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Professor Hafner
United States
Registrace 14. 10. 2011
Your concierge for learning physics.
I am a professor at Rice University. My lab develops new tools for molecular structure in biomembranes based on nanoparticles and vibrational spectroscopy:
hafnerlab.blogs.rice.edu/
I have taught sophomore and freshman physics at Rice for 15 years. These videos are from online courses I made with Rice Online for edX and Coursera, as well as homework solutions I made in my office. Here are links to the courses if you are interested:
edX
www.edx.org/course?search_query=hafner+ricex
Coursera
Physics 101 - Forces and Kinematics - www.coursera.org/learn/physics-101-forces-kinematics
Physics 101 - Energy and Momentum - www.coursera.org/learn/physics-101-energy-momentum
Physics 101 - Rotational Motion and Gravitation - www.coursera.org/learn/physics-101-rotational-motion-gravitation
I am a professor at Rice University. My lab develops new tools for molecular structure in biomembranes based on nanoparticles and vibrational spectroscopy:
hafnerlab.blogs.rice.edu/
I have taught sophomore and freshman physics at Rice for 15 years. These videos are from online courses I made with Rice Online for edX and Coursera, as well as homework solutions I made in my office. Here are links to the courses if you are interested:
edX
www.edx.org/course?search_query=hafner+ricex
Coursera
Physics 101 - Forces and Kinematics - www.coursera.org/learn/physics-101-forces-kinematics
Physics 101 - Energy and Momentum - www.coursera.org/learn/physics-101-energy-momentum
Physics 101 - Rotational Motion and Gravitation - www.coursera.org/learn/physics-101-rotational-motion-gravitation
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!
zhlédnutí: 458
Video
Guest Lecture on Plane Wave Interference
zhlédnutí 642Před 3 měsíci
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
zhlédnutí 725Před 5 měsíci
I needed to upload this for my Coursera class.
More Reasons Physics is Hard
zhlédnutí 13KPřed 5 měsíci
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
zhlédnutí 462Před 7 měsíci
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)
zhlédnutí 797Před 8 měsíci
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
zhlédnutí 447Před 9 měsíci
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
zhlédnutí 320Před 10 měsíci
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
zhlédnutí 420Před rokem
Cloudfall on the Ruta de los Volcanes, La Palma, Canary Islands
4 min 20 sec at Playa de Zamora, La Palma, Canary Islands
zhlédnutí 266Před rokem
4 min 20 sec at Playa de Zamora, La Palma, Canary Islands
Top Six Physics Words That Will Reveal Your Southern Accent (from Starbase)
zhlédnutí 506Před rokem
Top Six Physics Words That Will Reveal Your Southern Accent (from Starbase)
Online Physics Teaching and my Three Brushes with Hollywood
zhlédnutí 2,9KPřed rokem
Online Physics Teaching and my Three Brushes with Hollywood
PHYS 101 | Trajectories 4.5 - Advanced Beer Pong Correction
zhlédnutí 1KPřed rokem
PHYS 101 | Trajectories 4.5 - Advanced Beer Pong Correction
PHYS 101 | Trajectories 3.5 - Beer Pong Correction
zhlédnutí 887Před rokem
PHYS 101 | Trajectories 3.5 - Beer Pong Correction
102x Electricity and Magnetism Introduction
zhlédnutí 1KPřed 2 lety
102x Electricity and Magnetism Introduction
PHYS 201x Waves and Optics Introduction
zhlédnutí 668Před 2 lety
PHYS 201x Waves and Optics Introduction
Top Ten Comedians That Would Make Good Physics Instructors
zhlédnutí 960Před 2 lety
Top Ten Comedians That Would Make Good Physics Instructors
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
Best teacher ever
Thank you!
Great mind bender for the curious. Thanks!
GET A MAN'S HAIRCUT YA HIPPY FREAK.
Thanks
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.
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.
@@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.
Why your hair is so longg ?
I rarely cut it.
They always erase the board before I am done writing it down. --> Me...1980,81,82,83.
czcams.com/video/N52M3TN9KDo/video.html
@@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.
You are literarly the best, I wish my profs were like you....
bro i can't believe i found these videos before my final
I thought that you were a girl in the thumbnail.
How can we mathematically prove that the phase lag is 90 degrees?
so we cant calculate magnetic field in the center of loop with ampere's lwas?
Excellent! Thank you.
Excellent lecture. Thank you so much!
Thanks, professor. Hal in energy minimum
It's hard because most teachers are not suited to teach it. Would had want to go to such University....shit happened.
😂
This guy doesn't explain anything...
Fortunately there’s a giant internet out there for ya. :)
Why would unpolarized light be expressed as [1,1]?
What happened to the right hand rule?
It's been so long, but THANK YOU! From Brazil 🙏🙏
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.
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
Hi, What happens if you do this in a vacuum? If you are right, then nothing happens. Right?
THANK U MY LORD -- EXCELLENT
Great one..thanks alot sir
But professor... How the spark is produced???
Then... Why not that tape(+) and the left side of the (sphere a)(-) is producing spark???
Only attraction???
Nice one Sir
Will it work with a red light?
Amazing ❤❤❤ thank you so so so so so so so so much for this DEMO ❤❤❤❤❤😊😊😊😊😊
I trusted you. 😢
And that’s how the Herstein amphitheater burned down!
Need more bloopers! :p
Can I ask what else to substitute glass wool? Its a bit difficult to aquire over here
You should have learnt greek as well!
Thank you I was homeschooled so I never took physics but algebra is not difficult for me 😊
Never understood coupled oscillations until now! Thank you!! Other sources + my profs are so confusing, but this is great
great explanation
So this is why I had to take calculus in high school😊
I fell for this so hard lol. Hand on my head and everything 🤣
Why? Vf does not depends of L following his equations
That result does not match the total L
Why does he remind me of a vampire? (in a good way)
How dare you make me enjoy studying 😭❤️
Like a true Texan 5:00
Thank you! This really helped me grasp the concepts better. I've been enjoying your lectures so far, great content.
Beautiful demo but close examination of the action around the 00':07" mark (at 0.25x playback speed) shows the exact opposite motion to that described around the 03'40" timestamp in the theoretical exposition; the pendulum is initially repelled by the charged bell. I wonder if the influence of the negatively-charged Teflon rod on the suspended metallic ball dominates at first as they are closer and this attraction looks like "repulsion" by the RH bell at first. BTW, I'm not questioning basic electrostatics and I have a decent understanding of charge separation and dielectric polarization but just wanted to point out that the initial transient condition is a bit weird!
If a light source invert increasing progressive like prime number or buddhist flag color value will enought sun iintensity explode air or blindness result at any addressible position?
Thank you for everything that you do with this channel. I love listening to you break down Physics topics. I can tell that we are using the same textbook by your practice problems and chapters, but you explain the topics effortlessly and I appreciate how you go through the derivations that they skip. Thanks again, I've subscribed and plan on sharing your channel with whoever cares. Best !