EM Waves

[@mog7501]

I fell asleep watching something and somehow ended up on this video when I woke up

[@alanmonaghan8970]

Haha same boat here 😂

[@UncleCactorrio]

Same !

[@goat5815]

Same

[@Halfrightfox]

Yeah the YT algorithm is starting to piss me off

[@yoprofmatt]

Mo G, So sorry to wake everyone up with this nightmare! But if you're not annoyed, you might like my new website: www.universityphysics.education Cheers, Dr. A

[@MrBendybruce]

I know this is an old lecture, but honestly, it's just so damn good. Not only does it teach the fundamentals in a clear and easy to understand way, but it provokes thoughts and ideas for the curious listener. This is a real gift to the internet.

[@tomaelbrecht2179]

It would make you think that they invented anti gravity and high magnetic fields that can do stuff we can only dream of ages ago dont you 😊

[@malikamajjoud8324]

I also found this video by falling asleep and then waking up 20 minutes in 😂. But this lecture is great! Everything makes perfect sense and is very accessible. What a time to be alive where you can watch a lecture this quality at 7am on the other end of the planet

[@yoprofmatt]

Malik Amajjoud, Thanks for the comment, and keep up with the physics! You might also like my new website: www.universityphysics.education Cheers, Dr. A

[@ccarefful1289]

52 min in wow i slept that well lol he was calm tho

[@carsonthornburg7560]

Same, but instead of sleeping, I went away from my computer and came back and also noticed I was 20 minutes in as well.

[@artiscrutial]

Same, I’m about to really watch it now. I love science and technology so I get why youtube suggested it. :)

[@Elijah_arnold6969]

I watched the whole thibg i was watching like markiplier and i wake up to some math stuff

[@jemmari201133]

Whether you like or hate a subject is always on the teacher. Good teachers get your attention just by the way they teach and how much they belive in what they teach. This guy is a good teacher and interesting to hear. All teachers should teach like this. Thanks, you are great.

[@yoprofmatt]

Appreciate that. Cheers, Dr. A

[@HyenaEmpyema]

Electromagnetic Waves travelling from my screen to my retina are teaching me about themselves.

[@TheSatchmo93]

If you smoke anymore you will come up with a Unified theory, do you want strings? This is how you get multiple universes!

[@ShanksTv7]

TheSatchmo93 nb

[@smugqing5164]

mETaphYsIcS

[@ninuribandara3518]

😌

[@varunkumar2324]

I really laughed thanks.

[@Ejeby]

41:27 equation: electric and magnetic energy density 1:01:30 equation: what is the total power output of the sun 1:14:30 lens can be intensity of the sun 1:29:00 righthand rule 1:32:00 red shift, blue shift 1:35:15 why is this only true when v is much less than the speed of light; what are the complications when the relative velocity approaches the speed of light[[?]] 1:36:00 equation for rotating galaxy 1:39:20 the galaxy is moving away faster than its spinning, so both points (including the one moving "toward" earth) are red-shifted 1:43:15 polarization defined as direction of the [[electric field]]; there are only 2 possibilities (for lasers and what else[[?]]): horizontal or vertical polarization = "defined polarization" [[?]]; incandesecent sources, like sunlight or a lightbulb, have all the angles = "random polarization" 1:45:35 glare tends to be dominantly polarized in one direction [[?]] how come it never happens that when you put on polarized sunglasses you end up filtering out the object's light and keep only the glare[[?]] 1:48:00 [[electric field]] peak value 21.7millivolts per meter ; power = energy per time ; intensity = power per area 1:57:15 sunlight pushes on you a little bit ; "radiation pressure" refers to momentum transfer between wave and radiated object aka "absorber" ; equation of momentum transfer 2:00:25 "this is kinda like what we talked about..." [[?]] 2:01:00 Force = Delta P (pressure) over Delta T (time) ; pressure = average intensity / [[speed of light]] 2:03:40 [[?]] 2:04:00 inside spaceship a sheet of [[teflon]] foil or [[mylar]] that expands when it gets into outer space; this is called a solar soil ; mylar is a big reflector: the light that comes in hits the solar sail and pushes the spacecraft 2:06:45 intensity of sunlight on earth is roughly 1400 Watts per square meter; this is about as much as a hair dryer 2:09:35 1/4 lb ~= 1 Newton 2:11:00 [[solar sail]] keeps accelerating with weight of a marble forever

[@billbill3296]

Dude wrote a whole science paper

[@chrisredfield2404]

lmao lower the adderall dosage

[@lameiraangelo]

What a wonderful human being you are ❤

[@jstrunck]

@@billbill3296Maybe several of them.

[@byrontakahashi8373]

I’m now 66 years old and remember loving math thru high school. Might be my only regret in life that I followed other successful paths. Magnetism and EM waves are the most intriguing things I’ve ever seen! Thanks for your sharing, can you imagine just starting college now?! Your drawings and explanations are awesome and inspirational! Thank you!

[@yoprofmatt]

Thanks Byron, I really appreciate comments from my Fandersons of all ages, particularly ones as young as you. Cheers, Dr. A

[@thisisthewaymedia]

It’s never too late Friend.

[@TiagoYamashita]

​@@thisisthewaymedia Byron should mosdef go to college again, learning is fun

[@RichardAlsenz]

What is missed by everyone is the fact that space, "as Gauss stated, is not observable." It is the Electric Field that humans see and observe. The information which is transmitted to an observer through time is in the Coriolus component of the Electric Field ( has been referred to as the magnetic field). That information observed by humans is from the past.

[@snehasishsatapathy9331]

@@yoprofmatt i want to chat with you sir 😊 this session was fantastic

[@omealyjackson6795]

This method of teaching is absolutely beautiful. I love his approach. The way he builds up from the basics and expands on it is simply amazing. One of the best teachers out there.

[@slomo311]

Olukzllu oi5770mm fbt

[@ricko7902]

Yes I agree, he is a great teacher. Especially considering he seems to be writing backwards

[@FuzzyLlamaGuy]

@@ricko7902 t i

[@FuzzyLlamaGuy]

m ozombq

[@sarcosmic6982]

The effortless reflected handwriting is really impressive and neat! It’s fascinating to watch the writing appear almost as if by magic

[@justinchase781]

How does this board work?

[@sudo1500]

i thought they mirrored the video but I guess not

[@Chaingz]

Right I was thinking the same exact thing. He’s a legend for this skill

[@lilblackduc7312]

@@sudo1500 It appears he's left-handed.

[@Psylar87]

He's writing normally. The video is flipped and there are screens in his class that he encourages the students to look at instead of looking at him, since all of the writing will appear backwards if they look at him.

[@alondralalala5761]

All my teacher does during the pandemic is post the Hw and put youtube videos to teach us. You have literally been saving my grade!

[@imjustaguy4340]

Exactlyyy

[@ethanyochim7423]

Physics 2? That class hurt physically, but it was so worth it

[@texasbeaver8188]

@@ethanyochim7423 What do you mean by worth it?

[@ivoryas1696]

Alondra Lalala I can relate to that... didn't even pass the class. Stuff sucks :/

[@pilotrserra]

Ok…I don’t understand your philosophy; you are watching a KZbin video now…and he is talking about HW. What is the difference LOLO

[@korenaboyd8398]

Studying for my MCAT and thought I would NEVER understand waves. WOW. Thank you Dr. Anderson for making learning physics so accessible and rewarding

[@mpsdelhi]

Brilliant! The teacher and teaching style. Engineering and science students of today are so fortunate to have access to such material and great teachers like Prof. Anderson! Keep strong, Sir!!

[@enochbrown8178]

Wow, Dr. Anderson is a great teacher. He makes physics so clear and understandable. What a gift he is to teaching and science. When I first started watching this video, I thought, OMG an academic is about to make the difficult to understand even more difficult and I just may be wasting my time. Was I wrong! What a surprising blessing, for sure.

[@yoprofmatt]

Thanks for the wonderful comment. Glad to be of service. Cheers, Dr. A

[@thehapagirl92]

I agree. I've had professors who try to dumb down material WAY too much and I've also had professors on the other side of the spectrum who make things so difficult to understand. I'm glad Professor Anderson has achieved that healthy teaching medium.

[@robertdiggins7578]

Is the Earth gravitationally attracted to the position of the Sun, ~8 minutes ago? If yes, bye bye coherent solar system. If no, C is not a speed limit and something must be communicating instantaneously. Or I need more information. Thanks.

[@robertdiggins7578]

When you gave the example of the Sun for visible light, I thought that maybe it would have been good to add that the Sun isn't limited to visible light. Thanks.

[@robertdiggins7578]

Can waves propagate through no medium? Have you contemplated the existence of a medium in "free space"? Could a test, better than P&W, be devised to double check with more rigor? When you shield an antenna from the microwaves coming from the Earth's oceans, according to data from the Herouni Antennae, you do not measure any Cosmic Microwavve Background. Why don't we try that and why didn't we think about doing that before? Also, when light slows down through a medium, such as glass, how does it speed back up to C after it passes through the glass? Doesn't C actually fluctuate, except that it's tied to the meter, making the meter fluctuate? Thanks!

[@ardenkwong5299]

GENIUS! Someday ALL university physics "conversations, lectures, and problem solving" will be taught this way! Learning Glass technology, mirror image of Dr. Anderson "facing" his students, and his enthusiasm, explanations, texts, and illustrations projected normally -- all this makes learning personal, inviting, clear, and mutually fun for BOTH sides of the Glass! LOL for Dr. Anderson's "reverse-image-corrected" right hand rule explanation at 1:22:27 in which he has to use his actual left hand (with wedding ring) to project the image of his right!! This is a game changer for higher learning (like Dick Fosbury's "then-new-approach" to high jumping in 1964)!!!

[@yoprofmatt]

Arden, Wow, thanks for this, it really made my day. And also made me feel a bit old for knowing about the Fosbury Flop! Thanks for the comment, and keep up with the physics! You can also converse with me and my team at my new website: www.universityphysics.education Cheers, Dr. A

[@yoprofmatt]

Arden, I have a favor to ask. We would like to use your quote in some promotional material. Would that be okay? Email me at [e-mail] Cheers, Dr. A

[@coreys2686]

@@yoprofmatt You should describe the technology you're using for this in the video description. Its a clever use of physics. It'll also get the word out.

[@ardenkwong5299]

@@yoprofmatt Dick broke high school records in 1964-1965, set collegiate records in 1966-1967, and won Olympic gold in 1968 with a new Olympic record. By 1972, the straddle technique was obsolete, and the Fosbury Flop was THE new standard for almost all high jumpers! Best anti-aging agent? Innovation through new ways of teaching, new ways of learning, new ways of understanding of course! The "nota bene" that curiosity and persistence can sometimes turn out to be challenging AND fun is a bonus whether jumping over a bar or learning physics!

[@Killakutz69]

Yeah awesome comment.

[@michaelstone229]

I wish more physics professors were like you. This is actually really interesting.

[@sciencenex7964]

kzbin.info/www/bejne/hnLcYXx7d6Z7odE

[@rizkimeilana3903]

I9i

[@rizkimeilana3903]

9

[@rizkimeilana3903]

9i

[@NightRogue77]

Needs more pop culture references and woo-woo stuff. 1/10 would not fall asleep again

[@ElPasoTubeAmps]

I think your lecture is wonderful. I understood this as a child (I am now 72) as I was coached by my uncle, a chemist at ORNL, but have found few people that can comprehend or care about such things. But we love what we love. I would like to just randomly add that heating the concrete you mentioned around 1:15:00 is something I did a few years ago with a carbon arc. I think it was arcing at about 36V @ 70A. It ended up being a bad idea as apparently the water vapor in the concrete caused the hot-spot to explode (after becoming red hot) and blow very hot pieces of concrete all around and into my face. I was not injured seriously but it taught me a lesson that extreme temperatures (or anything else) can do unexpected things. Lastly, even after all these years, I still enjoy a good presentation like you posted here. I know it has been seven years since you posted but please keep up the good work and enjoy life. I know it would be subjective but it would be interesting to plot real-time ageing years with perceived ageing years as we grow older.

[@muhammadomarkhayyamkhan3593]

This teacher is not Just a Teacher he is a Scientist. wonderful teacher.

[@yoprofmatt]

Muhammad, Thanks for the comment, and keep up with the physics! You might also like my new website: www.universityphysics.education Cheers, Dr. A

[@hemanthkotagiri8865]

This is one of the most beautiful explanations I've ever seen. Thank you, prof. Matt.

[@joeboxter3635]

Yes, I agree. But its wrong. Read my comment.

[@hemanthkotagiri8865]

@@joeboxter3635 I am unable to find your comment, could you please reply the same in this thread here?

[@cerleywood]

You Sir are an amazing teacher. If all my teaches, instructors and professors were like you school would have been a whole lot easier. Thanks for sharing.

[@brendandrury2177]

I watch educational youtube videos because I cannot tolerate all the commercials on TV. I have been looking at DC motors and magnetism and running across this class was fortuitous. The professor is excellent ! Really.

[@charlesperry7300]

Excellent teaching! It is easier to follow the idea when the professor writes his flow of thought on the blackboard. The "front" blackboard is so innovative.

[@Mr7Crash]

Apparently, I'm not the only one who fell asleep on KZbin and woke up to this. It's an amazing video to wake up to tbh. KZbin algorithm doing it right!! I went on to get my Master's degree in Information and Digital Communication, but I have always had a passion for physics. This goes right in the feels! Thank you for this amazing course!

[@yoprofmatt]

Greenhead, You're very welcome. Glad you're enjoying the videos. You might also like my new site: www.universityphysics.education Cheers, Dr. A

[@WalterBethinE94]

Legit woke up to this today.

[@anxbis4718]

@@WalterBethinE94 same

[@RealDivaBoy]

No lie, just happened to me too. I woke up to it playing an hour in and was so confused...

[@darewin3847]

Sam here for real and I'm spooked out ! I fell asleep and woke up and saw this guy speaking. What sorcery is this (0_0)

[@jackson_the_stupid7221]

gee...my four years of studying electronics engineering ... summarized in this single video, and i actually learn more

[@mr.vought-sikorskyvs-3008]

You saved me from getting in trouble, I accidentally fell asleep with my computer on watching memes, and it ended up going onto this video, the downside is that now my dad is purchasing physics books and stuff like that.

[@s.mendez7160]

Dr. Anderson, the tools for teaching this make learning so much easier to understand, compared to physics taught in the 80's. So appreciate the cadence of your teaching. Just awesome! Your students are blessed to have you as an instructor. Thank you.

[@bennyhollis9679]

1 hr in and I just realized that you're writing everything backwards from right to left.. The amount of practice this must have taken is a dedication to teaching that should be commended. Thank you!

[@sciencenex7964]

kzbin.info/www/bejne/hnLcYXx7d6Z7odE

[@bobchelsy163]

or he just flipped the video

[@abdullahfarhat9848]

Or mirror maybe

[@1w2qqswa]

Thank you Prof. Anderson, this is an amazing video - I'm doing a subject as part of my masters and the amount of information I have to research is enormous. It's all about wireless communication and EM waves. Thanks to your video I finally got the basics of it. Keep up the amazing work.

[@yoprofmatt]

LE, You're very welcome. Glad you're enjoying the videos. You might also like my new site: www.universityphysics.education Cheers, Dr. A

[@32_gurjotsingh82]

well i searched for this video and i was lookin for something to change my perception that how mechanical transverse waves transfer energy and how em waves transer energy and after viewing this whole video it was no less than an enchanting lesson that no worldy thing can match. thanks and more power to you prof.

[@robinashaheen1713]

He is a gifted teacher. He expresses difficult concepts with such an ease and eloquence. Very few prof are of such a high calibre. I wish he was my physics teacher when I was in grad school.

[@vincecox8376]

Thank you for that. Well put!! My previous experimentations with the "B" field , about 2 years ago began quite simply after reviewing the Coral Castle installations I realized that after seeing that his generator was built to maximize the "B" field by using "V" magnets I wanted to see what effects the "B" field had on ordinary rocks . So I went to my front yard and picked up a stone and weighed it , 38 Grams, then I was carful only tap it with the "B" field of a magnet , It dropped in weight to 22 grams. I believe the key is to find the correct frequency to vibrate the "B field and it should float.. No wonder magnetic rocks were called "load stones

[@LucisFerre1]

I wondered, what are the odds of being able to write backwards, AND write backwards well, AND write backwards well...left handed. At this point I realised that it's far more likely that you're using a video camera to invert the image. Then I realized how cute it was that you demonstrated the Right Hand Rule using your left hand. lol

[@JivedSonen]

Ah...I get it now... I see the wedding ring

[@kraziecatclady]

I write with my left hand and I can read and write backwards fairly well so I didn't even think about this at all until I saw your comment... I can also write with my right hand though and write mirror images simultaneously with both hands that look similar. I cannot however, write different things with both hands at the same time.

[@kraziecatclady]

@@gustavofoss2280 I've been pretty busy lately so it took me a little while to get around to doing this. I hope this counts. I also hope KZbin lets me attach a link like this because this is the first time I've tried to link a video. kzbin.info/www/bejne/bqGcoKmejsx0ebs

[@imhoman8423]

wut?

[@breakingaustin]

@@kraziecatclady Lol.. GG for actually proving it.. you need to work on the mirror stuff a bit though 😉

[@andrewkina9611]

You're by far the best professor/teacher I've ever learned from on KZbin! Thanks for the AWESOME lectures!

[@yoprofmatt]

You're very welcome! I appreciate it. Cheers, Dr. A

[@LA6UOA]

I wish I could have had a teacher like you, when I was in school! All physics I have learned, I have teached my self after I reached 30 years old. That's mainly because bad teachers. Thanks for this video!

[@swerrock]

same here, I just realized why magnetic and electric waves are drawn perpendicular each other :)

[@LA6UOA]

@@swerrock I kinda new that, but not in that way. And I'm a radio amateur 🙄

[@alwaysdisputin9930]

_" That's mainly because bad teachers. "_ yeah I tried Open University & it just wasn't that great an explanation so i gave up. Before that I tried a book called Engineering Mathematics by Stroud. It was awesome & so easy even degree level stuff. Another great teacher on KZbin is DrPhysicsA

[@chrisaa746]

I remember learning about EMF when I was a kid (early 70's) - via the ARRL it is a Ham radio thing - it changed my life and started my life being devoted to science

[@csvegso]

Amazing explanation. I wish I had such physics teachers in high school and university.

[@DanielFBest]

I wish it wasn’t the end of the lesson

[@GerardVaughan-qe7ml]

Please let me know when you find a car with a wire from the top of the aerial.

[@tooshay7396]

No kidding. Clear and writes/draws so well (backwards for him) and he's a lefty too. Ya gotta wonder if he's chimed into what's coming . .the EMPCOE catastrophe. Lights out 3 days, INSANE ELECTRO MAGNETIC PLASMA CHANGE OVER EVENT STORMS, HELL WEEK. He knows the true workings of our flat earth plane

[@tooshay7396]

80s band The Fixx. Red Skies & Soundgarden's Black Hole Sun video.

[@mr.rabbit5642]

@@tooshay7396 Symmetry of our universe prevents you from knowing if this video isn't inverted again as well :P

[@cattywhompus1012]

Not only is this amazing in terms of content and easy comprehension (only 30 minutes in), but can we all just admire that he is writing backward on a transparent board. I’m sure some may find that common, but to explain it so well without skipping a beat and everything being so legible. Major kudos. I will now be subscribing.

[@yoprofmatt]

Thanks. Not to burst your bubble, but there's a trick: kzbin.info/www/bejne/eYirfqeJg7Crj6M Cheers, Dr. A

[@GoogleAccount-ey6xv]

Him: getting views from everyone accidentally falling asleep when watching videos Him: *S T O N K S*

[@user-gh5jc9tx5r]

Omg same

[@JuankQuinteroMejia]

this is really interesting yet I can't help getting sleepy with this, I'm starting to use this as ASMR for sleeping and returning back the next day to where I remember lol

[@__-pl3jg]

This is some great instruction (Not to mention free...Thanks!). However, I'm having a hard time conceptualizing how EM waves would travel along a solid medium such as a coaxial copper clad cable. Do the EM waves propagate THROUGH the diameter of the round center conductor? Or do the waves spiral around the outer edge of the center conductor?

[@scotfaber7926]

This seems a simpler than the heat-light-sound physics I had in college. It's still fun and informative. I am nearing retirement age and I keep toying with the idea of going back to school for a PhD in astronomy (which would mean an in-depth review of physics and algebra and trig and calculus and diff-EQ, etc etc etc). It's big commitment but it's not as if I would be in any hurry.

[@Ballif1]

rukulkuyttjjtkyuukiiuuuuuuuuuuuuuuupuukuuuuuuu

[@jazzycantbreathe4993]

I hope you went for it!

[@bassmanjr100]

Heat - infrared and light are electromagnetic waves.

[@drdjmcbnutz]

i honor your name Matt Anderson for the quality of your lesson(s) and your contributions to Physics! Thank You Father, all the glory and praise be to You! Your creation is amazing!

[@materac460]

7:00 When the charges come together the current is maximum, not zero. The current is zero when the charges are the moste displaced, but there is a maximum electric dipole moment then ... The current is derivative of displacement in time not the same or just value scaled function.

[@martyded]

Nice catch. I was wondering the same.

[@geeache1891]

Indeed, kinetic energy at max while in the middle (velocity, current) and potential electric energy at max while at the ends.

[@geeache1891]

Wikipedia: A common misconception is that the E and B fields in electromagnetic radiation are out of phase because a change in one produces the other, and this would produce a phase difference between them as sinusoidal functions (as indeed happens in electromagnetic induction, and in the near-field close to antennas). However, in the far-field EM radiation which is described by the two source-free Maxwell curl operator equations, a more correct description is that a time-change in one type of field is proportional to a space-change in the other. These derivatives require that the E and B fields in EMR are in-phase.

[@rajankandel8354]

Great explanation sir Thank you, it took my understanding to another level.

[@ethioupdatedinfo.]

I am addicted of professor Anderson lecture videos. Thanks professor! I wish if I have a chance to attend your course

[@fromexoplanet21]

okay sir, i am 3 minutes in and i'm completely blown away by how well you explain things.

[@lizajungmeyer1741]

Being a scientist is my hobby and I am starting to revisit the sciences because I now have the time to do so. Your point on the duality of em spectrum is actually true at any point of the spectrum because everything is truly made of particles and depending on your distance from the point of the spectrum every point becomes a wave. Do you agree with this? I am correct to make this conclusion? I am looking at this on point of view of chemistry.

[@erupter76500]

Kind of a late comment but you are correct, the reason things like gamma rays act like particles is because they are oscillating so extremely fast that when viewed over a longer distance it is almost indiscernible from a straight path. Shorten the distance enough though and you will be able to make out the wave like path that you typically see with all EM waves. On the opposite end of the spectrum you have the exact opposite. With low frequency radio waves they travel in long drawn out waves making them act more like a wave than a particle traveling through space. So when viewed over a longer distance they behave like waves. However, if you shorten observing distance, the waves are so stretched out that their path then when viewed over that short distance it looks like a straight line because of how gentle the oscillations are. I hope this helps if you never found an answer to your question.

[@mareklwhip4590]

I woke up to this playing, but from the comments it sounds like you know what you're talking about!

[@yellow_tatoes1473]

I literally just woke up to this playing lmao

[@yoprofmatt]

Marek'L Whip, Sounds like a nightmare. Hope I didn't scare you. Thanks for the comment, and keep up with the physics! You might also like my new website: www.universityphysics.education Cheers, Dr. A

[@mareklwhip4590]

@@yoprofmatt it wasnt a nightmare. I am obsessed with space, and this pairs with it, so its cool. Have a good night

[@vezulykamarari]

SAME!

[@lennardrogge7752]

OMG!, Me too xD

[@4fatcats]

This is one awesome video! Thank you professor Anderson!!

[@yoprofmatt]

Thanks. I usually try to keep them a bit shorter, but this one got away from me. Cheers, Dr. A

[@4fatcats]

No, the length is good. The prof at my university always tried to cover a whole chapter in 20 mins video. So I always read the book and went to your vids when I was confused about the concepts. Great that I had been having high A's in the past exams, now just one more final to go and I am gonna rewatch a few of your vids. Thank you again, and Merry Christmas to you and your family!!

[@saskiavanhoutert3190]

Can agree, good explanation somehow perhaps better than I had at my High Technical Education at Eindhoven, Netherlands. Thanks and like to see more.

[@zenithabcdeadlock8474]

@@yoprofmatt Excellent lecture Matt, I'll have to watch the others you've done. Presuppose this, if you were living in a closed system & the Sun was within that system how would this effect what you have transcribed..... ?

[@luckyaigberemhon7449]

Prof Matt.Please,can I get your video lecture on how to Deduce the Electromagnetic wave equation for magnetic field strength using the uniform plane wave components.

[@len_ny_y]

i literally subscribed to this channel in my sleep this is crazy not only am i waking up to this (no complaints from me this is amazing to watch from time to time) but i’m also going around subscribing to random channels i end up actually liking

[@yoprofmatt]

Sleep-subscribing! That's a new one, and explains why I have so many followers. Cheers. Dr. A

[@ЭхоНебытия]

It's amazing to watch him write and draw on that light board. He draws in "first person" while facing the viewer :)

[@elimiNator345]

is he writing backwards or did they flip it in editing. is the audience just watching a video ?

[@kerdraonfrederic4953]

I'm wondering as well. I'm a teacher an I'd like to publish videos like this for my students. Did you get an answer on that?

[@dhyskRand]

my guess is flip. Because; most people are right handed, wedding rings go on the left hand, mens shirts button left to right. Also pockets are generally on the left side of the shirt. Edit: also would mean he wears his wedding ring in his right hand and wears lady shirts

[@artmazonng7249]

he is writing backwards flipping would also flip the text, no?

[@dhyskRand]

@@artmazonng7249 it's possible, people used to learn this skill in the baby. However if he writes correctly on the back of the glass it's backwards to us.. then you mirror, not flip, the image and it's the right way.

[@yoprofmatt]

Andrew, The audience is watching on a monitor nearby with the image flipped. The board is called Learning Glass. You can check it out at www.learning.glass Cheers, Dr. A

[@lakshaygupta9061]

I've never seen a better explanation of em waves, atleast in high school

[@ashgonza92]

I've been sleeping in a hypnogogic state while listening to these lectures in my dreams. It's amazing how much I'm learning while my dreams listen in and put me in a cool classroom and different experiments with what he is explaining. It was like watching my own show on discovery channel.

[@yoprofmatt]

Thanks for sharing! Love the imagery. Cheers, Dr. A

[@ericzarahn9343]

Regarding the diagram at the beginning of the lecture: wouldn't the magnitude of the electric field at the midpoint get larger as the two oppositely charged point-masses move closer to one another? My reasoning is based on the 1/r in the electric field formula and superposition. As the charges move towards each other, the r term gets smaller. (edit): I was assuming that the E-field being plotted was that at the midpoint of the point-masses. Is that correct?

[@MrYaatri]

E filed of a single charge would get larger as we get closer to what is the midpoint of two oppositely charged point charges, if there were a single charge. But we have two charges. When the two charges overlap, are at the same point, the net charge is 0. So Dr Anderson is right since, no (zero) charge produces zero field. If you think of a point charge as a very small sphere of uniformly distributed charge, even then l, by Guass's law, the field produced at the center would be zero. As we approach the center, the distance from the center varies linearly. The 1 over r quare term in the field varies as 1 over r square but the enclosed charge varies is 1 over r cube. So the field falls linearly as r.

[@charanreddynallapareddy5418]

Very true! In fact, I too was thinking about that. He's right when he's saying that those oscillating charges produce oscillating electric field but not because of the reason he's saying. It is because of the acceleration of particles themselves. In SHM, the particle's acceleration is proportional to the displacement from the mean position. This implies that acceleration is zero at the mean position and highest at the extremes. Now, since the electric field is directly proportional to this acceleration, we see the electric field also following this "displacement analogy". The farther the particles, the higher is the acceleration and the higher is the electric field and vice versa. Hope this clears your confusion.

[@sameerdatta7287]

Was thinking the same but@@MrYaatri cleared the doubt.. Thanks man

[@darewin3847]

Fell asleep watching KZbin, woke up to this video.

[@itsSevens]

Same, was watching video game videos, passed out, and woke up in the middle of a formula.

[@OldManBOMBIN]

Same same

[@MrPeloseco]

Lol... Same here. I see a pattern!

[@martinsonkwame2786]

Same here 😂🤦‍♂️

[@FreeNomad88]

Same here!

[@youwu7724]

I am so impressed when you use the electric dipole to give a picture of EM waves. But I am curious that why the current at the endpoints correspond to the maximum current, and that at the middle correspond to a zero current. I just think that the velocity of the charges will be zero at the two endpoints. Since J=rho * v, the current will be zero at the two endpoints. But that will not give me the right picture of EM waves. Can you tell me what's wrong please? Thanks very much!

[@Freeknickers24]

Because 2 dimensional representations go invisible when viewed edit horizontally aligned. Perhaps that is it?

[@truthtuube]

This is THE BEST presentation for inducing sleep ever. The speed of my brain waves went from c to zero in 1 second. The frequency has increased to once a night and my health has never been better.

[@yoprofmatt]

Glad to be of help. Sleep is very important. Cheers, Dr. A

[@truthtuube]

@@yoprofmatt I thought I was being a smidgeon funny...until I kept reading and found a number of folks who "woke up" in front of their screen with you conducting this presentation. I liked the presentation; it's very interesting. But I'm 73 and I can sleep through earthquakes.

[@TSBigy]

I had to re-watch first 5 min multiple times. Cant understand how you are writting with your left hand with a mirror and flipped right to left print.

[@JAJA-wp5jt]

Thanks a lot for uploading this wonderful lecture

[@brucerulz5297]

beautiful. absolutely beautiful. 61 years of wondering just came together … on the same frequency.

[@akimbo360noscope]

~

[@HoHkennels]

If only had I had him as a professor, I would have found physics much more palletable. Great course, demostration and explanations with visual. Clear drawings, enunciation and clean delivery without bouncing all over the place. Fun video to watch, I actually learned something new.

[@yoprofmatt]

Thanks much, glad to be of help. Cheers, Dr. A

[@nomasan]

His reaction to a phone call is .. nice My teachers would destroy the phone and send the student to the principal

[@felipegalvezcarrasco7834]

Really thanks a lot, an amazing class, I´d like you to activate the subtitles in this video to help people who speak in other languages, I can help with Spanish. Greetings from Chile.

[@arkapaul42]

It really helped me for my exam!! Hope you will release a series about Astrophysics 😀😀

[@yarendagdeviren1582]

I started working on electromagnetic shielding this year for my capstone project as a materials science student and this video has been incredibly helpful ! Thank you so much Dr. Anderson!!

[@LeoFreemanAUST]

Thank you for your video; I never understood EM waves. Could you possibly explain why E and B are in phase? This seems to be a topic of some debate. I know that a steady current in a wire can have a magnetic field B. But a steady E field doesn't have a magnetic field. What is the relationship between current and E field in wires? I agree that when the current (i) is maximum, then B is also maximum. But happens to the E field when current is max? By your moving charges analogy, the current should be greatest when the charges are together in the middle, ie, when the E field = 0. That corresponds to the point where the E wave cuts the x-axis, and the _rate of change of E is greatest_. Shouldn't _that_ be the point at which B is maximum? In a dipole antenna, as charges flow in from the middle towards opposite ends of the dipole , the electric field around the antenna increases as the dipole moment increases. But IMHO, the maximum current actually flows at first, when there is no charge or E field on the dipole. That is when the magnetic field is greatest, when the current is greatest, not when the E field is greatest. Am I missing something?

[@yoprofmatt]

Leo, These are excellent questions and I'm not sure I can answer them all in a text box. I would encourage you to take a look at one of my hero's lectures: www.feynmanlectures.caltech.edu/II_toc.html In particular, see Ch. 20 & 21. Cheers, Dr. A

[@rameshthamankar1544]

fairly easy to arrive at the in-phase relation. Use Maxwell's 3rd and 4th equations and use little bit of mathematical manipulation and you will see that in-phase relation.

[@donegal79]

What a brilliant explanation you give.......not. But, then again, that was your intention.

[@hundle98]

You are thinking of induced electric field when the magnetic flux is changing through a closed loop. But in this case, you are simply looking at a rod with essentially AC current running throught it. In the beginning (at t=0+) the current just starts to move, so the velocity of the charges is low, which means the current is a low value. Then with the current close to 0, a tiny magnetic field is created. You can see through amperes law that the strength of the magnetc field is proportional to the current (i.e the electric field). When the current in the rod is at its peak, again through amperes law, you can see that the magnetic field will be the strongest. The current will then reverse direction and follow the same behaviour. This way makes sense in my head, but it might be wrong.

[@GodzillaGoesGaga]

Near and far fields from my understanding. en.m.wikipedia.org/wiki/Electromagnetic_radiation

[@acerovalderas]

Excellent explanations. Very clear presentation. Perfect speed for beginner students.

[@sniperatharvakalele5403]

question why isn't the b field a cos wave . Because if we see the slope of E field at points near the origin we have dE/dt maximum and Maxwell equation describes when change of electric flux is maximum magnetic field induced is maximum. I cannot find this answer if u have time plZ solve this querry.

[@TheQooDude]

no one EVER answers this question...

[@TheQooDude]

If change in E generates b, the the vertical axis should be labeled delta E

[@michaelmarzano2759]

Professor Matt Anderson is AMAZING!!! So easy to follow compared to other physicists I’ve met.Keep up the great work Professor. Electro Magnetism has never been so well explained in my experience.

[@yoprofmatt]

Wow, thanks! Glad you're enjoying the videos. Cheers, Dr. A

[@evahdarth4406]

Thought I was gonna watch a video of magic tricks... Ended up learning about electromagnetic waves

[@briankukk1487]

wake up every thing is magic

[@coreys2686]

@@briankukk1487 Any sufficiently advanced technology will look like magic to people who don't understand it.

[@joshliaw]

From the cover, you can tell this guy looks like the kind of person that knows what he's talking about~

[@yoprofmatt]

Josh Leo, That's photoshop! Thanks for the comment, and keep up with the physics! You might also like my new website: www.universityphysics.education Cheers, Dr. A

[@vijayshankar9529]

This is a great lecture , arguably the best on youtube

[@warriorcat16]

I fall asleep with youtube, usually i wake up to lawnmowing videos, BUT today A nice and casual learning experience i hope i end up here more often!

[@TRX-h7k]

He is behind that glass or what is it... nobody noticed that he is writing everything backwards?

[@lusher00]

That’s the only reason I visited the comments...

[@aaronslepkov5835]

He is not writing backwards. But because he is facing the studio, they see everything backwards. Typically both the teacher and students face the blackboard from the same direction. The video is processed to re-right the board, so we see everything the way the instructor saw them (not backwards). He continually tells the class to look at the monitor (i.e. at this video). Thus only the live audience saw things backwards. The instructor is writing things in the natural way.

[@art7046]

@@aaronslepkov5835 this comment is twisting my brain wtf

[@aaronslepkov5835]

@@art7046 Sorry. Got back to the easy stuff like E&M theory!

[@benhurj]

@@art7046 lol. I think what's happening is this: 1. He is writing on a glass board the normal way and there is a camera behind it filming it (the camera sees the writing written backwards) 2. The camera feed is reflected in the X axis so that the writing appears normal, and the resulting video is streamed to the students present and also uploaded on KZbin

[@zhara-lunethcarithuo275]

This is awesome! I'm so glad I found your channel. I really love physics, but unfortunately HS doesn't offer anywhere near as much detail as I like. I plan to major in software engineering for practical reasons in getting a job. However, I plan to try to get a master's in physics when I'm older, after making enough of a living beforehand.

[@yukchow4821]

Thank you for the great lectures on the electromagnetic wave. l particularly enjoyed the section on the antenna. Any recommendations on books for this subject?

[@teebarh_]

I am a little over an hour into this video and I have learned more than I thought I ever would regarding Electromagnetic waves. Thank you for this amazing class!

[@pradipkundu3149]

Did you upload the lectures of upper level physics that you mentioned . just curious. I love your videos by the way. Cheers!

[@larryhovis6230]

Are you writing this in reverse on the board, this is an excellent presentatiom, I worked in radio and radar electronics most of my life BUT how do you write all this on the backside of the glass. That part fasenates me... excuse my spelling...Thank You

[@CondensedComments]

He mentioned in another comment that the camera is flipped.

[@markovichglass]

@@CondensedComments that makes so much more sense. My mind was blown how fluid he was writing backwards. Science!

[@kylewolfe_]

Okay this is the first time I've seen one of these glass board instructors teach in front of a live audience. I always assumed you wrote normally and then mirrored the video to fix the orientation. But then how are you students reading it in person? This is bothering me lol.

[@yoprofmatt]

Kyle Wolfe, They are watching on a video monitor next to the glass. I'm not writing backwards (I'm not that talented). The board is called Learning Glass. You can check it out at www.learning.glass Cheers, Dr. A

[@slightlygruff]

@@yoprofmatt It would be nice if it could wipe itself so you don't have to

[@GustavoMouraD]

@@slightlygruff lol

[@trumanburbank6899]

@@slightlygruff Ya, like if it had pixels and a virtual pen, and you could erase the board with a wave of the hand.

[@HorusHeretic]

I prefer the illusion that you are righting left handed, and backwards xD

[@darylrandall8383]

Brilliant. You absolutely deserve the title of ‘Professor’. Thank you.

[@AnkhArcRod]

When the opposite charges are coming close to each other, how is it that the E field between them is growing weaker? When the two charges are close, the electric field due to the positive charge will point toward the negative charge and have a very large value (since field goes as 1/r). Similarly, the electric field due to negative charge will point in the same direction and will also have a very large value! Just because there is less distance between the two charges in which one can't draw the arrow does not mean that the field itself if zero. There is something fundamentally wrong in this explanation.

[@yoprofmatt]

AnkhArcRod, Excellent catch! You identified my mistake. In a line current analogy, I got a bit careless with the movement of the charge. Thanks for the comment, and keep up with the physics! You might also like my new website: www.universityphysics.education Cheers, Dr. A

[@rscaht]

The maximum gravity field is when I'm close to the earth , I guess it's the same with the electric field .

[@RWBHere]

@@rscaht And the gravity field is zero, when you are at the centre of the Earth. A lot of people miss that point. How does that compare with an electric field, if you could be at its centre?

[@rscaht]

@@RWBHere get inside a planet is possible because it's made of particles. Penetrate a particle that is made of what?, I see it quite difficult.

[@Jrez]

Teaching is hard enough without having to write everything backwards!

[@gilbertanderson3456]

Lots of fun watching him draw at 1.5x playback speed. 😁

[@snootdingo9365]

He was born and raised on Bizzaro world

[@barrowmeoct04]

What's even more fascinating is how he's getting that writing to just 'hang in mid air'.

[@altuber99_athlete]

I hope these comments are jokes.

[@Jrez]

@@altuber99_athlete mine was, I can't speak for the rest

[@youtuberteyze5345]

When writing on the glass like this, how does the writing look reverse on the camera?

[@SorinNicu]

Flipped video in post editing.

[@yoprofmatt]

KZbinr Teyze, Not writing backwards (I'm not that talented). The board is called Learning Glass. You can check it out at www.learning.glass Cheers, Dr. A

[@maskedmarvyl4774]

His demonstration of current going up and down in waves as it changes polarity, causing magnetic waves to be generated at right angles to that (perpendicular to the electric charge) is brilliant. Some professors have the ability to take a simple principle and make it incomprehensible; it's much rarer for a professor to communicate principles so that everyone can understand them.

[@ruwanthinayomi3502]

this's a awesome lecture i ever heard...thank uuuu

[@flakeyy4024]

I went from wood turning to this lol and also before this was a 3h video of vsauce saying prime numberd

[@MAG82619]

KZbin's rabbit hole goes DEEP my friend

[@yoprofmatt]

Flakeyy, It's a TRAP! Soylent Green is people! Thanks for the comment, and keep up with the physics! You might also like my new website: www.universityphysics.education Cheers, Dr. A

[@musataz]

Benedict Cumberbatch???!

[@apolloniuspergus9295]

Lol I'm not the only one who realised that.

[@thehapagirl92]

He's better looking than Benedict lol

[@samarasatya7474]

@@thehapagirl92 no way

[@zsanterre]

LMAO

[@raorohit9151]

maybe like ryan ronalds

[@jordanbosley142]

I just woke up here 20 minutes in and I rewound it so I could watch the whole thing thank you professor

[@Jimmy-B-]

He must have a degree in writing backwards

[@jacktsang3597]

He must be.

[@seheryldz4270]

he's not writing backwards it's just a combination of mirrors and here you go

[@xXxserenityxXx]

I imagine this is how cats and dogs think when they first experience glass.

[@Monkavenger]

@@xXxserenityxXx hee hee😜

[@dcamron46]

Yeah either that or you just flip the video later ..

[@farifairis7388]

For people that thinking if he was writing backwards: look on his shirt, the video is flipped..

[@SorinNicu]

That's smart! And he's not wearing wedding band on right hand. He was careful when he talked about "right hand rule" to use his left hand and he draw the B filed backwards from a normal blackboard!

[@conspiracyoftruth6770]

Fari Fairis I was just wondering about that!!! Thanks for clearing it up!

[@yoprofmatt]

Fari Fairis, Not writing backwards (I'm not that talented). The board is called Learning Glass. You can check it out at www.learning.glass Cheers, Dr. A

[@farifairis7388]

​@@yoprofmatt Yes, I know. I just tried to explain that it is not 'writing backwards'. Thank you, Professor! My wife is a lecturer in Organic Chemistry, she may need the Glass as we should make a lot of videos for online classes.

[@alwaysdisputin9930]

@@farifairis7388 maybe she could talk about fluorescence? He writes normally like you say on the glass using a fluorescent marker. The glass is illuminated from the side. The ink absorbs UV light & then re-emits it making the ink brighter. The light passes through the glass & reaches his audience's eyeballs - they see backwards writing. The light also hits a mirror which reflects it into a camera. As it does so it inverts the image so that the camera records the writing the correct way around. (Alternatively it could've been inverted using computers)

[@packratswhatif.3990]

Impressive how well he can write backwards.... and draw.

[@CondensedComments]

Camera is flipped, he mentions it in another comment.

[@dumpling3309]

Lol the video is flipped and he is writing in glass.

[@latouselatrec]

lightboard technology people

[@curious8321]

If I had a physics teacher like you in school, I wouldn't have left science after school..... Thanks for sharing this video.

[@yoprofmatt]

Then come on back! It's never too late. Cheers, Dr. A

[@PilotoZ]

Me, raising my hand on the first question: “magnetic field”!

[@e.v.a.l.s]

For all with OCD, at an hour 47 minutes in, he missed a spot.

[@nickforrest1018]

Would anyone mind editing the spot out please? It kind of spoils the whole thing.

[@louisalbd]

There's loads of other missed spots throughout the video

[@dennisysh]

Sir, are you writing and drawing backwards?

[@yoprofmatt]

Nope. Check it out here: www.learning.glass Cheers, Dr. A

[@SparkyLabs]

yea, is it me or is someone actually selling a sheet of glass as a product ? there are a few youtubers that do maths that use this technique. Basically any time you are writing on a board and only by seeing the board does the video have any purpose doing it like this makes sense. It also allows the speaker to face the camera.

[@So-Now]

Visually, his wedding ring is on his right hand and he is writing from the centre of his body to the outside with his left hand. It is recorded with the image reversed left to right. Hence, he tells his live audience to watch the monitor for it to make sense to them.

[@Herzeleydt_Diesentrueb]

He don't need no learning glass he is left handed - a commie ! Wake up America !!! The End is nigh ...

[@CandidDate]

@@Herzeleydt_DiesentruebI am sitting here racking my brain as to how this learning glass works !!!???

[@maryoneil6524]

You are a GREAT teacher... and that's truly a gift! Thank you sir!

[@daveeast9130]

I fell asleep watching this, still on when I got up

[@yoprofmatt]

Simon gold, That's how I feel all the time. Thanks for the comment, and keep up with the physics! You might also like my new website: www.universityphysics.education Cheers, Dr. A

[@aaabeverages7152]

Me toi.

[@HarryG98]

David always time to learn and/or go back to college!

[@lvitch]

Universal speed limit. 😂😂😂

[@deadhara3426]

Why you look like doctor strange :(. Anyway, thanks for the lecture sir! Very helpful for my thesis.

[@rahuls2111]

One of my favourite lectures. Thank you Professor Matt