What is Light? How Faraday Dreamed of Electromagnetic Waves!
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- Опубліковано 23 сер 2024
- What is Light? Well, it's an electromagnetic wave but what is that? The best way to explain it is to learn the story of why Michael Faraday came up with this crazy idea in 1846!
Enjoy
As usual the background music is from the fabulous Kim Nalley
These are hands down the best educational videos i have ever seen about electricity and the persons behind the discoveries. Please continue your work.
Aww thanks 😊
What he said!
I certainly agree.
If i can be like Faraday one day surely your my Jane Marcet🙆♂️
Kathy, I just discovered your video series on physics and the history of physics. Wow! Great stuff and much appreciated. As a retired college teacher and currently a corporate technical trainer, I am also a physics and technology history buff. Your videos are adding to my own accumulation of the history of science. Thank You!
Norm Christopherson so glad you liked it Norm. Feel free to share it around 😉
@@Kathy_Loves_Physics Now, let's explain the very same thing in terms of a corpuscular photon. Also, Kathy exaggerated about thousands of Faraday's discoveries. Thousands?
Great video Kathy.
Faraday is my most favourite scientist. His intution and ability to visualise things allowed him to predict without much math background.
Thank you, how can you not love faraday?
Kathy, thank you so much! You've added the last piece of the puzzle to make your channel the best on these subjects - you've added links and numbers to your related videos. That must've taken a lot of hard work to go through your whole catalogue and hyperlink everything. Your fans REALLY appreciate it - BIG THANK YOU!!
Go glad you liked it. It was a labor of love but still labor
"Faraday's errors were never attributed to his sex." Agreed. Unfortunate that Summerville's were, and that she did not persevere. On the other hand, Faraday's errors were attributed to his low birth. He had the drive to overcome the stigma.
This is a great video. Faraday supplies the missing link between light and electromagnetism and you explain it well.
Awesome video Kathy, many thanks. I can't help loving Faraday as he achieved so much with no formal education!
I so love Faraday. He is probably my favorite scientist of all time (or top 2 - I really adore Hertha Ayrton too).
A lot of Faraday's work and other works of that time, would later be important to laser and laser optic development. One discovery in particular is the Brewster angle. In the early days of laser development, gas lasers had optical windows on both ends of the laser tube in which the laser beam would exit. The ends were sealed off with a "Brewster window" at a critical angle that was complimentary to the specific wavelength of the laser gas. This critical angle allowed the laser beam to resonate between external mirrors with almost no absorption, refraction or reflection. The beam would resonate nearly unimpeded. This was very important because gas lasers of the time were very weak and laser emission would be absorbed by the glass windows if not for this critical optical phenomenon.
I think what truly fascinates about this period was just the fantastic degree of scientific research. People pursued topics simply out of interest and curiosity rather than research funding as it is now. We don't see this level of inquisitiveness nowadays. That someone could just sit down and out of sheer curiosity work to invent vector calculus or postulate polarization and actively experiment on it. Really fascinating
This channel is underestimated and not known enough. Will share.
You are the greatest. Wow. My curiosity mind was so ecstatic to see a clear picture of what electromagnetic wave means. These videos are magnitudes better than 99%+ current university classes in combing through the logic and intuition.
You remind me of the woman you talked about who wrote the chemistry book that taught Faraday.
10:00 Kathy hi, like your videos a lot. At around the marked time, you ponder if it is possible to move a magnet with light. Well, it is possible to put a conductor and make it act as an antenna! That conductor would need to be at half the size of your wavelength, and make a diode using geometry. You can find these kind of direct solar antennas referred to as a "optical rectenna" (optical rectifying antenna). It is nice for students to know their existence, especially for light, as it makes it clear in their minds that we are talking about the same phenomenon, electromagnetic waves, just at different sizes...
I think the way my physics teacher went over it briefly is more like: When an electron changes velocity, it either absorbs or emits an electric field and thus a magnetic one since they are interlinked. So when you are talking about electrons in electricity, you are generally talking about moving electrons, but they can be moved by absorbing light.
I never realized how close Faraday got - to the realization of Electro-magnetic light.
Thanks for your excellent review of this science.
So glad you liked it. Yeah, I am constantly amazed by Faraday
Thanks a lot for this fun and engaging piece of history. I have searched for a long time in vain for engaging videos on the history of science until I found this channel. Thanks again😊
Kathy you like a godess.whenever I watch your videos I feel Athena herself is revealing the secrets of mother nature.
My goodness, what a complement! I just looked it up and Athena is the goddess of wisdom, war, and crafts I hopefully have one out of three and I’m not telling which one 🤣
Hello Kathy!
I have been watching your history of science videos and for me, each one is a gem. Particularly this one on the electromagnetic waves. I really could not imagine this. I was always confused as to how could light have a magnetic component. The cloud of confusion cleared a bit when you gave the example of one oscillating charge making another charge oscillate at a distance and by extending the idea to how we see the red color of the rose. Thanks a lot!
Absolutely Brilliant! Your videos help bring facts into focus, and makes relevant connections between them. Very interesting and useful. 👍
Great content and superb presentation !! Keep the good work kathy ...
Thanks Tamil.
Lovely. This is what I have been looking for - Electormagnetic property of light explained in a simple and a lucid way. Thank you so much!
Niraj Shah so glad you liked it. Cheers.
Kathy Loves Physics waiting for your video on James Maxwell :)
Niraj Shah I made one but I forgot to fix the link. Here it is
ua-cam.com/video/DlMufPAtf4M/v-deo.html
Amazing, lucid and very interesting way you took us back in time!
Thank you so much for bringing all this in a chronological way..... Know most uncovered things are getting clear to me. .. doing a great job... Worth 100s of like. I was so long finding something like this.... Once again thank you
Watching a few of your videos before turning out the lamp for the night has become a nightly tradition now. What great material to ponder as I wait for sleep to take over.
Just filling in those gaps one video at a time. Thanks again.
Also, Lord Kelvin has to be one of the coolest scientist names.
William Thomson isn't as exciting is it? When I was pregnant my students wanted me to name the baby "Snellious De Broglie" (combination of the man behind Snell's law and Luis de Broglie). I... didn't.
Another very good video. I read about Faraday's experiment with polarised light in James Hamilton's excellent biography of him, but the book doesn't explain how the experiment worked. Your explanation makes perfect sense; thank you.
zh84 I’ve never read that biography! Sounds like I need to check it out. My favorite so far was “The Electric Life of Michael Faraday” by Hirchfeld. Still none of the biographies actually explain the physics. It’s infuriating.
I found it very interesting, but the author says that he doesn't really understand the science, and doesn't try to address it in detail.
zh84 how can you write a biography of Faraday without the science?? Arg, that is so wrong.
I still don’t understand how an electromagnet can alter polarization, but I appreciate your explanation of the phenomenon - knowing more details on how the experiment was conducted at least demonstrates the fact, which in turn will lead to a greater understanding with future ‘triggers.’
Beautiful narration. Thanks Ms Catthy.
Great vids Kathy, electrons are fantastic beasts.
Absolutely great, again, and again.
I didn’t know that about Faraday.
WOW!
Thanks! 👍
I never knew that polarization was the link of understanding between light, magnetization and electricity. I almost sang with the outro ladies, haha. Maybe I'll even perform that experiment! It would be cool to make an audio transceiver using that effect.
What an interesting interplay between theoretical science and the on-going development of the application of the discoveries. I always thought the Zeeman effect was the primary demonstration of the interconnectedness of electromagnetism and light, but now reflecting on it. I think it's a clearer demonstration of the quantum nature of the interaction (?). In any case what a great presentation on the interrelated nature of light and electricity. Thanks!
Charles Carlson fun fact: Faraday’s last experiment was on the zeeman effect (it was unsuccessful and zeeman used Faraday’s notes years later!!).
Faraday, can tears to my eyes.
Kathy, I am writing from Brazil. Another very good video. Your job deserves an award.
I love these presentations; the history brings them to life.
Kathy, this one is superb. I believe you are making a significant contribution to technical education.
I begin to think undergraduate physics ought to be taught in parallel with a series of lectures like these. They add a lot of depth.
At age 71, looking back over a lifetime of interest in electricity and physics, I realize I missed a great deal because this kind of content was seldom available,.
Thank you so much! I always wanted to know the journey that physicists took. How did they tackle the problem? How did they come up with new concepts. Textbooks are generally dry and they take away this element. Lots of respect from Nepal.
Thank you Kathy for your easy listening and informative series
I Love you. Your energy is the best!
Great video I'm glad you left out the concept of quantum particles.
Big fan Kathy.
Julian, I am so glad you like my videos. I started a Patreon page if you want to support them:
To join my Patreon (thanks!) go here:
www.patreon.com/user?u=15291200
If you are feeling a little cash poor (I totally understand!), then you can join my mailing list instead and I will send you a link to my videos a day early.
To be added to my mailing list (thanks!) go here:
mailchi.mp/99c964be329e/kathy
Thank you, you and your videos are simply great 😍
Thank you! You're amazing!
pure joy your videos
Mam you are also a scientist, genius, clever, brilliant and so on
thank you so much for sharing your knowledge
I like your every video
And I will watch your every video
You tell information in very easy way
I still don’t understand how an electromagnet can alter polarization, but I appreciate your explanation of the phenomenon - knowing more details on how the experiment was conducted at least demonstrates the fact, which in turn will lead to a greater understanding with future ‘triggers.’
This video is mind blowing. Thank you soon much
gr8 explanation mam. keep make this type of videos
Being colorblind, I was happy to discover that the Universe has no concept of the ‘color’ of a red rose, although I’m happy my mind can somewhat (my defect is more properly as a color deficiency). With some corrective measures, a blood red rose is produced by my favorite wavelength - probably why I tend towards field line (reddish) Golden Retrievers and most recent, an Irish Setter.
It’s a difficult affliction to describe, but without my corrective lens, my pups virtually disappear when standing in front of a green leafy shrub.
phenomenal 😊😊😊❤❤❤
As I go thru these in chronologic order, I see your hair was getting neater.
Faraday - one of Einstein's giants. He stood on his shoulders, to see further. A truly great scientist who was not constrained by conventional ideas.
Well, these vedios on electricity and magnetism are indeed ELECTRIFYING and ATTRACTING my mind.
Pun intended.
The most clear you tube on the subject that I have found. Thank you. :)
Alan Potter thanks. I was surprised that after years and years of teaching Physics even I found that discovering the history enhanced my understanding of the subject.
@@Kathy_Loves_Physics I wholeheartedly agree that learning the history in an engaging way such as your videos or Carlo Rovelli's books gives you a deeper understanding of subjects. Would love to hear if you have any recommendations on how to find content (videos, books, etc) of the history of chemistry. I'm learning that and I'm struggling to find videos like that. Your latest videos about the Bohr model was great and helped understand what I was learning chemistry much better. Thank you!
Can you make a video on Ada Lovelace please? Thank you for the Nice Simplified Science History; Liked, Subbed
Einstein had a picture of Faraday on his wall behind his desk. Or so I remember reading somewhere. Nother great video Kathy thanks 🙏
Yes. Einstein had a drawing of Newton, faraday and Maxwell on his wall.
Fantastic explanation madam
Standing wave-packaging holography, every observable point, time-timing sync-duration spacing, is Singularity positioning of e-Pi-i Fusion-Fission Function, and this is all a fractal AM-FM conic-cyclonic interference logarithmic condensation modulation cause-effect.
You have to teach yourself Faraday Fields style in the GD&P Polar-Cartesian self-defining QM-TIME relative-timing reciprocation-recirculation oscillation format and that may take as long as a piece of string theory manifestation.
Love the video but just think something should be clarified. Only reflective glare is from brewsters light but glare looking through a transparent material isn’t from low angle reflection light. Glare while looking through a transparent material is from the thickness of material creating double bounces and reflections from the inside that superimpose on top of each other, constructively interfering, adding up to bright lines. Anti glare film is made a special thickness that’s a multiple/submultiple of the wavelengths of light passing through, such that the light double bounces inside the film, first, to then go into the transparent material after in a way that the waves deconstructively interfere with the “glare” to cancel it out.
To clarify though, horizontal polarizing film that filters out “polarized light that has been reflected off of a flat surface” , like a road, while being viewed through a transparent material is not the same thing as anti glare film on a transparent material to reduce glare from the lens/transparent material itself. And still this is also not the same as anti reflective film put onto surfaces used to stop Brewster reflections by creating the same wavelength resonant thickness of film on the reflecting surface that provides a 180° phase shifted equally polarized light to cancel out the first external polarized Brewster reflection via deconstructive interference.
Light is an electromagnetic wave and electromagnetic waves are propagating with the speed of light.Since light is itself an EM wave,it means that light itself does propagate with the speed of light.
I just have some skepticism about Faraday's experiment on 6:04. Isn't it more accurate to conclude that magnetism affects light directly if the glass is not present? Just the magnetic field through the air. The presence of the glass brings uncertainty. Isn't it also possible to interpret that the property of the glass when electrified is what's responsible for the change of polarity, similar to how a liquid crytal works or some piezoelectric effect? Thus, the change in polarity is indirectly caused by the magnetic field.
I'm hoping to hear other people's insight.
Thank you!
hey Kathy !...1) where does the packed punch of Voltage Power 'reside' before it '' pushes '' the electrons to flow?. 2) How did Coulomb count and measure a single charge of electrons to minus1.6*10^ minus18, and eventually positive 6.25*10^18 electrons per second. What instrument did he use to count the number of electrons flow per second. How about the Constant: 1/4pai, excelon zero?. Please kindly work us thro as to a 10 years old curious kid.. We appreciate you.
The experiment that Faraday did looks like to be the essence of how lcd panels work. What do you think Cathy.
Oh my gosh are used to work on liquid crystal research in the 90s and you are totally correct and I never thought of it that way but yes the twisted LCD displays that we used to have are totally like this experiment. Look at crystals between cross polarizers where a magnetic or electric field would change the polarization and cause light to be able to pass the filter. You just blew my mind.
Its an honor to have you reply , your channel is the best.
@@jenko701 thank you so much, it was so sweet of you to say it really makes me feel good. Cheers, Kathy.
In Faradays’s experiment, what is the purpose of putting the light thru the glass (next to the magnet)? Shouldn’t the magnet rotate the polarized light wave regardless of whether glass is present or not?
I thought the same, good question. It’s almost as if the electromagnet re-polarized the glass, and not the wave. Or maybe it re-polarized both? I do not know; this will take some thought and maybe other perspectives. But at least the experiment established a link between light and electromagnetism, I’m just not sure where yet. Maybe the electromagnet re-polarized both, and the light was just there to provide verifiable evidence for a link?
Hi Kathy great video. Just a minor correction though. Its Lord Kelvin NOT Lord Calvin. Its the same guy who invented the Kelvin Temperature scale - and one of Scotlands many great scientists. Thanks for the video though.
Oh no did I write Lord Calvin? How embarrassing 😳
We can make very small magnets. Enough to see the effects of the light?
Kathy, you may not have any better answers than my retinologist or other experts Ive asked but.... How common is it for human beings to be able to see up into the ultraviolet portion of the light spectrum.?
I can see the UV image that butterflies see on the flowers of our "butterflybush". (I have no way of measuring how far but the UV image is refracted nearly the full width of the flower off tp one side.)
PS this is not the only anomaly with my sensory system. I have been tested to hear up past 26Khx (I can hear several species of bats - both the audio and the PRF) and I can feel the vibration of "the metal particles" on touching the chassis an electronic device and tell when it is turned on and off
No one so far has been able to understand the results of any their tests..... ????????
Light is such strange stuff, with many properties.
You should also mention Toby. Toby Maxwell.
Toby was such a good boi- I mentioned him in my video about Maxwell 😊
@@Kathy_Loves_Physics 😀I'll watch that next.🐕
Summerville should have taken heart from the fact that being 'wrong' can lead to someone being right later on by disproving your hypothesis. Like the 'Plum Pudding' model of the atom, wrong, but showing it was wrong was a step on the way to conceptualising the nucleus. Hence attributed. to Wolfgang Pauli 'Not even wrong' 'nicht einmal falsch' is far worse than being plain 'wrong'.
Yeah, being proven wrong is an important part of physics.
Kathy where did you get that EM radiation simulation at min 9:10? It shows a curling magnetic field like I've never seen before!
Eric Potratz I just searched electromagnetic wave gif on yahoo
Light is such a polarizing subject
Lol 😊
Ha! 🤣
Diode direction is forward and reverse,magnet direction is north and south pole,earth direction is north,south,east,west,.my question is (madam please denoted light directions)
Wondering now, what battery system they had back then.
She is in the league of the greats.
you are the light............of comprehension...hope thats spelled right.....correct..
Magnetic field traveling through what medium?
The medium is made up of lines of force that exist throughout the universe.
✅🎯
audrey hepburn references do not hurt even if it is just a meme.
It's electro magnetic but can't be attracted by magnets even when super tuned in a laser pixel
Now, let's explain the very same thing in terms of a corpuscular photon. Also, Kathy exaggerated about thousands of Faraday's discoveries. Thousands?
So light is just an excitation of electrons in atoms?
Fascinating wealth of ideas to describe electromagnetism but only a single idea to explain self-doubt. Strange.
"Even gravity has its own gravity field."
Except that unlike electric fields and magnetic fields, gravity fields are undetectable. If gravity is a real force, why don't we have devices that can detect it?
We do now, read about LIGO. Also, look into pseudo forces, gravity is listed when viewed from a non inertial frame of reference; Einstein’s warpage of spacetime is also discussed.
perfect but could it have english subtitles, too?
Mad as a hatter
Who's the kid
Light is a projectile, not a wave.
Light is not a wave, it comes in waves
Sexism:bad
Math
I like your videos, but why the earth is not enough for you? Earth is plenty and originality brings sorrow and isolation.
Petre Catalin Logofatu I’m sorry but I’m very confused by your comment. Care to clarify?
@@Kathy_Loves_Physics I assumed you identify with Mary Summerville except for her final choice to be of the earth and to stop chasing originality.