Id like to hear Phil talk about how the uncertainty principal relates to wireless data transfer. The faster the data rate, such as in video transmission, the more spread out the bandwidth is. Therefore you have a high loss transfer. In low data rates, you can have a tight spectrum and have lossless transfer.
Top marks for explaining physics soundwaves with metal chugs and top marks for playing an epiphone elite with the international headstock, it's a rare guitar and it's a great one as well.
I think a neat description of how momentum and position are inversely related can be shown with a photograph. If you throw a ball and take a photo in mid air with a camera that has an infinitesimally small shutter time, you will have a perfectly clear picture of the ball. You will know it’s position at that moment in time with 100% accuracy, but you can’t know anything about how fast it was moving. If you take a photo with a larger shutter time, the picture of the ball will be smeared a bit. You can measure the length of that smear, and by also knowing the shutter time you can get how fast the ball was moving. But if you try and say “Where was the ball when the photo was taken?” you have to gesture to the entire smear because it wasn’t in only one spot. The trick then is showing why this example is relevant to the quantum world.
But doesn't your ball actually still have definite positions and momentum regardless of the methods to measure them? An oscillation doesn't. Maybe if you got the ball bouncing to some rhythm and tried to locate the rhythm, then you'll see that the position of the ball is not the 'reduced' position of the oscillation. Also, the real trick is showing why quantum mechanics is relevant to the real world, not the other way around.
It's an analogy, it's not "This is literally how it works". It's just a way to visualize the relationship if you have a hard time thinking directly in terms of sine waves. And no, it goes both ways equally.
The position is absolute. You can not say that this is somewhere over there. It's like record a video of a race car, you can only find the position (absolute) with one frame, if you use all frames you can determine the velocity but can not find the absolute position. Edit: I was explaining the analogy itself and not the uncertainty of the particles.
I think you got your Fouriers wrong. The picture you gave us is the Utopian Socialist François Marie Charles Fourier. The person he's most likely talking about is Jean-Baptiste Joseph Fourier. Two completely different people.
After 3 quantum mechanics courses and 3 classes going over Fourier series heavily, this is the first time I feel like I’ve deeply understood the uncertainty principle…
This video is supremely important for anyone at the beginning of studying physics in university. Phil's seamless joining of Fourier transfers, wave mechanics and Heisenberg has opened a little door in my head that 'shines light' onto the information I've been studying. Bloody good job, kudos to prof. Moriarty.
GREAT! I find it so heartwarming that dedicated and experienced scientists try to communicate their understanding with art and music to make it easier to understand for everyone!
I wish I had a science teacher with the same passion and enthusiasm as Philip Moriarty when i was at school, rather than open a textbook up and read away... It would most likely have changed my career path. He's a pleasure to listen to.
When I first became a ham radio operator the idea that a morse code signal had *_any_* bandwidth confused me. Morse code transmissions intentionally don't switch very rapidly. This minimises "splatter" to either side of the radio dial. If you increase your sending speed (let's say from 5 to 45 words per minute) without switching faster, the dots and dashes begin to run together. At faster speeds you need to switch more quickly to transmit an understandable signal. The signal becomes more complex and takes up more bandwidth. Mathematically speaking, it takes more sine waves to recreate the original signal the faster it's switched on and off.
Similar restrictions exist with modulation of any kind. You can only send information at less than half of the carrier wave frequency (The Nyquist frequency).
Exactly. Thanks to the net it's fairly common knowledge now but back in the 1970's it was easier to experience it in practice. Hearing some fool CBer wipe out three channels to either side while splattering across the entire band because he thought overdriving the finals of an illegal linear amplifier would give him more power will drive home the concept much better than a TH-cam video.
@what else is on think about the fourier transform from the video and how the short guitar note made a wider fourier transform than the longerone. The radio "bands" are supposed to transmit the information on a specific frequency, so whoever is listening can filter out other frequencies. Shorter / faster input would make the fourier transform wider, hence if it got too wide, other bands could get polluted. Not sure what "illegal linear amplifier" is but I guess the concept is that the extra noise it would cause outside of the target frequency when interpreted from the fourier transform would be annoying to other people trying to receive different information through nearby frequencies.
I‘m a chemistry student (albeit leaning very heavily into Prof. Moriarty‘s field of quantum effects and nanoscience etc) and I have to say: this video has had such a profound impact on my intuitive understanding of uncertainty relations and Fourier transforms. Understanding the maths is one thing, but getting an intuitive grasp of the situation, a sort of big picture on it, really really helped me put all the various maths in context. I cannot understate how much of an impact this video has had on me. More like this, please!
For those that are interested, a true sine wave lasts for an infinitely long period of time. If it starts and stops, other frequency content is introduced and it's no longer a sine wave. The opposite of a sine wave is a Dirac spike, which lasts for an infinitely short period of time. This produces a horizontal line that rises and falls on an FFT, whereas a perfect sine wave creates a vertical line.
How does a wave ‘know’ it has an end? When I have a sine wave that lasts for only 10 sec, then during those 10 sec the wave must be pure/true. If it was not and the uncertainty of the wave would be present before the cutoff, then we would have communicated information from the future. So only after the 10 sec have passed can the stop be detected. Else I could detect the stop before it happened, but then decide not to stop, thereby creating a paradox.
@@Laurenss23 The sine wave, when measured as it's playing, is perfect. But it has to be measured in its entirely, otherwise it's like measuring just part of something but not the ends. There is a wide bandwidth on the start of a sine wave that quickly narrows but it never reaches a true single frequency. It always has sidebands because we aren't measuring it lasting for infinity seconds. It's the same for Dirac spikes. We can never produce an infinitely short-lived impulse because it's a mathematical concept, not a reality. The impulse would last less than a Planck length of time, just as a "perfect" sine wave has to last for infinity time to produce one individual frequency with no sidebands. Both perfect sine waves and Dirac spikes are physically impossible and we have to deal with that reality. I don't know how mathematicians deal with it, though. I'm just a sound engineer, car mechanic and TH-cam commenter.
@@JimGriffOne you mentioned you were a sound engineer and just made me think of spike testing of acoustic environments to get data for convolving reverbs. So, yeah, the spike contains energy across the whole audio spectrum in one brief click, as you said.
We've already had the wave explanation on Sixty Symbols. But the notion of reciprocal space and the link between frequency and momentum was mind-blowing.
I know that the chance of professor Moriarty reading this is minimal, but for that small chance I would like to to express that his videos are by far the favorite for one with a bachelor in physics.
I normally zone out when watching most videos on Science (even if they're well made), but I have no trouble watching Sixty Symbols videos. Love this channel.
Finally we got a Sixty Symbols video on this that actually explains uncertainty properly! The amount of time I've spent understanding this concept makes me wish this was uploaded a few years ago...
The epiphany: *One can never hear a pure sine wave. Never has, never will!* This particular phrasing, although following naturally from the explanation, actually puts it as an even more astounding realisation. Any claimed 'pure' sine wave one hears is but truncated, so it's eventually divergent from the ideal sine wave that theoretically exists in temporal infinitude! Amazing!
Only it's not true. Science has proven that humans can hear up to 10 times faster than Fourier time-frequency Uncertainty. This demonstrates quantum coherence as noncommutative phase and study Penrose and Hameroff for details.
Loved this video. The Professor's passion and enthusiasm is captivating, and I genuinely found myself understanding more about uncertainty and quanta than before. Great work all involved.
I wish I had found this when I was an undergraduate physics major. Quantum mechanics was the only grade I got less than an A. I kept waiting for them to tell me why. Years later I read QED by Richard Feynman and accepted that no one knows why. This video gave me a grasp of uncertainly (40 years after) that had been elusive. I still wonder about QM - part of retirement is that I have the time to continue to wonder on the unanswered questions...
Hi, Joe. I remembered your comment under this video from a few months back and thought you might be interested in the material for "The Quantum World" module that I'm about to start teaching. Best wishes, Philip (Moriarty)
Im a Chem first year w no real physics background and I SO nearly have a comprehension of this but it keeps slipping away from me. One of the best videos I've found trying to get a handle on quantum mechanics - thank you.
Does this have anything to do with differential calculus? As we all know, it's about calculating the relation between two points where the distance between them is infinitely small? do we lose accuracy in calculating momentum? we don't know the time or the distance exactly for example, but we know the relation (speed) and that's all it matters.
You could also run the analogy of E.G. tapping on a table. Tap it once (Short duration or Time) and you'll get [in essence] every frequency. However, if you start tapping it faster (longer Time) you'll narrow the frequency range and begin to produce a specific tone(s).
I was lucky enough to have a physics teacher in school to show us that before I even went to university. I also like the recurring theme of "explaining physics with Heavy Metal."
I'm picturing it as a square with a set area. Push one side to be thinner and the area can't change so the other side expands out. It isn't helpful with understanding which properties have this effect but it helps make sense of why knowledge increasing in one aspect inversely impacts the other.
One of the things that took me the longest time to understand was that silence ALSO is a sum of sines. A lot of silence with a small bump is a very, very complicated sum of sines.
It is all but impossible to portray any aspect of quantum phenomena via the methods of language and macroscopic examples. However, in my 50 years as a nuclear physicist this is one of the best, possibly the best and well thought out examples that I have ever seen. Congratulations Mr Moriarty.
I envision it this way. In regards to location and momentum. A vehicle moving on a road. The more precisely that you are able to measure its location the less certain you are of its momentum.
@@ht3k I am not sure how many cool science teachers in India also love the legendary Canadian rock band, *Rush.* But it might be a fascinating study! ☺
velocity is distance divided by time. Distance is just the position1 minus position2 (the direction is irrelevant in this case), something like this: v=(r1-r2)/t. Now take the calculator and put values to r1 and r2 (position) and consider the t (time) as one defied constant. As r1 is closer to r2 you know more precisely the position, but then velocity (v) drops down. As you take more disperse values for r1 and r2, the velocity is better defined. There you go: velocity -> momentum, position->position). Just imagine yourself walking on the street and then your friend calls you asking where you are. You were just passing around the corner but by the time you said it to your friend you were actually done with the corner, because of your velocity you were less able to define your position, if you'd be less in a hurry, the information you said that you are passing around the corner would have been much more precise. Resuming: In order to have speed you must have different positions and in order to have your position you must not have velocity.
Furthermore, a harmonic note produced on a guitar by lightly tapping a vibrating string with your fingertip on let's say the 12th fret, would sound much closer to a pure sine wave compared to the same fundamental note if it was played lower down the neck. This is because the string vibrating in its fundamental mode would have more overtones and harmonics naturally being present. And the fundamental pitch you would be hearing is accompanied by more of these complex harmonics, which makes the waveform more complex and less sine-wave-like.
Love this natural science channel, his voice has the spirit of radio and the camera eye is working, man. Couldn't get the subdivisions between the different strings and the permanent waves tho. If time stand still we'll detect mystic rhythms?
In the end, we've got to learn the lessons and track those vital signs. I do the best I can but we never get something for nothing. It all comes down to our freewill and yet we just seem to keep losing it. But then the afterimage lingers and we're left with the scars...
Very cool video. Phil gets very excited about physics. Brady, you are becoming a knowledgeable astrophysics/quantum physics/chemistry journalist who is asking more perceptive questions than you did a few years ago. I like the cartoons too, very much. They often humorous and ironic as well as being illustrative.
This is unbelievably interesting and has real applications in my opera work. One aspect of vocal virtuosity is being able to articulate many notes in a short time, and vocal staccatos, that is notes plucked out of the air with no connection between them and the adjacent notes are considered especially challenging. Now I know exactly why. It is much more difficult to produce that exact package on frequencies with your vocal chords on a short note, than on a long sustained note. So I guess my question is, what simplifies that "package" that would make these short notes less demanding to produce? A purer/simpler fourier series. Is there a way of quantifying this mathematically, and then also aurally? It must be the case that certain sounds are easier to produce quickly than others. I guess it comes down partly to the purity of the vowel itself. Would love any input if anyone can offer any?
Something interesting: the plucked string presents purer frequencies, and the palm muted note requires more frequencies to describe it (thus widening the band). Yet the same hand played both notes intuitively, without considering about the math. Something creates these quantum objects effortlessly and perfectly without needing any mathematical restraint, even though we need the math to describe how it works. IDK if that is a redundant fact, but it fascinates me and speaks to the question of whether math is invented or intrinsic...
Let me see if I'm getting this right: The wave-like behaviors of the particles makes the location uncertain because the wave is spreading out and there's no way to tell where it originated, unless it's not moving at all in which case you can't tell how fast it's going.
I'm sure this is an excellent and elegant explanation, but if I were given to doing gratitude exercises, one thing I'd count tonight is that I don't have to understand this. Not for a class, not for a test. Because he lost me at the beginning and I never recovered despite listening to some of it twice. I thought he was going for the difference between a guitar sound and a whistle (in harmonic complexity) but he wasn't (so why bring it up??). He was saying a short guitar note has ... a less defined frequency than a long one? How can that possibly be? Their mix of frequencies is the same!!! OTOH, Fakjbf's comment example of a photo of a moving object makes PERFECT sense, but I have a feeling it's not what Prof. Moriarity was aiming at. He wanted frequency to have something to do with it, and a moving ball doesn't HAVE frequency. Or maybe it does. I have no idea anymore.
I've always been partial to Wavelet. You're inches away from it, too. You should cover it just cuz it's so cool. Start with Haar and work up to Ingrid Daubechies.
I can tell this person is a great lecturer. Passionate, able to simplify stuff star trek style XD Any other person would overload my short term memory and prevent much of it going into my long term memory as the body would not be able to process such a huge amount of information.... like trying to put gravel through a sieve.
Phillip said something without realizing it. He's trying to measure position of the string on a guitar, but when he uses his pick, it doesn't change the strings position, he changes its shape. When Phillip whistles, he's altering the medium of the air around him. The recorder is picking up the alteration to the air. We're trying to measure these things we call electrons/photons/etc. What if we are fundamentally incorrect in our view of what it is, and thus measuring it incorrectly? Imaging that we can only use a seismometer to measure animals. Different animals would give different readings. However, we wouldn't be able to really grasp what the animals are by only using a seismometer.
Wasn't there a very similar video uploaded before on this channel. I remember Professor Moriarty talking about the uncertainty principle and how it was similar in everything with wave properties.
it is however impossible to create a perfect square wave from loads of sine waves. You can only approximate the square wave. This by the way, is why the Yamaha DX7 synthesizer sounded so different. It was based on mixing a number of sine waves to generate any other waveform. And it could never quite make a pure square wave so it sounded different, and fantastic I might add. It was called FM which stands for Frequency Modulation and it was based on Fourier Analysis. I can recommend any keyboard player to dive into that a bit more.
It works the same in politics, economics, military, ecology, etc. Once you know the co-inverted (harmonic) principles, you can predict the relative functionalities of the systems and their probable comparative performances. Generally speaking, more complex and diverse systems are also more robust and enduring, but they are also harder to control. Likewise, highly controlled and/or heavily bounded systems are markedly more unstable. Sometimes the diametric variances over time can be juggled to some extent, but this is also a form of control that leads to further levels of instability. In the histories of societies and empires, Persia was never going to conquer the Greek city-states; and the Soviet Block was never going to overcome NATO. Within a society, free people outproduce slaves, and agnosticism erodes religions. In architecture, a building that is designed tightly in isolation will not be as functional as one that is more open and adapted to the landscape. In agriculture, mono-cropping leads to famine and collapse. In biology, predators with a single prey are more vulnerable to extinction. GI Joe used to say, "Knowing is half the battle." The weird truth is that leaving room to not-know is often the other half. This is how Lao Tzu realized that the better ruler (or manager, sage, gardener) is the one who acts "lightly." This is not philosophy. This is physics. The ability to improvise within a loose but functional framework is a key ingredient to success. It also makes the best music :)
I am not sure I understand the sound analogy. I am getting sharpest possible spike in fourier analysis even for just one period, if I set the window I analyse to EXACTLY one period of the sinewave. That guitar analogy seems just wrong to me. How I see it - they were not analyzing just the wave, but the wave multiplied by decay envelopes. Those envelopes could also be considered a kind of (subsonic) waves. Fast envelope (strings blocked by palm) is like having our pure wave multiplied by a faster wave vs slow decay (not blocking strings) is like having our original wave multiplied by a slow wave. And (like in ring modulator in analog, or just multiplying samples in digital) it is known that when we multiply values of two waves with frequencies f1 and f2, the result will contain f1+f2 and f1-f2 ... and that's why it gets broader in fourier analysis, because if the note would be 200 Hz and the decay would envelope would be 1/4 of second long (so something like 4Hz) then we would get 196 Hz + 204 Hz in the result. But if the decay is 4 seconds long, it's something like 1/4 Hz and on fourier we'd see 199.75 Hz and 200.25 Hz which are closer to each other, so it seems less broad. By the way, the device which professor used in "another sound of bonding" video for transposing into audible range, is based on this same principle.
You always ask great questions to your guests. Suspiciously great questions... My question is are you studying before your interviews or do you cut your bad questions, hmm?
Jokeritu I think it comes much more natural since they’re all in the same university. They basically speak the same language academically speaking. It’s a matter of understanding about the subject. I guess.
Brady's doing this for so many years already (I wonder when this channel started? I started following it around 201...3?) that he's learned about the things quite a bit himself - and also about asking great questions. I think Brady's questions have been getting better and better over time.
Phil on Unmade Podcast: th-cam.com/video/_cevGdtPyuk/w-d-xo.html
Id like to hear Phil talk about how the uncertainty principal relates to wireless data transfer. The faster the data rate, such as in video transmission, the more spread out the bandwidth is. Therefore you have a high loss transfer. In low data rates, you can have a tight spectrum and have lossless transfer.
Top marks for explaining physics soundwaves with metal chugs and top marks for playing an epiphone elite with the international headstock, it's a rare guitar and it's a great one as well.
Try this, professor: four -- eee --:eh (eh sounds like the long A sound, as in space)
I think a neat description of how momentum and position are inversely related can be shown with a photograph. If you throw a ball and take a photo in mid air with a camera that has an infinitesimally small shutter time, you will have a perfectly clear picture of the ball. You will know it’s position at that moment in time with 100% accuracy, but you can’t know anything about how fast it was moving. If you take a photo with a larger shutter time, the picture of the ball will be smeared a bit. You can measure the length of that smear, and by also knowing the shutter time you can get how fast the ball was moving. But if you try and say “Where was the ball when the photo was taken?” you have to gesture to the entire smear because it wasn’t in only one spot.
The trick then is showing why this example is relevant to the quantum world.
You made this so easy
But doesn't your ball actually still have definite positions and momentum regardless of the methods to measure them? An oscillation doesn't. Maybe if you got the ball bouncing to some rhythm and tried to locate the rhythm, then you'll see that the position of the ball is not the 'reduced' position of the oscillation.
Also, the real trick is showing why quantum mechanics is relevant to the real world, not the other way around.
It's an analogy, it's not "This is literally how it works". It's just a way to visualize the relationship if you have a hard time thinking directly in terms of sine waves. And no, it goes both ways equally.
Well, really It only goes both ways if you're not scientific and 'believe' in QM theory.
The position is absolute. You can not say that this is somewhere over there. It's like record a video of a race car, you can only find the position (absolute) with one frame, if you use all frames you can determine the velocity but can not find the absolute position.
Edit: I was explaining the analogy itself and not the uncertainty of the particles.
I think you got your Fouriers wrong. The picture you gave us is the Utopian Socialist François Marie Charles Fourier. The person he's most likely talking about is Jean-Baptiste Joseph Fourier. Two completely different people.
Lol yeah. This fourier is a very boncus guy indeed
Brady's bad - mea culpa!
hawk eye
But really, how certain can we be?
LOL
What a knowledgeable djentleman.
Nice to see another djentleman...
Thall.
What a djentlemanly thing to say
haha
i love when professor Moriarty explains really complicated quantum physics with metal music and instruments.
After 3 quantum mechanics courses and 3 classes going over Fourier series heavily, this is the first time I feel like I’ve deeply understood the uncertainty principle…
This was more enlightening than several dozens of videos on the Uncertainty Principle that I've seen before. Thank you!
This video is supremely important for anyone at the beginning of studying physics in university.
Phil's seamless joining of Fourier transfers, wave mechanics and Heisenberg has opened a little door in my head that 'shines light' onto the information I've been studying.
Bloody good job, kudos to prof. Moriarty.
GREAT! I find it so heartwarming that dedicated and experienced scientists try to communicate their understanding with art and music to make it easier to understand for everyone!
I've just noticed the title of the slide (I think)! "From Fourier to Fear Factory" haha brilliant!
I wish I had a science teacher with the same passion and enthusiasm as Philip Moriarty when i was at school, rather than open a textbook up and read away... It would most likely have changed my career path.
He's a pleasure to listen to.
When I first became a ham radio operator the idea that a morse code signal had *_any_* bandwidth confused me. Morse code transmissions intentionally don't switch very rapidly. This minimises "splatter" to either side of the radio dial. If you increase your sending speed (let's say from 5 to 45 words per minute) without switching faster, the dots and dashes begin to run together. At faster speeds you need to switch more quickly to transmit an understandable signal. The signal becomes more complex and takes up more bandwidth. Mathematically speaking, it takes more sine waves to recreate the original signal the faster it's switched on and off.
Similar restrictions exist with modulation of any kind. You can only send information at less than half of the carrier wave frequency (The Nyquist frequency).
Exactly. Thanks to the net it's fairly common knowledge now but back in the 1970's it was easier to experience it in practice. Hearing some fool CBer wipe out three channels to either side while splattering across the entire band because he thought overdriving the finals of an illegal linear amplifier would give him more power will drive home the concept much better than a TH-cam video.
Yeah that must have been easier to understand in practice... because I have no idea what you're talking about.
@what else is on think about the fourier transform from the video and how the short guitar note made a wider fourier transform than the longerone. The radio "bands" are supposed to transmit the information on a specific frequency, so whoever is listening can filter out other frequencies. Shorter / faster input would make the fourier transform wider, hence if it got too wide, other bands could get polluted. Not sure what "illegal linear amplifier" is but I guess the concept is that the extra noise it would cause outside of the target frequency when interpreted from the fourier transform would be annoying to other people trying to receive different information through nearby frequencies.
"Particles starrt to behev like wehvs"
Accents are tribal are disgusting because they're performative and you should speak clear and concise rather than pretending you can't
I am a 2nd yr undergraduate student and this cleared up all concepts of Fourier transforms. Thank you so much.
I love Professor Moriarty's passion. You can feel his excitement.
I‘m a chemistry student (albeit leaning very heavily into Prof. Moriarty‘s field of quantum effects and nanoscience etc) and I have to say: this video has had such a profound impact on my intuitive understanding of uncertainty relations and Fourier transforms. Understanding the maths is one thing, but getting an intuitive grasp of the situation, a sort of big picture on it, really really helped me put all the various maths in context. I cannot understate how much of an impact this video has had on me. More like this, please!
14:10 atoms, momentum and things like that, they are waves of... THE MUSIC OF AINUR
For those that are interested, a true sine wave lasts for an infinitely long period of time. If it starts and stops, other frequency content is introduced and it's no longer a sine wave. The opposite of a sine wave is a Dirac spike, which lasts for an infinitely short period of time. This produces a horizontal line that rises and falls on an FFT, whereas a perfect sine wave creates a vertical line.
Jim Griffiths
How does a wave ‘know’ it has an end? When I have a sine wave that lasts for only 10 sec, then during those 10 sec the wave must be pure/true.
If it was not and the uncertainty of the wave would be present before the cutoff, then we would have communicated information from the future.
So only after the 10 sec have passed can the stop be detected. Else I could detect the stop before it happened, but then decide not to stop, thereby creating a paradox.
@@Laurenss23
The sine wave, when measured as it's playing, is perfect. But it has to be measured in its entirely, otherwise it's like measuring just part of something but not the ends.
There is a wide bandwidth on the start of a sine wave that quickly narrows but it never reaches a true single frequency. It always has sidebands because we aren't measuring it lasting for infinity seconds.
It's the same for Dirac spikes. We can never produce an infinitely short-lived impulse because it's a mathematical concept, not a reality. The impulse would last less than a Planck length of time, just as a "perfect" sine wave has to last for infinity time to produce one individual frequency with no sidebands.
Both perfect sine waves and Dirac spikes are physically impossible and we have to deal with that reality. I don't know how mathematicians deal with it, though. I'm just a sound engineer, car mechanic and TH-cam commenter.
@@GammaPunk
Nope. It's a perfectly flat line covering the whole frequency spectrum from zero to infinity Hz, rising and falling instantaneously.
@@JimGriffOne you mentioned you were a sound engineer and just made me think of spike testing of acoustic environments to get data for convolving reverbs. So, yeah, the spike contains energy across the whole audio spectrum in one brief click, as you said.
Glad you guys did a video on this. I have been saying for years that this is the easiest way to understand this.
W E H V S
S T R Y P E R
T O M B R U H
S P Ë H S
VAFS
Ok
We've already had the wave explanation on Sixty Symbols. But the notion of reciprocal space and the link between frequency and momentum was mind-blowing.
This is a really good explanation, one of the best videos yet
We’ve got a new classic right here
I know that the chance of professor Moriarty reading this is minimal, but for that small chance I would like to to express that his videos are by far the favorite for one with a bachelor in physics.
I normally zone out when watching most videos on Science (even if they're well made), but I have no trouble watching Sixty Symbols videos. Love this channel.
Nice Ok computer image
This is awesome. I will share this with my physics class. Thank you so much!!!!!
Finally we got a Sixty Symbols video on this that actually explains uncertainty properly! The amount of time I've spent understanding this concept makes me wish this was uploaded a few years ago...
The epiphany: *One can never hear a pure sine wave. Never has, never will!*
This particular phrasing, although following naturally from the explanation, actually puts it as an even more astounding realisation. Any claimed 'pure' sine wave one hears is but truncated, so it's eventually divergent from the ideal sine wave that theoretically exists in temporal infinitude! Amazing!
Only it's not true. Science has proven that humans can hear up to 10 times faster than Fourier time-frequency Uncertainty. This demonstrates quantum coherence as noncommutative phase and study Penrose and Hameroff for details.
Loved this video. The Professor's passion and enthusiasm is captivating, and I genuinely found myself understanding more about uncertainty and quanta than before. Great work all involved.
FFT and music pave the path to understanding reality. Metal kicks it into high gear.
Best video about uncertainty principle on TH-cam
I wish I had found this when I was an undergraduate physics major. Quantum mechanics was the only grade I got less than an A. I kept waiting for them to tell me why. Years later I read QED by Richard Feynman and accepted that no one knows why. This video gave me a grasp of uncertainly (40 years after) that had been elusive. I still wonder about QM - part of retirement is that I have the time to continue to wonder on the unanswered questions...
Hi, Joe.
I remembered your comment under this video from a few months back and thought you might be interested in the material for "The Quantum World" module that I'm about to start teaching.
Best wishes,
Philip (Moriarty)
Im a Chem first year w no real physics background and I SO nearly have a comprehension of this but it keeps slipping away from me. One of the best videos I've found trying to get a handle on quantum mechanics - thank you.
Been watching sixty symbols for a while think this is the best video you’ve ever uploaded
Thinking about this and Tolkien lore is really cool. Turns out the real world can be thought of as being made through music in a sort of way too.
Does this have anything to do with differential calculus? As we all know, it's about calculating the relation between two points where the distance between them is infinitely small? do we lose accuracy in calculating momentum? we don't know the time or the distance exactly for example, but we know the relation (speed) and that's all it matters.
Great presentation on a hard to conceptualize subject. Thank you very much.
You could also run the analogy of E.G. tapping on a table. Tap it once (Short duration or Time) and you'll get [in essence] every frequency. However, if you start tapping it faster (longer Time) you'll narrow the frequency range and begin to produce a specific tone(s).
Best explanation on the topic I’ve ever seen.
I'm a huge fan of all the science/math channels you guys have on here -- and this is one of your best vids yet! Awesome work & great explanations.
3blue1brown made an awesome video about this, except he went more for the math part with Fourier Transformations
Well you share the link of that video?
i'm very much into music and science, the relationship between both always stuns me.
I was lucky enough to have a physics teacher in school to show us that before I even went to university. I also like the recurring theme of "explaining physics with Heavy Metal."
*WOW - I understood that* I even understood how Planks Constant related to momentum and frequency - what an amazing explanation...
I'm picturing it as a square with a set area. Push one side to be thinner and the area can't change so the other side expands out. It isn't helpful with understanding which properties have this effect but it helps make sense of why knowledge increasing in one aspect inversely impacts the other.
this is why i absolutely enjoy this channel. fantastic video
One of the things that took me the longest time to understand was that silence ALSO is a sum of sines. A lot of silence with a small bump is a very, very complicated sum of sines.
He was and will always be my favorite professor, but I'm not even 2 minutes in and he's won my heart 🤘
This is probably the most informative 60symbol videos I watched . The way it was broke down awsome
THANK YOU for these bridges, that's what makes my picture far more complete.
Wow. That was the best analogy I have ever seen.
What an amazing explanation!!! Best one out there ! Phil you rock !
It is all but impossible to portray any aspect of quantum phenomena via the methods of language and macroscopic examples. However, in my 50 years as a nuclear physicist this is one of the best, possibly the best and well thought out examples that I have ever seen. Congratulations Mr Moriarty.
The best explanation of the uncertainty principle. Well done.
I envision it this way. In regards to location and momentum. A vehicle moving on a road. The more precisely that you are able to measure its location the less certain you are of its momentum.
I'm 16 and i love this channel a lot! Wish teachers in India were like this
He has a PhD in Physics so... that's part of the reason
@@ht3k
I am not sure how many cool science teachers in India also love the legendary Canadian rock band, *Rush.* But it might be a fascinating study! ☺
samitmohan I doubt there are too many high school teachers like professor Moriarty anywhere...
...Must not make detective reference...
Yeah but Indian science teachers are agh.
ok?
Oh. Thats funky. My mind is blown. Thanks Prof.
velocity is distance divided by time. Distance is just the position1 minus position2 (the direction is irrelevant in this case), something like this: v=(r1-r2)/t. Now take the calculator and put values to r1 and r2 (position) and consider the t (time) as one defied constant. As r1 is closer to r2 you know more precisely the position, but then velocity (v) drops down. As you take more disperse values for r1 and r2, the velocity is better defined. There you go: velocity -> momentum, position->position). Just imagine yourself walking on the street and then your friend calls you asking where you are. You were just passing around the corner but by the time you said it to your friend you were actually done with the corner, because of your velocity you were less able to define your position, if you'd be less in a hurry, the information you said that you are passing around the corner would have been much more precise.
Resuming: In order to have speed you must have different positions and in order to have your position you must not have velocity.
Best explanation of the Uncertainty Principle yet.
I agree with Phil. This should be taught earlier on. I first really hear it on TH-cam years after I graduated
Furthermore, a harmonic note produced on a guitar by lightly tapping a vibrating string with your fingertip on let's say the 12th fret, would sound much closer to a pure sine wave compared to the same fundamental note if it was played lower down the neck.
This is because the string vibrating in its fundamental mode would have more overtones and harmonics naturally being present. And the fundamental pitch you would be hearing is accompanied by more of these complex harmonics, which makes the waveform more complex and less sine-wave-like.
So THAT'S how metal guitarists make that sound! That was almost more enlightening than the rest of the video!
Love this natural science channel, his voice has the spirit of radio and the camera eye is working, man. Couldn't get the subdivisions between the different strings and the permanent waves tho. If time stand still we'll detect mystic rhythms?
In the end, we've got to learn the lessons and track those vital signs. I do the best I can but we never get something for nothing. It all comes down to our freewill and yet we just seem to keep losing it. But then the afterimage lingers and we're left with the scars...
Ok. Now I'm going to buy a guitar. Excellent analogy! First time I've wrapped my head around this principle. So, thank you!
Very cool video. Phil gets very excited about physics. Brady, you are becoming a knowledgeable astrophysics/quantum physics/chemistry journalist who is asking more perceptive questions than you did a few years ago. I like the cartoons too, very much. They often humorous and ironic as well as being illustrative.
Learned something new today about something I got taught decades ago.
Very nice presentation...Thank you professor....
Lovely discussion of uncertainty. Thank you
I will have to watch this again a couple of times. I feel that this is an important video
It's been a long time. We need more Sixty Symbols videos!
Great illustration of an elusive concept
The best explanation I ever saw of this principle used radar to illustrate the point. Sadly, I can't find the video now.
In fast jazz solos the notes you play do not all matter - the timing is much more important base the ear will also be able to tell that easier.
This whole video is a beautiful composition.
That was actually really helpful, thanks
This is unbelievably interesting and has real applications in my opera work. One aspect of vocal virtuosity is being able to articulate many notes in a short time, and vocal staccatos, that is notes plucked out of the air with no connection between them and the adjacent notes are considered especially challenging. Now I know exactly why. It is much more difficult to produce that exact package on frequencies with your vocal chords on a short note, than on a long sustained note. So I guess my question is, what simplifies that "package" that would make these short notes less demanding to produce? A purer/simpler fourier series. Is there a way of quantifying this mathematically, and then also aurally? It must be the case that certain sounds are easier to produce quickly than others. I guess it comes down partly to the purity of the vowel itself. Would love any input if anyone can offer any?
Something interesting: the plucked string presents purer frequencies, and the palm muted note requires more frequencies to describe it (thus widening the band). Yet the same hand played both notes intuitively, without considering about the math. Something creates these quantum objects effortlessly and perfectly without needing any mathematical restraint, even though we need the math to describe how it works. IDK if that is a redundant fact, but it fascinates me and speaks to the question of whether math is invented or intrinsic...
Let me see if I'm getting this right:
The wave-like behaviors of the particles makes the location uncertain because the wave is spreading out and there's no way to tell where it originated, unless it's not moving at all in which case you can't tell how fast it's going.
That glas of honey on the book shelf....
Very nice expained!
I'm sure this is an excellent and elegant explanation, but if I were given to doing gratitude exercises, one thing I'd count tonight is that I don't have to understand this. Not for a class, not for a test. Because he lost me at the beginning and I never recovered despite listening to some of it twice. I thought he was going for the difference between a guitar sound and a whistle (in harmonic complexity) but he wasn't (so why bring it up??). He was saying a short guitar note has ... a less defined frequency than a long one? How can that possibly be? Their mix of frequencies is the same!!! OTOH, Fakjbf's comment example of a photo of a moving object makes PERFECT sense, but I have a feeling it's not what Prof. Moriarity was aiming at. He wanted frequency to have something to do with it, and a moving ball doesn't HAVE frequency. Or maybe it does. I have no idea anymore.
I've always been partial to Wavelet. You're inches away from it, too. You should cover it just cuz it's so cool. Start with Haar and work up to Ingrid Daubechies.
I can tell this person is a great lecturer. Passionate, able to simplify stuff star trek style XD
Any other person would overload my short term memory and prevent much of it going into my long term memory as the body would not be able to process such a huge amount of information.... like trying to put gravel through a sieve.
Love the Rush shirt.... (says the Canadian.... ) :0)
Emanuel de Matos He’s a feminist AND a Rush fan, ugh could he be more wrong?
@@Mortiis558 Hey! Rush is great! You watch it, buddy! >.
Kristopher Poulsen I’m not your buddy, guy!
Mortiss558 - you may not be a fan of their music, but it's hard to deny that they're masters of their instruments.
justyo96 They know how to play their instruments decently. But I’ve never been blown away by anything I’ve heard.
I'm liking the Quentin Blake style graphics
Phillip said something without realizing it. He's trying to measure position of the string on a guitar, but when he uses his pick, it doesn't change the strings position, he changes its shape. When Phillip whistles, he's altering the medium of the air around him. The recorder is picking up the alteration to the air.
We're trying to measure these things we call electrons/photons/etc. What if we are fundamentally incorrect in our view of what it is, and thus measuring it incorrectly? Imaging that we can only use a seismometer to measure animals. Different animals would give different readings. However, we wouldn't be able to really grasp what the animals are by only using a seismometer.
You brought up stryper!! Excellent!!!!
Amazing way to explain the concept.
Love your videos, always something interesting, keep doing what your doing!
Thank you for leading me this video.
Wasn't there a very similar video uploaded before on this channel. I remember Professor Moriarty talking about the uncertainty principle and how it was similar in everything with wave properties.
Awesome video. Deep ideas, but still accessible.
it is however impossible to create a perfect square wave from loads of sine waves. You can only approximate the square wave.
This by the way, is why the Yamaha DX7 synthesizer sounded so different. It was based on mixing a number of sine waves to generate any other waveform. And it could never quite make a pure square wave so it sounded different, and fantastic I might add.
It was called FM which stands for Frequency Modulation and it was based on Fourier Analysis. I can recommend any keyboard player to dive into that a bit more.
Everything i love in one video, math, music and Q. fisics.
6:03 Anyone knows which spectrum analyser and oscilloscope software was used here?
Why would it matter - its all low frequency stuff, any package can easily do it.
An awesome professor
about time we had another video
It works the same in politics, economics, military, ecology, etc. Once you know the co-inverted (harmonic) principles, you can predict the relative functionalities of the systems and their probable comparative performances. Generally speaking, more complex and diverse systems are also more robust and enduring, but they are also harder to control. Likewise, highly controlled and/or heavily bounded systems are markedly more unstable. Sometimes the diametric variances over time can be juggled to some extent, but this is also a form of control that leads to further levels of instability.
In the histories of societies and empires, Persia was never going to conquer the Greek city-states; and the Soviet Block was never going to overcome NATO. Within a society, free people outproduce slaves, and agnosticism erodes religions. In architecture, a building that is designed tightly in isolation will not be as functional as one that is more open and adapted to the landscape. In agriculture, mono-cropping leads to famine and collapse. In biology, predators with a single prey are more vulnerable to extinction. GI Joe used to say, "Knowing is half the battle." The weird truth is that leaving room to not-know is often the other half.
This is how Lao Tzu realized that the better ruler (or manager, sage, gardener) is the one who acts "lightly." This is not philosophy. This is physics. The ability to improvise within a loose but functional framework is a key ingredient to success. It also makes the best music :)
I am not sure I understand the sound analogy. I am getting sharpest possible spike in fourier analysis even for just one period, if I set the window I analyse to EXACTLY one period of the sinewave. That guitar analogy seems just wrong to me. How I see it - they were not analyzing just the wave, but the wave multiplied by decay envelopes. Those envelopes could also be considered a kind of (subsonic) waves. Fast envelope (strings blocked by palm) is like having our pure wave multiplied by a faster wave vs slow decay (not blocking strings) is like having our original wave multiplied by a slow wave. And (like in ring modulator in analog, or just multiplying samples in digital) it is known that when we multiply values of two waves with frequencies f1 and f2, the result will contain f1+f2 and f1-f2 ... and that's why it gets broader in fourier analysis, because if the note would be 200 Hz and the decay would envelope would be 1/4 of second long (so something like 4Hz) then we would get 196 Hz + 204 Hz in the result. But if the decay is 4 seconds long, it's something like 1/4 Hz and on fourier we'd see 199.75 Hz and 200.25 Hz which are closer to each other, so it seems less broad. By the way, the device which professor used in "another sound of bonding" video for transposing into audible range, is based on this same principle.
He rarely makes sense and his analogies are mostly wrong.
Cool Proffs! Love their enthusiasm!
You always ask great questions to your guests. Suspiciously great questions... My question is are you studying before your interviews or do you cut your bad questions, hmm?
Jokeritu I think it comes much more natural since they’re all in the same university. They basically speak the same language academically speaking. It’s a matter of understanding about the subject. I guess.
Brady's doing this for so many years already (I wonder when this channel started? I started following it around 201...3?) that he's learned about the things quite a bit himself - and also about asking great questions. I think Brady's questions have been getting better and better over time.
Pyry Kontio exactly!