I was studying for quantum mechanics exam and couldn't understand how uncertainty prevents electron form collapsing. This is the first place when someone actually gave a satisfactory answer. Thank you!

[@DrDeuteron]

read wikipedia on Compton Wavelength of the electron, and then compare with the Bohr radius

[@physics_enthusiast_Soorya]

OMGGGGG VERYYY EXITED TO WATCH THIS 21 mins and 22 seconds of quantum mechanics on this channel!!! YAAAYYYYYYYYYYYY (Edit:) Nvm. I watched the video, it's a really great video, but sadly, nothing was new for me (hence didn't enjoy like I do before in this channel, Ig it's an exception for quantum physucs 😭)because I only see these types of content everywhere. His explination was what amazes me always. :) thank you sir. You're a very great teacher ❤️✨️ Keep it up!

[@Damn-Age]

How I wish such well crafted presentation was given during my school lectures. The future is so bright with folks like Mahesh, who are able to reach to so many people and potential future generations with such good videos explaining the unintuitive quantum objects, which were hiding from us since the inception of time, in simple intuitive concepts!

[@bogdanrotaru6101]

I think the biggest mistake in physics is that we confuse objects (electrons, etc), with object behaviors (waves). Waves is something that all particles do, it's just a behavior, not a thing on it's own. Imagine a hill, it's a solid object, right? Now imagine that same hill collapse under a landslide, and that hill suddenly looks like it flows (like a wave, like a liquid).

[@utkarshgautam8556]

Only that the quantum OBJECTS are not collapsing and turning into a wave like flowing mess. Quantum OBJECTS are like being a hill that is solid and flowing at the same time.

[@abhaysinghania9468]

The best explanation of Heisenberg's Uncertainty Principle ever. Just loved it. 🙌

[@tanushjain7679]

Thanks a lot!! Cleared a lot of misconceptions i had

[@Asaad-Hamad]

You are extremely exceptional in simplifying everything.. But simplifying Hiezinberg uncertainty principle is your best one because this is the most mind blowing phenomenon.. Your wonderful video came very handy while I'm working on quantum energy fluctuation.. Thank you very much.

[@vdiitd]

How do you even come up with these intuitive explanations man? I genuinely want to know.

[@epajarjestys9981]

There's nothing particularly innovative about these explanations. It's been done thousands of times before in books and lectures and is probably taught in just about any beginner quantum mechanics university lecture, or even in high school. He just presents them very nicely.

[@kavitha.k2792]

I asked my teacher why is this principle accepted? why is this true?..but she didn't give me proper answer...I'm glad i got answers for my doubts here...thank you so much sir!!!

[@luzzattoran]

This is the first time I've come close to understanding this topic Great work.

[@Spirate_0]

The uncertainty principle is a concept that applies to waves in general. The wider de wavelet in time, the narrower the fonction is in Fourier space. And since the position of the electron is given by the wave fonction in regard to time and the momentum is given by the wave fonction in Fourier space, the more precise you are in one dimension, the less you are in the other.

[@levshyrokov6464]

Yeah, that is the reason why an increase of a bit-rate of digital signals increases their frequency spectrum, as for higher bit-rate we have to decrease a lenght of signal impulses

[@cyberbiosecurity]

0:46 the problem with this analogy is that in this case we know exactly where the ball is, we have full information on it's location. though the photo of it is blurred, we do know that the ball is positioned on the edge of this blurry stain, not anywhere else.

[@solconcordia4315]

Yes, you may know where it can be but there are clearly *TWO* different edges allowed by the direction of the momentum of the ball. When we measure the momentum of an electron, we also get a two-edged ambiguity which we call electron spin.

[@cyberbiosecurity]

@@solconcordia4315 very interesting observation, thank you

[@ViranchiAggarwal]

This is the best science channel on KZbin. The way you address common misconceptions about these principles is immaculate and have really enhanced my understanding of the subject

[@tpros6289]

Everybody gangster til Schrodinger tells you to hold his cat.

[@misnik1986]

I am a PhD student and this is the best video I have ever seen in my life about the Heisenberg uncertainty princple

[@eric-vm3oz]

lets ask the most important question: where did you get that tshirt?

[@gianlucacerrone2103]

Man you are amanzingly clear and practical, it’s so important to give intuitive and practical explanations of physical, avoiding to get lost in the mathematics with no understanding of the real deal. I think you are better than many university professors (maybe you are one of them, in that case good for your students). Keep going

[@subramanianchidambaram8900]

What do you mean add more momentum to electron ? If each electron had only one wavelength then how do we simply add different wavelengths to it to create localisation to identify its position ?

[@MichaelPiz]

I asked essentially the same question in my comment, though much less effectively than your version.

[@drdca8263]

This isn’t describing a physical process of adding something to an object. It is describing a sum of different functions, added pointwise

[@MichaelPiz]

@@drdca8263 Right, I get that. But what justifies doing that? It just seems random - add a function so it proves our theory. What function? Why _that_ function? Is this another function associated with this electron? If so, what property does it represent? If not, where does it come from? There's no explanation in the video for adding a function, it's just done.

[@drdca8263]

@@MichaelPiz He’s just saying that a sum of sine waves with different frequencies can result in something that is more localized than an individual frequency, which is suggestive of the fact (which can be shown more carefully, but he was aiming at intuition, not rigor) that something localized roughly in one region can be expressed as a linear combination of many different frequencies. So, a wavefunction for the quantum object being close to some location, can be seen as a linear combination of wavefunctions for a variety of different values of momentum. So, you can see it as “it is a mix of positions mostly with the ones near here” or as “it is a mix of different momenta”. It is two different overcomplete bases .

[@MichaelPiz]

@@drdca8263 Again, I understand that. I'm trying to figure out _why_ that's the case. Or, probably more accurately, what exactly are these additional sine waves? Where do they come from? Do they represent different possible values for the electron's momentum? That would make sense, if I understand correctly, because the electron can have any of infinitely many possible values for momentum. (And the more of them we have or, better, the more we use, the more precisely we can determine the electron's position.) If not, then what? (Side note: Is this collection of sine waves a superposition?) I'm probably doing a poor job of stating what I'm asking.

[@allenmano]

My favourite teacher 😢😢 !!! Love from Tamilnadu ❤

[@parthhooda3713]

You did give us the intuition about how it works but what about the formula and that 2pi in it? I can somewhat understand how plank's constant was there but how did 2pi show up there? It could probably be related to sine waves or the waves that define the position of electron but I need a more detailed explanation about how that formula was derived so plz make a video on that also. I think we would need a understanding of the schrodinger's wave equation (I already know about that though) so you may make a video related to that first and I will be curiously waiting for both of them.

[@Mahesh_Shenoy]

Yea, I ran out of time for that. You can derive the expression using the single slit experiment actually. It's pretty cool.

[@carultch]

It has to do with whether the Hertz frequency variant of Planck's constant matters, or whether the radian frequency version of Planck's constant matters. The standard formula with Planck's constant uses Hertz frequency, which is E=h*f for the energy of the photon. Planck's constant therefore has the units, Joules per Hertz, and is the energy of a hypothetical 1 Hz photon. The reduced Planck's constant, hbar, is h/(2*pi). This is what you'd get if you replace E=h*f with E=hbar*ω. The value of hbar has the units of Joules per (radian per second). It's very common in differential equations, that the radian frequency is directly determined by the coefficients of the diffEQ, rather than the Hertz frequency. You may be familiar with this, from the frequency of a mass/spring being given by ω=sqrt(k/m), while the equivalent formula for Hertz frequency will be this divided by 2*pi. This is because the calculus of trig functions is most elegant, when the trig units are radians, rather than full cycles or degrees. You end up accumulating chain rule coefficients, if you try to make it work with other angle units.

[@HafsaBatool-mc1de]

This guy is being feynman to us. I really appreciate your content. This is true science that most teachers fail to capture.

[@solconcordia4315]

Yes, his videos may have errors but he strives to give us a good feel for the subjects involved. When I asked in high school the question, "How does the electron know that it should show up not on this path, but on the other path ?" during discussion of the diffraction of electrons from a nickel crystal, exhibiting matter wave, 🤔 the teacher replied, "We *DON'T* discuss electron psychology in this class !" 🤐🤪

[@BerndSchnabl]

Heisenberg, Ohm and Schrodinger are in a car. They get pulled over. Heisenberg is driving, and the cop asks him, “Do you know how fast you were going?” “No, but I know exactly where I am,” Heisenberg replies. The cop says, “You were doing 55 in a 35.” Heisenberg throws up his hands and shouts, “Great! Now I’m lost!”

[@Charoncalronn]

This is a terrible joke. I love it

[@vaibhavnegi9273]

Mahesh sir is best teacher in english and hindi as well . He explains any topic with a very easy manner and tells evrey detail of the topic.❤

[@Tarlo95]

This channel is probabbely the most intuitive physics channel on youtube.

[@ishangautam7325]

Plot twist: Albert Einstein denied the credibility of the uncertainty principle

[@joycee69]

😮

[@m.n152]

Yes but he can't get a unifying theory before his death

[@YouAreReadingThisDuh]

i really appreciate that you separated the sponsor from the rest of the video with timestamps and that humble "i have made a video about that but you dont have to watch it, not farming views here." and definitely your enthusiasm. very nice job, you've earned a subscriber, keep it up!! and i dont usually comment but i really wanted to let you know!

[@ohlookadandelion]

Ive been a fan since ur 'why is the speed of light constant' video! U explain SO WELL. Pls dont stop making videos!!!

[@gvanish6000]

this was the best explanation of the uncertainty principle i have seen , now i understand the world even better

[@BBQDad463]

Thank you for this video. You offer perhaps the clearest explanation of Heisenberg's Uncertainty Principle I have yet seen.

[@itsiwhatitsi]

When you are saying that you add waves to the electron/wave do you mean that you add photons (waves)with different characteristic (phase,frequency… etc) ?

[@dewannazrul1969]

Bhai i have been suffering from the bug of Heisenberg's uncertainty principle for 3 years but at last to i set free from it. Thanks for setting me free from the bug. huge respect forever gratefull to you

[@LeopoldoGhielmetti]

I known the uncertainty principle, but I had never connected it to the atom stability. It's really eyes opening. Thank you

[@jannelaaryan]

Marvellous and astounding explanation I've ever seen , how do you simplify all these terrific topics ?

[@pablotejada7696]

Excellent explanations of the uncertainty principle (indeterminacy), that is, momentum and position of quantum particles. Thank you Mahesh, you are brilliant like your sponsore

[@Ed-quadF]

To be able to explain this stuff to me requires a genuine in depth understanding of the event. Thank you!!!!!!!

[@Care2WorldBuild]

Love this! I am seeing so many relations in the world of physics and appreciate growing in understanding. I appreciated learning to the level of being able to teach the idea, although it would also be good to learn the math behind it too. So a question I thought of worth for Gemini or ChatGPT that gave a non-definite relationship was, "And what would the relationship be thereby from the wavelength of a proton to its constituent quarks?" Then ask, "So do quarks have a wavelength?" You'll get into the de Broglie equation and quark confinement.

[@DrDeuteron]

don't use AI. pls. I assure chat GPT doesn't know jack about proton structure.

[@hgtrad7655]

I learnt to derive Schrodinger wave equation and Heisenberg uncertainty, having a solid background in advanced electromagnetics, your explanation clarifies many untangled questions thank you.

[@spencerwenzel7381]

Great video, this helped to clarify a few tings! I had a few questions: 1) You added waves to find more certainty in the position (FFT). What physical process causes the addition of the waves for the inteference? Is it measurement? 2) Imagine there is a radioactive element surround by a spherical detector. When the radioactive element decays it emits an alpha particle and the detector finds the alpha particle in one location. Could I not know both the position and momentum at the same time? I know the position because the alpha particle hit at one point on the spherical detector. I could determine the momentum because I have the mass of the alpha particle and the distance and the time could be determined. Unless is there uncertainty in the time?

[@martinschrage]

I have had a semester of quantum mechanics undergrad and three semesters in graduate school. I am also very knowledgeable in Fourier Theory from a signal processing point of view. For the first time ever I "understand how it works". Buy the way, this also applies to antennas. Small aperture implies broad beam of radiation and the inverse as well. But antenna behavior is classical. Bravo to you.

[@daanskiel1236]

Mahesh you are lowkey the best in intuitively explaining complicated subjects like these, thank you for these video's.

[@Jagdishtemkar1]

At the beginning it seemed too basic, but the realisation of the localisation of wave itself being a particle, blew my mind. Well explained Mahesh! I may now better understand how entangled particles may interact from a larger distance.

[@gokulkrishnans4474]

please dont stop....We will keep support...These kind of videos and explaination are not so much online...U will reach heights one day..and your videos going to change our life ofcourse ❤️❤️❤️

[@JacksHQ]

I never before understood that the Heisenberg's Uncertainty Principle was a fundamental law. I thought that it was more of an observation. My mind is blown. Thank you!

[@rb9805]

Your lectures are absolutely FANTASTIC!!!!!!!!!!!!OUTSTANDING

[@willo7734]

Nice! That’s the most comprehensible explanation of Heisenberg’s Uncertainty Principle that I’ve heard anywhere. Thank you.

[@kraetyz]

This video is giving me wonderful insights. I love the specificity in highlighting that "wave-particle duality" doesn't mean that the object *is* a wave and a particle, which is how most people (even non-expert teachers!) will explain it. I'll definitely be taking that away from the video, if nothing else, though the thorough step-by-step in outlining the uncertainty principle is fantastic too.

[@markTheWoodlands]

Feynman would have loved you Mahesh. Brilliance plus passion plus exceptional communication skills.

[@guillaumebourgault5532]

your enthusiasm and fascination is contagious. Wonderful!

[@AnnuPriya-jm2fr]

What was that 😍😍... I just got some real feelings of joy in this 21 min video. Sir requesting please don't stop uploading this kind of mind-blowing video that give explanation of science the way it should be done.❤❤❤ Lots of love 😘

[@AumchanterPiLetsPlay]

I am a teacher by profession. Your enthusiasm and genius at explanation makes these the best, by a long way, videos I have seen on these subjects. You make me want to read Feynman. Amazing work. Please keep uploading. And thank you. 😊😊😊

[@holo2886]

Ok, you actually earned a sub. I love how you explain things that makes it super clear, especially since I only exclusively study math but now I wanna study physics too

[@naeemhaq176]

I'm not a physicist, but I love your explanation. It is simple and straightforward. The one question i have is what affect does temperature have on Heisenberg's uncertainty principle? Again, I am not a physicist, but my understanding is that Wein's Displacement Law states that the wavelength is proportional to the inverse of the absoulte temperature.

[@rudihoffman2817]

I just finished day 602 on Brilliant, great courses, I am glad they are a sponsor of this brilliant video!

[@iakobkv271]

Dude you are a freaking genius! Thank you so much for explaining this. And thank you for your passion! People like you make the earth a better place! And of course people like Heisenberg, Schrodinger, Einstein, Newton...

[@bryanreed742]

This is a really good video for breaking down common misconceptions without having to invoke advanced mathematics. A tricky balance, to be sure! For those who are curious about the math details that are left out, the search term you want is "Fourier transform." It turns out there's an uncertainty principle even for classical waves. And the usual deltax deltap formula doesn't come from a vague thought experiment; there's a rigorous derivation for it. If you're careful about which sinusoidal waves you sum together, you can pack the wave amplitude pretty tightly in space, but there's a hard mathematical limit no matter how cleverly you select your sine waves.

[@ijaygee1]

Excellent explanation. I always understood the 'what' of uncertainty ( x vs p), but until now, not really the 'why'. Many thanks.

[@muntedfinger]

Wow, you’re an incredible educator. Your excitement is infectious and you have a great way of explaining things. Thank you

[@kirankumar6557]

thanks a lot Mahesh sir, i struggled a lot to understand Heisenberg uncertainty principle , i finally ended up my search at your video .your way of explanation and the way you are setting our minds at the beginning of the video that these are special entities like we should not see them as particles or waves and they are quantum particles which share properties of particles and waves made my mind ready to accept completely new things. thank you sir.

[@avinashbabut.n4123]

You feels like myself studying Physics interestingly... I like your videos very much.

[@sdsa007]

This was the best short vid on Heisenberg uncertainty that I have seen on youtube! Thank You! I think you were so genuinely excited that you forgot how to pronounce probability, hiliarious! I am glad you referenced the Feynmann Lectures, and I plan on reviewing them!

[@vinayk7]

12:00 brilliant part starts here, the way you related the pattern of double slit experiment with the graph just brilliant!

[@ggyanwali]

You have such a charming personality. The way you explain smilingly is cherry on top! Keep up the good work.