Wave-Particle Duality and the Photoelectric Effect

Look, up in the sky, it's a particle! It's a wave! Actually it's both. It's light! How do we know about this stuff? Well, because of Einstein for one. He did more than E = mc^2, you know. But don't stare at the sun to see for yourself, we've got science now.
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[@ProfessorDaveExplains]

Guys! When I said that the smallest fundamental unit of energy is the Planck energy, that's totally wrong. That is a completely different parameter that is actually a macroscopic amount of energy. I confused it with the Planck time and Planck distance, so that label is being used incorrectly. Sorry!

[@Adityasingh-pl9mc]

A wave has a frequency... How can particles (photons) have frequency.

[@Elegyforthend]

@@Adityasingh-pl9mc I think it's because at that time light is regarded as a wave and not a particle. not sure tho.

[@Trypanosoma_]

@@Adityasingh-pl9mc photons emit a vertically-oscillating electric field that are described by the corresponding wave function of the photon

[@active-ed]

@@Adityasingh-pl9mc particle is a packet of wave..... that is why particle can have frequency

[@active-ed]

@@Adityasingh-pl9mc particle is a packet of wave that is why particle can have frequency

[@mariamhashemi3950]

This saved my life! thank you. Especially, your saying "confused? you should be".......SIGH OF RELIEF!!!!!!!

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I just signed up to be your sponsor on Patreon. I love your videos. I work as a science teacher at a small school and use your videos as a source of inspiration to make new lesson plans. Your comprehensions are also used in my lessons for my students. Keep doing what you do and I hope you will get enough funds to fulfill your passion. Love from Berlin.

[@ProfessorDaveExplains]

thanks so much for your contribution!

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You make Khan Academy seem like a wast of the attention span; not bagging on them but you are literally the most efficient and effective teacher I've seen on the internet; especially when we consider this is chemistry. Don't stop dude! Explain everything forever yo.

[@ProfessorDaveExplains]

that's the plan! please tell your friends to subscribe :)

[@TheHamza1999]

I second you! Khan Academy is so much blabbering and time wasting, the videos seem so unplanned. While this guy is just amazing; concise, to-the-point knowledge.

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Naah...Khan academy is a good source for boredom and time wasting

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Professor Dave Explains this is the definition of a real G kids 😂

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@@LeatherCladVegan that moment when my chem teacher,(got second place for best science teacher in my state) shows this video in class to explains this topic...

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heyy I am from India and I was browsing through so many videos and it was so much of textbook language and the concept wasn't really explained properly.I just discovered your channel and your videos are really amazing.They help to understand the concept quickly.Keep making more amazing videos. -Love from India

[@icybear49]

This is in Chapter 2 of 11th grade Chemistry.

[@shynishibu4082]

Helped a lot for 11th grader like mee🙏🏻🙏🏻🙏🏻🙏🏻...❤️❤️❤️from India

[@aryanaryan99899]

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[@Kamoj85]

Thank you for this channel. it's very refreshing to have these chemistry topics explained easier than just reading a very wordy textbook that doesn't exactly explain the topic in terms to someone still learning the subject.

[@zapperz2000]

Hi Prof. Dave. Thanks for your videos. I've linked a couple of them in my astronomy class that I taught last Spring. With regards to the PE effect, the notion that no electrons will be emitted for photons with energy lower than the work function, no matter how intense the light is, is only true for single-photon photoemission phenomenon. Since we now have intense laser sources, we can detect multiphoton photoemission. This is where photons with energy lower than the work function can cause an electron in a band (conduction band usually) to be raised to an intermediate state. But before it can decay back to a lower state, another photon comes by and excite it to another higher state. If this final state is a vacuum state, then it has the chance to escape. Multiphoton photoemission technique has been used in the study of materials, and also is a common phenomenon in particle accelerator photoinjectors. None of these means that Einstein's original model is wrong. It is just that we now know that the standard photoelectric effect is specific to the single-photon photoemission. Cheers!

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He does a lot about the science stuffs Professor Dave explains!

[@pedrosso0]

hm, I always thought it was "he knows a lot" but hey I might be wrong

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@@pedrosso0 yeah i also thought the same

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And then it happened as I am now loving science. It was a journey from boredom to awesomeness and lastly to curiosity about everything

[@sehmio]

Hi Professor Dave, I've probably said this a million times but thank you for these videos. They make me feel super nerdy because I get excited to learn about science!c

[@ProfessorDaveExplains]

woo! let's spread that science fever!

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You teach a lot better than my teacher!!!!!

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I am watching your videos for these two days for my quantum chemistry assignment..it is very easy to understand basic theory ..thank you very much..keep it up

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i only understand what is quantized when i see Professor Dave, Thank you Dave

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Time saving, 3 min, only one mid roll ad at the end of the vid,teachs actually better than my teacher OUTSTANDING

[@mary_melody]

Thank you for this video! It was very helpful.

[@scienceexplained38]

Quantum mechanics unveiled a mind-bending reality: particles like photons and electrons blur the lines between waves and particles, showcasing a dual nature known as wave-particle duality. In experiments, these entities exhibit wave-like behaviors-interference, diffraction-similar to undulating waves, yet they also display discrete, localized impacts akin to particles. Attempts to confine them to a single definition falter; they exist in a state of quantum uncertainty, oscillating between wave-like and particle-like attributes based on experimental setups or observation methods. This profound concept revolutionized physics, dismantling classical notions and propelling us into a universe governed by probabilities rather than certainties.

[@lepidoptera9337]

There are no particles in nature. There are only people who can't remember the eight word sentence "A photon is a small amount of energy." that they were taught in high school science class.

[@stupidteous]

​@@lepidoptera9337what ?

[@lepidoptera9337]

@@stupidteous We are teaching the basics of quantum mechanics in high school. Have been for almost 50 years. :-)

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Sir , u seriously explaining physic in very simpler way,i deeply feel satisfy after clearing concepts explain by u.

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12 videos and it’s already more than I learned in all of high school chem.

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hands down most concise, clearest explanations out there

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You’re a saint, doing this for no other reason than to teach people

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Nice video man, you explain things really clearly, keep them coming :)

[@Jess-xi2vc]

"confused? you should be!" ... "Thanks to Einstein and others ..." XD Thanks for this, very helpful

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Thanks! You really help me in my study. My lessons become more easy because of you!

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A very helpful work. Even people living here in Brazil can learn some physics.

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Cool video. Clear and concise.

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And that video is the example of precision! really helpful...Thanks prof dave😊

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Good video. My knowledge has expanded greatly thanks to your efforts.

[@rajeswarikalyanasundaram6041]

Professor dave what's the relation between stopping potential frequency and wavelength?

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I do love to watch your videos, it is full (complete) of info and easy to understand.

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I'm in 11th Grade and I've been doing a bit of a refresher before school starts and this is is doing a lot of help. Thanks!

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Such a helpful video-- thank you so much!!

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Literally felt like Ranbir Kapoor explaining omg doppelganger

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Why can't college courses be taught like this?

[@adityathakur6424]

please explain me what is the proprties of wave and particle

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You explain the easiest way anyone in the world can understand thank you so much.................... because of you our study become easy

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really good video! short yet concise.

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[@user-lb8qx8yl8k]

Dave one small objection if I may, but it might be a bit misleading to say that light "is a wave and particle AT THE SAME TIME." One of my QM texts (I can find out which one if you'd like) devoted a paragraph or so to explain that a quantum entity may exhibit both wave properties and particle properties, but never will it exhibit both wave and particle properties simultaneously. I asked gpt-4 to explain the concept of wave-particle duality and here's the relevant part: "The wave and particle aspects of quantum entities are complementary, meaning they cannot be observed simultaneously; observing one necessitates that the other is not being observed." I trust this is true because, like I said, one of my texts made this very point. The double slit experiment is a good example. Electrons exhibit wave properties when not being observed and particle properties when being observed. That just blows me away!! Even in spite of this and the thing about planck energy you noted here in the comment section, this is a very clear explanation of the photoelectric effect and the works of Planck and Einstein.

[@lepidoptera9337]

Yes, that was complete bullshit. ;-)

[@mariaangelaabalos8273]

Oh my I got goosebumps upon learning about thiss. Thanks professor daveee!

[@sweetdemon5372]

Hello professor Dave I am watching ur videos since 2 months And I love ur videos Can u please do a QNA

[@rifathossain6140]

dope intro dude i like it

[@joelthomasjaison7748]

Thank you professor Dave ................... You explained Grate... Continue with this

[@sinemihlentshangase692]

“Confused? You should be” 🤣✋🏾

[@Drderp-hd5bb]

Awesome videos dude, really helping, plz keep making!!

[@fabiomariaantoniali3096]

Hi Dave, the video is very effective! Actually Einstein used the term "energy quanta" in its 1905 paper, whereas the term "photon" was introduced in 1926 by G.N.Lewis.

[@iiiiii5772]

Thank you very much for helping me finish my Physics assignment....

[@iiiiii5772]

@@schmetterling4477 well you're not wrong there....we only have 2 physics teachers and 1 of them cannot teach at all....and I got that teacher

[@equinoxboy]

When Jesus teaches you science.

[@frustratedmel]

totally agreed 😂

[@anonymousdubb4695]

😂

[@rudymelo880]

"Confused? You should be." That's how I always feel when I learn wave-particle duality

[@wcomsa]

very clear explanation thank you

[@78anurag]

Oh my god I finally realise what people meant by saying "Quantum mechanics is confusing" damn they were not lying

[@78anurag]

@@schmetterling4477 That's true, but it's concepts or theories are quite hard for the average brain to comprehend

[@Zephyr6083]

I have to say it again, your videos are so clear and so well explained. Don't stop! I recommend to all my friends now! By the way, will you be doing any videos on amino acid synthesis (gabriel, strecker)?

[@ProfessorDaveExplains]

thanks kindly! right now i'm focusing on biology and math so no more organic chemistry in the works, but maybe one day!

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best teacher on youtube....

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I have an online exam today this is very useful to tq soo much profresser dave can u do more videos on spectrum

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Here I am wishing my Chemistry professor is just as good as you

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Thank you, your explanations are amazing!

[@xgg4017]

is planck energy the same as Planck's constant?

[@RR42636]

This is really, really good stuff man. Thanks!

[@TomHendricksMusea]

Ask an astronomer "How are photons created or destroyed", talks about quantum jumps. Q. The only interactions a photon has are to be created or destroyed. My idea is that the photon pops up as an electron positron pair that power the quantum leap or releases a photon. That means that the leaping electron interacts with the electron positron pair. One electron and positron annihilate which powers the left over electron to jump. That means that in space time photons are always electron positron pairs.

[@CesarTheWelfareCaptain]

i finally understood what quantized mean, thanks Dave.

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it's a bit early to find out about you, I hope it's the same. Thank you so much

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Oh my god! I have never been so happy you literally saved my life once again. Thank you so much!

[@funkydrummerplatypus]

Really great video. Short, accurate, and to the point. Thanks so much Dave!

[@user-rh1mc6es6x]

If we consider the Lummer and Pringsheum Intensity Distribution Diagram of Black Body Radiations can we conclude that higher frequency radiations want higher temperature to be radiated from a Black body i.e Frequency of the Black body radiations is directly proportional to the temperature of the Black body and for a particular temperature a particular frequency of radiations are emmitted?

[@anuugrah]

sir , could you post a video on waves and their super positions

[@ProfessorDaveExplains]

actually one is coming in the physics course very soon!

[@matifadzaaa]

I UNDERSTAND HAHAHA THANK YOU PROFESSOR DAVE!!! im so hyped!

[@MedSou]

Thank you,nice explanation👍👍👍👍

[@johnweldon1259]

Thank you! Understand this better now

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I love your videos!! please make more!!! I am using them for mcat studying! They are simply amazing and to the point!

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The last time my mind was blown was when I watched Loki. Now this time, I am completely out of my mind.

[@sanjuansteve]

Since we know we’re in a sea of undetectable dark matter but don’t know exactly where it’s distributed and since everything in the universe from electrons to solar systems is in orbit with something else, why isn’t the first assumption of how or why a photon acts like a particle but also as a “wave packet” for every physics student to think every photon might be in orbit with a dark matter particle pulling it into a polarizable axial or helical apparent wave as they travel?

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YOU ARE A LEGEND!

[@sophie8869]

you are the reason im going to pass my chemistry final

[@legendrybeast3398]

Very interesting video cleared all doubts

[@madisonmeyers3907]

“ Confused? You should be”

[@nimitapurohit3986]

Awesome teaching

[@AroundTowniCome]

love the outro music haha

[@josephcallahan1664]

Excellent. Thanks.

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I adooooooore your song😍😍😍😍😍😍😍😍

[@ProfessorDaveExplains]

yeah yeah!

[@osta9016]

Thanks for the video. It really helped.

[@atomx8723]

He knows a lot about the science stuff!professor dave!

[@jimylmazkinglegaspi5749]

I'm here because our teacher asked us to go to this link to learn more on Photoelectric Effect.

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Great video information very informative ❤ thank you for sharing your knowledge and experience 🇵🇭🫡

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Thank you for helping me with physics.

[@fatimahashhmi]

lol hte intro is so funny... love it --wakes me up

[@PP-op1ql]

Hi :). I have got question. Maybe not about photoelectric effect, but about wave and atom. If electron is wave it should propagate in some medium . But in atoms there is only electron (outside nucleus) and he is also particle. So, how it's going? Electron propagate in itself?

[@adityathakur6424]

professor why stationary electron will be pulled in nucleus but moving electron will not

[@haseebali576]

Sir you are great love the way you teach stay happy respected Sir

[@manwakan6965]

Where is my post on butterfly Using wave partial duality with insulated wings using the wave and little hole in dust lens law magnetic flux that binds the butterfly to the Schumann resonance ?

[@tiffanyproa863]

"the speed limit of the universe" Love you dave LOL

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Not LOL it's LUD

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You’re such a life saver 💘

[@yashpatel4683]

But number of electrons ejected is proportional to the intensity / brightness of the light . ( I just read it in my journal ) .

[@eunieverseee]

"confused?" "you should be" gee thanks papa cheezus

[@paulperez3013]

If sound is also a wave, why doesn't sound have particles along with its waves? What happens to the particle along the wave spectrum, or does waves reach a certain energy that it attracts particles, traps or knocks particles out of somewhere? Are the missing particles the fundamental building blocks of waves or things that pop in an out of existence all the time? Why doesn't sound have particles?

[@ProfessorDaveExplains]

Because it's a reverberation of the particles in the air.

[@paulperez3013]

Thank you. I relearn something again. Had a science mental block

[@ahmedumar7117]

Hey I think you may have made a mistake in the formula c=f x wavelength (can’t find its symbol here), I think you wrote v instead of wavelengths