Sunlight is way older than you think - Sten Odenwald

[@Zhoshyn]

Ô Great Photons, your travel was long and full of obstacles ... but last you have reached my eyes. They welcome you as old friends and accept the gifts you gathered from your long and perilous journey.

[@Dptl]

@David Z - well said

[@cutiebunnyamber3447]

fuckin poetry.

[@gf4453]

Beautifully said.

[@BestFitSquareChannel]

superb… crisp, concise, beautifully illustrated, easy to absorb… thank you… keep up your important work…

[@jumbochamploon2591]

Best Fit Square Channel there was just one *probelm* with it

[@thebeast5215]

@@GriuGriu64 are you an astrophysicist? Please bless me with your infinite knowledge

[@eddieking2976]

This science stuff warms my inner core.

[@Patrick-cy2zh]

Eddie King lol

[@J.5.M.]

Core workout? 😉

[@zac8471]

Science joke

[@Wetnapkin69]

Beer warms my inner core, lol

[@Luisa-xr2jf]

Yes

[@FengkieJunis-97]

This is one the best Ted-Ed video I'd ever watched. So compact yet so much information.

[@broncos435]

just like a photon 😳

[@lokynokey4822]

Now that's what we want from TED-Ed.

[@하예진-g6b]

ohgcg dfgae!dda fsf

[@pedroheck3667]

The sound and visual effects were awesome!

[@krexite250]

When you learn more about science from KZbin than from school.

[@riasharma3927]

Change your school then.

[@udayjadhav4134]

Ok boomer

[@bukucinho]

Krexite Thats cause they dont teach this stuff bro

[@CatatonicImperfect]

that's because these clips are just interesting factoids, while school will try to give you a deep and comprehensive understanding of a subject matter.

[@sirk603]

Julian bru they don’t do that.

[@glory6998]

Sometimes i think my life is full of struggles bt watching universe fastest thing struggling for 170000 yrs ......makes me think that my life is so much easy....💙 thank u for that amazing video

[@alanhatfield8643]

Great stuff. If I wasn't retired, I'd use it in class tomorrow. Still follow all things SpaceMath.

[@MsCybervamp]

Since this is your area and my math skills are so poor, can you explain to me why that equation regarding the steps it takes to get a km away from the house works? They said you step a meter every time and that you take a million steps. How is that putting you just a km away? Do they mean because it’s a random direction each time it is taking you off course from the destination of a km? And are they saying that the goal is a straight line km from the door, and that is why (because of the random altered steps) it takes you that long to get there?

[@EmbeddedWithin]

Hi

[@EmbeddedWithin]

@@MsCybervamp hi

[@mrararatovich]

@@MsCybervamp I'm sure it's one km away in any direction

[@rickrose5377]

We had to invent clothes while waiting for those damned photons to reach us.

[@jimmyhsp]

to us, it spent ~170k years. to light, everything occurs instantly within an infinitely small amount of time.

[@jonitalia6748]

I came, thanks.

[@AngelLPena]

@@jonitalia6748 Pause

[@jinxy72able]

Great video! Though the one problem with it is it says the light bounces around. Actually it is reabsorbed and re emitted, but the effect of it being reabsorbed and re emitted is similar to it bouncing around, so I understand them using bouncing around as an analogy to explain the photons journey. It's just easier to explain it in those terms.

[@7ANKOUCH]

Idk about you guys but each time i hear their intro and outro i get goosebumps and i LOVE IT

[@nataliegutierrez2458]

Ngl this is making me appreciate my days better.

[@shadowsfromolliesgraveyard6577]

How much of the sun's light is made in the core? The surface is plenty hot enough to produce a lot of light on its own.

[@michagrill9432]

But the surface is by far not dense enough

[@donnikolaus5869]

The surface isn't dense or hot enough for nuclear fusion. The heat in the outer layer comes from the radiation of the inner core (and a bit by friction). So, most of all light comes directly or indirectly from the core.

[@SergioBobillierC]

@Kieron is right, not every photon emitted by the sun comes from nuclear fusion, the plasma on the surface of the sun is certainly hot enough to emit visible light (and perhaps even more energetic waves). So its incorrect to say that all the light coming from the sun is ~170k years old.

[@AjayJain-ef2mz]

Hey! What happens to wavelengh or frequency of light as it comes out of the core? I mean does the wavelenght/frequency increase or decrease? And how does it start intially? Thnx.

[@wengsbacay]

You lost me before the first minute but I finished the video because of the very good voice, sound and illustration. ❤️

[@yogeshhm7165]

It was neat a explanation, not so difficult to understand.

[@umamaraza9381]

Clean explanation + great animation= superb video..thanks for this video.

[@thepillar_2864]

Seeing the end of the video, made me realize my whole entire existence. I'm scared and worried.

[@sudarshanbadoni6643]

Thanks , great voice, great expression, great maths and a great scientific modal expressed in shortest time, great video overall. Thanks again.

[@VishanPamnani]

Guys u won't believe this co-incidence,if u have a slow internet connection,try getting buffering at 3:09 .......

[@warlikelaughter6230]

1:27 so many steps would it take before you would actually take 2 full strides? :-D

[@bobologic6849]

170,000 years pinballing its way towards the Sun's surface, all while still moving at the speed of light...that's awesome

[@anandu6859]

The speed of light in a medium is constant in every frame of reference. So it doesn't changes.

[@BlackKevin808]

Probelm?

[@misclickable]

+Caligula138 They misspelled "Problem" as "Probelm".

[@misclickable]

Kabitu1 Somebody asked why people were commenting "Probelm" and if they have missed something.

[@AnstonMusic]

1:18 to anyone who's wondering.

[@TheFlightSimFreak]

Anston Music Oh... Well that's a Probelm!

[@joseph-kim]

+Kevin Le They fixed it.

[@talzO9]

That was really interesting and the animations were great! :D

[@devins7457]

This idea has been around for soooo long. I think it was around 2005 when this was announced. 10 years late TED -tisk-

[@billsomen7953]

That's a real example that the results people show up today come from years of hard work

[@normalkettle]

The 3D part looks adorable.

[@alexb1972]

Brilliant video - very informative - thank you!

[@hugo2871]

This was a very interesting episode

[@alexandravxo]

This was really fascinating!

[@511dydy]

What about time dilation? Does it have any effects?

[@killerjg]

Yes, it was missed.

[@sandeshhonmane1287]

What about the photons generated at the surface of the sun? They have to travel only the space between the sun and the earth, requiring only 8 minutes?

[@mesachen]

Love this video!

[@oicub2]

Sooooo, who was it that measured the distance between photons? I'm just kind of curious how they made such a measurement

[@omarab.soliman4963]

Amazing video! Please keep up creating this content!

[@kamran.A]

Unless I'm mistaken... does this suggest that light emanates ONLY from the core of the sun!? I never thought of it that way... always thought it's a big and, more or less, uniform "ball of light" 🤔

[@auumedone]

Muchas gracias TED-ed para tus videos educationales. Nos necesitamos esos para aprender rapido.

[@vishalmishra3046]

Protons are not like "mirrors" reflecting photons that you see 170,000 years later. The nucleons (protons and neutrons) in the sun are constantly absorbing existing photons and generating new photons usually of lower energy and therefore lower frequency. This difference in photon energy keeps the sun hot due to increased thermal vibrations of nucleons due to the energy absorbed. So technically what you "see" on earth are just 8 min (500 seconds) old new photons who have parents and ancestors that date back to ~100K years starting from the core of the sun.

[@pambennett8967]

The core is a doorway and the sun isabentuty holding it open. The light is conscious and builds abridge to reach us .. I sense this

[@valrhonaar5486]

I basked for a second to appreciate the existence of these tiny photons.... my heart.

[@aimalisapro123]

I’m awed right now

[@Azumiyoko93]

very informative and super impressive with the information organisation especially love the convey method that details go into more details

[@StanJan]

Theory. You should start by saying, " one of the theorys..." and not sell any of this as "fact". TED is the best ! Thank you. Stan

[@climbamtn111]

So, how can I apply this to Plinko?

[@fun1k]

Very informative, thank you.

[@TheBenenene10]

Why is a proton huge for a low energy photon? (And small for a high energy one)

[@MilitanT07]

***** Wavelength. Since speed is fixed for all wavelength of light, the higher the frequency, the shorter the wavelength, the less the energy. That's why microwaves can't escape your microwaves door even with big bores in the metal shield.

[@TheBenenene10]

But how does the wavelength affect the relative size/chance of interaction?

[@MilitanT07]

***** Because the wave is so large that it is unlikely to miss the proton. Photons are wave until they are about to collide with something. That's the best of my understanding as a Mechanical Engineer.

[@EmosGambler]

MilitanT07 wait.. isn't it the less energy, the longer wavelenght, the LOWER frequency?

[@EmosGambler]

MilitanT07 for example: gamma particle got the highest frequency and the shortest wavelength, E = h*v, so the energy grows with frequency

[@Liquafire]

The Random Walk Probelm? Never heard of it... I have heard of the Random Walk Problem though... interesting stuff... just an FYI TED editors!

[@blackraven4842]

00:22 the aienser ? or the aahn-ser ?

[@HarisEka]

How could they have formulas for everything?! 😮

[@lionwolf7424]

My question is, How do people get these measurements of the suns diameter and distance? A Guess-timation based off of Highly complicated math? I'm honestly curious.

[@ChopStixize]

Science?

[@Sekstant]

The prophet of Cory Leo Valdobinos I think it's parallax, check it.

[@ajtronic]

The prophet of Cory Leo Valdobinos Simple geometry for the distance, then use that distance in Netwon's law of universal gravitation to find the mass of the Sun.

[@Theraot]

The prophet of Cory Leo Valdobinos Ancient greeks used parallax to estimate the distance to the sun, with little success. Using the equinoxes and kepler equations works better. Also currently there are currently better measurement instruments that makes parallax calculations more reliable to get both distance and size of the sun. Finally if we have a good estimate of the distance, you can use a picture to calculate the size - given you know the lens curvature - via geometrical optics calculations.

[@saintherip8624]

I'm never going to see and feel the sunlight the same way again.

[@5thActFinally]

So theoretically there's a given amount of photons still ricocheing inside the sun from the day the sun first started shining and they could be still bouncing around in there till the sun dies or reach the surface and escape. Not only that but photons that were started at the beginning of the universe before our own sun that collided with our own sun and possibly got trapped from bumping into it while on a course towards wherever. That's pretty amazing and interesting at the same time

[@dekippiesip]

Yeah, because it's a random proces it takes 170.000 years on average. So there is some tiny chance a photon could be stuck in the sun for billions of years, and because of the extremely large number of photons, some actually are stuck for that long....

[@cncrim1]

Knowledge is power

[@gregorycotter6461]

I have a question. So light takes all that time to reach the surface of the sun and approximately 8 minutes to reach Earth. What would happen if the sun itself hypothetically cease to exist? We know that we'd have 8 minutes of sunlight to enjoy. But what about gravity? When would the Earth no longer feel the suns gravity? Do gravitational forces or lack thereof happen faster, slower or equal to light.

[@dekippiesip]

Exactly equal to the speed of light

[@ajtronic]

Amazing.

[@manco9607]

imagine u get this kind of learning video in daily school instead of just looking at books when we are young

[@majermike]

isn't the photon technically absorbed and then reemitted? also, don't electrons absorb photons and reemit them too?

[@adamthornton7880]

Are they the same photons, though?

[@johndoecro984]

Great episode. I wish I knew physics and math better. Also, remind me, how did we calculated Sun's mass?

[@tunlinaung5668]

I think that the calculation of the first estimating has some mistake.. because the Sun's protons are evenly spread out,making the average distance between them about 1.0 x 10^-10 meters. To random walk the 690,000 kilometers from the core to the solar surface would then require 4.8 x 10^37 steps (Not- 3.9 x 10^37 steps), giving a total travel time of 500 billion years (Not- 400 billion years).

[@Dartmorin]

How does the photons wavelength change while it travels through the sun? A photon travels at the speed of light and so does not experience any time. Therefore, it cant change. So, there would have to be an exchange of high energy to lower energy photoms somewhere. Where?

[@Dartmorin]

How would you change the wavelength of a photon without also changing the photon? What other characteristic does a photon have? And you cant change the photons wavelength anyway, because at the speed of light, there is no time experienced, so nothing can change. For a photon, from its creation to its end, it is just an instant.

[@Medhusalem]

David Markus frequenzy, for example would be another characteristic

[@Dartmorin]

Frequency is inversely proportional to wavelength. All photons with the same frequency have the same wavelength.

[@Dartmorin]

What? A photon is always a wave and a particle. They behave like both. They dont behave like one and then the other depending on how we observe them. And wave and particle dualism is characteristic of photons, but not one of their characteristics if we want to seperate one photon from another. Mystery of Quantum Physics? Really? It isnt a mystery. Light is light, in quantum physics. For our own understanding, we characterize them as being either wave or particle, but really, they just are. And observation only causes a collapse of a wave function in a particle that is in a superposition of two states. The double slit experiment showed that electrons can behave like waves at well. It had little to do with light.

[@Dartmorin]

Ace Ventura No, not all photons have the same wavelength. Obviously. But the Doppler effect in light only changes what wavelength the observer measures. It does not change the inherent wavelength of the photon. And the Doppler effect cannot be an explanation for the change of wavelength of light coming from the suns core. I just figured that out. Light gets absorped by the photons and the reemitted. Somewhere there has to be some energyloss in that process.

[@greenageguy]

And I think to myself... What a wonderful day.

[@Ykhraam]

Fascinating

[@nelle5546]

Thank you for the series of existential crisis.

[@TroubledEar42]

YOOOOO, this is dope dude

[@BjarturMortensen]

My only issues is, at what point does it stop being the same photon when it is absorbed and emitted out as a new photon in these collisions?

[@vaitrafra]

Bjartur Mortensen does photons have identities (seriously)?

[@Noltosaurus]

How come we do not see the inside of the sun when we look at it, as the light hitting our eyes or telescopes is from the centre?

[@angryface7135]

Animation The sun's light get diffused. like when you beam a flashlight onto a bottle with cloudy water, the whole bottle shines. In the sun's case, the bottle is spherical and thus you see a circular shape here on Earth.

[@LughSummerson]

Animation Because you see an image only when the light reaches your eye in roughly the same formation that it left the object. You don't see where it came from before that. If you look at your hand you see the light that it reflects in the shape of your hand, but you don't see an image of your lightbulb. When you look at the Sun (don't look at the Sun), the image you see is composed of the light that left the surface travelling in the same direction and hitting your retina. Before it reached the surface of the Sun it was bouncing around randomly, so there is no image to see. Think of it like pixels. They don't make an image unless they stay in the correct order.

[@teli6350]

Do you know why the ice ages existed? There was some traffic jam inside the Sun because the road maintenance workers forgot to increase the speed limit after their work was done. That made Earth not get it's daily Photon wage, and as such went on a temperature strike. The maintenance workers finally changed the speed limit back up again recently, but they wrote 511 km/h instead of 115 km/h, and now the earth is getting toasty.

[@thepillar_2864]

Who else thought of "Centipede" the arcade game, when they talked about the protons getting hit by photon??

[@rektrakboi3127]

Is it just me or do I really like the sound it makes when a proton gets hit

[@AnakinSkywalker_has_Padme]

0:14 This means that sun is just from it, s core to it, s surface is thousands of light years and the milky Way is just 200 thousand light years but Betelgeuse, VY canis majoris and UY scuti are all bigger than our sun along with thousands of other stars Edit- have a look at 0:24 Edit no. 2-sorry but milky Way is only 100,000 light years across

[@farkler4785]

No. It’s not close to that size, it’s that the light doesn’t take a straight path

[@lifeinindia4694]

I don't know how to process this information!! Does this mean that the sun we see is 170k years + 8 minutes old?

[@robh6638]

But how far into space does little travel after it passes by earth ? Would be older the further it traveled.

[@mashelauma]

Thanks to science we have TEDEd.🙏🏾

[@jaydeeeep]

Sounds was dope.

[@welltech4792]

thanks for sharing

[@badoocee1967]

Very Interesting...but I don't have Thousands of years to appreciate it...better learn quickly, no??

[@ragbra]

How do you solve the random walk problem for heat-radiation in people?

[@tomasbeno4213]

PERFECT !! :) thank you

[@aparnabhave3550]

I think that due to the intense heat, the surface of the sun has gone incandescent, so it glows

[@icanrememberthis]

Neat! Great video, I sure hope it is accurate, otherwise I'm going to look like an even bigger jerk when I pop-quiz my, now, ignorant family & friends.

[@MilitanT07]

So you're saying the sun we see in the morning is merely 170k years old image?!

[@digsfossils]

MilitanT07 The sun we see in the morning is about 8 minutes old which is the time for the light from the sun's surface to travel to earth. But the photons which make up the light were created about 170,000 years ago.

[@dannyarmstrong2013]

Yea, but it gets dark at night..

[@AshutoshGuptaiitb]

mindblowing

[@Monster_Mover_Stocks]

You lost me. I was told that there would be no math.

[@AsratMengesha]

Sun light from the sun reaches us as it is now.

[@naso724]

Mind bending

[@halloooo1duuuuu]

I don't understand the calculation... :/

[@aleksandarstevanovic5854]

I don't know how did you calculate something random? A photon can miss most of the particles? It can, its still random, and get to the core fast... Or can it hit every single particle in the way... Twice... It's still random, right? And take much more time to get out... You know what i mean?

[@novafawks]

Probabilities. But even then, it's real iffy. I'd take this with a grain of salt, because I'm positive when we learn more the estimated time will change since it's so based off probability. But if we can more reliably figure out how spread apart they are, we can get a much, much more decent estimation.

[@calebengelbrecht7812]

This is something to think about.

[@mitchdavis8293]

I love how we don't even know what's in the middle of the planet we are on and ppl act like the know what's in the middle of the sun

[@Jade-mm1wl]

we do know what the core of our planet is made out of lol

[@eivilcow33]

So..... What about the photons generated by the radiative emissivity of every single particle within the sun? I am pretty sure that not ALL of the light of the sun is generated by the fusion reaction's resultant photon emissions. As everyone knows, when you heat something up, it glows. So, when you have a star's worth of mater that is a minimum of 10,000 degrees; I think that is producing a large portion of the sun's light. So if a particle in the outer layers of the sun produces a photon, it wouldn't take that long....

[@99therohit]

What about surface reactions?

[@Justin-bc8gi]

Probelm :)?

[@Caligula138]

Did he say problem funny or something here? What am I missing?

[@BazicShotz]

Caligula138 on the video, at 1:20 it says "probelm" intead of problem (e and l are switched)

[@Caligula138]

Oh I see... I was too busy listening to the information. Thanks for clearing that up. 0__o

[@adityakhanna113]

Caligula138 "intead" can't miss it

[@digsfossils]

Justin Jung Ted-Ed was testing to see how observant we are. You passed!

[@PAWNB3YOND]

Me: *Gets sunburn* Me: What took you so long?

[@Caimbul]

Random Walk Probelm?? Really?@1:19*lol* Random spelling problem?

[@tazz250]

One thing the video did not even touch on, but should have, that will lead to a misunderstanding, is this... 170,000 years is not the age of all the light leaving the sun, it is merely the AVERAGE time the light would take to leave the sun. All the light is not that age. Some photons could be much older, if it had a lot more collisions and kept changing directions pretty equally, and some photons could be much younger, having made just the right journey in mostly the same direction, towards the surface. Both of these happen all the time. The 170,000 year answer is just a mathematical calculation on the median probability of escape time, that's all. So you are seeing light from many different ages, with 170,000 being in the middle. A small number of photons probably made it out very quickly, with almost no collisions at all (just by chance), while some photons may have been made while the sun was first forming, and STILL haven't made it out yet. One other thing to mention is, if too many collisions happen and it takes longer, it will likely be of lower frequency, and vice versa. So if the age is far enough removed from the average, it may not even be visible light, but it would still be radiation, and it could be pretty much any age.

[@LordPandaLad]

So for 170,000 years and 8 mins the sun was basically invisible from the location of Earth? Spooky.

[@dannyfulkerson6512]

This description of the path of a photon seems to be from the point of view of an observer on Earth. However, and I welcome correction if I am wrong, according to Albert Einstein a traveler whose speed increases will have time slow down until reaching the speed of light (the speed of our photon), time will have stopped. So, from the point of view of the photon, it is created and instantly arrives at earth, with no passage of time.

[@joakimleed4047]

I've heard that quantum tunneling has a role in the photons' journey inside the Sun, can someone explain me how quantum tunneling is related to this?

[@jpcampello]

Quantum tunneling is responsible for fusing the hidrogen atoms together.. thus generating the photons...

[@biohazard724]

There's a typo. You're not clever or observant for pointing it out.

[@daemonace5910]

I know :) It's just for our childish amusement

[@viklondon3466]

Well, he is observant at the very least.

[@ritvikvaishnav3472]

THERE IS NO TYPO

[@novafawks]

Yeah, i'm so confused too.

[@durdleduc8520]

There is?