Dietterich LabsIn this video, I show how to use the raising and lowering operator method to solve the Dirac equation for relativistic Landau levels (the Dirac equation in a constant magnetic field).
Relativistic Landau Levels From The Dirac Equation | Relativistic Quantum MechanicsDietterich Labs2023-01-05 | In this video, I show how to use the raising and lowering operator method to solve the Dirac equation for relativistic Landau levels (the Dirac equation in a constant magnetic field).
My Quantum Mechanics Lecture Series: youtube.com/playlist?list=PLSpklniGdSfSsAFCzO-YWGlJ4TNv8sMdyNepenthes Attenboroughii Near Miss | PlantsDietterich Labs2023-01-21 | In this video, I tell you about a nearly very expensive lesson I learned in the horticulture of the rare highland pitcher plant, Nepenthes attenboroughii.
Note: They were sitting in water only briefly just after watering. None of my nepenthes have ever had root problems.A Very Old Science Book | BooksDietterich Labs2023-01-09 | In this video, I unbox and discuss a 7th edition CRC handbook of chemistry and physics. In particular, I compare it to a 31st edition copy and a 63rd edition copy, to highlight how much they have changed over the decades.Dirac Landau Levels Using Cylindrical Coordinates | Relativistic Quantum MechanicsDietterich Labs2023-01-08 | In this video, I show you one last technique for solving the Dirac equation for relativistic Landau Levels, and that is the use of the power series method in cylindrical coordinates.
Clarification: By uncoupled, I don't just mean that there is no term in which k_z and m multiply each other. I am also referring to the fact that they multiply different alpha matrices. The relations satisfied by the alpha matrices ensure that cross terms don't show up. In this video, I only remembered to mention this at the very end.
My Quantum Mechanics Lecture Series: youtube.com/playlist?list=PLSpklniGdSfSsAFCzO-YWGlJ4TNv8sMdyRelativistic Landau Levels + Dirac Equation: Power Series Method | Relativistic Quantum MechanicsDietterich Labs2023-01-06 | In this video, I show how to use the power series method to solve the Dirac equation for relativistic Landau levels (solving the Dirac equation in a constant magnetic field).
Clarification: By uncoupled, I don't just mean that there is no term in which k_z and m multiply each other. I am also referring to the fact that they multiply different alpha matrices. The relations satisfied by the alpha matrices ensure that cross terms don't show up.
Typo: At 5:43, it should be Y(l , m+½) = (Sqrt { [ ( 2l + 1 ) ÷ 4π ] ⋅ ( l − m − ½ )! ÷ ( l + m + ½ )! } )⋅[exp i(m+½)φ]⋅P(l , m+½)Bhabha Scattering With The Spinor Helicity Formalism | Quantum Field TheoryDietterich Labs2022-12-09 | In this video, I use the spinor helicity formalism to perform a calculation that I have already done in another video (the calculation of the ultra-relativistic Bhabha differential scattering cross section), for practice and comparison.
Note: the bosonic normalization I chose to use in the general differential scattering cross section is not arbitrary, apart from not including mass factors. It is the one consistent with the usual spinor-helicity formalism.Encephalartos Natalensis X Woodii And Another Latifrons | PlantsDietterich Labs2022-12-02 | In this video, I unbox my new Encephalartos natalensis X woodii plant, and show the second Encephalartos latifrons (Trappes Valley form) that I invested in.Time Dependent Perturbation Theory Part 2 Of 2: The Dyson Series | Quantum MechanicsDietterich Labs2022-12-01 | In this video, I explain how to use the interaction picture to derive the actual expansion formula for time dependent perturbation theory.
Quantum Mechanics Lecture Series: youtube.com/playlist?list=PLSpklniGdSfSsAFCzO-YWGlJ4TNv8sMdyZamia Pseudoparasitica (the only known epiphytic gymnosperm) Unboxing And Repot | PlantsDietterich Labs2022-11-21 | In this video, I unbox and then pot up a specimen of the worlds only known epiphytic gymnosperm, the rare cycad Zamia pseudoparasitica.Time Dependent Perturbation Theory Part 1 Of 2: The Interaction Picture | Quantum MechanicsDietterich Labs2022-09-28 | In this video, I explain the need for and how to construct the interaction picture, in the context of time dependent perturbation theory.
Quantum Mechanics Lecture Series: youtube.com/playlist?list=PLSpklniGdSfSsAFCzO-YWGlJ4TNv8sMdyThe Variational Method (QM approximation) | Quantum MechanicsDietterich Labs2022-09-11 | In this video, I introduce, prove, and demonstrate the variational method from quantum mechanics. A technique used to compute an upper bound on the energy of the ground state of a quantum system.
Clarification: I ignored the negative root because it would not lead to a smooth trial function, and would therefore be much worse than the simple square guess that we were trying to improve on. Also, one in general has to check that the root one does select actually is a minimum, a step that I skipped here.Unboxing Maybe The Rarest Cypress, And More On The Bermuda Cedar | PlantsDietterich Labs2022-09-11 | In this video, I unbox two of the rarest cypresses in the world and then discuss the history and importance of the Bermuda cedar.Growing Genuine Rosewood At Home | PlantsDietterich Labs2022-09-09 | In this video, I unbox and then sow four species of rosewood seeds, and nine species of tree fern spores. I then show some of the germinated rosewood seeds. To be clear: when I say "less reputable suppliers", I mean from a seed viability perspective, not from a plant poaching perspective. I do not support plant poaching, and do not buy poached plants.Extremely Rare Cycad Unboxing | PlantsDietterich Labs2022-09-09 | In this video, I unbox a very special plant: Encephalartos latifrons. It is one of the rarest cycads you can ethically buy, and I decided to make the investment.Intro To Degenerate Perturbation Theory | Quantum MechanicsDietterich Labs2022-09-04 | In this video, I explain the basics of quantum mechanical perturbation theory in the presence of degeneracy.
The link to my non-degenerate perturbation theory video: youtu.be/ZjUj7GHU2UMSuper Rare Cedar Tree Unboxing | PlantsDietterich Labs2022-09-04 | In this video, I unbox the latest edition to my unusual tree collection: Juniperus bermudiana. To be clear, I realize that it isn't technically a cedar (genus Cedrus), but actually a rare juniper tree.Constraint Forces Do No Work: Block And A Wedge Example: Classical MechanicsDietterich Labs2022-08-26 | In this video, I use Lagrange multipliers to explicitly calculate the constraint forces in a simple system, and show that they do zero work.West Indies Mahogany UnboxingDietterich Labs2022-08-26 | In this video, I unbox the latest edition to my exotic timber tree collection.Intro To Time Independent Non-Degenerate Perturbation Theory | Quantum MechanicsDietterich Labs2022-08-21 | In this video, I explain how time independent non-degenerate perturbation theory works, in detail.
My Quantum Mechanics Lecture Series: youtube.com/playlist?list=PLSpklniGdSfSsAFCzO-YWGlJ4TNv8sMdyRedwood Seedling Unboxing + A Look At My Rare Tree Collection | PlantsDietterich Labs2022-08-21 | In this video, I unbox a package of live redwood tree seedlings (giant sequoia, and coast redwood), and also show what I have so far in my unusual tree collection.When Will The Ball Fall? | Classical MechanicsDietterich Labs2022-08-03 | In this video, I demonstrate a way of using Lagrange multipliers to solve for when a ball looses contact with a circle that it's rolling off of. This technique could be applied to other cases where a constraint applies for only some of the time evolution of a system, and it is necessary to calculate the point where it stops applying.
Typo at 2:25: On the RHS of the first equation of motion, there should be a square on the theta-dot.Nepenthes Attenboroughii Unboxing + A Look Inside My Highland Terrarium | PlantsDietterich Labs2022-07-31 | In this video, I unbox my new Nepenthes attenboroughii, and show the contents of my highland terrarium. I then end the video with an explanation of how my terrarium works.Shocking A Hydrogen Atom With An Electric Field | Quantum MechanicsDietterich Labs2022-07-25 | In this video, I do an interesting time dependent perturbation theory problem, that makes use of the Wigner-Eckart theorem. I consider the problem in the context of experimentally testing physical theory.
Note: It appears that I forgot to explicitly enter q=0 in the first selection rule, in the second line after the Wigner-Eckart theorem.Hanging A Mass From A Centrifugal Force | Classical MechanicsDietterich Labs2022-07-19 | In this video, I work through a fun problem which displays the possibility of of stably hanging a mass from nothing but a well tuned centrifugal force.Hydrogen Atom In A Crystal | Perturbation Theory | Wigner-Eckart Thm. | Quantum MechanicsDietterich Labs2022-07-13 | In this video, I calculate the first order correction to the ground and first excited state hydrogen atom energy levels due to the weak coulomb field of a large ion crystal lattice. It is a good degenerate perturbation theory exercise, and a good demonstration of the utility of the Wigner-Eckart theorem in saving a lot of time.
I suppose I should have draws the 2s orbital bigger.A Pendulum On A Free CartDietterich Labs2022-07-08 | In this video, I solve the "pendulum on a free cart" mechanics problem using lagrangian mechanics, and then compare it to some closely related problems.
Harmonic oscillator pendulum cart video: youtu.be/tHHLKUAMdgIProving The Wigner-Eckart Theorem | Quantum MechanicsDietterich Labs2022-06-30 | In this video, I show you how to prove the Wigner-Eckart theorem. I also give a bunch of other information on tensors and Clebsch-Gordon coefficients in the build-up to that.
My Quantum Mechanics Lecture Series: youtube.com/playlist?list=PLSpklniGdSfSsAFCzO-YWGlJ4TNv8sMdyThe Double Pendulum | Classical MechanicsDietterich Labs2022-06-19 | In this video, I show you how to handle the double pendulum problem mathematically. We derive the lagrangian, and the equations of motion. We then make the small angle approximation, and calculate the normal frequencies and normal modes.
Typo: In my initial expression for y_1, the angle should be theta_1.
Note: A good point was made in the comments section of this video. What I called an eigenvalue problem isn't exactly that, because neither V-tilde of T-tilde are the identity. One could take the base matrix equation, and multiply it by T-tilde-inverse to convert it into one, but that doesn't change how the system is actually solved. I therefore kept calling it an eigenvalue problem without fully converting it into one.Laplace–Runge–Lenz Vector Operator Relations | Quantum MechanicsDietterich Labs2022-06-15 | In this video, I show you how to derive some important relations satisfied by the Laplace-Runge-Lenz vector operator in quantum mechanics.
My Quantum Mechanics Lecture Series: youtube.com/playlist?list=PLSpklniGdSfSsAFCzO-YWGlJ4TNv8sMdyCovariant (Dirac method) Bosonic String Quantization | String TheoryDietterich Labs2021-09-06 | In this video, I cover the covariant Dirac method for first quantizing the free bosonic string, sometimes called the "old covariant" method.
Making this video was a bigger job than any I had made yet, so if you know anyone who would like it, please don't hesitate to share it with them.
There is a typo in this video at 49:31. I meant to write and say "and h_γδ describes a massive analogue of a graviton (the traceless part of h_γδ) and a massive scalar (the trace of h_γδ)." The massless case shows up in the closed string.How To Add Neutrino Masses To The Standard ModelDietterich Labs2021-07-06 | In this video, I extend the results arrived at in my last particle physics video (youtu.be/j0TrmTizio4) by adding neutrino masses.
The laser is a 40 watt carbon dioxide tube laser.Carbon Dioxide LASER TestingDietterich Labs2021-04-24 | I bought a new laser, and tried it out.
It is a basic 40 watt CO2 tube laser.The Standard Model Of Particle Physics Complete LagrangianDietterich Labs2021-04-06 | In this video, I show you how to unite QCD and QEW to form the famous Standard Model Of Particle Physics.
My video on the complete QEW Lagrangian (my last mathematical physics video): youtu.be/mnArKhQNsck
Minor Typo: In the unbroken QEW and standard model Lagrangian densities, the subscript “l” on the left hand factor in the last quark Yukawa coupling term is supposed to be a subscript “q.” The same issue shows up in the attached tables of definitions for “L-tilde_q”. Hopefully these fairly obvious typos don't confuse people too much.The Wildfire In My BackyardDietterich Labs2021-03-30 | I certainly didn’t expect to see a wildfire in a wet Minnesota spring time, but apparently the sun dried the dead grass, and my neighbor decided to have a campfire despite the high winds.The Complete Quantum ElectroWeak (QEW) Lagrangian | Quantum Field TheoryDietterich Labs2021-02-25 | In this video, I explain how to generalize the one-generation-of-leptons QEW theory from my last video.
My last video on spontaneous symmetry breaking in QEW, where I introduce QEW theory for one generation of leptons: youtu.be/A4hRN5Gqjcs
Minor Typo: In the complete unbroken QEW Lagrangian density, the subscript “l” on the left hand factor in the last quark Yukawa coupling term is supposed to be a subscript “q.” The same issue shows up in the attached table of definitions for “L-tilde_q”. Hopefully these fairly obvious typos doesn’t confuse people too much.Quantum ElectroWeak Theory & Spontaneous Symmetry Breaking | Quantum Field TheoryDietterich Labs2021-01-24 | In this video, I explain how spontaneous symmetry breaking works in the quantum electroweak theory.
There are a few places in this video where I wrote out the finished charged current lagrangian without using the psi notation that I broadly adopted for Dirac fermion fields. The way I accidentally wrote it is a common alternative notation, and the context still makes everything clear, so it shouldn't be a big problem, but I still wanted to clarify. Also, the subscript "SM" on the last two Lagrangians is supposed to be "WSM" standing for Weinberg-Salam Model. When I state the gauge transformation laws, "R" refers to the right handed sector, which consists only of e_R. I meant to just write e_R, but I accidentally mixed in an alternative notation again.SU(3) Higgs Mechanism Example | Quantum Field TheoryDietterich Labs2020-12-28 | In this video, I work through the problem of spontaneous symmetry breaking in SU(3) Yang-Mills theory, induced by a Higgs field transforming in the fundamental representation.
It's worth pointing out that I chose to leave the vector boson interactions inside the field strength tensor terms, to keep the result compact. This does mean that the Proca Lagrangian density doesn't appear explicitly in the final answer, although it is clearly present. It also means that the massless and massive vector boson Lagrangians do contain fields of the other type via the still-implicit vector boson interaction terms. Because it is clear where all the important parts are, I decided that this would be a good compromise between clarity and compactness.Fermion Masses From Spontaneous Symmetry Breaking | The Yukawa Interaction | Quantum Field TheoryDietterich Labs2020-12-03 | In this video, I explain how spontaneous symmetry breaking can be used to produce masses for more than just vector bosons via the Higgs mechanism. I show how spontaneous symmetry breaking can also give mass to fermions through Yukawa couplings.
At 4:28 there is a minor typo. In the very bottom right most equation, there is an A_mu on the left side of the equals sign that clearly isn't supposed to be there.Spontaneous Symmetry Breaking In An Arbitrary Orthogonal Yang Mills Theory | Quantum Field TheoryDietterich Labs2020-11-26 | In this video, I work through the problem of the higgs mechanism in an arbitrary orthogonal Yang-Mills theory.
Quantum Field Theory Lecture Series: https://www.youtube.com/playlist?list...
It's worth pointing out that I chose to leave the vector boson interactions inside the field strength tensor terms, to keep the result compact. This does mean that the Proca Lagrangian density doesn't appear explicitly in the final answer, although it is clearly present. It also means that the massless and massive vector boson Lagrangians do contain fields of the other type via the still-implicit vector boson interaction terms. Because it is clear where all the important parts are, I decided that this would be a good compromise between clarity and compactness.Sleep BarkingDietterich Labs2020-11-26 | I always wonder what she is dreaming about when she does this.SO(3) Higgs Mechanism Example | Quantum Field TheoryDietterich Labs2020-10-23 | In this video, I cover a fun and illuminating Higgs mechanism example intended to help elucidate how the Goldstone theorem works in the context of the Higgs mechanism. The problem I discuss here is the one where the scalars transform in the fundamental representation.
It's worth pointing out that I chose to leave the vector boson interactions inside the field strength tensor terms, to keep the result compact. This does mean that the Proca Lagrangian density doesn't appear explicitly in the final answer, although it is clearly present. It also means that the massless and massive vector boson Lagrangians do contain fields of the other type via the still-implicit vector boson interaction terms. Because it is clear where all the important parts are, I decided that this would be a good compromise between clarity and compactness.Arsenic Trichloride UNBOXINGDietterich Labs2020-10-22 | In this industrial chemical unboxing video, I unbox a sample of the liquid arsenic compound arsenic trichloride. Don't try anything you see in this video at home.
Quantum Field Theory Lecture Series: youtube.com/playlist?list=PLSpklniGdSfSsk7BSZjONcfhRGKNa2uouSpontaneous Symmetry Breaking And The Higgs Mechanism | Quantum Field TheoryDietterich Labs2020-09-29 | In this video, I use a set of example theories to explain and demonstrate spontaneous symmetry breaking and the Higgs mechanism.
A clarification on tachyon condensation: Tachyon condensation handles the tachyon problem at high energy in theories that are used for phenomenology. The first two theories discussed in this video only contain the scalar field used for breaking symmetry. There is therefore nothing for the tachyons present at high energy to decay into. Tachyon condensation therefore doesn’t take care of the problem for these theories. This is ok, however, because they aren’t used for phenomenology. In theories like the third example and ones like the standard model, which are used for phenomenology, tachyon condensation is free to take place on account of there being many particles that the tachyons can decay into. So when I say that tachyons don’t imply unphysicality at high energy, I mean that they don’t guarantee it. It ultimately depends on the theory.
Generalizing Gladstones Theorem To Complex Fields: The way that I stated the Goldstone theorem in this video was that the number of broken generators (and Nambu-Goldstone bosons) is equal to the number of unbroken directions in isospin space, resulting from the zero isospin components in the new vacuum about which we were expanding the theory. This makes perfect sense when the scalar field is real, and there is therefore one field per component. How this could be correct for a complex scalar field, where there are two fields per component is a little less obvious. It turns out that the immediate generalization is to say that there are as many broken generators (and Nambu-Goldstone bosons) as there are fields set equal to zero in the vacuum about which we are expanding. However, we can always recast an N component complex scalar field as a 2N component real scalar field, in which case the original statement would apply again. So in a round about way, that statement of the Goldstone theorem is generally valid, even for a complex scalar field. Take the U(1) example in this video. It includes a one component complex scalar field. The new vacuum about which we are expanding the theory is real. One field has therefore been set equal to zero in that vacuum, namely the imaginary component. From this and the Goldstone theorem, we would expect one broken generator, one Nambu-Goldstone boson, and one massive gauge field. This is exactly what we see. We could always recast the U(1) theory as an SO(2) theory with a two component real scalar field, instead of a one component complex scalar field. The new vacuum would then have one zero component, and one real constant component, and the earlier statement of the Goldstone theorem would apply and produce the same answer. One final note on the U(1)/SO(2) problem. One is used to seeing residual symmetry associated with zero isospin components in the scalar field, but in U(1)/SO(2) theory, there is only one generator to be broken, so there is no residual symmetry.Spherical Cavity Resonator | Solving The Wave EquationDietterich Labs2020-09-12 | In this video, I show you how to solve the wave equation for the acoustic resonances of a spherical cavity.
*l is a nonnegative integer1/0! + 2/1! + 3/2! + 4/3! + 5/4! + 6/5! + 7/6! + 8/7! + ... = ?Dietterich Labs2020-09-11 | In this video, I show you how to sum this series in the title using a few algebra tricks.
To be clear, more physics videos will be coming (this will eventually includes more quantum field theory videos), I am just producing more diverse content.Foreign Mushrooms Invaded My PotDietterich Labs2020-09-10 | Mushrooms of an unknown type invaded the pot of one of my house plants. If you know what kind of mushroom these are, let me know in the comments.