The Uncertainty Principle and Waves - Sixty Symbols
Вставка
- Опубліковано 4 жов 2018
- Professor Philip Moriarty on uncertainty.
Phil on Unmade Podcast: • 17: Evil Genius (with ...
Phil's book: amzn.to/2OaeXSb
More links and info below ↓ ↓ ↓
Patreon: / sixtysymbols
Previous uncertainty videos on Sixty Symbols:
• Measuring Error Bars w...
• Uncertainty - Sixty Sy...
• Heisenberg's Microscop...
More Philip Moriarty on Sixty Symbols:
bit.ly/Prof_Moriarty
Visit our website at www.sixtysymbols.com/
We're on Facebook at / sixtysymbols
And Twitter at / sixtysymbols
This project features scientists from The University of Nottingham
bit.ly/NottsPhysics
Sixty Symbols videos by Brady Haran
www.bradyharanblog.com
Additional editing and animation by Pete McPartlan
Email list: eepurl.com/YdjL9
Wrong Fourier is depicted - sorry Jean-Baptiste Joseph Fourier for showing François Marie Charles Fourier instead! - Наука та технологія
Phil on Unmade Podcast: ua-cam.com/video/_cevGdtPyuk/v-deo.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 love when professor Moriarty explains really complicated quantum physics with metal music and instruments.
What a knowledgeable djentleman.
Nice to see another djentleman...
Thall.
What a djentlemanly thing to say
haha
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
This was more enlightening than several dozens of videos on the Uncertainty Principle that I've seen before. Thank you!
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!
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…
We’ve got a new classic right here
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
I love Professor Moriarty's passion. You can feel his excitement.
"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
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.
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 UA-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.
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 UA-cam commenter.
@@BlazeOrangeDeer
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.
FFT and music pave the path to understanding reality. Metal kicks it into high gear.
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.
This is a really good explanation, one of the best videos yet
14:10 atoms, momentum and things like that, they are waves of... THE MUSIC OF AINUR
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 am a 2nd yr undergraduate student and this cleared up all concepts of Fourier transforms. Thank you so much.
Great presentation on a hard to conceptualize subject. Thank you very much.
Glad you guys did a video on this. I have been saying for years that this is the easiest way to understand this.
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...
He was and will always be my favorite professor, but I'm not even 2 minutes in and he's won my heart 🤘
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.
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 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.
this is why i absolutely enjoy this channel. fantastic video
This is awesome. I will share this with my physics class. Thank you so much!!!!!
THANK YOU for these bridges, that's what makes my picture far more complete.
Love your videos, always something interesting, keep doing what your doing!
Been watching sixty symbols for a while think this is the best video you’ve ever uploaded
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 probably the most informative 60symbol videos I watched . The way it was broke down awsome
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.
It's been a long time. We need more Sixty Symbols videos!
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.
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
The best explanation of the uncertainty principle. Well done.
Great job guys!!! You're simply amazing!!!!
Lovely discussion of uncertainty. Thank you
Cool Proffs! Love their enthusiasm!
Best video about uncertainty principle on UA-cam
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 understand how much of an impact this video has had on me. More like this, please!
Oh. Thats funky. My mind is blown. Thanks Prof.
Best explanation on the topic I’ve ever seen.
Good vid. Lots in there - link to classical waves, Fourier transforms, wavefunctions, normalisation, complex conjugates. Really needed the minimum uncertainty though (h/4pi) to show that position can't be locked to a single point (momentum=0). This is a BIG one for explaining minimum energy states, bound states, and quantum phenomena. Good excuse to do a follow up and a chance to bring in Planck! :-)
It's the same for any oscillation tho, not unique to 'quantum phenomena'.
Not disagreeing, and not really my point. I do think it is important to explain though - it's pretty fundamental to the uncertainty principle put forward by Heisenberg and shows it is not an infinitely sliding scale. You can never truly know the absolute exact value of any complementary variable.
Wow. That was the best analogy I have ever seen.
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."
Best explanation of the Uncertainty Principle yet.
I've just noticed the title of the slide (I think)! "From Fourier to Fear Factory" haha brilliant!
I will have to watch this again a couple of times. I feel that this is an important video
Amazing way to explain the concept.
What an amazing explanation!!! Best one out there ! Phil you rock !
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.
This whole video is a beautiful composition.
That was actually really helpful, thanks
insightful. love this. and what a bop too
Awesome video. Deep ideas, but still accessible.
Very nice presentation...Thank you professor....
Learned something new today about something I got taught decades ago.
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.
Thank you for leading me this video.
You brought up stryper!! Excellent!!!!
Everything i love in one video, math, music and Q. fisics.
So THAT'S how metal guitarists make that sound! That was almost more enlightening than the rest of the video!
This was so well done.
Ok. Now I'm going to buy a guitar. Excellent analogy! First time I've wrapped my head around this principle. So, thank you!
I'm liking the Quentin Blake style graphics
I agree with Phil. This should be taught earlier on. I first really hear it on UA-cam years after I graduated
wow i really learned something with reciprocal space there thanks!!
I'm loving the animation style
Very well explained
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.
I love this explanation!
well done with the images. They really made the content relatable.
wow i really learned something with partial space there thanks!!
Great illustration of an elusive concept
*WOW - I understood that* I even understood how Planks Constant related to momentum and frequency - what an amazing explanation...
Great metaphor and functional examples!
Loved this amazing video. But did you get your fouriers right?
about time we had another video
great explanation and analogies
This was simply beautiful
That glas of honey on the book shelf....
Very nice expained!
Beautiful explanation - and video editing. Absolutely love the bits of chaotic music. Who made those? Thanks for the video. :)
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 ever . Love it! Thanks ( for all the fish 😄 )
Great teacher.
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)
Well done!
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.
An awesome professor
You, sir, are legendary!!
11:47 that higher pitch dirty tone made me think of the highscore tune in the C64 game Samurai Warrior - The Battles of Usagi Yojimbo. :D
Sold I’m buying the book.
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.