Hi everyone, thank you very much for watching! If you'd like some more physics content, check out this video I made recently, discussing Potential Energy in 5 levels of difficulty: ruclips.net/video/Iu48lfJXgww/видео.html Also, do check out my quantum mechanics playlist here for more videos on this topic: ruclips.net/p/PLOlz9q28K2e4Yn2ZqbYI__dYqw5nQ9DST Finally, let me know what other topics to cover in future videos :)
When the box containing Schrodinger's cat's opened, the wave function collapses into a single spike. Please could you say how/if that spike is made out of a million sine waves added together?
Could you please do a video on general relativity and space time ripping as it reaches the ringularity or singularity inside a black hole? Please do explain the mathematics also in a intensive level. I mean the 4×4 matrix stuff, explained in simplicity like you usually do. And thanks a lot for such spectacular videos.🎉🎉
String theorist: "Maybe you are looking at the wrong dimension." Heisenberg: "Don't try to measure its velocity. You can't find it." Einstein: "God knows where it is."
Thanks,Parrth - very clear as always. Couple of comments: When you say 'check out this video here', and point, you points to nothing onscreen! Put the link in the comments, please! The other thing is would you number each video - so that we can see if we've missed any - and also, the correct order to view them for progressive understanding. Many thanks for all the good work. I wish you'd been around when I was doing undergrad physics. But you weren't even born then!
I don't know, I feel like wave functions "exist" because they're a useful model for the things they're useful for modeling. Like, the question of why wave functions are normalizable: if they WEREN'T normalizable, they'd be no good for describing particles that aren't uniformly detectable everywhere all the time. Before we had wave functions, we had the Bohr model of the atom, with electrons moving in tidy circles at fixed distances from the nucleus. And that was a great model ... until it wasn't. Then we found a better model. But both Bohr and wave functions are MODELS, which is to say, they have no reality of their own.
Well, technically, you've just described how modern science works,. You observe, hypothesise a model (with a test that defines a failure and that covers all we know to this point on the same subject), test and if it fails, reject or amend - if it passes, start over and do more observations and see if there are things the model missed..
@@TheoWerewolf I notice people talk about wave functions like they're real things with physical reality of their own, and I think I detect some of that in this video. Maybe this exposes a limited understanding on my part, but as far as I'm concerned, a wave function is nothing more than a versatile description of a quantum mechanical system, to the limits of our ability to measure it. So when people get into arguments about, say, the Many Worlds Hypothesis, I feel like they're confusing the map with the terrain: just because the wave function doesn't provide a great guide as to which event will be measured, doesn't mean that all events will actually take place somehow.
@@kingbeauregard - Can't your model vs reality argument be applied to our mathematical model of macroscopic physical reality as well? After all, neither space nor time can be physically detected - their existence must be inferred from our measurements of the behavior of the physical objects we can detect. Likewise, the existence of a complex-valued quantum domain can be inferred from the verifiable behavior of the subatomic particles described by the quantum wave function.
@@QuicksilverSG Well, sure, a good map is useful, but no map completely captures all the details of a thing. By all means, use a model; but be mindful of the shortcomings of a model.
Quick question: If we assume the electrons wave function must me normalizable, since we assume it is *somewhere* in the universe (if it was there before): What happens when it gets destroyed, say by hitting an anti-electron? Do you need to assume this electron is the only thing in the universe for the wave function to be normalizable?
Electrons are not "somewhere". They are not objects. Total electric charge is conserved (at least locally and with high precision for the energy range below 1TeV), but the charge of individual electrons is not. The "electron as an object" ontology is simply a 19th century leftover. You have to learn to avoid it.
Sorry for the late reply but, you are correct that in non-relativistic quantum mechanics, the time evolution of a system is described by the Schrödinger equation, and if the initial wave function of a particle is normalizable, it remains normalizable for all time. This implies that the probability of finding the particle exists throughout time. In the specific case of an electron and its corresponding antiparticle, the positron (anti-electron), their annihilation process cannot be described solely within non-relativistic quantum mechanics. The annihilation of an electron and positron involves the conversion of their mass into energy, and such processes require the inclusion of relativistic effects (mass energy conversion E = mc^2). A more advanced model. Quantum field theory.
If Parth does it, it’s going to be from a fundamental mathematics perspective not kindergarten analogies. So it would have to be about hyperbolic geometry and lorentzian transformations?
I did maths at Uni, maybe a quarter of a mile south of you, ending up as more of a mathematical physicist by the end. People talk to me about it as if maths is all about numbers and I correct them by telling them it's actually about starting with a set of assumptions and seeing how far we can get by applying logic to them. I'm sure it's the same for historians correcting people who think all they do is memorise stories and dates. It was good to see you starting this video off by saying pretty well the same thing about physics as I do about maths!
I don't know any channel in youtube that goes as deep as you go or talks about complex topics as you do. That's why I subbed and that's why you should keep going :)
Whenever I see a video or talk about Quantum Mechanics, it usually refers to everything theoretically - like an electron being constrained to being in a box etc etc. What I'd like to see is some 'real world' experiments that bring the Wave Function (and associated probabilty) alive. An example that brings electron spin alive is the Stern Gerlach experiment. What experiments bring Wave Functions and the Schrodinger equation alive?
I don’t think there are any (and that’s exactly why people disagree on interpretation of QM), unless you count the double slit experiment. And some are claiming even that is widely misunderstood, and that it doesn’t mean quite what others think it means.
I am surprised by your definition. My book says nothing about existence of a wave function, however, it does say, a system is described by one for QM to work. The big difference being "described" versus "exists". I mean the wave function is a tool, existence to me would imply it as a real thing, which it isn't.
A better way to look at it is "quantum systems all have a common property - that for certain properties of the system, the probability of finding the system in a given state can be described with a function and that function is derivable from a function that describes a wave-like distribution. We don't understand HOW systems that seem discrete and deterministic can work this way, but they do and this models their behaviour very accurately." I feel it's a mistake to go from the model to the real world as it leads to valuing the model over the experiment.
That's not the history of how we got here. We got here by combining three things from the real world and ended up with the model - not the other way around. First came the idea that an electron was a solid thing, but at the dawn of the quantum age, we were faced with two questions. Why did electrons cause unique spectral lines for each element? (They seem to occupy only unique energy levels around an atom.) Are electrons really waves? If true we can characterize them in orbit with a continuous function and we have a well-known equation for finding the mass of a standing wave on a stringed instrument, like a violin. That was the wave function applied to the electron and Schrödinger, along with others, expected it to work for experimental results. It failed. Now comes the third part - bridging a frequency (like a violin note) with a frequency (how often do you skip breakfast, what is the probability for that). If you look at time to frequency transform equations, you'll rapidly hit complex exponentials (specifically e^(-iωt) and you may recall that Ψ = e^i(kx-iωt)) and if you look at various probability equations, they often include exponential definitions. There's a reason for that. Anyway that's the piece that Born put together - instead of frequency description of a + ib pairs to describe spectral components, get the magnitude of the point from the origin and treat it as a probability value. That basically worked, that's how we got here. Avoid anyone telling you physicists don't look at the real world or only care about their models because that's just not true. That's the battle cry of con artists and pseudoscience. The map is not the territory. Parth is trying to explain a very nuanced situation before you're fully equipped to handle the nuances - and it does not matter how we got here at this level, only how to recognize the signposts of what is at this level. It's going to get a lot weirder and none of it is caused by a century of physicists worldwide forgetting or being too stupid to consider the real world. Hope that helps!
It should really be "for all properties of the system" Every physical property in QM is described by a wavefunction / the wavefunction of the system as a whole
There is a big gap in my understanding or particle physics regarding physical experimentation. Explainers of physics like yourself tend to describe things like electron spin, or quark colour without relating whether or not these things have been demonstrated experimentally or are just postulates. My knowledge of detection doesn't go much further than the cloud chamber. I'm sure there are far superior detectors these days, but what are they and on what principles do they work?
Our wave function is fundamentally a complex number, such that plotting the wave function should involve a real and imaginary component. Eulers formula tells us that we draw out a helix of sorts by plotting a complex function. If we filled in the volume contained by the helix, it should look the same as revolving our real component about the X-axis. The volume contained between any two cross sections as compared to the total volume would therefore be equivalent to taking the normalized square modulus of the real function. If the wave function is indeed rotational in nature (hence requiring complex numbers), then it seems the probability of finding a particle between any two points is just the percent of volume that space occupies as compared to the whole.
"Our wave function is fundamentally a complex number" is not the answer for the question in the video. It's just another assioma. The point is that the biggest probability of finding an electron is somehow assumed to be similar to the maximum intensity of a ligth radiation.Since a radiation behaves like a sinus function, the maximum intensity is given by the square of the maximum sinus amplitude. A good way to represnt this is the product: psi(cos ft - i sen ft) x psi(cos ft + i sen ft)= square psi, always positive.
6:48 The wave function does not "exist" as a physical entity exists, it is a mathematical model used to explain quantum phenomena, and make testable predictions.
The quantum wave functions exist otherwise we should not have interference phenomena in Young double slit experiments for example, there is no other explanations.
@@GH-li3wj The quantum wave function is a mathematical model of what is happening in the real world. The function itself does not exist in the real world. The quantum world is modeled by the function and some day we may find a better more complete mathematical model. Quantum phenomena will always be there but the FUNCTION may be obsolete. My point is that people tend to confuse the mathematical equations with the real world phenomena they model.
@@wayneyadams wave function is part of the reality otherwise you won't have interference. It's like number Pi Pi is not just a mathematical model, it is a part of the physical reality, without the Pi number you won't have waves , you won't even exist, and nothing else will replace this mathematical being as the Pi number.
@@GH-li3wj Please don't lecture me on Physics, I have an M.S. in physics and taught the subject for 33 years. Let me try this one more time. The wave function is a MATHEMATICAL MODEL OF THE REAL WORLD, it does not exist on its own, just as pi is not an actual object, but the result of a mathematical calculation. The reason I am so emphatic about this is because Physicists become so enamored with the math that they forget that results of calculations are meaningless unless they have testable results in the real world. As long as the wave equation is an accurate model that makes accurate (meaning testable) predictions it is useful, however, if there are predictions that are proven false, it would need to be modified, or in the worst case abandoned.
Love your videos! Can you do a video about the size of a photon, in terms of how many wavelengths exist? The single wavelength of a photon is well defined but the number of wavelengths seems rather vague and often described as a "wave packet" with just a few (5-10) wavelengths. There are various experiments that restrict the frequency bandwidth of the photon to very small values. A minimum (Fourier-limited) time-bandwidth product would seem to require a corresponding large number of wavelengths.
Following on from some of your recent videos, this question came to mind: given that E=mc^2, can Potential Energy be converted into mass or does the PE need to be converted into another form of energy before that transformation can happen? And if only some forms of energy can be converted to/from mass, what is the distinction given to the different forms of energy?
PE in a system contributes mass. E.g., if you can do relativistic kinematics, consider two relativistic masses (m) moving head on with +/- v. They collide via a massless spring that "catches" them with no losses, and is clamped shut at maximum compression: What is the final mass M of the system (2m + compressed spring)? If M > 2m, where is the mass-excess coming from? Can it be converted back to kinetic energy?
Don't take my word for it, but as far as I know, yes, potential energy does count. For example, a lot of the mass of a proton comes from interactions between quarks, which has a potential energy associated with the strong force.
You're confusing two concepts. Energy can be converted into _matter_ by creating particles or changing particles into heavier ones. Energy _is_ mass, always was, and you don't "convert" it. If you have a chemical battery, coiled spring, or anything else that contains potential energy, a careful enough measurement of its mass will indicate that the potential is contributing mass. For example, take a perfect closed box that nothing can enter or leave, not even neutrinos. You know nothing about what goes on inside but can measure the mass of the whole thing, via gravity. If a sample of uranium decays inside the box, the daughter elements are lighter but contain kinetic energy which you understand adds mass to the system. The mass of the box seen from outside is unchanged. Now also in the box is a generator and battery. The fast moving atoms spin the turbine and charge the battery while causing those daughter atoms to come to a near stop. The kinetic energy is gone, no atoms have changed into other kinds of atoms. But the box still registers the same mass. Now the excess mass is held by the potential chemical energy in the battery.
Pretty sure the wave function does not exist. Talk to me if you want to find out why I think so. The short answer is that the wave function summarizes our knowledge of a system, so it is epistemic, not ontic. People who assume it is ontic get into all sorts of trouble having to do cartwheels to justify their reasons. Not that they are wrong, I just have some thoughts why they are not doing physics, physics is not ontology, ontology is metaphysics. Longer answer is how I would show the wave function is only epistemic, and that takes longer than a YT comment. Not that I have a "proof," but I do have _an_ argument for how fairly ordinary physics can create _appearances of_ wave behaviour. Anyone can try this game: if you can justify why particles _seem to_ carry information like they were waves, but always get detected as particles, then you've shown the wave function is a convenient fiction, like all fields. Feynman was I think first to point this out as far as I know... the fields are auxiliary data propagated on Cauchy hypersurfaces, _necessary_ if you ask for a _Hamiltonian time evolution,_ so you should perhaps not ask! In the spacetime (least action) formulations there is no need for such data if you treat the fundamental interactions the way Feynman originally did. Why we _do_ ask for a Hamiltonian is partly tradition, but partly that old physics honey trap, which is that sometimes it is easiest to use a fiction to compute solutions. The spacetime or Lagrangian or least action formulation goes over to sum-over-paths in the quantum theory, and it is bloody hard to use the path integral approach in most cases, and if you have a Hamiltonian ready and available which you can just SHO mode expand, then I'd recommend using it! Just do not pretend it represents reality, don't take the fields too literally.
Good talk. I like that you presented qm as a model with postulates. When I try to explain it to people I go right to the particle in a box model, because that shows how boundary conditions dictate quantization. The problem is , many people dont know enough calculus to get the gist, which always makes me wonder why someone would try to tackle quantum mechanics...really ANY topic in physics....without a basic math background!
My personal belief - the wave function is a real wave in a field. The field is a real yet immaterial thing, or medium. This medium seems to be a superfluid, with closer resemblance to Bose-Einstein condensates than normal matter (there are others sharing this idea). This superfluid can explain dark matter. Particles? They don't exist. At least, they are not little objects. They are interactions of waves. Non-linear interactions, that is. Linear interactions are just normal interference. They are short-lived blips that take place at some place at some time, and look like "particles" only because they gather up energy to some threshold (quantized) value. What about atoms? Only the protons are stable and real particles, because they are not fundamental. They are trapped energy that keeps interacting with itself. And they trap "electrons", that don't exist (as particles). It's only around atomic nuclei things get quantized. Matter... It's trapped electromagnetic energy, like a tiny hotspot. Many hot yet tiny spots becomes a large boiling soup. Think of earth. This ball of matter is like a boiling pot in space. And due to all this energy, it becomes like bubbles in a pool of water that reduces the surface tension (used for practicing diving from hights) - the density gets lower. And if the density of the medium is lower close to earth, while getting denser with increased altitude... Guess what that is? Spacetime curvature and gravity. The only little piece that doesn't fit anywhere in this picture is special relativity. That's a theory that has to go. Lorentz ether theory still works though.
First rule of Quantum Mechanics is you do not understand Quantum Mechanics. Second rule of Quantum Mechanics is you do not understand Quantum Mechanics. Third rule of Quantum Mechanics, If you believe you understand Quantum Mechanics, you do not understand Quantum Mechanics.
IT IS SIMPLE, MY DEAR BROTHER! THE WAVE IS THE HUMAN CONSCIOUSNESS AND THE QUANTUM FIELD IS OUR "REALITY". YOU ARE TRYING TO FIND OUT THE "FORMULA" OF CREATING REALITY! SOME OF US ARE DOING IT NATURALLY. YOU, INSTEAD, ARE TRYING TO ESTABLISH A WRITTEN FORMULA USING PERSONAL SUPPOSITIONS. BLESSINGS!
Combine: 1. cosmological constant in Dxy [m^-2] = lp^2/λ^4= lp^2 nxy ^2 [m^2] [m^-4] 2. schrodinger solution 3. Planck E= h f= h n 4. n = number of superpositions = wave function frequency And you get: dark matter = superposition of the electron Dxy [m^-2] = lp^2/λ^4= lp^2 nxy ^2 [m^2] [m^-4] Nxy = sqrt(Dxy / lp^2)=. (Dxy / lp^2) ^0.5= [m^-1] [m^-1] = m^-2 Then nxy = sqrt ( 10^-52 / 10^ -70) = 10^18 ^0.5 = 10^9 Schrodinger solution: n^2 h^2 / ( 8 m L^2) = h n 8 m L^2 h n = n^2 h^2 m = n^2 h^2 /( 8 L^2 h n) m = n h 0.125 L^-2 m= 10^9 10-34 = 10^-25 ( all superpositions). 1 particle = 0.331 10^-25 / ( 0.4 10^9) = 0.828 10^-34 kg = 46 eV If you count only the positive wave function amplitudes: n = 10^4.5 then 1 particle = 0.331 10^-25 / ( 0.4 10^4.5) = 0.828 10^-30kg 5.6 10^35= 10^5 ev = 0.5 Mev Superposition of electron causes dark matter?
Extremely big RESPECT for this great video! Excellent explanation, without any superfluities and without the usual "you have to be funny when explaining something difficult" (firstly, it's usually not funny, secondly, it's always incredibly annoying and distracting). This is exactly how I would like to see explanatory videos in science and mathematics. Once again THANK YOU for this great work, I am looking forward to all the other videos on this channel (already available and upcoming).
Combine: 1. cosmological constant 2. schrodinger solution 3. Planck E= h f= h n 4. n = number of superpositions And you get dark matter n^2 h^2 / ( 8 m L^2) = h n m = 0.3313 10^18 10^-34 = 0.3313 10^-16 kg ( all superpositions). 1 particle = 0.331 10^-16 / ( 0.4 10^18) = 0.828 10^-34 kg = 46 eV
How can I contact you and have you help me articulate? My idea of the reason why wave function exists in a way that's concurrent. I do have an AI assistant. That's helping me with the math. Because I am a poet till. I look at the world through a different lens and not just a poet that writes verse. I am the odd fellow that frost spoke about. I have seen the world different since I was a child. I understand the wave function. I understand the drift. When I was a child I stared at a flower for 3 hours and my grandmother was shocked. And she asked me what I was looking at.I told her because I couldn't explain it that I saw all of the stars in there, but I was lost in the drift.I was in the wave.I understand what it is.I just don't understand how to explain it in the terms of physics yet.I'm using a I to help me.
Rule 1 about Q.M: you can never really know Quantum Mechanics. Rule number 2: You already know quantum mechanics. Rule number 3: you sometimes know quantum mechanics. Rule number 4: i don't know what im talking about, this is just quantum woo.
Hey bro.. am a physicist and did my master's from IIT Bhubaneswar. In the early times when was learning the quantum mechanics for the first time .. i usually Frustrated with QM. Unlike the classical mechanics it do not give any physical meaning. Many of questions becomes clear after reading Beiser and Shanker QM book. Your video is good enough for beginners who like to learn the quantum mechanics .... 💐
Quantum Mechanics is not to be understood. Quantum Mechanics is to be APPLIED. (by means of "shut up, sit down and calculate!") Thats what I learned when studying physics in the late 90s.
This is all ok - basic of quantum physics. But the question is, why is the Wave Function a function with complex number values? Wave function is not a field function with real values, like a gravitational field function with real number values, which calculates gravitational force in every point of the Universe. Wave function calculates something in a complex number space, not in real number space.
Hi, an intuitive way to understand Psi wavefunction is to think of it as an existence wave in 3D; that is the meaning of what Born said, it is a probability of existence in that 3D zone at a given time. So the wave is the oscillation of quantum 3D space between its 3D space and a 4th dimension that carries the essence of physical values, i.e., its total energy, total momentum, total charge, etc. That is what Schrodinger wavefunction is, an weirdness of QM will almost disappear. I read that in a short amazon book, "Space, main actor of quantum and relativistic theories. Since nature doesn't contain full information, on each fluctuation, the compact particle will assume an exact valid solution (eigenstates, eigenfunctions) and, from cycle to cycle, nature assumes aleatorily a different valid solution; one each time. The expectation value will be the average of all the eigenstates or the eigenvalues pondered by its probability. Imagine a twisting Einstein's dice, the top face will be in fluctuating changing value at a rate of its energetic frequency, the eigenvalues will be from one dot, up to six dots, its expectation value will be 3.5 dots, BUT never a superposition of all six possibilities, just one solution at a time at a frequency near 10^20 per second... think about it and QM is more understandable... maybe you will do a video about this new view-interpretation. Regards
You're assuming a lot more than just 1 postulate there. For instance, that there's such a thing as a quantum system to study, and that there are these definite measurements to take. Also, the Born rule there is being assumed as well. I think a better way would be to just have one wavefunction that obeys the Schrödinger equation, and then derive everything else. It works, has much fewer assumptions, and only has two questions left of "why is there a wavefunction, and why does it obey the Schrödinger equation?", which might just be philosophical questions.
Your title is both misleading and incorrect. Particles exist and have wavelike properties. Wave functions are some specific wavelike mathematical relations. Quantum theory tries to explain some particles' wavelike properties using some wave functions. Some people do know why particles exist and have wavelike properties. Search keywords: matter theory marostica.
Perhaps you didn't know but the wavefunction exists because it tells us how the particle responds to a measurement. This is what Schrodinger was saying in his famous 'heat' equation. I should say in my view.
They exist probably because light and emr are always observed to be a wave. And never a particle. So some way to take what’s observed ...ie waves,...and express it mathematically as a quanta of energy.
Using postulates in physics goes back to Archimedes, but it was Newton in Principia who established that physics follows the axiomatic method. Laws of physics are axioms. Einstein followed this principle as well. I would argue that the axiomatic method is a main component of the scientific method.
This is a good video but it’s a click bait title. The answer as to why comes from the history of science. Why did it replace the previous theory? Because, as indicated, it’s the best theory we have to explain objective reality. Why will it be replaced? Because something better is found. We don’t “assume it to be true”. That’s maths, not physics.
Hang about... If the area under that graph has to be equal to 1, how do we have particles popping in and out of existence? Say your electron happens to choose that exact moment in time to turn into a virtual photon and virtual electron, it's no longer there to be found. So what of the wave function then? Surely there is a probability that it won't have done that and the electron will be there so there has to be a wave function for that moment in time, but if it can disappear altogether for a bit how can the probability of its existence everywhere be 1? Wouldn't it have to be just a little less than 1? I hope that makes sense.
So it's a leap of faith, given the Schrodinger equation was seemingly pulled out of a hat. Why was this proposed with confidence in the first place. Let's get into it, how was it created.
unfortunately this is wrong. why? well, the wave function is a mathematical way of describing something that exists. it does not necessarily has an existence in itself. so it seems this is a formal way to describe physics that can be tested by experiments. the outcome of the experiments must be interpreted in that the theory describes the real world to a certain extent. not is equal to the real world. in other words, the map of germany is not germany.
Imagine if biology just assumed that the normal distribution was true? Would d that mean an individual's phenotype is in a superposition of genotype until we measure it ?
The reason why they insist on wave functions is because they are limited by what they can imagine and the limitations of our means of perception. Both qualities skew their attempts to figure out going on.
Parth G can you make a video on general relativity. I would like it if you would explain a bit more about the mathematics in simplicity like you usually do.
The mathematics of general relativity is tensor calculus. The channel MathTheBeautiful has an extremely in depth and intuitive explanation of tensor calculus. I learned the math of GR from his tensor calculus playlist, then I read a book about certain solutions to the field equations to fully understand the math.
ruclips.net/p/PLlXfTHzgMRULkodlIEqfgTS-H1AY_bNtq This is assuming you know multi-variable calculus, and the basics of differential equations, oh and maybe some linear algebra.
At 5:56, there is a wave function because Schrodinger designed it to model the waves of a medium. What medium? The electrical medium of Maxwell's Aether Electro-Magnetic field, i.e. electric charge density. When Max Born stole the WAVE equation to apply his "rule", he also applied the idea of *material particles* to WAVE math. How does that make any sense? Don't material particles bounce off each other when they collide? ...while waves in a medium will pass through each other...
material particles interact with a scattering amplitude. In the S.E., that would appear as a short (or not) range interaction V = V(|r1-r2|). With that interaction, asymptotic free-particle wave states scattering into one another. QM then says the amplitude connecting an initial state |i> to a final state |f> is , to 1st order. A second order correction would sum over all intermediate (aka virtual) states |k>: , and so on to all orders. Meanwhile, the asymptotic states remain eigenstates that don't overlap (e.g., superposition is fine):
@@DrDeuteron ** Is that "scattering amplitude" a velocity of a particle? ** "Wave state" of a particle? I can understand a "wave state" of a set of waves vibrating through a medium. Do you mean a particle wave-state, as in a billiard ball oscillating back and forth? ** So you are saying a "particle is the same thing as a wave"? Or that you can model the break-up of a set of billiard balls, just like waves through a medium?
I wish I had found this channel much earlier. Your explanations are clear, straightforward, and make sense. Thank you for doing this and keep those vids coming.
We have physical evidence that the quantum wave-function must exist in some operational sense. The interference patterns observed in Double-Slit experiments are produced by the complex-valued mathematics of the wave-function, which must operate in some underlying domain outside physical space-time.
The only sense in which wave functions "exist" is as part of the solution theory of quantum mechanical equations. They are primitive tools, too. They do, for instance, not make direct physical predictions. A cursory look into atomic/molecular/nuclear physics textbooks will show you that von Neumann's solution theory has to be translated to be actually physically useful.
Hi everyone, thank you very much for watching! If you'd like some more physics content, check out this video I made recently, discussing Potential Energy in 5 levels of difficulty: ruclips.net/video/Iu48lfJXgww/видео.html
Also, do check out my quantum mechanics playlist here for more videos on this topic: ruclips.net/p/PLOlz9q28K2e4Yn2ZqbYI__dYqw5nQ9DST
Finally, let me know what other topics to cover in future videos :)
When the box containing Schrodinger's cat's opened, the wave function collapses into a single spike. Please could you say how/if that spike is made out of a million sine waves added together?
Could you please do a video on general relativity and space time ripping as it reaches the ringularity or singularity inside a black hole? Please do explain the mathematics also in a intensive level. I mean the 4×4 matrix stuff, explained in simplicity like you usually do. And thanks a lot for such spectacular videos.🎉🎉
What's the implication of not setting it to one
Respect for you from India
Can you cover electromagnetism?
"I've lost my electron" "Where did you last have it?" "I'm not sure but I'm 100% certain it's somewhere in the universe"
String theorist: "Maybe you are looking at the wrong dimension."
Heisenberg: "Don't try to measure its velocity. You can't find it."
Einstein: "God knows where it is."
If it ran into a proton in a nucleus at just the wrong moment and participated in inverse beta decay, you're out of luck.
@@user-yt198 Richard Dawkins: "God doesn't exist, therefore you cannot find your particle."
Thanks,Parrth - very clear as always. Couple of comments: When you say 'check out this video here', and point, you points to nothing onscreen! Put the link in the comments, please! The other thing is would you number each video - so that we can see if we've missed any - and also, the correct order to view them for progressive understanding. Many thanks for all the good work. I wish you'd been around when I was doing undergrad physics. But you weren't even born then!
I don't know, I feel like wave functions "exist" because they're a useful model for the things they're useful for modeling. Like, the question of why wave functions are normalizable: if they WEREN'T normalizable, they'd be no good for describing particles that aren't uniformly detectable everywhere all the time.
Before we had wave functions, we had the Bohr model of the atom, with electrons moving in tidy circles at fixed distances from the nucleus. And that was a great model ... until it wasn't. Then we found a better model. But both Bohr and wave functions are MODELS, which is to say, they have no reality of their own.
Well, technically, you've just described how modern science works,. You observe, hypothesise a model (with a test that defines a failure and that covers all we know to this point on the same subject), test and if it fails, reject or amend - if it passes, start over and do more observations and see if there are things the model missed..
@@TheoWerewolf I notice people talk about wave functions like they're real things with physical reality of their own, and I think I detect some of that in this video. Maybe this exposes a limited understanding on my part, but as far as I'm concerned, a wave function is nothing more than a versatile description of a quantum mechanical system, to the limits of our ability to measure it. So when people get into arguments about, say, the Many Worlds Hypothesis, I feel like they're confusing the map with the terrain: just because the wave function doesn't provide a great guide as to which event will be measured, doesn't mean that all events will actually take place somehow.
@@kingbeauregard - Can't your model vs reality argument be applied to our mathematical model of macroscopic physical reality as well? After all, neither space nor time can be physically detected - their existence must be inferred from our measurements of the behavior of the physical objects we can detect. Likewise, the existence of a complex-valued quantum domain can be inferred from the verifiable behavior of the subatomic particles described by the quantum wave function.
@@QuicksilverSG Well, sure, a good map is useful, but no map completely captures all the details of a thing. By all means, use a model; but be mindful of the shortcomings of a model.
Quick question: If we assume the electrons wave function must me normalizable, since we assume it is *somewhere* in the universe (if it was there before): What happens when it gets destroyed, say by hitting an anti-electron? Do you need to assume this electron is the only thing in the universe for the wave function to be normalizable?
Electrons are not "somewhere". They are not objects. Total electric charge is conserved (at least locally and with high precision for the energy range below 1TeV), but the charge of individual electrons is not. The "electron as an object" ontology is simply a 19th century leftover. You have to learn to avoid it.
Sorry for the late reply but, you are correct that in non-relativistic quantum mechanics, the time evolution of a system is described by the Schrödinger equation, and if the initial wave function of a particle is normalizable, it remains normalizable for all time. This implies that the probability of finding the particle exists throughout time.
In the specific case of an electron and its corresponding antiparticle, the positron (anti-electron), their annihilation process cannot be described solely within non-relativistic quantum mechanics. The annihilation of an electron and positron involves the conversion of their mass into energy, and such processes require the inclusion of relativistic effects (mass energy conversion E = mc^2). A more advanced model. Quantum field theory.
Postulates = "We don't know why this works, but it works, so let's say this is how the universe works."
welcome to modelling
If you want to know how the universe works just ask a religious apologist.
Oh I know this. If it looks like a duck, swims like a duck, and quacks like a duck, then it is a duck. I wouldn't think quantum mechanics is so easy 😁
To be fair, it *is* how the universe works, to the best of our knowledge. Which is how we know everything. Not perfectly, but better than before
This happens in coding. When you don't know why it works, but it works
Parth please make a similar series on relativity 👍
If Parth does it, it’s going to be from a fundamental mathematics perspective not kindergarten analogies. So it would have to be about hyperbolic geometry and lorentzian transformations?
@n.d.: Yes, please!
I did maths at Uni, maybe a quarter of a mile south of you, ending up as more of a mathematical physicist by the end. People talk to me about it as if maths is all about numbers and I correct them by telling them it's actually about starting with a set of assumptions and seeing how far we can get by applying logic to them. I'm sure it's the same for historians correcting people who think all they do is memorise stories and dates. It was good to see you starting this video off by saying pretty well the same thing about physics as I do about maths!
Veritasium just recently released a video on "i" (the square root of -1), and part of it talks about how it ended up in Schrodinger's wave equation.
I watched that two days ago
I don't know any channel in youtube that goes as deep as you go or talks about complex topics as you do.
That's why I subbed and that's why you should keep going :)
Thank you for the kind words!
PBS Space Time is a pretty good one that's only slightly less technical.
The Science Asylum is worth checking out too: ruclips.net/user/Scienceasylum
Einstein's wife asked him to bring her two things - Time and Space
Einstein replied- what is the second thing?
Einstein's wife was mad at him, so she kicked him out and said "Give me time, I need space!!"
Whenever I see a video or talk about Quantum Mechanics, it usually refers to everything theoretically - like an electron being constrained to being in a box etc etc. What I'd like to see is some 'real world' experiments that bring the Wave Function (and associated probabilty) alive. An example that brings electron spin alive is the Stern Gerlach experiment. What experiments bring Wave Functions and the Schrodinger equation alive?
I don’t think there are any (and that’s exactly why people disagree on interpretation of QM), unless you count the double slit experiment. And some are claiming even that is widely misunderstood, and that it doesn’t mean quite what others think it means.
: You don't know any experiments that show us that wavefunctions exist??? Do you study physics?
"1"
(My life was in a quantum mechanic style, that I never knew my position and where I am going!)
mmm *one*
I am surprised by your definition. My book says nothing about existence of a wave function, however, it does say, a system is described by one for QM to work. The big difference being "described" versus "exists".
I mean the wave function is a tool, existence to me would imply it as a real thing, which it isn't.
Thanks a lot Parth! Could you someday cover the subject of spontaneous symmetry breaking?
A better way to look at it is "quantum systems all have a common property - that for certain properties of the system, the probability of finding the system in a given state can be described with a function and that function is derivable from a function that describes a wave-like distribution. We don't understand HOW systems that seem discrete and deterministic can work this way, but they do and this models their behaviour very accurately." I feel it's a mistake to go from the model to the real world as it leads to valuing the model over the experiment.
That's not the history of how we got here. We got here by combining three things from the real world and ended up with the model - not the other way around.
First came the idea that an electron was a solid thing, but at the dawn of the quantum age, we were faced with two questions. Why did electrons cause unique spectral lines for each element? (They seem to occupy only unique energy levels around an atom.)
Are electrons really waves? If true we can characterize them in orbit with a continuous function and we have a well-known equation for finding the mass of a standing wave on a stringed instrument, like a violin. That was the wave function applied to the electron and Schrödinger, along with others, expected it to work for experimental results. It failed.
Now comes the third part - bridging a frequency (like a violin note) with a frequency (how often do you skip breakfast, what is the probability for that). If you look at time to frequency transform equations, you'll rapidly hit complex exponentials (specifically e^(-iωt) and you may recall that Ψ = e^i(kx-iωt)) and if you look at various probability equations, they often include exponential definitions. There's a reason for that. Anyway that's the piece that Born put together - instead of frequency description of a + ib pairs to describe spectral components, get the magnitude of the point from the origin and treat it as a probability value.
That basically worked, that's how we got here. Avoid anyone telling you physicists don't look at the real world or only care about their models because that's just not true. That's the battle cry of con artists and pseudoscience.
The map is not the territory. Parth is trying to explain a very nuanced situation before you're fully equipped to handle the nuances - and it does not matter how we got here at this level, only how to recognize the signposts of what is at this level. It's going to get a lot weirder and none of it is caused by a century of physicists worldwide forgetting or being too stupid to consider the real world.
Hope that helps!
It should really be "for all properties of the system"
Every physical property in QM is described by a wavefunction / the wavefunction of the system as a whole
There is a big gap in my understanding or particle physics regarding physical experimentation. Explainers of physics like yourself tend to describe things like electron spin, or quark colour without relating whether or not these things have been demonstrated experimentally or are just postulates. My knowledge of detection doesn't go much further than the cloud chamber. I'm sure there are far superior detectors these days, but what are they and on what principles do they work?
For spin, research the Stern-Gerlach experiment.
Whenever I get discouraged in my physical chemistry course, I come here for motivation.
Our wave function is fundamentally a complex number, such that plotting the wave function should involve a real and imaginary component.
Eulers formula tells us that we draw out a helix of sorts by plotting a complex function.
If we filled in the volume contained by the helix, it should look the same as revolving our real component about the X-axis.
The volume contained between any two cross sections as compared to the total volume would therefore be equivalent to taking the normalized square modulus of the real function.
If the wave function is indeed rotational in nature (hence requiring complex numbers), then it seems the probability of finding a particle between any two points is just the percent of volume that space occupies as compared to the whole.
"Our wave function is fundamentally a complex number" is not the answer for the question in the video. It's just another assioma. The point is that the biggest probability of finding an electron is somehow assumed to be similar to the maximum intensity of a ligth radiation.Since a radiation behaves like a sinus function, the maximum intensity is given by the square of the maximum sinus amplitude. A good way to represnt this is the product:
psi(cos ft - i sen ft) x psi(cos ft + i sen ft)= square psi, always positive.
Love your work. Would like to see a video on Bell's Inequality.
Make a video on bizarre of double slit experiment !!
6:48 The wave function does not "exist" as a physical entity exists, it is a mathematical model used to explain quantum phenomena, and make testable predictions.
The quantum wave functions exist otherwise we should not have interference phenomena in Young double slit experiments for example, there is no other explanations.
@@GH-li3wj The quantum wave function is a mathematical model of what is happening in the real world. The function itself does not exist in the real world.
The quantum world is modeled by the function and some day we may find a better more complete mathematical model. Quantum phenomena will always be there but the FUNCTION may be obsolete.
My point is that people tend to confuse the mathematical equations with the real world phenomena they model.
Alternatively, there's only one wavefunction, and it's the only thing that "exists" on a fundamental level.
@@wayneyadams wave function is part of the reality otherwise you won't have interference. It's like number Pi Pi is not just a mathematical model, it is a part of the physical reality, without the Pi number you won't have waves , you won't even exist, and nothing else will replace this mathematical being as the Pi number.
@@GH-li3wj Please don't lecture me on Physics, I have an M.S. in physics and taught the subject for 33 years.
Let me try this one more time. The wave function is a MATHEMATICAL MODEL OF THE REAL WORLD, it does not exist on its own, just as pi is not an actual object, but the result of a mathematical calculation.
The reason I am so emphatic about this is because Physicists become so enamored with the math that they forget that results of calculations are meaningless unless they have testable results in the real world.
As long as the wave equation is an accurate model that makes accurate (meaning testable) predictions it is useful, however, if there are predictions that are proven false, it would need to be modified, or in the worst case abandoned.
Love your videos!
Can you do a video about the size of a photon, in terms of how many wavelengths exist? The single wavelength of a photon is well defined but the number of wavelengths seems rather vague and often described as a "wave packet" with just a few (5-10) wavelengths. There are various experiments that restrict the frequency bandwidth of the photon to very small values. A minimum (Fourier-limited) time-bandwidth product would seem to require a corresponding large number of wavelengths.
Following on from some of your recent videos, this question came to mind: given that E=mc^2, can Potential Energy be converted into mass or does the PE need to be converted into another form of energy before that transformation can happen? And if only some forms of energy can be converted to/from mass, what is the distinction given to the different forms of energy?
PE in a system contributes mass. E.g., if you can do relativistic kinematics, consider two relativistic masses (m) moving head on with +/- v. They collide via a massless spring that "catches" them with no losses, and is clamped shut at maximum compression:
What is the final mass M of the system (2m + compressed spring)? If M > 2m, where is the mass-excess coming from? Can it be converted back to kinetic energy?
Don't take my word for it, but as far as I know, yes, potential energy does count. For example, a lot of the mass of a proton comes from interactions between quarks, which has a potential energy associated with the strong force.
You're confusing two concepts. Energy can be converted into _matter_ by creating particles or changing particles into heavier ones.
Energy _is_ mass, always was, and you don't "convert" it. If you have a chemical battery, coiled spring, or anything else that contains potential energy, a careful enough measurement of its mass will indicate that the potential is contributing mass.
For example, take a perfect closed box that nothing can enter or leave, not even neutrinos. You know nothing about what goes on inside but can measure the mass of the whole thing, via gravity. If a sample of uranium decays inside the box, the daughter elements are lighter but contain kinetic energy which you understand adds mass to the system. The mass of the box seen from outside is unchanged.
Now also in the box is a generator and battery. The fast moving atoms spin the turbine and charge the battery while causing those daughter atoms to come to a near stop.
The kinetic energy is gone, no atoms have changed into other kinds of atoms. But the box still registers the same mass. Now the excess mass is held by the potential chemical energy in the battery.
@@JohnDlugosz That's a very clear explanation, thank you.
Pretty sure the wave function does not exist. Talk to me if you want to find out why I think so. The short answer is that the wave function summarizes our knowledge of a system, so it is epistemic, not ontic. People who assume it is ontic get into all sorts of trouble having to do cartwheels to justify their reasons. Not that they are wrong, I just have some thoughts why they are not doing physics, physics is not ontology, ontology is metaphysics. Longer answer is how I would show the wave function is only epistemic, and that takes longer than a YT comment.
Not that I have a "proof," but I do have _an_ argument for how fairly ordinary physics can create _appearances of_ wave behaviour. Anyone can try this game: if you can justify why particles _seem to_ carry information like they were waves, but always get detected as particles, then you've shown the wave function is a convenient fiction, like all fields. Feynman was I think first to point this out as far as I know... the fields are auxiliary data propagated on Cauchy hypersurfaces, _necessary_ if you ask for a _Hamiltonian time evolution,_ so you should perhaps not ask! In the spacetime (least action) formulations there is no need for such data if you treat the fundamental interactions the way Feynman originally did.
Why we _do_ ask for a Hamiltonian is partly tradition, but partly that old physics honey trap, which is that sometimes it is easiest to use a fiction to compute solutions. The spacetime or Lagrangian or least action formulation goes over to sum-over-paths in the quantum theory, and it is bloody hard to use the path integral approach in most cases, and if you have a Hamiltonian ready and available which you can just SHO mode expand, then I'd recommend using it! Just do not pretend it represents reality, don't take the fields too literally.
Very well thought out comment and I agree.
Are there other things that can be understood about a quantum system, from its wave function, besides its probable location in space? maybe velocity?
Yup you can have a wavefunction for any physical property not just position
Good talk. I like that you presented qm as a model with postulates. When I try to explain it to people I go right to the particle in a box model, because that shows how boundary conditions dictate quantization. The problem is , many people dont know enough calculus to get the gist, which always makes me wonder why someone would try to tackle quantum mechanics...really ANY topic in physics....without a basic math background!
This is really very, very good. To reduce something complex to something of such clarity takes a mind that really knows its stuff.
Rather than probability of electron existing at a location isn’t it also the probability we will be able to ensnare/detect/absorb it at a location?
I've thought this same thing and wondered what the implications would be on test results or the way they interpret them.
My personal belief - the wave function is a real wave in a field. The field is a real yet immaterial thing, or medium. This medium seems to be a superfluid, with closer resemblance to Bose-Einstein condensates than normal matter (there are others sharing this idea). This superfluid can explain dark matter.
Particles? They don't exist. At least, they are not little objects. They are interactions of waves. Non-linear interactions, that is. Linear interactions are just normal interference. They are short-lived blips that take place at some place at some time, and look like "particles" only because they gather up energy to some threshold (quantized) value. What about atoms? Only the protons are stable and real particles, because they are not fundamental. They are trapped energy that keeps interacting with itself. And they trap "electrons", that don't exist (as particles). It's only around atomic nuclei things get quantized.
Matter... It's trapped electromagnetic energy, like a tiny hotspot. Many hot yet tiny spots becomes a large boiling soup. Think of earth. This ball of matter is like a boiling pot in space. And due to all this energy, it becomes like bubbles in a pool of water that reduces the surface tension (used for practicing diving from hights) - the density gets lower. And if the density of the medium is lower close to earth, while getting denser with increased altitude... Guess what that is? Spacetime curvature and gravity.
The only little piece that doesn't fit anywhere in this picture is special relativity. That's a theory that has to go. Lorentz ether theory still works though.
the interrelation of quantum chemistry to the overall field model, ie VSPER
We don't know if it exist or not, so lets assume it does
=Quantum physics in a nutshell.
Keep up the good work parth .👍
Hello, great video! Would you be able to make a video on what experiments validate the current Quantum mechanics postulates? Thanks!
No Aryabhattas were harmed in making the thumbnail...
Now that you commented about it , I really noticed it lol . That's hilarious
First rule of Quantum Mechanics is you do not understand Quantum Mechanics.
Second rule of Quantum Mechanics is you do not understand Quantum Mechanics.
Third rule of Quantum Mechanics, If you believe you understand Quantum Mechanics, you do not understand Quantum Mechanics.
IT IS SIMPLE, MY DEAR BROTHER!
THE WAVE IS THE HUMAN CONSCIOUSNESS AND THE QUANTUM FIELD IS OUR "REALITY".
YOU ARE TRYING TO FIND OUT THE "FORMULA" OF CREATING REALITY!
SOME OF US ARE DOING IT NATURALLY.
YOU, INSTEAD, ARE TRYING TO ESTABLISH A WRITTEN FORMULA USING PERSONAL SUPPOSITIONS.
BLESSINGS!
Combine:
1. cosmological constant in Dxy [m^-2] = lp^2/λ^4= lp^2 nxy ^2 [m^2] [m^-4]
2. schrodinger solution
3. Planck E= h f= h n
4. n = number of superpositions = wave function frequency
And you get: dark matter = superposition of the electron
Dxy [m^-2] = lp^2/λ^4= lp^2 nxy ^2 [m^2] [m^-4]
Nxy = sqrt(Dxy / lp^2)=. (Dxy / lp^2) ^0.5= [m^-1] [m^-1] = m^-2
Then nxy = sqrt ( 10^-52 / 10^ -70) = 10^18 ^0.5 = 10^9
Schrodinger solution:
n^2 h^2 / ( 8 m L^2) = h n
8 m L^2 h n = n^2 h^2
m = n^2 h^2 /( 8 L^2 h n)
m = n h 0.125 L^-2
m= 10^9 10-34
= 10^-25 ( all superpositions).
1 particle = 0.331 10^-25 / ( 0.4 10^9) = 0.828 10^-34 kg = 46 eV
If you count only the positive wave function amplitudes: n = 10^4.5
then 1 particle = 0.331 10^-25 / ( 0.4 10^4.5) = 0.828 10^-30kg 5.6 10^35= 10^5 ev = 0.5 Mev
Superposition of electron causes dark matter?
Extremely big RESPECT for this great video! Excellent explanation, without any superfluities and without the usual "you have to be funny when explaining something difficult" (firstly, it's usually not funny, secondly, it's always incredibly annoying and distracting). This is exactly how I would like to see explanatory videos in science and mathematics. Once again THANK YOU for this great work, I am looking forward to all the other videos on this channel (already available and upcoming).
Combine:
1. cosmological constant
2. schrodinger solution
3. Planck E= h f= h n
4. n = number of superpositions
And you get dark matter
n^2 h^2 / ( 8 m L^2) = h n
m = 0.3313 10^18 10^-34 = 0.3313 10^-16 kg ( all superpositions).
1 particle = 0.331 10^-16 / ( 0.4 10^18) = 0.828 10^-34 kg = 46 eV
How can I contact you and have you help me articulate? My idea of the reason why wave function exists in a way that's concurrent. I do have an AI assistant. That's helping me with the math. Because I am a poet till. I look at the world through a different lens and not just a poet that writes verse. I am the odd fellow that frost spoke about. I have seen the world different since I was a child. I understand the wave function. I understand the drift. When I was a child I stared at a flower for 3 hours and my grandmother was shocked. And she asked me what I was looking at.I told her because I couldn't explain it that I saw all of the stars in there, but I was lost in the drift.I was in the wave.I understand what it is.I just don't understand how to explain it in the terms of physics yet.I'm using a I to help me.
2 nd rule of quantum mechanics is you Do NAT TaLK AboUT QUANTUM MECHANICS!!!!!!
How do I make my children as smart as you?
Is it genetic or the way one is raised?
Encourage them to love learning. Don't force it, just encourage.
There are a lot of good books, papers, classes, and videos that teach physics.
Both: en.wikipedia.org/wiki/Intelligence_quotient#Genetics_and_environment
@@user-yt198 true
Rule 1 about Q.M: you can never really know Quantum Mechanics.
Rule number 2: You already know quantum mechanics.
Rule number 3: you sometimes know quantum mechanics.
Rule number 4: i don't know what im talking about, this is just quantum woo.
Hey bro.. am a physicist and did my master's from IIT Bhubaneswar. In the early times when was learning the quantum mechanics for the first time .. i usually Frustrated with QM. Unlike the classical mechanics it do not give any physical meaning. Many of questions becomes clear after reading Beiser and Shanker QM book. Your video is good enough for beginners who like to learn the quantum mechanics .... 💐
Quantum Mechanics is not to be understood.
Quantum Mechanics is to be APPLIED. (by means of "shut up, sit down and calculate!")
Thats what I learned when studying physics in the late 90s.
This is all ok - basic of quantum physics.
But the question is, why is the Wave Function a function with complex number values?
Wave function is not a field function with real values, like a gravitational field function with real number values, which calculates gravitational force in every point of the Universe.
Wave function calculates something in a complex number space, not in real number space.
Hi, an intuitive way to understand Psi wavefunction is to think of it as an existence wave in 3D; that is the meaning of what Born said, it is a probability of existence in that 3D zone at a given time. So the wave is the oscillation of quantum 3D space between its 3D space and a 4th dimension that carries the essence of physical values, i.e., its total energy, total momentum, total charge, etc. That is what Schrodinger wavefunction is, an weirdness of QM will almost disappear. I read that in a short amazon book, "Space, main actor of quantum and relativistic theories. Since nature doesn't contain full information, on each fluctuation, the compact particle will assume an exact valid solution (eigenstates, eigenfunctions) and, from cycle to cycle, nature assumes aleatorily a different valid solution; one each time. The expectation value will be the average of all the eigenstates or the eigenvalues pondered by its probability. Imagine a twisting Einstein's dice, the top face will be in fluctuating changing value at a rate of its energetic frequency, the eigenvalues will be from one dot, up to six dots, its expectation value will be 3.5 dots, BUT never a superposition of all six possibilities, just one solution at a time at a frequency near 10^20 per second... think about it and QM is more understandable... maybe you will do a video about this new view-interpretation. Regards
You're assuming a lot more than just 1 postulate there. For instance, that there's such a thing as a quantum system to study, and that there are these definite measurements to take. Also, the Born rule there is being assumed as well.
I think a better way would be to just have one wavefunction that obeys the Schrödinger equation, and then derive everything else. It works, has much fewer assumptions, and only has two questions left of "why is there a wavefunction, and why does it obey the Schrödinger equation?", which might just be philosophical questions.
Your title is both misleading and incorrect. Particles exist and have wavelike properties. Wave functions are some specific wavelike mathematical relations. Quantum theory tries to explain some particles' wavelike properties using some wave functions. Some people do know why particles exist and have wavelike properties. Search keywords: matter theory marostica.
Pal, you really need to check out the Clickbait video of Veritasium. Your title isn't good for everyone, just your subscribers...
Perhaps you didn't know but the wavefunction exists because it tells us how the particle responds to a measurement. This is what Schrodinger was saying in his famous 'heat' equation. I should say in my view.
They exist probably because light and emr are always observed to be a wave. And never a particle. So some way to take what’s observed ...ie waves,...and express it mathematically as a quanta of energy.
Using postulates in physics goes back to Archimedes, but it was Newton in Principia who established that physics follows the axiomatic method. Laws of physics are axioms. Einstein followed this principle as well. I would argue that the axiomatic method is a main component of the scientific method.
This is a good video but it’s a click bait title.
The answer as to why comes from the history of science. Why did it replace the previous theory? Because, as indicated, it’s the best theory we have to explain objective reality.
Why will it be replaced? Because something better is found. We don’t “assume it to be true”. That’s maths, not physics.
ISN'T IT INTERESTING THAT ALL IS CONNECTED TO 1 OR ALL YOUR "WAVES" INTERSECT 1?
THE ONE?
THE OBSERVER?
Namaskar Partha (Partha Ghosh??).
Your videos are informative and contains in depth touch. Thank you
Plz make some video on other postulate of quantum mechanics..........
Hang about...
If the area under that graph has to be equal to 1, how do we have particles popping in and out of existence?
Say your electron happens to choose that exact moment in time to turn into a virtual photon and virtual electron, it's no longer there to be found. So what of the wave function then?
Surely there is a probability that it won't have done that and the electron will be there so there has to be a wave function for that moment in time, but if it can disappear altogether for a bit how can the probability of its existence everywhere be 1? Wouldn't it have to be just a little less than 1?
I hope that makes sense.
So it's a leap of faith, given the Schrodinger equation was seemingly pulled out of a hat. Why was this proposed with confidence in the first place. Let's get into it, how was it created.
Hlo parth ,
Can you please explain 'Chandrasekhar limit'
Thank you
Hey Parth, please, make an video about Yang Mills mass gap problem (one of those millennium problems)?
wave function is abstract mathematical tool that do not actually exist ....just model to describe what happen
We don’t have to assume. Simply imagine a giant observing a geodesic on the earth’s surface. What he sees is just wave function.
very much like postulating the actual physial existence of lines of longitude and latitude on your front lawn.
unfortunately this is wrong. why? well, the wave function is a mathematical way of describing something that exists. it does not necessarily has an existence in itself. so it seems this is a formal way to describe physics that can be tested by experiments. the outcome of the experiments must be interpreted in that the theory describes the real world to a certain extent. not is equal to the real world. in other words, the map of germany is not germany.
Imagine if biology just assumed that the normal distribution was true? Would d that mean an individual's phenotype is in a superposition of genotype until we measure it ?
The reason why they insist on wave functions is because they are limited by what they can imagine and the limitations of our means of perception. Both qualities skew their attempts to figure out going on.
please do not follow scientism and atheism like arvin ash ...your channel is beneficial for me unlike the fancy pop physics channel
I don't like quantum mechanics uncertainty is fun but deep down I feal it is flawed
Your confusion is because you are thinking about this exactly backwards
Maybe you answered this but it seem they always give meaning to the wave squared. But what is the meaning of the wave itself without squaring?
Basically Quantum is just mathematics trying to explain the universe not cience.
Goodman, Pls slowdown the speed. Afteral I am a beginner and many like me is enchanted to follow you
There are several papers out there that derive Hilbert space calculus from first principles. Dude, you need to read the literature.
Please cover black holes.. static, non static, stationary ,non stationary.
Again such an annoying "please hit the thumbs up button and subscribe" Video
Parth G can you make a video on general relativity. I would like it if you would explain a bit more about the mathematics in simplicity like you usually do.
The mathematics of general relativity is tensor calculus. The channel MathTheBeautiful has an extremely in depth and intuitive explanation of tensor calculus. I learned the math of GR from his tensor calculus playlist, then I read a book about certain solutions to the field equations to fully understand the math.
ruclips.net/p/PLlXfTHzgMRULkodlIEqfgTS-H1AY_bNtq
This is assuming you know multi-variable calculus, and the basics of differential equations, oh and maybe some linear algebra.
Hey would you be making any videos on feyman path integral pls :)
what is momentum ? really, feeling frustrated in confusion
How do you know when you uploaded video if you are in process of making video lol :D
Hey Parth, do a video on computational physics pls.
Parth Bhai, English में तो सब बाउंसर जा रहा है। हिंदी में होता तो मजा आता।
By the way have you made a video on Higgs Boson or even the Hadron Collider yet?
Thanks yt for recommending this channel .
How do they what is seen in an atom smasher is not just a destroyed particle?
Please do a video on the second uniqueness theorem in electrostatics
Plz make some videos on ktg.. Those things are weird😐
Hey Parth, we need a video about the density of states please!
The United States is pretty dense.
please make a video about momentum and heat energy
Please make a video on vector potentials in ED.
Great video! 👍
Your videos are cool too!
Thank you :D
@@fizyknaut8108 🥰
Which camera do you use to make your videos.?😀
At 5:56, there is a wave function because Schrodinger designed it to model the waves of a medium. What medium? The electrical medium of Maxwell's Aether Electro-Magnetic field, i.e. electric charge density. When Max Born stole the WAVE equation to apply his "rule", he also applied the idea of *material particles* to WAVE math. How does that make any sense? Don't material particles bounce off each other when they collide? ...while waves in a medium will pass through each other...
material particles interact with a scattering amplitude. In the S.E., that would appear as a short (or not) range interaction V = V(|r1-r2|). With that interaction, asymptotic free-particle wave states scattering into one another. QM then says the amplitude connecting an initial state |i> to a final state |f> is , to 1st order. A second order correction would sum over all intermediate (aka virtual) states |k>: , and so on to all orders.
Meanwhile, the asymptotic states remain eigenstates that don't overlap (e.g., superposition is fine):
@@DrDeuteron **
Is that "scattering amplitude" a velocity of a particle?
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"Wave state" of a particle? I can understand a "wave state" of a set of waves vibrating through a medium. Do you mean a particle wave-state, as in a billiard ball oscillating back and forth?
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So you are saying a "particle is the same thing as a wave"?
Or that you can model the break-up of a set of billiard balls, just like waves through a medium?
@@itsbs there are no particles.
@@DrDeuteron **
It's all waves from our perspective... now, can we agree that waves require a medium to wave? :)
@@itsbs You want him to say aether is real, don't you?
Beautiful parth heads of you
Please do videos on rotational mechanics
You better teach English in a convent.
Hey
Please make a video on vector spaces
It exist because people like you found it.
I wish I had found this channel much earlier. Your explanations are clear, straightforward, and make sense. Thank you for doing this and keep those vids coming.
Yes, and they are also wrong. ;-)
We have physical evidence that the quantum wave-function must exist in some operational sense. The interference patterns observed in Double-Slit experiments are produced by the complex-valued mathematics of the wave-function, which must operate in some underlying domain outside physical space-time.
The only sense in which wave functions "exist" is as part of the solution theory of quantum mechanical equations. They are primitive tools, too. They do, for instance, not make direct physical predictions. A cursory look into atomic/molecular/nuclear physics textbooks will show you that von Neumann's solution theory has to be translated to be actually physically useful.