How Does Light Actually Work?

[@HistoryoftheUniverse]

Get Surfshark VPN at surfshark.deals/universe - Enter promo code UNIVERSE for 83% off and three extra months for free.

[@Angl0sax0nknight]

Always love your videos, some I’ve watched multiple times…..

[@liqd]

I assume you're seeking to earn a coin on your hard work, which I am very interested in supporting. Do you offer an alternative to buying products or services I am not interested in? Direct monthly donations etc.?

[@Donnirononon]

How did the universe look like before atoms formed?`Like was it like today just only plasma or was it really plasma everywhere so no false vacuum?

[@smlanka4u]

Newly Born western fake science tries to make a new universe with a fake Big Bang theory.

[@PetraKann]

Good video - pity about the glaring 5 errors. It would be good if you corrected these 5 errors - it would certainly improve the presentation and limit confusing viewers. There is no need to apologise at this point in time.

[@CallmeKenneth-tb1zb]

I'll tell you what I think, I think this series is better than anything the BBC, Discovery, or anyone else on the internet is putting out right now. High quality coupled with a knack for making incredibly complex subjects easy to understand by the laymen. I also think the more we learn about Quantum Mechanics the more bonkers it gets.

[@CarlosLopez-wq8oi]

@@FooodConfusion it's this channel. On youtube

[@MorganSullivan]

Especially Discovery... Everything is an action movie for them, insufferable!

[@jeremyt7722]

This channel, SEA and Kosmos tend to have very subdued narration, no sports arena type announcer. Also a very chill soundtrack.

[@chriskelly6574]

and then all of a sudden it isn't bonkers but, still completely abstract.

[@pathic2449]

Facts on all accounts

[@leahime]

i’m still so amazed i get this for free while im sitting on the toilet. thank you.

[@jhwheuer]

TMI, you know.

[@Flesh_Wizard]

The creation of the pooniverse

[@keanureeves4025]

Reading this while sitting on the toilet xD

[@rodrigoodonsalcedocisneros9266]

I feel you xD

[@warpdriveby]

Quality going in, waste going out, you're definitely doing that exchange right! All the poor people in their crazy echo chamber threads have exactly the opposite arrangement! 😥...🤔...🤣🤣🤣

[@jimmoore6033]

Thanks! As an 80 y/o graduate in Physics and life-time science nerd, I enjoy learning about discoveries that reveal the complexities of our wondrous universe with its two trillion galaxies. Viewing videos such as this is a mind expanding joy. Your explanation that a photon sees neither time nor distance in its journey has helped me finally accept quantum entanglement.

[@HistoryoftheUniverse]

Thanks for your support Jim!

[@kounkieinc3714]

i have been trying to wrap my head around quantum entaglment for a while now without much improvement but the moment the pieces connected bcs if this video was pure bliss

[@kristinessTX]

Like many religious fanatics, I blindly accept it because it feels right. You guys helped my connect his information to understand more of the “why”. Edit: it may feel right because I have a psychic connection to my mother, son, and my father to some extent. My son has type 1 diabetes and that connection saved his life more than once.

[@wicked1172]

@@kristinessTX We must not ask Why, instead we must ask How in order to understand.

[@BoB-Dobbs_leaning-left]

I'm with you buddy, ten years ahead in time but... Share this photon. 🎇

[@mikenccc1955]

John Rendle below put it perfectly. This is stunningly well done. I first was taught physics at this level 51 years ago and this, is the single clearest, best written, most approachable / comprehensible documentary on quantum science & field theory that I have ever seen. How CAN this only have 0.5m views. BRILLIANT.

[@Swanwgm]

High school physics in 1957 still defined the aether (sp?) as: "Light is a transverse wave motion in a hypothetical medium called the aether."

[@persephone342]

Thank you for being a teacher. I went to a fundamentalist Christian school. I taught myself Calculus, Physics, Anatomy and Physiology. I thought my piers Algebra, Geometry, Old Testament, and World Religion. I’m Jewish, and they never could convert me. Because of the classes I taught my peers, my sister and I went for free. I continued teaching after graduating so my sister’s tuition was covered. I graduated at 16, and received a BS with dual majors in Mathematics and Physics. I wanted to be a professor, but my husband developed MS, my father had NH Lymphoma and I spent a year re-learning how to walk after being hit head on at 60mph. I went to Med School instead. It was the right path for me. Teachers are so important yet often overlooked as the humanitarians they are. Thank you for sharing your knowledge with others❤

[@RH-nk7eo]

I have so often heard about light travelling through the universe and us seeing into the past but that introduction showing the photons journey was really mind blowing.

[@eoinoconnell185]

3.5m views now. It will continue to grow, as this presentation is .... timeless.

[@einfisch3891]

I've heard this sentiment commented here before, but I have an undergraduate degree in physics and yet these videos give me so much insight into these concepts I've learned. I have learned the formulas of relativity and those which govern photons and light on a classical scale and yet the way you present these concepts is incredibly illuminating and never fails to blow my mind, so thank you for producing such incredibly high quality educational content for free.

[@deltalima6703]

Really?

[@Phdintheory]

g=9.81m/s2

[@danielhenderson7050]

@@deltalima6703 really what?

[@jonnyqwst]

It’s like a university textbook

[@jf5505]

​@Daniel Henderson Delta Lima is a person of very few words

[@joshonemoore]

“The bizarre world of quantum mechanics never disappoints.” Neither do these videos. Thanks.

[@maxeadon2021]

The only difference between you and an electron is the giggling space it can be in two places at once. This shrinks as objects increase in size. You yourself are in multiple places at once until your boss looks at you and can determine your location.

[@ryanbaker7404]

Hands down, the best science channel on KZbin. I grew up with Carl Sagan's/PBS' Cosmos series on both broadcast and then VHS. This channel and its series are the modern equivalent of that prior gem, and here they are in full modern resolution and quality and essentially made free for all. Amazing. Whoever the creative geniuses are behind this channel, thank you! 👏🙏

[@xyzzyx7812]

except that he is talking with such a paauseeeeeeeeeee that it comes across as full of crap

[@swordigo5101]

@@xyzzyx7812 play ur video at 2x

[@HowlinWilf13]

@@xyzzyx7812 Yeah, one or two of them could've been edited better, but in the context of the whole beautifully written episode, they fade into nothing at all. Why would that be your immediate reaction to what you just watched, to the mind-expanding subject matter??? Did you even watch it? Maybe you're a failing wannabe competitor to this You tube channel? Otherwise I think you might be missing a large chunk of your personality package. You should ask for a refund - yours sucks.

[@Bass0hr]

You can use the pauses to rethink and understand the meaningful words

[@JB-db4gf]

No offense @@xyzzyx7812 but there are many, many intelligent comments on this channel. And then there's yours.

[@Iveri.REP.]

pre-teen here. i discovered this video after getting inspired after watching the movie Oppenheimer, the process of the Manhattan Project. i’ve watched this a little over three times, wrote four papers about light and gave two to my science teacher which she is planning on hanging up in her class, and i am currently creating an entire journal to organize the information listed in this video, so whenever im bored with no internet, i can easily just pull out the journal and start reading. in addition, i’ve screen recorded this video so again, when i have no internet i can watch this video if i dont feel like reading. thank you for giving me and many others the opportunity to find something they are passionate about! update : my teacher suggested i come up with something to show the class so im currently working on google slides to present voluntarily:) another update : im still obsessed with physics even after 6 months. i want to be a physicist and my dad is helping me find places i could work if i went through with this plan, and i’m sure that i want to get the best education i can in physics (hopefully a PhD, and hopefully from a good school)

[@mxRian4]

Keep seeking this kind of knowledge, kid! School isn’t going to teach it, and this is really what life and reality is about! You’re off to a great start ❤️

[@eustab.anas-mann9510]

You're twelve and wrote 4 papers!?

[@Iveri.REP.]

@@eustab.anas-mann9510 11 actually lol

[@jamyemoreno3877]

Take this initiative and run with it. I had the same drive as a kid, ended up not doing anything with it until I was 21, I’m in the Navy now training to be a nuclear reactor operator, but I still wish I hadn’t wasted my time not pursuing sciences younger. You’re getting a great start right now, keep going!

[@Iveri.REP.]

@@eustab.anas-mann9510 11 actually lol

[@undeathbysnipe2986]

as a Physics major in college, i understood many (if not all) of the concepts you talked about in the video/documentary(?), yet i still learned so much in this past hour. in education, we learn all of these formulas and briefly cover the idea where they come from, but you covering the history, the historical figures, and the slow accumulation of collective knowledge taught me so much. the beauty of science and math is what attracted me to pursue physics as a career, and this hour long experience reminded my burnt-out brain of my absolute love for these wonderous concepts!

[@Cornell90]

@Andy V Underrated comment. Yes you can remember all these things about physics, but to actually understand them and apply them is a total different thing. But I'm a dumdum, I don't believe in the big bang theory, neither do I believe in god. Only thing I believe in, is that we are never going to find the truth. It's designed that way. Science changes all the time. I've paid attention enough to know this. And there are genius people out there who created the world we live in today, many of them are gone. But when it comes down to the big question, how the world started and what we live in, personally I always had the belief it's designed for us to never truly know. You can find smart people in the science world who don't buy into the big bang theory, you can find people who work with stuff like this who believe in a god. I accepted along time ago we will never get the answer. I just think it's troubling when people think the big bang is a fact and not a theory, wish it is. It's great science behind the theory, but were did the fire come from? it's always a question we can't ever answer. Were did space itself come from. How can it be anything. It's an impossible task for us to comprehend. Big bang theory is based upon a "let's say" and what I mean by this, they started the theory on "It was fire" but where did the fire come from? It's no way to explain these things. Space itself, even when it's just emptyness, shouldn't exist. Nothing should exist. It makes no sense.

[@DrDeuteron]

@Andy V not true. If you can’t solve the homework problems you don’t understand the material

[@DrDeuteron]

If what you didn’t understand was the so-called time ordered virtual particles, then don’t worry. That was misleading at best.

[@LairdPrydae]

This doesn't even begin to show the worth of this video as a scientific piece, and falls even further away from appreciating it's value as an entertainment piece. Well done on the masterful ability to put those two things together, and bring some semblance of beauty AND knowledge to millions that otherwise would not have experienced it. Well done and thank you, from all of us, somewhere in time.

[@HistoryoftheUniverse]

Thank you, very kind words.

[@groovergabe]

I would like to add an appreciation for the timelining and historical account of how and when things were discovered and so seamlessly into the science and storytelling

[@DontHateMeCausImSexy]

Lol 10 bucks for attention so sas

[@tomasinacovell4293]

So... it's really about clickbait?

[@Coral_pepe]

Give to poors instead

[@johnrendle1303]

This must be one of the most beautifully presented episodes in an almost poetic series. Incredibly produced and written with superb delivery. Wow!

[@parallelparkdaudette2863]

Thanks for actually educating us, instead of clickbaiting us like 99% of other space documentary channels.

[@-AndAllThatJazz..]

To the team who produced this one : You have outdone yourselves this time. In theory content, visuals and as usual . . the most compeling storytelling way of how to explain it . General audience that lives and dies on the arena . . We salute you .

[@828Brian]

This channel and your History of the Earth are putting out some of the best content on KZbin! I'm always blown away by your releases! Thank you for sharing your work and I'm looking forward to the next video!

[@stefanieberg1569]

Watch History Time and Voices of the Past… it’s his brother and him… just as great!

[@zactar]

opening story of a single photon being detected by a telescope was beautiful

[@lxathu]

As always. Poetry with moving pictures.

[@Charok1]

I could tell it was going there from the start, but the faster than light expansion of the universe part never makes sense.

[@aaronperelmuter8433]

But unfortunately they got it _very_ wrong; at about 2:43 the narrator says that the photons “travelled for nearly 14 billion light years” but this is absolutely incorrect, if they’re referring to us, which obviously they are since they mention the Milky Way, etc. the photons actually travelled about 42 billion light years, that’s not a typo, FOURTY TWO billion! They forgot about this unimportant thing, umm, dark energy, which has been causing the universe’s expansion to accelerate. Actually, they forgot about the universe expanding at all in that statement.😱

[@Charok1]

@@aaronperelmuter8433 Something had to be made up to fit their math and what has been observed. There still isn't a good answer.

[@aaronperelmuter8433]

@@Charok1 Dunno why anyone needs to make anything up. The observable universe is about 92 billion ly in diameter, so I simply halved in and, oops, should have written 46b ly, not 42 - had 92b on my mind when I wrote the comment. Anyway, what do you mean something needs to be made up? What, and for what reason? Not sure I understand…?🤔

[@sweethaven-nc]

I can't express my awe in this series. My mind is continuously blown even though I have never taken physics! I applaud your presentation and how you can allow me, a simple man, to peak into our amazing universe. Thank you for this gift. I will tear up every time I look to the sky because of you. The revelations at 46 & 54 minutes are just...... amazing...! Thank you.

[@Warpded]

I watch a lot of videos about these concepts through a plethora of channels, but your work here captivates me by far the most and it's not even close. I love to discuss these ideas with my friends and family. The complexity tends to ruin discussion because it can all be nigh impossible to visualize these concepts. Your analogies clear up the confusion. I thank you for that. Wonderful video, wonderful channel. Keep up the good work, please.

[@thomasmartin7524]

@@simonebest6013no. this is not helpfull.

[@brianmangan2459]

One of the best documentaries on light that helped me finally understand wave to particle.

[@antonystringfellow5152]

If you think you understand, you haven't understood. Light and all matter is made up of quantum particles. All quantum particles have wave-like properties. All quantum particles have particle-like properties. No quantum particle is either. Clear now? The terms "wave" and "particle" can be used as analogies to describe certain properties of quantum particles but they are just that... analogies. These are not realities. Electrons have spin states too, yet they do not spin. It's called spin because it is angular momentum. Like a spinning ball, they have angular momentum yet they do not spin. Unlike a spinning ball, this angular momentum is both up or down and left or right. So, here we have yet another anology which is not reality. Nobody understands quantum particles nor what a quantum particle is. Most likely, none of us have that ability. It is unlike anything we can directly observe in just about every way it could be. Not a single anology actually fits any properties of a quantum particle. And the "fields" that these "waves" and "particles" exist in.... most particle physicists don't believe they actually exist. These are just another analogy, a useful construct that enables them to do calculations that make predictions. So, the next time you think you understand, think again.

[@easley421]

@@antonystringfellow5152 I bet you're fun at parties. Joking. I get it. I like to take a more optimistic look at it. We've only just begun. Instant access to information will have a profound effect on our evolution and understanding. I, for one, am pretty happy with what's capable with our current "understanding" of quantum physics. Whatever analogies we needed to get a super computer in our pockets that's letting me talk to you from a mountain top in the desert, half way around the world, is OK by me. It's fascinating we can even ponder it, let alone build kilometers long, underground colliders to find them.

[@Coral_pepe]

Give to poors instead

[@melissachristensen614]

I’ve been studying light and gravity for a while, and this is the most complete and succinct explanation of its mysteries I’ve come across

[@Heracles_FE]

You need to study The Electric Universe by the Thunderbolts project . This rubbish is the very definition of Psuedo science. Something , a proton , can not be both a particle and a wave , nor can you manipulate a construct or perdibation , bending of spacetime . Modern theoretical physics is a non science , it is a religion .

[@timwalsh6283]

Maybe you could help. I don't understand. How are we measuring this in years? What is a year?

[@Heracles_FE]

@Tim Walsh we measure galactic scaled distance in light years , which represents the distance light in a vacuum travels in one year , which is roughly 58000000000000 miles . We do this mainly because Einstein wrongly assumed light travels, and it travels at a constant speed, therefore making it , not the aether the constant frame for reference in the universe . As most PHD level theoretical physicists know , Einstein was wrong about light and relativity.

[@timwalsh6283]

@@Heracles_FE so what is a year?

[@Heracles_FE]

@Tim Walsh A year represents the amount of time it takes for the stars to make a complete turn over our heads and return to the exact same place in the sky to an observer , approx 365 1/4 Earth days .

[@nik-btd]

Alright so I do like this series very much since the beginning, but this one litteraly blew my mind. I'm amazed at the extraordinary quality of both the script and the illustrations - you manage to give a grasp of the madness of quantum physics in an amazingly clear way. I feel smarter with each episode (then I realize I have even more questions, hehe). This is an absolute jewel of a production on KZbin, by far the best astrophysics material for laymen out there since Feynman's lectures ;) Outstanding work, can't wait for more.

[@MrEvers]

I love how this series is not only a history of the universe, but also a history of physics itself.

[@sootuckchoong7077]

How did the first heat or whatever begin?? 🤔🧐

[@system0fadowner251]

​@@sootuckchoong7077 well that's one of the, if not the biggest, mysteries of physics. What caused a sudden expansion of energy and space that led to existence? We'll likely never know, but it's amazing to ponder.

[@RT-qd8yl]

@@system0fadowner251 I think my biggest personal questions are: -What brought the initial singularity before the big bang into existence? -What was beyond that, and what is outside the boundaries of our current universe (observable and unobservable) if there is one? I think I'm just baffled by the actual idea of nothingness, I confuse myself even thinking about what I'm trying to wonder about and that's why I LOVE this stuff.

[@natjonestower3035]

This is one of the most digestible bits of physics i've ever seen. Well done.

[@Anon-xd3cf]

Digestible? It's full of inaccuracies and falsehoods. It's based on out of date information and lacks understanding of human history while claiming to understand the complexities of the universe. It's well produced and easy on the ears... But it's mostly nonsense.

[@yohannesgaim6459]

I'm an accountant by trade, yet I could swim in cosmic and subatomic knowledge thanks to this program's way friendly presentation. As always it was immersing and impressive. I cant wait to watch the next episode!

[@jaxwylde2139]

Incredible! It's difficult for me to express, in words, how phenomenal these videos are. I'm familiar with many of the topics having an interest in this area and having watched countless other programs on BBC, YT, etc.. BUT, the way your videos are written, presented, and narrated makes everything else pale in comparison. I'm often breathless after watching. I can't get enough. WOW!

[@SciVerse-k9x]

I absolutely loved the photon journey to the telescope analogy. Just represents the quality of these documentaries. Can’t believe it’s actually free

[@TimTeatro]

Stunningly beautiful. I'm a physicist, and many of the visuals in this video are very close to what I see when I close my eyes and think about these things. It's cool to see in on a screen, because my mind has to generate it from the math.

[@TheScienceOfAdventure]

This is the most amazingly approachable and well written channel on KZbin. Thank you for making my days complete with your kickass work. I watch/listen to your videos a ton and it makes me wish I had taken physics courses when I was young. Epic work sir!

[@LandonBell11]

There is a perfect amount of awe and wonderment in the narrator's tone. The writing and production are also top tier. Gold star 🌟

[@KipIngram]

17:00 - Whoa there. When he first set out to study electromagnetic fields moving through the vacuum of space, he *did not know* that light was an electromagnetic field. He realized this when he calculated the speed of his EM waves and lo and behold the already known speed of light fell out of the arithmetic. This was a huge shock to him, and I can only *imagine* the utter joy he must have felt at the discovery. What a moment that must have been for him!

[@soosik9494]

I always wait for the new video. When it finally arrives, I sit comfortably, grab a cup of tea, turn off the lights, and simply enjoy the journey through space and time.

[@RootsMj]

Can't thank you enough for all the incredible content you put out. Your storytelling and visuals makes complicated topics actually understandable. My absolute favorite channel of all time! ❤️

[@Coral_pepe]

Give charity instead to poors

[@DimensionalDisorientation]

​@@Coral_pepewhy do you care what other people do with their money?

[@Coral_pepe]

​@@DimensionalDisorientationwe should

[@wesleygibson5546]

​@RoEnlightenEd That's what we pay taxes for. That little bit of money wouldn't do shit to help any of us poor folk anyways...we need socio-economic reform and a reasonable maximum wage for the rich and for them to pay their fkng taxes, not random little handouts. And every charity on earth is a joke. Most are just money laundering schemes and/or tax write-off generators, and donate around 10% of incoming donations to people in need.

[@Coral_pepe]

@@wesleygibson5546 true, like American taxes going for genocide in Gaza. 270b+ 😨 donation to only Israel 😆

[@andyfox6023]

You hold a vast and so well researched wealth of knowledge. Your videos are marvelously narrated and make the education that you provide incredibly interesting, holding the listener's attention to the last word! Thankyou very much for all of your hard research and for sharing it freely with everyone!

[@stevebrindle1724]

I love it when the great Paul Dirac gets a mention, voted by a poll of scientists to be the second-greatest UK physicist ever behind only Isaac Newton. He should be as well-known a name with the public as Einstien! His biography "The strangest man" is a fantastic read that I would recommend to one and all!

[@ngonzalesiii]

Dirac is one of the most brilliant people ever. My favorite scientist. He never gets enough credit. I wish I could have known him personally. Yeah.

[@stevebrindle1724]

@@ngonzalesiii Sometimes I imagine who I would choose from History to attend a dinner party with, Dirac is always on my list although I believe he was very pedantic, but so am I, so no problem, if I had to choose 3 others they would be Karl Marx, Richard Feynman, and Aldous Huxley. Who would you choose?

[@DeftPol]

Beautiful episode. Love how you and your writers manage to make science so poetic

[@JHaven-lg7lj]

Perfect description, poetic

[@robertgoss4842]

I'm just a bohunk from south Georgia, USA, but I must say that this video is the finest presentation of some very complex ideas that I have seen. Superbly written, expertly presented. This is some very tough stuff, but I relished every frame.

[@peaceandloveusa6656]

This is the most well laid out explanation of our understanding of light throughout time I have ever witnessed. Even at about an hour run time, I was thoroughly intrigued and entertained the whole time. Very well done.

[@thomass.586]

This documentary is amazingly well done - the content, the visuals but to me even more so the beautiful comprehensible narration. It is the first time that I feel I got a little grasp on quantum mechanics and effects. This is on par with expensive BBC productions, thank you for putting high quality content like this on KZbin for free.

[@jakobfredriksson2272]

The quality of the content on/of (I'm struggling with English prepositions sometimes) this channel is out of this world.

[@kadourimdou43]

Correct on the first one. _On_

[@redridingcape]

​@@kadourimdou43 The quality of content on this channel. The quality of content of this channel. The first does sound better, but I'm 80% sure both are correct.

[@kadourimdou43]

@@redridingcape 🤷‍♂️ Maybe. Just thought _on_ sounded less clunky.

[@redridingcape]

@@kadourimdou43 I agree, just didn't want OP to think wither was grammatically incorrect.

[@agnosticmuslim6341]

Well since you are open to learn, the sentence in the brackets should have been - "I sometimes struggle with English prepositions" or " I struggle with English prepositions sometimes" or maybe remove the sometimes from your sentence if you want to use the word "I'm struggling" but it wouldn't capture the whole picture that you are trying to tell. English is my second language too so if anybody finds this wrong, kindly correct me.

[@smoorej]

It’s just insane that this level of quality documentary is available on KZbin. It’s ridiculous. And a human voice, probably the best narrator voice in the history of the world, not some idiotic AI voice that’s like nails on a chalkboard. Please, please continue to be successful and continue to generate content like this. If you run out of funds just setup a Patreon account. I would gladly pay for this content.

[@HistoryoftheUniverse]

Voice is me - thanks for the support!

[@RT-qd8yl]

@@HistoryoftheUniverse This person is right, your voice is PERFECT for it. It brings me back to the old school NG and PBS documentaries I grew up with. They set the standard back in the day, and you've taken over admirably. Just as good if not better than what I grew up with. Thank you so much.

[@hypermobilesinger]

these videos have been so good for my understanding. It’s really difficult to look at something like physics and approach it, with all its broad complexity, when you don’t have a background already. It’s so useful to be able to see the history of the debates and the evolution of the theories, it feels like these ideas are really clicking now.

[@johnpurdy6284]

From a channel that consistently produces brilliant content, this video stands out. Telling the story of mankind's understanding of the nature of light, paired with the story of a photon from the early days of the universe, this is one of the very best science documentaries I have ever seen. Entertaining, informative, and authoritative. Bravo.

[@andrewreeve5537]

Brilliant documentary on the toughest of subjects. Probably the best I have ever seen cover such a range in one hour, information, illustration and commentary first class. Thank you. PS. One tiny comment: at 51:13 think you should stop left clock to show time difference and not let it catch up with right, which has already stopped.

[@roysam-sin5389]

That was a real rollercoaster ride. Photon is a wave, no its a particle, no its a wave acting like a particle. Its neither but both! Yes but its quantum entanglement. I’m beginning to understand, i think. This is science education at its finest. Bravo 👏

[@chrzan9608]

Wow, this was incredible! The story-telling mixed with a documentary is the ultimate combination. The production value on this is something else. Well done!!!

[@DW-ng9ke]

I’m always happy to see that this channel has delivered another video. Thank you for your hard work. They are always masterpieces and although I haven’t seen this yet I’m sure I won’t be disappointed.

[@BunkyFitches]

2 out of 2 D.W.'s agree!

[@GM-cf6jv]

I keep watching this over and over again trying to make sense of what is said. I can’t! I will keep watching it because its so much fun to think about and yet painful to come to any conclusion. To all the great minds that have worked and continue to work on this, I salute you for sharing with this lay person.

[@ezekielnow425]

Satan is the author of confusion.

[@j.edmondson4927]

@@ezekielnow425LOL. This guy 👆👆👆

[@kevingreen3781]

Where does light get its speed From

[@happysonnyamudeza]

Where does the proton get its mass from?

[@NelsinhoRodriguez]

Good question. I had never made that question before and i am really thinking about it.

[@genoadams2463]

You know where

[@HeebieJeeBee]

A friend of a friend

[@CommackMark]

I think the most fundamental question is where does energy come from. All else is a transformation of energy. What indeed is energy?

[@Rafaga777]

This is, together with History of the Earth the best KZbin has to offer. Every single episode is a masterclass of writing and narration. And every episode is a joy to watch. Thanks a lot and please keep on the good work.

[@3dgar7eandro]

This channel should be illegal... I'm literally 🙊 speechless... What a remarkable way of depicting the path of a single tinny "Photon" whit such an elegance and simplicity, while casually but rigorously narrating how the brightest minds on our short human history have come to acknowledge what actually 'Light' is, and what are the principales that ultimately make it work that way. I just wanted to thank you for making this topic so accesible and interesting for all KZbin viewers out there. Please keep improving, and making us wonder. This channel, Veritasium, and Kurtzsgesat are definitely among my all time favorites 😁👌

[@prototropo]

You sound like my kind of science lover! Have you seen "Cool Worlds?" The Columbia University astrophysics star--David Kipping--is astoundingly charismatic and blistering smart.

[@3dgar7eandro]

​@@prototropoyes indeed I have, and yes it is also a wonderful channel 😁👌

[@crayons9120]

I love your content. Like a black hole devouring its stellar neighbours, I’ve devoured your content. It’s well researched, well told, well animated, and well spoken. I’m not gonna lie I have fell asleep a few times late at night watching these mind bending, but relaxing videos. I always go back and watch anything I miss. Thank you so much for doing this.

[@charlievalentine4123]

Io0 no ng

[@joer.6458]

For the (idea of) electrons agreeing to swap the photon, over the vastness of space-time, they had to know it would get there (the photon would cooperate and so would everything else [including the stuff we're still not certain of]).

[@Joeyplanets]

This is such an inspiring video, HOTU. My dream is to become a science teacher and my goal would be to make my students feel the same way your videos make me feel. Awe, intrigue, and overall captivating in the face of the massive cosmos that is our existence.

[@MayaWu44]

I feel exactly as you feel, trying to look deeper into reality. If it means something;)

[@joesands8860]

Joey, I commend you for wanting to teach young people about science, but have you seen kids in schools these days? There is no such thing as respecting elders (teachers) anymore and with cellphones that every kid has, they are paying no attention to anyone but the latest stupid little dances.

[@MayaWu44]

@@joesands8860 I shall say, it's because Elders try so hard to be that way. Do not expect respect when you give none, do not except understanding when you do not say how nor why, do not expect thinking, if you instead teaching them only how to remember. Working in school do not make you a teacher. Throw away your old books, take this phone you hate to your hand. Show them, how to use it proficiently, show them how fun it can be to use phone to do curious things. That's the way you should teach. If you walk into class and require respect 'on credit' than kids already know you are a fool and will give you none. Kids are smart, remember that.

[@einfisch3891]

I wish you the best of luck on your journey. A single, passionate and knowledgeable teacher can really change someone's whole life.

[@einfisch3891]

@user-jo1gy3kx3j you are a robot but you don't know, cut off your own fingers to verify. It's ok, they aren't real.

[@Caicedo685]

I've watched this episode 3 times now and each viewing increases my understanding. I have a maths/physics degree from King's College, London but that was way back in 1973. I subscribe to a lot of similar sites but I've found this series to top the lot. The commentary is excellent as is the content.........and this episode was the best so far, IMHO. Kudos to you all.

[@ruththinkingoutside.707]

You guys are a gift.. I’m so so glad to have had you to watch or listen to for years now.. you’re amazing.. better than tv could hope to be.. and the effort is seen & appreciated..thank you, for these 2 channels and the History ones..I watch and rewatch again.. Absolutely one of the best anywhere.. 🥰

[@farzadgarmiani3653]

Not only the best science channel currently on youtube, but also the best narrator of all time including BBC. You tell the story like you've been there and take us into your journey. Keep up the best work man!

[@UKBulldog2004]

This has been the best explanation of this complex subject that I’ve seen so far. Wonderful…… even though I will have to watch it a few times over !!

[@dritemolawzbks8574]

Despite his reputation for being petty and a difficult person to get along with, the genius of Isaac Newton never ceases to amaze me. It seems impossible that a single person would have had the ability to contribute so much to the field of mathematics and classical physics. I know he didn't create all of classical physics, calculus, and optics by himself, but it's been hundreds of years and he's still considered one of the greatest sciencist in human history. The relativistic modifications to mechanics, gravity, electrodynamics, and the development of quantum mechanics and modern physics have made him underappreciated. Sometimes it gives the impression that all of his theories are no longer relevant and have been completely replaced.

[@sherifitzgerald6886]

Great narration & beautifully rendered graphics makes this channel one of the best for scientific breakdown of processes. The BIG questions are asked and answered. I love it. Thank you for all you do to help us understand this strange universe we live in. ✌🌎💖

[@tasmedic]

This is a lovely presentation but there is one matter I must take issue with. The Crookes Radiometer has nothing to do with light "pushing". If a good enough vacuum is drawn inside the device, it stops working. It's rotation appears to be caused by differential heating of the small amount of residual gas present in the device, occurring at the edges of the vanes. This has been considered the best explanation of it's operation for a very long time. Also, if a spinning radiometer is moved into a cold environment, it starts spinning in the opposite direction, probably due to black body radiation of the darker sides of the vanes surpassing the edge effect in heating the gas. There's no better way of showing that it's activity has nothing at all to do with light "pushing" the vanes around, but instead is dependent on the presence of a small amount of gas in the tube, which is differentially heated by the edges of the vanes where the black sides are close to the silver or white sides. Counter-intuitively, light has momentum but no mass. Such contradictions are, alas, common in quantum mechanics.

[@kawsaralam2411]

An absolute masterpiece, I always thought the universe and its inner workings are mostly per-determined but the extent that star's electron handshake with a human's eyes electron and then the photon emitted adjusted its direction and started its journey of thousands of light-years to say the least is exceptionally special and humbling thought. I wonder the reasoning for the mechanism of the universe to treat humans with such dignity.

[@ryanhampson673]

I remember when I was younger I had an epiphany. Time stops at the speed of light. A photon travels at the speed of light. So to a photon it never really exists or it in its own eyes is eternal. The moment of a photons emission up to its absorption, to a photon this happens faster than instantly, no time has passed for it. To a 14 year old it blew my mind, and still does today at 43.

[@josephhall5681]

lol making up things doesnt make you sound cool bud.

[@phunkyjunkee]

@@josephhall5681 he’s not.

[@BoxingDawg]

​@@josephhall5681 of course your name is Joseph

[@coreyc47]

Yes! This is already known!

[@halsmith7642]

Probably not related but when I was 6 years old 60 years old I remember asking my 1st grade teacher a question about magnetism. The question; "is the earth magnetic because of all the magnets on the earth in the material have poles or does the earth cause the poles in the material?" She said I don't know and said she would look into it. A few days latter I asked "so what did you find out?" and she just said that doesn't have anything to do do with magnetism". I have remembered this and after hearing about Feynman wanting to travel to Tuva, thought how it would have been great to learn more from someone like him when I was younger.

[@ChrisMaveric]

My mind is intrigued beyond imagination by this video and its content. I only wish I was 18 yrs old and not 58... Bravo for the simplicity in presentation whilst covering the absolute scope of "light". I believe this to be the most powerful video I've ever enjoyed! "Thankyou" to the creator(s)

[@RT-qd8yl]

I'm 35 and already feeling that way... I'm making the most of it now, but thinking back there's plenty I'd have done differently.

[@Vanguardw]

Honestly, best documentary series on the universe I've ever seen. I absolutely love these channels. You should make some pins for merch

[@saltydodger9597]

Such a wonderful combination of narrative quality, wonder, and scientific rigour. Unparalleled content, thanks.

[@mcorbett01]

Fabulous documentary. I’ve just been discussing it with my wife. Have we got this roughly right (in theory)? …. When she looks at a star, an electron on the star and an electron in her eye ‘agree’ on the photon that ‘arrives’, which because it ‘travels’ at the speed of light ‘arrives’ instantly since no time or space has been traversed, despite the star being perhaps millions of light years away. (BTW when I mentioned Feynman she immediately jumped up and grabbed a copy of ‘Surely you’re Joking Mr Feynman’ and insists I will love it when I read it).

[@LWT80]

Its only instant from the photons point of view, not yours. From your point of view it takes time for the photon to cover that distance.

[@ryzikx]

@@LWT80 the video said one electron sends a message from the past while the other from the future, so yes time passes but the message was still exchanged in an instant from the photon's perspective. at least that's how i'm understanding it

[@monicarenee7949]

@@ryzikx yeah we see stars as how they looked in the past. The further away they are, the more in the past the image is from our perspective. Only to light is it instant but it took light-years to reach our eyes so we don’t see stars as what they actually look like right now.

[@doronron7323]

This episode has illustrated what I've been struggling with for years and answered all my questions. Finally, I understand what a particle of light is and what it does. I'm no mathematician or physicist, but had vaguely understood, a photon being massless, relative to its self, actually goes nowhere. Instantly. That's how brilliant light is!

[@davidczajkowski5956]

These are hands down the most educational, well put together, and enjoyable to listen to physics/astronomy videos on KZbin. Please keep producing content!!! You are raising the intelligence of every person that finds this channel!!

[@michaelwang1730]

Do you have a patreon page? Because I'm sure many of us would love to support you. This is perhaps the greatest youtube channel I have ever seen!

[@Pfhorrest]

Given that from the photon's frame of reference there is no time or distance separating its emission from its absorption, the notion of the emitting and absorbing electrons needing to agree across time to exchange the photon becomes superfluous. The photon *just is* the event of those two electrons interacting at the same place and time, effectively touching each other for an instant. And since fundamentally all particles are lightlike to begin with, massless and moving at c, only slowing down and acquiring mass in the process of interacting with each other, it is that perspective of all time and distance being zero that is most fundamental and true, and the apparent separation of different things across vast reaches of space and time being emergent from the structure of the pattern of interaction between the various fields, which interactions just are the particles of the universe. (Because even zero-extension objects can still have an order between them, so there's still a sequence where first these fields interacted this way, then those fields interacted that way, etc, in order, even if each interaction and so the sum of all the interactions adds up to zero time elapsed).

[@robertpotvin8872]

I WENT OUSTSIDE AND SHOOTED MY LASER AT MY NEIBOURGS WINDOWS ,NOTHING HAPENNED BECAUSE LUCKYLI NO ELECTRONS IN IS HOUSE AGGRED ,OTHERWISE HE WOULD HAVE CALLED THE POLICE LOL, 😂👽

[@JackKirbyFan]

That was daring to cover Feymann's quantum field theory. It is an incredibly difficult theory to understand as the mathematics is WAY beyond my understanding but you explained the concepts as I understand them myself - (which for me is a very superficial and layman) - and went way beyond my own understanding and I was so impressed. Brilliant work!

[@ngonzalesiii]

Feynman is a self absorbed b.s. artist. He overcomplicates his material knowing most people can't or won't understand it. Then he attaches rudimentary diagrams to it acting like they're some modern day masterpieces, pats himself on the back and laughs at people thinking of how he made fools of them. But he is brilliant though. Yes.

[@lucabaumert7764]

@@ngonzalesiii Seems like you succesfully made a fool of yourself all without his bullshittery!

[@mack8488]

Your clear precise relaxed and understandable way of narration ,and no excessive music, make these videoos a great joy to watch!! Thank you.😊

[@larrygraham3377]

Really loved this video. It explains a lot of complex physics without getting bogged down in the complexities of mathematics. Again, THANK YOU !!! 🤯🤯🤯

[@binbots]

General relativity and quantum mechanics will never be combined because they take place at different moments in time. Because causality has a speed limit (c) every point in space where you observe it from will be the closest to the present moment. When we look out into the universe, we see the past which is made of particles (GR). When we try to look at smaller and smaller sizes and distances, we are actually looking closer and closer to the present moment (QM). The wave property of particles appears when we start looking into the future of that particle. It is a probability wave because the future is probabilistic. Wave function collapse happens when we bring a particle into the present/past. GR is making measurements in the predictable past. QM is trying to make measurements of the probabilistic future.

[@Shabobidhuffy]

How do you explain quantum entanglement then. Or time independent Schrödinger eq. Or for special relativity order of events happening for different observers . or cmb 14 billion yo , yet set in place by the quantum interactions early on during early universe. Or current ratio of protons /neutrons, set in place 14 billion years ago by quantum laws. I don’t understand.

[@jay252589]

Yay, another video to watch 10 times over, I love watching them.

[@nikhilashri6615]

When will this channel get the support it deserves! Soooo underrated and genuinely brought back my passion for STEM. Genuinely.

[@teddp]

To say that this video's notions, concepts and theories are just mind-boggling would be the understatement of the millenia!

[@ReadingRambo152]

Thank you for sharing how amazing reality is. The videos on this channel are incredibly enlightening ❤ 😉

[@arsenusthearsenalswagus4200]

Professor Geraint F. Lewis' writing is just brilliant.

[@LisaPalumbo-sq5qc]

"A photon is a quantized version of light." Thank you so much for this one line. This whole series is just absolutely exquisite, and this is exactly the description of a photon that I needed. Thank you to every single person involved in making this wonderful series.

[@Victor76661]

This is such a brilliant work, selfless... congratulations to the whole team and my sincere Thank You! Have yourselves an amazing day ahead :)

[@JB-db4gf]

These videos are incredibly well done. Thank you for doing your part in advancing knowledge.

[@dharma2035]

I am always excited to see a new edition of this series. I think this is among the best science content on KZbin. One of the things that makes it so outstanding is the writing, so please accept this criticism in the spirit of love and respect with which it is offered. The recurring use of the adverb “forever,” (ie: “…Albert Einstein changed physics forever.”) seems deeply strange in a scientific context. To support this assertion, we either have claim we have foreknowledge of the future to the end of time, or we have to assume that we are at the end of history and no further change is possible. If neither one is true, “forever” just becomes an unnecessary and inappropriate rhetorical flourish that stands out as glaringly unscientific. Sometimes, good prose is good because of what is left out. With love.

[@willong1000]

Let's assume we exist in a physical universe and not some fever dream or simulation where natural laws are altered at the whim of the programmer. Thus, if you've quoted correctly and it was "…Albert Einstein changed physics forever," the adverb "forever" is hardly the only problem with that assertion. Neither Albert Einstein nor any other theoretician "changed physics." What they do is refine, or in rare cases such as Einstein, fundamentally alter, our understanding of physics when their theories are confirmed by observation and experimentation.

[@JB-db4gf]

"Forever" is used with creative license and maybe a little showmanship to great effect. IMO.

[@wearemany73]

This is how I view “time” and a photon’s journey is instantaneous 😊 The Surf Shark ad slipped into the narration like a buttered ferret, bravo 👏

[@TheHexCube]

An outstanding production in every way. Thank you for this incredible and beautiful series. I'm speechless!

[@tjmachaka9023]

I am no scientist or physicist, but i follow science, and this documentary is definitely one of the I have EVER come across.

[@Masoch1st]

It's definitely one of the documentaries, ever

[@tosehoed123]

You dont say

[@Aesir510]

Lol what does that even mean

[@Hammondfreak]

It seems as if Quanta have some kind of consciousness - electrons communicating through time - fields interacting with a purpose. We have learnt so much but have so much more to understand if we ever will. Absolutely brilliant video!

[@AliAkbarAzizi]

Thank you for your great video For me one thing is very strange, if photon is a handshake between 2 electron, what is the second electron for the photon which trapped inside black holes and may live forever

[@Nostromo2144]

That intro actually made me well up a bit for that poor, lost, lonely photon, flying through inter-galactic space in isolation for almost 14 billion years, even if it was in the blink of an eye for it. I hope it re-emmitted, found its pair/partner particle and re-united with it and lived happily ever after! :D

[@treestandsafety3996]

"Time is what clocks do.."

[@patmc09]

Or are clocks what time is🤔

[@treestandsafety3996]

@@patmc09 Timing, marking the changes..

[@jj53368]

This is one of the most gorgeous documentaries I've ever had the privilege of watching. I cried. You are on-par with Carl Sagan and Neil Degrasse Tyson.

[@tlahe2]

Good job explaining a complex subject so that it's more comprehensible. Thank you.

[@mef9327]

Extremely well done historical development and analysis. - from someone who watches countless other similar topic channels. *New subscriber earned!*

[@sagic7287]

This video actually blew my mind, and I thought I already knew alot about physics. Spectacular work.

[@ajayhadiya97]

I am waiting for your video for so long ... ! Please do more.. like this

[@TheEnigmaUniverse-vt2pm]

"Love stuff like this to fall asleep to. (Not in a bad way) Has to have the right kind of voice👍"

[@luthiervandros]

“Let there be light.” Takes on a deeper meaning.

[@Some1inFNQ]

the light was there anyway. it didn't require permission.

[@Aesir510]

@@Some1inFNQ😂

[@PauloSilva-ts3wk]

Obrigado! The way science is presented here, is really nice. Always waiting for a new episode and I'm happy to contribute with payments because you really deserve

[@davidrichard2761]

Thanks for that, I’m no scientist and no mathematician but I find this lecture fascinating. Thanks.

[@karnovalex]

Literally the best documentary format ever❤ “Handshake” of electrons is completely mind blowing 🤯🤯