Professor Hafner
Professor Hafner
  • 1 341
  • 2 520 685
Chromatography Toy Model
This is a lecture from my new class. Here we look at a very simple "toy model" of chromatography, where molecules are separated as they flow through a column. The model gives reasonable results!
Переглядів: 504

Відео

Guest Lecture on Plane Wave Interference
Переглядів 6814 місяці тому
I guest lectured in a class and recorded it on my laptop because someone was sick. It is not the best quality but I figured I'd put it here on YT anyway. It has some typical "pre-lecture shtick" that isn't in the online classes.
Foucault's Pendulum at the Houston Museum of Natural Science
Переглядів 7726 місяців тому
I needed to upload this for my Coursera class.
More Reasons Physics is Hard
Переглядів 13 тис.6 місяців тому
As a followup to "Why Physics is Hard," here are more reasons as you go through your career. They aren't all about math!
The "Ring of Fire" Eclipse from Refugio, TX
Переглядів 4638 місяців тому
I recorded this with a simple Nikon DSLR and some filters. I am not a fancy photographer, but at least the colors aren't fake! :)
Trailer for PHYS 201x Waves and Optics (the early edX version)
Переглядів 8299 місяців тому
They are coming. www.coursera.org/learn/oscillators-waves www.coursera.org/learn/light-materials www.coursera.org/learn/geometrical-physical-optics
Top Ten Things I'm Going To Do On My Sabbatical
Переглядів 4729 місяців тому
My sabbatical is actually over, so here we look at what I intended to do. One thing I accomplished was to get my PHYS 201 Waves and Optics loaded onto Coursera! It has been passed off to them and should be out in a week or so.
Macro Raman - Starbase Concrete
Переглядів 32210 місяців тому
I was recording some short videos and images to use in talks, and things kind of spiraled from there. Music: www.bensound.com License code: MNV8QGMIQSVTVRDQ
Cloudfall on the Ruta de los Volcanes, La Palma, Canary Islands
Переглядів 429Рік тому
Cloudfall on the Ruta de los Volcanes, La Palma, Canary Islands
4 min 20 sec at Playa de Zamora, La Palma, Canary Islands
Переглядів 270Рік тому
4 min 20 sec at Playa de Zamora, La Palma, Canary Islands
Top Six Physics Words That Will Reveal Your Southern Accent (from Starbase)
Переглядів 514Рік тому
Top Six Physics Words That Will Reveal Your Southern Accent (from Starbase)
From Rice to Starbase
Переглядів 259Рік тому
From Rice to Starbase
Online Physics Teaching and my Three Brushes with Hollywood
Переглядів 2,9 тис.Рік тому
Online Physics Teaching and my Three Brushes with Hollywood
PHYS 101 | Trajectories 4.5 - Advanced Beer Pong Correction
Переглядів 1 тис.Рік тому
PHYS 101 | Trajectories 4.5 - Advanced Beer Pong Correction
PHYS 101 | Trajectories 3.5 - Beer Pong Correction
Переглядів 895Рік тому
PHYS 101 | Trajectories 3.5 - Beer Pong Correction
Lavoisier and the Kilogram
Переглядів 870Рік тому
Lavoisier and the Kilogram
Why Physics Is Hard
Переглядів 479 тис.Рік тому
Why Physics Is Hard
DEMO: Hafner's Cradle
Переглядів 2,8 тис.2 роки тому
DEMO: Hafner's Cradle
Burnt Rice Pt. 1
Переглядів 6442 роки тому
Burnt Rice Pt. 1
Le Krewe de Jones
Переглядів 3222 роки тому
Le Krewe de Jones
PHYS101x Mechanics Trailer
Переглядів 2,4 тис.2 роки тому
PHYS101x Mechanics Trailer
102x Electricity and Magnetism Introduction
Переглядів 1 тис.2 роки тому
102x Electricity and Magnetism Introduction
PHYS 101x Mechanics Introduction
Переглядів 1,6 тис.2 роки тому
PHYS 101x Mechanics Introduction
PHYS 201x Waves and Optics Introduction
Переглядів 7012 роки тому
PHYS 201x Waves and Optics Introduction
Canvas HW 5.01 - 5.05
Переглядів 5572 роки тому
Canvas HW 5.01 - 5.05
Update 7
Переглядів 6252 роки тому
Update 7
Top Ten Comedians That Would Make Good Physics Instructors
Переглядів 9742 роки тому
Top Ten Comedians That Would Make Good Physics Instructors
PHYS 125 Pledge Problem Hints
Переглядів 1,2 тис.2 роки тому
PHYS 125 Pledge Problem Hints
Nanobelt Synthesis - Sample NB7c-20x
Переглядів 2282 роки тому
Nanobelt Synthesis - Sample NB7c-20x
Gold Nanobelt Synthesis
Переглядів 3352 роки тому
Gold Nanobelt Synthesis

КОМЕНТАРІ

  • @CobraSting
    @CobraSting 21 годину тому

    Physics is hrd when you dont listen

  • @JEEVANRANIL
    @JEEVANRANIL 21 годину тому

    Thank you sir...

  • @davidg3944
    @davidg3944 День тому

    Thanks for this demonstration [yes, I'm almost a decade late, but heck, for me that's timely].

  • @cooldude11_1
    @cooldude11_1 2 дні тому

    its 3 am and i cant get enough of your demos!!! every one of them is really really interesting and helps in understanding the concepts a lot!!! thank you so much for your work sir

  • @observer4322
    @observer4322 2 дні тому

    Respect for becoming a conductor for our amusement.

  • @user-iy4we2rh8c
    @user-iy4we2rh8c 3 дні тому

    Dear Professor let's apply Tungsten mold on a cube of 10Cm3 solid block of Iodine.Now we heat Tungsten so that Iodine molecules dissociate into electronegative iodine atom and draws electron from Tungsten.The Iodine will not be able to withdraw more electrons than 10^18 electrons and form Iodine negative ions.Rest iodine atoms will be intact and try to draw more electrons.If it worked dielectric breakdown is not an issue as at a given point It will not attract more than 10^18 electrons and Iodine atoms will try to attract electrons only not really gains it.Its a hypothetical theory one needs to verify.❤This high voltage is for breaking Water molecules I need your opinion over it.

  • @fanman421
    @fanman421 5 днів тому

    Yep… and you can put two coils of wire on both sides of the tube, and two more coils above and below the tube, and feed signals to the coils and make the beam go back and forth, and up and down, really fast. And if you put phosphors where the beam hits that glow, and then controllably turn the beam off and on really quick, you can create a picture. 😉😊

  • @h7opolo
    @h7opolo 6 днів тому

    Maine State Police are torturing me with constant seismicity. They dialed in the frequency to the most biotoxic, i.e. 8-9 Hertz.

  • @leusmaximusx
    @leusmaximusx 7 днів тому

    next is how to quantify (magnetohydrodynamic formulas) this phenomenon for a non-purposeful & purposeful application i.e arc blast explosion & arc furnace steel production , the energy balance equations to produce the effects thnks for the wonderful instructional video

  • @HarshKalyani1234
    @HarshKalyani1234 7 днів тому

    Thankyou sir for explaining

  • @alr22_570
    @alr22_570 10 днів тому

    Lmaooo😂😂🩴

  • @CMAenergy
    @CMAenergy 11 днів тому

    Lots you do not know about toroid's !

    • @Prof-Hafner
      @Prof-Hafner 11 днів тому

      I only need to know enough to teach intro E&M.

  • @bekiao
    @bekiao 12 днів тому

    Techer tanks from 🇪🇹Ethiopia

  • @kio64x
    @kio64x 13 днів тому

    omg ty goat

  • @alikansoh4604
    @alikansoh4604 14 днів тому

    Love youuuuu

  • @stevenanderson724
    @stevenanderson724 16 днів тому

    Advanced math is a lot like religion.You just gotta have faith that it works

  • @Student-qh7nc
    @Student-qh7nc 16 днів тому

    Watching from india..thanks prof.

  • @animal_shorts1
    @animal_shorts1 18 днів тому

    my method: acc will be same everywhere on rope, so we can say, tension should be 150N (i.e mg) to just lift the body. so on monkey side, 150 - 100 = 10a a › 5

  • @alikansoh4604
    @alikansoh4604 19 днів тому

    Best teacher ever

  • @dracygon
    @dracygon 20 днів тому

    Thank you!

  • @mrbrown6421
    @mrbrown6421 20 днів тому

    Great mind bender for the curious. Thanks!

  • @sanuratennakoon7979
    @sanuratennakoon7979 23 дні тому

    Thanks

  • @stauffap
    @stauffap 23 дні тому

    I'm afraid that you made a mistake here. As far as i can tell you can't explain Diamagnetism with a Lorentz-force perpendicular to the current loop. Because that could never change the angular momentum (conservation of angular momentum) and if the angular momentum doesn't change the magnetic moment wouldn't change. So that can't explain diamagnetism. I tried to make this work for a week now and i wasn't able to. My conclusion is that you have to use electromagnetic induction to explain Diamagnetism classically. The induced voltage in the loop can indeed change the angular momentum and therefore the magnetic moment. I can mention relevant sources that go through all the necessary derivations, if anyone is interested in the details.

    • @Prof-Hafner
      @Prof-Hafner 23 дні тому

      Thanks! As you can tell this was just meant to be a very qualitative definition, and describing magnetism classically is kind of pointless anyway. But you probably have something more solid there. I'll see if I can pin the comment so folks will see it.

    • @stauffap
      @stauffap 23 дні тому

      @@Prof-Hafner That's very kind of you. Since you highlighted my answer i'll add some additional information for those, who might be interested: 1. There's a video on youtube with the title "L20v4 Worked Example Force on a Magnetic Dipole" There are more scholarly sources, but this one just explained the formula better. It shows that the force on a magnetic dipole/current loop is dependent on the magnetic moment of the current loop. He also derives the formula in his next video. 2. A formula and derivation for how induction changes the magnetic moment of a current loop can be found in the feynman lectures (Volume II, 34). 3. Most of you probably have seen the formula for the magnetic moment of a current loop (just google magnetic moment or Bohr Magneton, if you haven't see it). This formula makes it clear that the magnetic moment is dependant on the angular momentum. These formulas can be derived classically, but we are presupposing information from quantum mechanics like the knowledge that electrons have two spins of opposing direction or that spin behaves a lot like a quantum mechanical angular momentum or that we know the amount of angular momentum an electron has (the amount and the amount in the direction of measurement). It's not rigorous, but it was done and it was used historically to figure stuff out and i find it helpfull to build a better intuition of what spin is and isn't.

  • @cangimotcaiten
    @cangimotcaiten 24 дні тому

    Why your hair is so longg ?

  • @mrbrown6421
    @mrbrown6421 24 дні тому

    They always erase the board before I am done writing it down. --> Me...1980,81,82,83.

    • @Prof-Hafner
      @Prof-Hafner 23 дні тому

      ua-cam.com/video/N52M3TN9KDo/v-deo.html

    • @mrbrown6421
      @mrbrown6421 23 дні тому

      @@Prof-Hafner Thank you sir. I was laughing at myself about my college days and how wonderful it is that I can stop your video and study it, and then follow your channel.

  • @MichalDemeterTvrdon
    @MichalDemeterTvrdon 25 днів тому

    You are literarly the best, I wish my profs were like you....

  • @shejoubson9428
    @shejoubson9428 26 днів тому

    bro i can't believe i found these videos before my final

  • @homie_Big
    @homie_Big 26 днів тому

    I thought that you were a girl in the thumbnail.

  • @edvinsiewertson7724
    @edvinsiewertson7724 26 днів тому

    How can we mathematically prove that the phase lag is 90 degrees?

  • @mustofa-misbahulmustofa5536
    @mustofa-misbahulmustofa5536 27 днів тому

    so we cant calculate magnetic field in the center of loop with ampere's lwas?

  • @valeriereid2337
    @valeriereid2337 27 днів тому

    Excellent! Thank you.

  • @valeriereid2337
    @valeriereid2337 27 днів тому

    Excellent lecture. Thank you so much!

  • @jkinkamo
    @jkinkamo 27 днів тому

    Thanks, professor. Hal in energy minimum

  • @AndreeaCe
    @AndreeaCe Місяць тому

    It's hard because most teachers are not suited to teach it. Would had want to go to such University....shit happened.

  • @whyphy5190
    @whyphy5190 Місяць тому

    😂

  • @leonardosoto5669
    @leonardosoto5669 Місяць тому

    This guy doesn't explain anything...

    • @Prof-Hafner
      @Prof-Hafner Місяць тому

      Fortunately there’s a giant internet out there for ya. :)

  • @CrowMagnum
    @CrowMagnum Місяць тому

    Why would unpolarized light be expressed as [1,1]?

  • @CrowMagnum
    @CrowMagnum Місяць тому

    What happened to the right hand rule?

  • @hoffiliz3762
    @hoffiliz3762 Місяць тому

    It's been so long, but THANK YOU! From Brazil 🙏🙏

  • @gytis321s2
    @gytis321s2 Місяць тому

    Nasa scientists thinks that if you shape this force around the object with asymmetric field. It can produce thrust effects. Pushing object in to the direction the asymetri is pointing. Imagine 3D heart shape. They believe this technology might be used by UAP. This is how they can just hover around without sound or any means of propulsion. Just electrostatic force.

    • @BDizubz
      @BDizubz 18 днів тому

      What an interesting concept, we see em all the time so they’re real, whether it’s government aircraft or not, just to understand how something moves that fast n doesn’t die would be awesome

  • @kruimels
    @kruimels Місяць тому

    Hi, What happens if you do this in a vacuum? If you are right, then nothing happens. Right?

  • @kaursingh637
    @kaursingh637 Місяць тому

    THANK U MY LORD -- EXCELLENT

  • @yzhehzjixofjdoap
    @yzhehzjixofjdoap Місяць тому

    Great one..thanks alot sir

  • @RajaRaja-qp5ic
    @RajaRaja-qp5ic Місяць тому

    But professor... How the spark is produced???

    • @RajaRaja-qp5ic
      @RajaRaja-qp5ic Місяць тому

      Then... Why not that tape(+) and the left side of the (sphere a)(-) is producing spark???

    • @RajaRaja-qp5ic
      @RajaRaja-qp5ic Місяць тому

      Only attraction???

  • @onyeziasopuluchukwu7699
    @onyeziasopuluchukwu7699 Місяць тому

    Nice one Sir

  • @Lhundra
    @Lhundra Місяць тому

    Will it work with a red light?

  • @MusaShah-qh5jr
    @MusaShah-qh5jr Місяць тому

    Amazing ❤❤❤ thank you so so so so so so so so much for this DEMO ❤❤❤❤❤😊😊😊😊😊

  • @Douglas-Murad
    @Douglas-Murad Місяць тому

    I trusted you. 😢

  • @sweet_starshine
    @sweet_starshine Місяць тому

    And that’s how the Herstein amphitheater burned down!

  • @sweet_starshine
    @sweet_starshine Місяць тому

    Need more bloopers! :p