And we let it swing back and forth. 	 Pustimo klatno ga da se njiše i da se vrati u početni položaj.


One person has to be standing next to you and you should not look at the sun. 	 Jedna osoba treba da stoji pored vas i ne treba da gledate Sunce.


Who did not see white light? 	 Ha, ha, ha.


So, we will do this first at 5 degrees. 	 Prvo ćemo to da uradimo za 5 stepeni.


So I am going to put this in and stir. 	 Stavljam kiselinu i mešam.


And that means if I hold it one minute in my lungs and then puff it out, you will not see blue light but you will see white light. 	 To znači da ako za trenutak u plućima zadržim dim, umesto plave svetlosti videćete belu svetlost.


So just keep looking. 	 Samo gledajte.


Art history! 	 Istorija umetnosti.


But of course they evolved in a way that grew substantially. 	 Naravno, ona su postajala sve bolja.


So the sky is blue. 	 Zato je nebo plavo.


And even the density fluctuations of the air molecules themselves, are clearly smaller than a 10th of a micron. 	 Karakteristične fluktuacije gustine molekula vazduha su isto manje od desetine mikrona.


Who saw the white light? 	 Samo neka kaže da.


4x mins 22. 	 4x minus 22.


And when it comes down on the floor there is an enormous speed. Great amount of kinetic energy, and so you will get energy out of nothing. 	 A kada dođe do poda, ima ogromnu brzinu nosi veliku kinetičku energiju.


In 26-100, the center of MIT, you are seeing in the lecture hall, THE RED SUNSET! 	 Ovde u amfiteatru, u centru MIT-ja, gledate zalazak crvenog sunca.


Because, then I don't have to look at it. All I have to do is when it gets close to 10, I have to watch for the moment of stopping it. And then I will end it. 	 Sve što ću uraditi je da kad se približimo broju 10 pažljivo uočim trenutak kad se klatno nađe u amplitudnom položaju i tad ću da zaustavim merač.


You will very quickly see why it is 10. 	 Vrlo brzo ćete videti zašto je bolje meriti 10 perioda.


So that is the meaning of g. 	 A to je i značenje od g.


Audience Member - "Thank you for a beautiful lecture, I am tempted to ask you what pi is but I think I ask instead... 	 Hvala za ovo divno predavanje. U iskušenju sam da pitam šta je pi. Ali mislim da imam bolje pitanje.


So, the only light that makes it to you is red. 	 Jedina boja koja dolazi do vas je crvena.


But, lets first do the Rayleigh scattering with cigarette smoke. 	 Ali idemo najpre na rasejanje na dimu cigarete.


And you should or may also understand now why the sky is blue. 	 Ali trebalo bi i da razumete zašto je nebo plavo.


Tenu choice heuchi A. 	 Odgovor je A. ...


To show you rain scattering of cigarette smoke. 	 Rejlijevog rasejanja na dimu cigarete.


Rainbows what? 	 Kako je duga...?


Ta pare âme y-intercept ta jani pariba kau point through re jauchhi seti point re sasei ki. 	 I možemo da nadjemo odsečak na y osi zamenom ove tačke kroz koju linija prolazi.


Thank you! "Audience Applause" 	 Hvala.


All colors scatter equally and so white light scatters off particles that are half a micron or larger, remain white. 	 Sve boje se rasejavaju jednako tako da bela svetlost na česticama od pola mikrona ili većim ostaje bela.


Why is what? 	 Šta...?


And the way that I am going to do that is prominently demonstrate it on the cover of my book. 	 A način kako ću to da učinim je prikazan na korici moje knjige.


It is very well known. 	 To je dobro poznat efekat.


I have to start all over. 	 Moramo sve iz početka.


So I will start it at some moment, you will see when, and then you do the counting. 	 Kada krenem da merim vreme. vi počnite da brojite.


Claire will come to you with the microphone and then I hope we can communicate that way. 	 Kler će doći do vas s mikrofonom. Tada ćemo moći da komuniciramo.


Tenu y heuchhi minus 10, jete bele ki x heuchhi 3. tenu x ra 4 guna, x heuchhi 3. jukta b. tenu seita kete? 	 Znači y je jednako minus 10 gde je x jednako 3. Znači 4 puta x. x je jedanko 3. Plus b.


So maybe my reaction time is a little better than a tenth of a second. 	 Možda je vreme moje reakcije bolje od 0.2 sekunde?


You ready? 	 Da li ste spremni? Jesmo.


Our pendulum that we have here is really the mother of all pendulums. 	 Klatno koje imamo ovde je zaista primer dobrog klatna.


100 percent polarized! "Audience Applause" 	 100% polarizovano.


Predominantly blue! 	 Uglavnom plava.


You may not have noticed it because it is not an overwhelming thing. 	 Možda to niste primetili jer to nije tako ogromna stvar.


That would be a violation of the conservation of energy. 	 To bi narušilo zakon održanja energije.


And in fact the sun is so red now that I think the sunset is very close. 	 I zapravo, sunce je toliko crveno da će uskoro sasvim zaći.


And I will measure 10 periods, not one. 	 Meriću 10 perioda, ne samo jedan.


And when an article was written about me in the New York Times a few years ago. On the second page of the New York Times is the Wisdom of the Day. 	 Kada je o meni objavljen članak u Njujork Tajmsu pre nekoliko godina na drugoj strani objavljuju mudrost dana.


I'm wondering how rainbows relate to Rayleigh scattering, do they? 	 Uključeno je? Pitam se kako je rasejanje povezano s dugom. Da li je?


Tenu amarre answer heuchhi C. 	 Znači, naš odgovor je C.


For reasons that are not so clear, I picked MIT because a whole new field was born here in Cambridge, Massachusetts. 	 I iz nekog nejasnog razloga izabrao sam MIT gde je rođena nova oblast, ovde u Kembridžu, Masačusets, koju je započeo profesor


That makes it very difficult! 	 A to će biti jako teško izvesti.


I have here a bucket which is filled with sodium thyosulfate. 	 Ovde imamo posudu napunjenu natrijum-tiosulfatom.


And I have to tell you something, I couldn't sleep all night. 	 I da Vam priznam nešto. Nisam mogao da spavam čitavu noć.


And so I have decided that I am going to create in 26-100. A blue sky for you and a red sunset Killing two birds with one stone. 	 I ja sam odlučio da ovde u amfiteatru napravim plavo nebo i crveni zalazak sunca, čime ću ubiti dve muve jednim udarcem.


Tenu âme janichhu je ei équation ta y is equal to mx ra form heba, jauthiki m is a slope. Slope ti ku bahara kariba. 	 Znači znamo da ovo ima oblik gde je y jedanko mx, gde je m koeficijent pravca.


You are going to pass this course! 	 Izgleda da ćete položiti ispit. 6, 7, 8, 9, 10.


That was also the case with the smoke experiment. But I didn't mention it. 	 To je bio slučaj i sa eksperimentom s dimom ali to nisam pomenuo.


It is the sun that is the over whelming thing. That makes the entire sky red. 	 Sunce je nadmoćno i u stanju je da čitavo nebu učini crvenim.


That is o.k. 	 To je u redu.


Dekha jau. copy au paste karuchhi. 	 Samo da vidim. Kopiraj i nalepi.


And there goes the ball higher. In the second one it again goes higher. 	 Ona ide sve više i svaki sledeći put se penje više.


My lecture will be about 40 minutes, and after that I will give anyone the opportunity to ask me questions. 	 Moje predavanje će trajati oko 40 minuta. Nakon toga, moći ćete da postavljate pitanja otprilike 15 do 20 minuta.


Because if you look at the sun, even though there is no sunlight left, you still, your retina is still too over exposed. 	 Jer ako gledate u Sunce, iako je preostalo malo sunčeve svetlosti, vaša mrežnjača je previše izložena svetlosti.


They offered me a professorship and I never left. 	 I ja je nisam napustio.


There is something else in here which is even more counter intuitive and that is.. 	 Postoji nešto što je još manje intuitivno.


But, there is not such thing in physics as a free lunch. So that is not going to happen. 	 Ali takve stvari se ne dešavaju, u fizici nema besplatnog doručka i to je zabranjeno.


Anna is my Facebook friend. 	 Ana je moj prijatelj s Fejsbuka.


So now for the first time in your life, may have an explanation of why clouds are white. 	 Sada ste, možda prvi put u životu, dobili objašnjenje zašto su oblaci beli.


And here is is the pendulum. 	 Kao i klatno.


This happens sometimes. 	 Dešava se, ponekad.


So, this side of the cloud is also red. 	 Ova strana oblaka se vidi crveno.


Audience Member - My glasses. But the key thing was after that I was supposed to stare at a white wall. 	 Ključna stvar je ono posle toga jer je trebalo da gledam u beli zid.


So it has to be very small! 	 To mora da je jako, jako malo.


And this is very unpleasant! 	 Ovo je vrlo neprijatno.


But, if you look at 1 over Lambda to the fourth, the green is gone. 	 Ako pogledamo u 1 kroz lambda na četvrti i zelena je otišla.


And so if you take 1.5 to the power of 4, excuse me, ya, 1.5 to the power of 4, you'll get 5. 	 Ako uzmete 1.5 i podignete ga na stepen 4 verujte mi, da je 1.5 na stepen 4, jednako 5.


And I know that too! 	 I ja to imam u vidu.


jete bêle âme x ku 1 unit change kariba, sete bele y re kete change heuchhi? y kete unit badhuchhi kimba kamuchhi? 	 Dakle, ako povećamo x za 1, za koliko povećavamo... ili smanjujemo y?


Now, you can immediately see that the 2 is about half a percent of 4.58. 	 Možete lako da vidite da je 0.02 s oko pola procenta od 4.58 s.


Problem 29. 	 Zadatak 29.


Now we have about 15 minutes left for questions. 	 Imamo još 15 minuta za pitanja.


Well, that would solve the world's energy problem. 	 To bi rešilo energetske probleme čovečanstva.


On average the preparation for 1 lecture is about 40 - 60 hours. 	 U proseku, priprema jednog predavanja traje između 40 i 60 sati.


I see blue light and when I look at the sun it looks a little reddish already. 	 Nebo je plavo A ako pogledamo u sunce ono je crvenkasto.


So we are first going to do that demonstration. 	 Idemo da pogledamo demonstraciju


I told you physics works! "Crown Applause" 	 Kažem ja vama, fizika je zakon.


So that is why the sky is blue. 	 Zato i nebo vidimo plavo.


Jetebele x is equal to 0, y is equal to 0. 	 Pa kada je x jednako 0, y je jednako 0


In this bucket. 	 U ovoj posudi.


Sei ta bahariba karibara best upaya heuchhi, x au y ku ei numbers gudakare replace kari dekhiba. 	 Pa, najbolje stvar je verovatno samo zameniti ove brojeve za x i y i videti koji od njih se uklapa.


Anna please use the microphone; although I am so close to you that I can probably understand. 	 Ana, molim te koristi mikrofon, da bih mogao da te razumem.


Doesn't it matter whether the bulb, we call this the bulb, whether it is 1 kilogram or 500 kilograms? 	 Uopšte nije važno kolika je masa klatna, a sva masa je u ovom telu, i sasvim je nebitno da li je to 1 ili 500 kilograma!


It is after that hour that we will do book signing. 	 Potom ću potpisivati knjigu.


So the smoke particles will grow, they will be become small water drops, larger than 0.5 microns. 	 I one će porasti. Postaće male vodene kapljice, veće od 0.5 mikrona.


And that would mean... "Crowd Laughter" 	 A to bi značilo...


And I said how do you spell that. 	 Lako je, kaže on.


So, there is no potential energy. 	 Tada telo nema potencijalnu energiju.


These people have a better view. 	 Ljudi ispred videće bolje.


THANK YOU! 	 Hvala.


Jete bele x is equal to 0, sete bele y-intercept ta 0 kahinki heuchhi? 	 Kada je x jednako 0, y je jednako 0.


Eita thik kama karuni. 	 Ovo se ne uklapa.


It doesn't have any green any more. 	 Nema više ni zelene.


We'll get back to that later 	 Vratićemo se na to kasnije.


I really don't. 	 Zaista nemam.


Because of the compression, if it were a tennis ball then this would certainly happen. 	 Kada je u pitanju teniska loptica, to se sigurno dogodi.


All Off! 	 Sva svetla.


Very easy to do at home. 	 To ćete lako da proverite kod kuće. Uzmite konac dug 1 metar. Okačite jabuku na jedan kraj i pustite da se klati.


Now comes the problem. 	 Sad nastaje problem.


That's why they pay such a high tuition at MIT! "Crowd Applause" 	 Zbog toga plaćate visoke školarine na MIT-u.


"Crowd Applause" Now comes the hardest part. 	 Sad dolazimo do najtežeg dela.


So, we could be off by 5 centimeters. 	 Dakle, možemo da pogrešimo za 5 centimetara u dužini.


And if you hate it, it is because you had a very bad teacher! 	 A ako je mrzite, to je zato što imate lošeg profesora.


If I scatter white light off very small particles, then the blue light is scattered more than the red light. 	 Ako se bela svetlost raseje na malim česticama, onda se plava svetlost rasejava više nego crvena.


So I did, I saw a red spot moving around. 	 Ali on je meni bio crven. Jasno mi je šta hoćete da kažete.


There is something else I haven't told you. 	 Oh, nisam vam nešto rekao.


We'll just give it a little more time. 	 Pričekajmo da prođe još malo vremena.


Now, the last time that I gave this lecture with the pendulum, is 12 years ago; I was 63. 	 Poslednji put sam predavanje o klatnu držao pre 12 godina. Tad sam imao 63 godine.


This is also not a pleasant demonstration. 	 Ni ovo nije prijatna demonstracija.


Oh! It's still counting? 	 Uh, on još broji?


So a very useful skill. Audience Member - But here is what I would like to ask you... When you started teaching physics and how your lectures evolved over time. 	 Ali ovde želim da Vas pitam kada ste počeli da predajete fiziku i kako su se Vaša predavanja razvijala vremenom?


There is a certain period. 	 To će trajati jedan period.


And that is not because of the dotting of the line, because I could already do that in high school. 	 Ali ne zbog tačkastih linija jer sam to mogao da uradim još u srednjoj školi.


That indeed the last fraction of the setting of the sun that you may but not always see a green flash. 	 Neposredno pred sam zalazak Sunca možete videti, ali ne uvek, nešto kao zeleni bljesak.


Audience Member - Well, I just want thank you for the lecture and I was wondering... 	 Želim da Vam se zahvalim na predavanju.


Anna is at or near the top, she almost always has it right, and she sometimes writes me emails and it says Walter I have worked 8 hours on this one and really have to give up. 	 Ana je izuetno uspešna. Skoro uvek tačno odgovori. Ponekad mi pošalje u mejlu, da je radila osam sati. i da ne može više, jer nema više vremena.


15.5 kilograms, and the length of this pendulum is 5.21 meters. 	 Masa mu je 15.5 kg a dužina mu iznosi 5.21 metara.


"Crowd Applause" 	 Ko je video belu svetlost?


And for the physicists in my audience, I am going to kill 3 birds with one stone. 	 Za fizičare u publici tri muve jednim udarcem.


45.9 plus or minus 0.02, period is 4.59 plus or minus 0.02. 	 Koliko je? 45.9 plus ili minus 0.2. Period je 4.59 plus ili minus 0.02 sekunde.


Well h is this distance here. 	 Dalje, h je rastojanje u metrima.


So we have the pendulum. And suppose I bring the pendulum all the way out here, we call that the amplitude of the pendulum. 	 Dakle, imamo klatno i pretpostavimo da ga stavimo u ovaj položaj ovde.


With a tennis ball, there also what we call the dissipation of heat when it hits the floor. 	 Kod teniske loptice, mi imamo nešto što se zove rasipanje toplote kad ona udari pod.


Suppose the object has a mass m, that is the distance h from the floor 	 Pretpostavimo da telo ima masu m i da se nalazi na visini h iznad poda. Ovde je pod.


Students love it when the glass breaks! 	 Studenti vole kad se razbije staklo.


So, t is going to be 4.57 plus or minus 0.2 divided by 10, plus or minus 0.02 seconds 	 Dakle, T je 4.57 plus ili minus 0.2 podeljeno s 10 odnosno plus ili minus 0.02 sekunde.


And I want you to look at the sky. Here is the sky! 	 I gledajte u nebo, koje je ovde u posudi.


You better go out of the way because gonna, this is a dangerous experiment. 	 Bolje Vam je da se sklonite jer ovo je opasan eksperiment.


When I turn the light on, you will not even see any light from that bucket. 	 Kada uključim svetlo, nećete videti svetlost iz posude.


That means, that it's 1% of 5 centimeters is 1% out of 521. 	 A to je 1% ukupne dužine klatna, 5 cm je 1% od 521 cm.


I will write in the book for Emily and sign Walter Lewin. If you don't in a piece of paper it's going to take so long. 	 Bez tog papira, ovo će trajati jako dugi.


And then you will do the counting. 	 A vi ponovo brojite.


Audience Member - Hi, what advise do you have for students who want to be a physicist? 	 Šta savetujete studentima koji žele da postanu fizičari? Morate da volite fiziku.


The hardest part is that we have to change the mass of this object. 	 Najteži deo je jer hoću da promenim masu klatna.


Thik achi. 	 U redu.


What do you have, what? 	 Šta...?


I will not bother you to tell you about the wave length of light, that may confuse you. 	 Neću vas zamarati s pričom šta je talasna dužina svetlosti. To će vas možda malo zbuniti.


As the object goes down it picks up speed. We associate with speed, energy, which is called Kinetic Energy. 	 Kako telo pada, ono povećava svoju brzinu koju povezujemo sa drugom vrstom energije - kinetičkom energijom.


For the physicists among you, light that scatters over an angle of 90 degrees, this light that scatters in this direction; the people who paid the most tonight, who are sitting right here. The light is also linearly polarized. 	 Za fizičare među vama, svetlost rasejana pod uglom većim od 90 stepeni, ova svetlost, rasejana tamo, prema ljudima koji su platili najviše, koji sede ispred, ta svetlost je linearno polarizovana.


And you will see blue light. Just like with the smoke. 	 Videćete plavu svetlost, kao kad ste gledali dim.


But, I will tell you that blue light has a wave length which is about 1.5 times lower than red light. 	 Ali važno je da zapamtite da plava svetlost ima talasnu dužinu koja je 1.5 puta manja nego za crvenu svetlost.


Do not confuse that with the .02, that has to do with the length. 	 Nemojte da vas zbuni ovih 0.02 s. To ima veze sa dužinom. U redu.


Yep, this gentleman here. 	 Da, gospodin tamo.


It really is! 	 Zaista boli.


I'm going to close my eyes. 	 Sad ću da zatvorim oči. Ne želim to da gledam.


Now, the situation is difficult with a pendulum because a pendulum doesn't hit the floor. 	 Sa klatnom, situacija je malo drugačija jer klatno ne udari u pod.


It is true. 	 To je istina.


Take your seats. 	 Sedite molim.


And so that is the reason the sun looks red. 	 I to je razlog zašto je sunce tada crveno.


I am going to make it completely dark and then I'm going to hold it in there. 	 Sada ćemo da napravimo potpunu tamu i postaviću dim tamo.


Seita heuchhi minus 10 is equal to 12 jukta b. ame 12 ku bijukta kariba dui patu au amaku miliba 22. 	 To je minus 10 jednako je 12 plus b Možemo da oduzmemo 12 od obe strane ove jednačine, i dobijemo minus 22.


Mun just 3 gunana x junta 6 gunana y kari ki dekhuchhi seita kete heuchhi. 	 Samo uzimam 3 puta x plus 6 puta y i gledam čemu je jednako.


Audience Member - What inspired you to become a professor and a great one at that! 	 Šta Vas je inspirisalo da postanete tako dobar profesor? Šta Vas je inspirisalo da postanete tako dobar profesor?


So, we all agree that it is white light which is coming up and you don't see the white light here because there is nothing that scatters it in your direction, so you don't see light here. 	 Slažemo se da je ovo bela svetlost, koja nastaje ovde. Vi sad ne vidite ništa, jer nema rasejanja svetlosti koja se rasejava prema vama. Dakle, ne vidite svetlost.


I dry run this lecture 6 times. 	 Probao sam ga šest puta.


Yes, I'm going to hang on that pendulum! 	 Da, ja ću da visim na klatnu.


Timing is not easy! 	 Merenje perioda nije jednostavno.


You count! 	 Brojite. Jedan.


It is really the blue that dominates, that has the highest probability. 	 Očekivano je da plava preovlađuje, jer je za nju najveća verovatnoća rasejanja.


Don't count on it because you haven't seen the rest yet! 	 Ne računajte na to jer niste videli ostatak priče.


It is not so easy for me to understand you. 	 Nisam Vas najbolje razumeo.


Speak as loud as you can as I have a hearing disability. 	 Govorite glasnije, ja sam malo nagluv. Ovo je više lično pitanje.


So, now 10 degrees. Ya! 	 Sada smo na 10 stepeni.


Slope is heuchhi y ra kete change heuchhi, jete bele x ra tikiye change heuchhi. 	 Koeficijent pravca jednak je promeni u y za datu promenu u x ili promeni u y kroz promenu u x.


The equation says no, it doesn't. 	 Jednačina kaže: ne!


That is the HOLIEST of all laws in physics. 	 A to je najsvetiji od svih fizičkih zakona.


But since the air drag is so small, there is almost no dempy. 	 Pošto je otpor vazduha mali, skoro da nemamo prigušenje.


But, it is amazing that many physics professors want to know how I make those dotted lines!!! "Audience Laughter" 	 Ali zapanjujuće je da mnogi profesori fizike žele da znaju kako pravim tačkaste linije.


If you can live with that than every measurement that I make, no matter how long it is, it is uncertain to 2 tenths of a second. 	 Ako možete da živite sa tim, to znači da svako merenje vremena koje ja izvršim, bez obzira koliko traje, ima grešku od 0.2 sekunde.


You raise the question and I will try to give the answer. 	 Vi formulišite pitanje ja ću pokušati da odgovorim.


Ame 27 number problem re achhu. ebong question heuchhi, keun prasna ti upara graph pain upajukta tenu uttara dekhiba agaru, dekha jan âme kana kana âge bahara kari pariba, ehi graph ru kahi pariba ki, ehi graph ra y-axis ta kauthi pain? jade line ra equation ti heuchhi y equal to mx jukta b, taha hele m heuchhi slope, au b heuchhi y-axis re jeuthi cut heuchhi setika bhaga. 	 Sada smo na problemu broj 27. i pitanje je koja jednačina najbolje odgovara grafikonu iznad? Ali pre nego što pogledamo ponuđene opcije, hajde da vidimo sta možemo da razumemo sa grafikona iznad. Koja je tačka ove funkcije na y osi?


You can derive how long it takes for the pendulum to make one complete oscillation and we call that the period of the pendulum. 	 I to vreme ćemo zvati period klatna.


What I do is add another teeny weeny bit of sulfuric acid. To speed up the process. 	 Ako traje dugo, dodam još sasvim malo kiseline da bih ubrzao proces.


Table re tarikha dekheuchhi bi-cycle rent kariba ku kete tanka lagiba? Jadi hours heba h, jeuta ku ame horizontal axis re draw kariba. 	 Podaci u tabeli pokazuju cenu iznajmljivanja bicikla na jedan sat, uključujući i depozit. ...


Because if it did make a difference there would be in that equation the amplitude, which is not. 	 Jer ako bi postojala razlika, u jednačini bi se pojavila amplituda, a nje nema.


You see that it going to make 2.0 seconds. 	 I videćete da će period biti upravo 2 sekunde.


It probably wasn't red but green. 	 Verovatno tačka nije bila crvena, već zelena.


That means this whole equation has to be divided by 10. And now you will see why measure 10 oscillations. 	 To znači da čitavu ovu jednačinu treba da podelim sa 10, jer ste videli da sam izmerio 10 oscilacija.


The wisdom of the day was... Physics works and I'm still alive! "Crowd Applause" 	 I mudrost tog dana je bila "Fizika je zakon i ja sam još uvek živ."


And I said well, it would be better, wouldn't it, if you write it on a piece of paper. 	 Tad sam ja zaključio da je bolje da napišete ime na papiru.


I hold the ball here it is 5 degrees. 	 Ako postavim klatno ovde, to je 5 stepeni. Ovde je 5 stepeni.


If I have a tennis ball in my hand, and drop the tennis ball from a certain height, give it no speed and it will bounce back. Then it can never bounce higher than where it started from. 	 Ako imam tenisku lopticu u ruci i pustim je sa određene visine tako da nema početnu brzinu, ona će da odskoči, ali nikad neće premašiti visinu s koje je krenula.


Jete bele slope ti 4, sete bele ame line ra y-intercept formula re equation la lekhiba jeuta ki y equal to mx plus b. 	 Koja je jednačina linije koja ima koeficijent pravca 4 i prolazi kroz tačku 3 zapeta minus 10?


It cannot be higher. 	 Ne može da se vrati na veću visinu.


So the person next to you, when you look like this, should say LOOK NOW! 	 A onda osoba koja je pored vas, dok vi gledate ovako, treba da kaže, GLEDAJ SAD. I onda vi pogledate i tako se to vidi.


And the sunlight comes in like this. 	 Sunčeva svetlost prodire ovako.


You will come next. 	 Vi ćete biti sledeći.


So you have indeed done something to your retina and it is the message that is sent to your brain. That tell you about the green after effect. 	 Uradili ste nešto sa svojom mrežnjačom i ona je poslala poruku vašem mozgu koja je protumačena kao zeleno naknadno dejstvo.


And then I have a surprise for you to also show you Mie scattering. 	 Potom ću vas iznenaditi, pokazaću vam Mijevo rasejanje.


The best way to do it is to start the timing when the pendulum comes to a stop. 	 Najbolji način da to uradim je da počnem u amplitudnom položaju, kad klatno kao da zastane.


OK, we have time for a few more questions. 	 Dobro, imamo vremena za još par pitanja.


So here comes someone from Turkey to me, and I said what is your name? 	 I onda je došao neko iz Turske i rekao mi svoje ime. Kaže da se zove Atittta.


All lights off! 	 Gasim svetla.


Eita heuchi h. 	 Znači na horizontalnoj osi imam sate, h.


You have to love it! If you don't love it, don't touch it! 	 Ako je ne volite, bežite od nje.


And so the light that will come to you is blue. 	 Svetlost koja dolazi do vas je plava.


And even though I knew nothing about astronomy at the time, I decided it was time to change fields. 	 I iako u početku nisam ništa znao o astronomiji odlučio sam se da počnem s tim da se bavim.


That means a thousand times smaller than the thickness of your hair. 	 To je hiljadu puta manje od prečnika vlasi kose.


And it was, but now I am 75, and so my reaction time is no longer 0.1 seconds. 	 I bilo je. Sada imam 75 godina. I vreme moje reakcije nije više 0.1 sekund.


We give that a name in physics, we call that Rayleigh scattering. 	 I mi tu pojavu u fizici zovemo Rejlijevo rasejanje.


And when I hold the ball here it is 10 degrees. 	 A kada je klatno ovde, to je 10 stepeni.


Then 1 week before the lecture I dry run again, then I'm very close to the time. 	 Nedelju dana pre predavanja, ja probam ponovo. I onda sam blizu s vremenom.


And it is wonderful to be back here. But it really HURTS! To know that this is my last lecture in 26-100. 	 I uvek je divno vratiri se, ali zaista boli saznanje da je ovo moje poslenje predavanje na ovom mestu.


I'm going to put my life on the line, to show you that I really believe in the conservation of energy. 	 Staviću moj život na crtu da bih vam pokazao koliko zaista verujem u zakon održanja energije.


Cost taku âme vertical axis re draw kariba. 	 I cene su nacrtane na vertikalnoj osi, samo da nacrtam vertikalnu osu. ...


I know you guys! 	 Momci, znam vas.


Just say yes. 	 Da.


One more question. 	 Još samo jedno pitanje.


You would think, wow, there must be a difference, it must make a difference in the periods. 	 Pomislili ste da sigurno postoji razlika u periodu.


The people who are sitting there, the angle of scattering is not 90 degrees, so they won't see it too well. 	 Publika koja gleda svetlost rasejanu pod uglom manjim od 90 stepeni Neće videti ovo dobro.


I'm going to take the place of the glass. 	 Staću na mesto gde je bilo staklo.


All colors are gone! 	 Sve boje su otišle.


Ei line ti jauchhi point 3 au negative 10 thorugh deiki jauchhi. 	 Znači ako prolazi kroz tačku 3 zapeta minus 10.


The way that I will do that is to leave 26-100 in my own private rocket. 	 Učiniću to tako što ću otići mojom


That's where you can 4 tenths of a second and then you look like an idiot in front of the students. 	 Tu možete da omašite za 0.4 sekunde i onda ispadnete idiot pred svojim učenicima.


For those of you who think that lecturing is easy... NO! "Crowd Laughter" 	 Ima vas koji misle da je lako predavati, ali nije.


Now you will say that is meters per second, per second. 	 I vi ćete reći, šta je to metar u sekundi po sekundi.


seita thin choice heba ni. ei ta, ama pakhare 3, ei ta 3 gunana 1 jukta 6 gunana y 6 gunana negative 1/6 tenu dekha jau ei ta 3. seita 3 sahita saman. ta pare, 6 gunana 1/6 is 1, kintu sethare minus rahichhi. tenu seita minus 1. seita 2 sahita saman heuchhi. seita thik laguchhi. 	 To ne može da bude tačan odgovor. Ovaj ovde, imamo 3, ovo 3, puta 1. Plus 6 puta ovo y.


We have here. By the way if you ever want to test this pendulum, this equation for yourself, put in l equals 1 meter, and use this number, you will get a period of 2.0 seconds. 	 Uzgred, ako želite da proverite ovu jednačinu stavite da je L=1 metar i izračunajte.


I dry run the lecture in an empty classroom with everything on the blackboard that I am going to write on the blackboard; pretending that there is a full class in front of me. But there is no one. 	 Najpre održim predavanje ovde u praznoj učionici i napišem na tabli sve što planiram kao da su studenti ovde mada nema nikog.


You can buy books, you can buy books in the hall and you can come down. 	 Možete da je kupite gore u holu.


So, I need your collaboration, when I count down from 3 to zero. 	 Zato mi treba Vaša pomoć.


And I talk them as if there is one. 	 Ja pričam kao da su tu.


Audience Member - What do you do for fun, besides give lectures? 	 Šta Vas zabavlja, osim predavanja?


My answer is yes. 	 Video sam to nekoliko puta.


The atmosphere is full of very small dust particles, smaller than a 10th of a micron. 	 Atmosfera je puna malih čestica prašine, manjih od desetog dela mikrona.


I do that 2 weeks before the lecture. 	 To uradim dve nedelje pre predavanja.


So, the biggest problem right now is Walter Lewin, himself. Which is my reaction time. 	 Najveći problem ovde sam ja, Valter Luvin lično, odnosno vreme moje reakcije.


So every morning when I wake up and during the day about two dozen questions come to me by email from all over the world. 	 I svakog dana, dobijam dvadesetak mejlova iz svih delova sveta.


tenu semane jani baku chahuchhanti cost ta hours ra function re kemiti heba. dekha jau. eita sidha line formula heba. 	 OK, samo žele da znaju cenu kao funkciju sati. Hajde da vidimo. To je linearna veza.


Can't you count a little faster? 	 Možete li da brojite malo brže?


Anyone of you who has the courage to say no? 	 Ima li neko hrabrosti da kaže ne? Ko nije video belu svetlost?


Put in the book a piece of paper and write down with very clear letters to whom I address the book. 	 Stavite u knjigu, na papiru ispisano štampanim slovima, kome posvećujem knjigu.


In fact when you saw the demonstration I just did, you may have noticed that you really didn't this. 	 Zapravo, kada ste posmatrali demonstraciju koju sam uradio mogli ste da primete da niste videli ovo.


That is what I will do. 	 I ja ću to da uradim.


All off! 	 Sva svetla.


Yes, we see a new hand here. 	 Da, vidim Vašu ruku.


Tenu jadi âme x is 0 and y is 2 kariba taha hele 3 gunana 0 jukt 6 gunana 2 samana 0 jukta 12. 	 Znači ovde je x jednako 0, y je 2. Hajde da vidimo. 3 puta 0 plus 6 puta 2 jednako je sa 0 plus 12.


I will only do that for a few seconds. Then I will remove it and I will empty my lungs. 	 Udahnuću dim a potom ću da ispraznim moja pluća.


It can not go higher. 	 Loptica ne može da ide više.


Therefore, I will have to stretch my body, so that when it is here it is completely parallel to the floor. 	 Zbog toga, ja ću istegnuti moje telo tako da je ono gotovo sasvim paralelno s podom.


But, for those of you who are sitting here, I can show you with my polarimeter that when I rotate my polarimeter I turn the blue sky completely dark and I can turn the blue sky completely bright again. 	 Ali za vas koji sedite ispred, mogu vam pokazati da kada rotiram polarimetar mogu da napravim da plavo nebo postane tamno. I plavo nebo postane ponovo svetlo.


So I accepted the offer at MIT. 	 Prihvatio sam ponudu s MIT-ja.


It is all scattered in a new direction. Just like here with the sunset. 	 Sve se raseje prema vama, kao kad imamo zalazak Sunca.


It is a very good question and if I tell you how I prepare them then my colleagues at MIT are going to hate me. 	 Jako dobro pitanje. I ako Vam kažem kako ih pripremam kolege će početi da me mrze.


Because, energy we believe is conserved. Now, when it hits the floor, some of that kinetic energy may be converted into heat. 	 Kada telo dodirne pod, deo kinetičke energije može da se pretvori u toplotu usled sabijanja.


Thank you. 	 Hvala.


I don't want to see it! And I am going to count down from 3 to 0. 	 Krećem da brojim.


You take my word for it! So, now I can make a prediction. 	 Sad ćemo da napravimo predviđanje koristeći samo ovu jednačinu.


semane amaku kahuchhanti, slope ti 4. tenu line ra equation heuchhi y is equal to 4x junta the y-intercept. 	 Kažu nam da je koeficijent pravca 4. Znamo da je jednačina linije y je jednako 4x plus odsečak na y osi.


And then 5:00 AM of the morning of the lecture. You can ask my wife. I am at MIT and I give the same lecture, dry run for an empty classroom at 5:30 in the morning, when the lecture is at 10:00 AM. 	 I potom u 5 ujutro, na dan predavanja, moja supruga može da to potvrdi ja sam ovde u učionici i mada je sve prazno u 5:30 ja ponovo održim predavanje što ponovim pred studentima u 10 i 11.


And so there is an uncertainty in the measurement of the length which we have to be honest about because we are physicists after all and the uncertainty we estimate is about 5 centimeters. 	 I da postoji greška u merenju dužine klatna o kojoj treba da vodimo računa jer mi smo fizičari, pre svega. I ovu grešku ćemo proceniti na 5 cm.


I know exactly what you saw. 	 Crvena tačka koja se pomerala.


But, we do that on Facebook! 	 Poslaću Vam to na fejsbuku.


So who wants to go first? 	 Ko će biti prvi?


Are you ready? 	 Da li ste spremni? Da.


I did not stop it, I really didn't. 	 Ja ga nisam zaustavio. Zaista nisam.


You already know what g is. 	 Već znamo šta je g.


And that potential energy is mgh. 	 I znamo da je potencijalna energija jednaka m g h.


That's the way I prepare. Don't tell my colleagues or they will hate me. 	 Ali nemojte to preneti mojim kolegama, mrzeće me.


"Crowd Applause" 45.7, so that becomes that t. 	 45.7 s. Sad možemo da nađemo T.


There's a question here and there's one there. 	 Imamo još pitanje ovde i ovde.


Now what I did was at Sunset I stared at the sun. 	 I onda sam ja gledao u sunce koje zalazi. Gledali ste u sunce?


When I do that, very small sulfur particles, smaller than the 10th of a micron, will precipitate in that solution. 	 Kada to učinim male čestice sumpora, manje od desetine mikrona talože se u ovom rastvoru.


Why is what? Audience Member - What inspired you to become a professor? 	 Šta Vas je inspirisalo da postanete profesor?


Second, the timing is tricky. 	 Drugo, merenje vremena je teško.


Those of you who see blue say YA! 	 Vi koji vidite plavo, kažite: Daaa. Daaa.


The first way that I am going to do that is to make it completely dark in the lecture hall. And have light going straight up here. 	 Najpre ću napraviti mrak u učionici i ovde ću napraviti snop svetlosti prema gore.


Well, that is the half of percent uncertainty due to the square root of l. 	 To je pola procenta od perioda.


You better see an eye doctor! 	 Treba da posetite očnog lekara.


And I couldn't even read it. 	 Čak i ako ja to ne mogu da pročitam.


The sun looks just white light as it was before. 	 Sunce je belo, kao što je bilo i ranije.


NO NOISE! NO COUGHING! 	 Kada brojim unazad od 3 do 0, molim Vas za potpunu tišinu.


If the object goes down, hits the floor then the Potential Energy is zero, all that energy is converted to Kinetic Energy. 	 Ako se telo kreće nadole kada dodirne pod njegova potencijalna energija je 0. I tada je čitava energija pretvorena u kinetičku energiju pošto je energija, verujemo, očuvana.


And I would even appreciate it if you go 3 seconds without breathing. 	 I bio bih Vam zahvalan, ako te tri sekunde, ne biste ni disali.


This layer of atmosphere is now so enormously large that more than 99 percent of all the sunlight on the way to you is scattered away! 	 Sloj atmosfere je sada toliko velik da preko 99% sunčeve svetlosti koja ide prema vama se raseje i ode.


2 sahita samana nuhe, 12 sahi ta samana heuchhi. 	 Nije jedanko 2, jednako je 12.


Problem 30. 	 Zadatak 30.


That's why I said that I'm going to kill 2 birds with 1 stone. 	 Zbog ovoga sam rekao da ću ubiti dve muve jednim udarcem.


g is what we call gravitational acceleration, which is approximately the same everywhere on earth but it is very close in Boston to 9.80 meters per second, per second. 	 Ako ne znate šta je pi, ja ću vas napustiti ovog trenutka. I na kraju, g je gravitaciono ubrzanje, koje je približno jednako svuda na Zemlji. Ovde u Bostonu je 9.80 metara u sekundi u sekundi.


And now I am going to explain to you, in fact you could probably guess that. Why the sky is blue? Why clouds are white? 	 Sada ću, verovatno pretpostavljate, objasniti zašto je nebo plavo i zašto su oblaci beli.


You will see that. 	 Da vidimo.


And, it would help me if you could count how many oscillations that we have made. 	 I kada je u amplitudnom položaju deseti put, zaustavite merač. I bilo bi mi od velike pomoći ako biste brojali koliko oscilacija je klatno napravilo, jer ne mogu da vodim računa baš o svemu.


And the Kinetic Energy of an object mass m, is one half mv squared. M is the mass and v is speed of that object. 	 Kinetička energija tela mase m jednaka je 1/2 m v na kvadrat. m je masa a v je brzina tog tela.


I can't hear? 	 Šta je?


Not a very good idea. 	 To i nije baš pametno. Treba s tim biti oprezan.


So, if you bring a pendulum at a certain distance above the ground, like this, and you let it swing when it comes back here. It is almost exactly at that same height. 	 Ako pustimo klatno sa neke visine iznad tla, na primer ovako, i pustimo ga da se klati, ono će da se vrati na skoro istu visinu.


Audience Member - O.K., Are familiar with the alleged phenomenon of a green flash at sunset and can you explain that, please? 	 Da. Tamo ste mogli videti šta je pi(ta). Da li ste upoznati sa navodnim fenomenom zelenog svetlucanja tokom zalaska.


You can buy the book there if you want to and I'll sign it. 	 Knjigu možete da kupite gore i ako želite ja ću je potpisivati ovde.


I am going to hold this object at my chin. 	 Staviću klatno na svoju bradu.


All of you can see. 	 Svi možete da ga vidite.


By the way, I made an exception for this lecture. 	 Uzgred, napravio sam izuzetak za ovo predavanje.


For me it's already beginning to turn a little bluish. 	 Meni se čini da ovo već postaje plavkasto.


But, there is no way that it could go higher than h. 	 Ali ne postoji način da odskoči više od h.


It is well described. I have seen it many times in Austria, in the mountains. 	 Video sam to mnogo puta u planinama, u Austriji.


So you damaged your eyes and so you asked for it. 	 I onda ste oštetili vid i sad želite da postavite pitanje o tome.


But look how much did you pay for this. 	 Ali setite se, koliko ste platili za ovo?


"Crowd Applause" 	 ličnom raketom.


Dekha jauchu mote cut and paste kari baku padi ba ki. 	 Samo da vidim da li mogu da isečem i nalepim ovaj.


Then I will light a cigarette and the smoke of the cigarette has particles that are smaller than a 10th of a micron, so the light that you will see that is scattered off the smoke will be blue. 	 Potom ću zapaliti cigaretu, čiji dim sastoji od čestica manjih od desetog dela mikrona. Svetlost koju ćemo videti da se rasejala na dimu biće plava.


But you see this is neurology, and so it is not our responsibility to explain it. 	 Tako da nisam odgovoran da to objašnjavam.


So I will add to the sulfuric acid. 	 Sada ću dodati sumpornu kiselinu.


I didn't get it! Ya! 	 Da.


The blue is gone. 	 Plava boja je otišla.


Are we, Claire? Who has the microphone? 	 Kler, kod koga je mikrofon?


Tenu line equation kauthire fit heba? 	 Znači cena je na vertikalnoj osi.


It's also the moon that is red when it comes up. 	 I Mesec kada izlazi je crven.


I normally, after this demonstration, tell the class, physics works and I'm still alive! 	 I naravno, nakon ove demonstracije mogu da zaključim: Fizika je zakon i ja sam još uvek živ.


I think I was always eccentric! 	 Mislim da sam oduvek bio čudan.


And then you let it swing 10 times, and then when it comes to a stop, you stop it. 	 A onda ga pustite da se klati 10 puta.


Doesn't that a difference in the periods? 	 Da li će ovo promeniti period?


There is only one color which has the largest wave length. Which by the way is 650 nanometers. 	 Ima jedna boja sa najvećom talasnom dužinom, koja iznosi 650 nanometara.


Look at that SUN! 	 Pogledajte to sunce.


There are clouds here in the sky. And that cloud sees light that all the low small wave lengths have been scattered out. 	 A ovde je oblak na nebu, i sa njega se vidi svetlost u kome su sve male talasne dužine rasejane okolo.


It is a well known phenomenon. 	 To je dobro poznata stvar.


Not for two more attempts. 	 Dobro.


White light, like sunlight is composed of all the colors that you see in the rainbow. 	 Bela svetlost sastavljena je od svih boja koje mogu da se vide u dugi.


And so the reason is simply that it is Rayleigh scattering off the dust particles, in the atmosphere. 	 A razlog je jednostavan, imamo Rejlijevo rasejanje sunčeve svetlosti na malim česticama atmosfere.


It is a difficult demonstration! 	 To je jako teška demonstracija.


I wasn't supposed to tell you, but I decided to. 	 Nije potrebno da vam kažem, sigurno pretpostavljate.


Many ask questions and I answer every single email. 	 Mnogi postavljaju pitanja i ja odgovorim na svako.


Today, there are 100 of my lectures that can be viewed on the web. 	 Danas postoje stotine mojih predavanja koja su dostupna na internetu.


Audience - "Thank you for a beautiful lecture, I am tempted to ask you what pi is... 	 Hvala na ovom divnom predavanju. U iskušenju sam da pitam šta je pi.


But you people see if very well don't you? 	 Ali vi ispred vidite to sasvim dobro? Da.


This is glass. 	 Ovo je stakleni zid.


So, if you are ready for that, you see here is the timer. 	 Ako ste spremni za to, treba da pratite merač vremena.


It is! 	 Jeste.


This whole idea is behind demolishing buildings. 	 Ova pojava se koristi prilikom rušenja zgrada.


So now you understand why it is meters per second, per second. 	 Sada je jasno zašto je ubrzanje dato u metrima u sekundi u sekundi.


It's a RIOT! 	 To je haos.


You can read that in my book, you should buy it. 	 O tome možete da čitate u mojoj knjizi. Kupite je.


Ya, Anna. 	 Da, Ana.


IF I inhale the smoke and I leave it in my lungs for a minute, there is water vapor in my lungs, and this water vapor will precipitate on to these very small smoke particles. 	 Ako udahnem dim i ostavim ga za trenutak u mojim plućima, čestice dima će biti u vlažnoj sredini. Vodena para u mojim plućima će navlažiti male čestice dima.


Does that answer your question? 	 Da li sam odgovorio na Vaše pitanje?


But, the equation says, sorry, it doesn't and I am going to demonstrate that to you to. 	 Ali jednačina kaže: "Izvinite, period ne zavisi od mase!" I ovo planiram da vam pokažem.


If you ask me my favorite. Artists, we can talk about it. 	 Ako me pitate ko je moj omiljeni umetnik to mogu da Vam odgovorim.


First course for freshmen, the second course Electricity and Magnetism, and the third course for Sophmores, Vibrations and Waves. 	 Elektromagnetizma. I kurs sa druge godine Oscilacije i talasi.


Then make it immediately dark. 	 I napravimo tamu.


So the 10 t is then going to be some number plus or minus my own inability, which is my .2 seconds reaction time. 	 Dakle 10T će biti neki broj plus ili minus moja nesposobnost, koja je 0.2 sekunde.


Aw, we still have 5 minutes for questions. 	 Imamo još samo pet minuta.


What was the last question? 	 Šta je poslednje pitanje? Kako su se Vaša predavanja razvijala vremenom? Nisam shvatio.


And I am going to demonstrate that to you. That it is quite remarkable, that indeed that period is independent of amplitude if you don't go to extreme values of the amplititude 	 I ja ću sad da vam pokažem tu neverovatnu činjenicu da period ne zavisi od amplitude ako ne idemo do nekih velikih vrednosti amplitude.


The sun is infinite far away. So the sun comes in like this. 	 Sunce je jako daleko i svetlost dolazi ovako.


I've seen it many times the explanation is not as simple as you may think. 	 Objašnjenje nije tako jednostavno.


Setebele eita 0 hoi jiba. 	 Znači ovo će biti jednako 0.


And if you ever want to see it you have to be with two people. 	 I ako želite zaista da vidite ovaj efekat, povedite dva čoveka.


Can you translate? 	 Možete li da prevedete? Nisam čuo. Šta Vas je inspirisalo?


And the same lecture is at 11:00. 	 Tako se ja pripremam.


Why the puzzle mine is 0.02? 	 Zašto plus ili minus 0.02 s?


Why don't we take that first and then there is a woman over there. 	 Zašto ne bismo krenuli odavde? Potom imamo ženu ovde.


Laguchhi, ei ta good idea. 	 Da, mislim da je dobra ideja.


Nothing is scattered in your direction. 	 Ništa se ne rasejava prema vama.


So, it is twice that, and after 3 seconds, it is 3 seconds. 	 Udvostručena je. Nakon tri sekunde, brzina je tri puta veća.


You already know what l is, if you don't know what pi is you might as well leave right now! 	 L je dužina klatna.


So, my prediction can be no better than that. 	 Moje predviđanje ne može biti bolje od toga.


So, the object can never go any higher than h. 	 Prema tome, telo ne može da dođe na veću visinu od h.


He said my name is Ataachia. 	 Pitam ga kako se to piše?


O.K. 	 Dobro.


High speed and you demolish thereby the walls. 	 Objekat se pogodi ogromnom količinom energije, velikom brzinom i sruši se zid.


I have therefore decided that I want to leave you in style. 	 Stoga sam odlučio da vas napustim u velikom stilu.


So what is scattered away is... 	 Šta je rasejano?


I have to measure the period, to convince you that it is independent of amplitude and to convince you that it is independent of mass. 	 Moram da merim period da bih vas ubedio da period ne zavisi od amplitude i mase klatna.


Audience Member - Hi, what advise do you have for students who want to be a physicist? 	 Zdravo. Šta savetujete studentima koji žele da postanu fizičari?


I love all the subjects 8.01, 8.02, or 8.03. 	 Volim sve što sam predavao. Volim sve što sam predavao.


If it did, then we physicists would say that it's a gross violation of the conservation of energy. 	 Kada bi je premašila, mi fizičari bismo rekli da je prekršen zakon održanja energije.


I would suggest, and I mean it seriously that since a short answer is not possible that you look it up on the web. 	 Predlažem i pri tome sam sasvim ozbiljan, pošto ne mogu da dam kratak odgovor, da ga potražite na internetu. na internetu.


And here is say roughly the top of the atmosphere. 	 Ovo je, otprilike, gornja granica atmosfere.


Tenu line ra equation heuchhi y is equal to 2x. 	 Znači dobijemo da je koeficijent jednak 2, znači jednačina ove


That moment is crucial! 	 Ovaj trenutak je suštinski.


So it is very little. 	 To je vrlo malo.


I have 2 marks on the floor here. 	 Ovde imam dve oznake na podu.


And it is well known that after volcano eruptions, the sunsets and sunrises are truly fantastic! 	 Dobro je poznato da posle erupcija vuklana izlasci i zalasci sunca izgledaju fantastično.


But the third bird comes a little later. 	 Ali treća muva će doći na red kasnije.


Awh! 	 Ah, ovo stvarno boli.


Rayleigh scattering only happens when the particles of which the white light scatters is smaller than a 10th of a micron. 	 Da bi se desilo Rejlijevo rasejanje potrebno je da se svetlost rasejava na česticama čiji je prečnik manji od desetog dela mikrona.


For about 15 or 20 minutes. So, the whole thing will be about 1 hour. 	 Sve ovo će trajati približno jedan sat.


Oh! That was luck. 	 Oh, to je bila sreća.


And even the stars and planets. 	 Takve mogu biti i zvezde i planete.


However, you must understand that it is very difficult to measure that to very high accuracy. 	 Treba da budemo svesni da je vrlo teško izmeriti dužinu klatna sa velikom preciznošću.


But, now look! 	 Ali pogledajte sad.


Executed beautifully by Riccardo Giacconi who received, not too long ago, the Nobel Prize for that. 	 To je nastavio Rikardo Điakoni za šta je nedavno dobio Nobelovu nagradu.


Audience Member - Do rainbows have anything to do with Rayleigh scattering. 	 Da li je duga povezana s rasejanjem svetlosti? I zašto je duga kružnog oblika?


Now comes the hardest part. 	 Sada dolazimo do najtežeg dela.


The light that is scattered here comes to you is predominantly blue. 	 Svetlost koja se rasejava i dolazi do vas je dominantno plava.


You make 1 meter, put an apple at the bottom and you swing it, the 1 meter had to be accurate. 	 Napravite klatno dužine tačno 1 m.


It really kept going and kept going. 	 Klatno se neprestano klatilo na isti način.


Audience Member - So this I guess is a more personal question. 	 Ovo je više lično...


"Audience Counting" 10 T with Walter Lewin. What is it? 	 10T sa Valterom Luvinom.


When we have the sun rise or sun set, the sun is there and the light comes from this side, and you are standing here. 	 Sunce je ovde svetlost dolazi odavde vi stojite ovde.


So then I do it a 10 degrees and then we get again 10 t, we get the number. and then we get again plus or minus 0.02 seconds. 	 Potom ćemo da idemo na 10 stepeni. I opet ćemo meriti 10T. Dobićemo broj.


Ya, you need the microphone here. 	 Da, treba nam mikrofon ovde.


So, I'm first going to make a period measurement at 5 degrees. And then 10 degrees. 	 Sada ću da merim period kada je u amplitudnom položaju klatno nagnuto 5 stepeni, a potom ću da merim period za nagib od 10 stepeni.


Rayleigh scattering! 	 Rejlijevo rasejanje.


If the sun is high in the sky, the total amount of sunlight that is scattered in your direction is only 1 percent. 	 Ako je sunce visoko na nebu, ukupna količina svetlosti koja se raseje prema vama je samo 1%.


You are doing very well! 	 Odlično brojite.


Stare at that light for some time and then all a sudden look at the white wall and you see a different color. 	 I onda iznenada pogledate u beli zid. Videćete različitu boju.


First of all it is PAINFUL! 	 Pre svega, bolna je.


Minus 10 minus 12 heuchhi minus 22. ei 12 tiye dui patu gala. jeuta ki b. tenu amara line ra equation heuchi 4x jukta b. jauta ki ama bahara karichhi minus 22. 	 Minus 10 minus 12 je minus 22. Ovo 12 očigledno nestaje. Jednako je b.


And so the light that comes out here has no blue in it any more. 	 I svetlost koja izlazi odavde nije više plava.


Then for reasons that are still unclear to me, but George Clarke who is in the audience knows probably why. 	 I tada, iz meni nejasnih razloga Džordž Klark, koji je u publici, on možda zna zbog čega, ponudio mi je profesuru.


I have an art crisp on Facebook. Twice a week and then my Facebook friends who can answer the questions always mention everyday that they have the answer right. 	 Dva puta nedeljno pravim kviz o umetnosti i moje fejsebuk prijatelje svaki dan podsećam da pošalju odgovore.


Tenu âme kaki pariba je, jeté bele x re 1 unit change heuchi, sete bele y re 2 unit change heuchhi. Tenu ama kahi pariba he slope it 2. 	 Dakle, možemo reći se y menja za 2, za plus 2 kada se x menja za plus 1.


So if I bring this object. Exactly at that glass wall. And if I'm clever enough to let it go with zero speed, it could not break that glass. 	 Ako postavim klatno tačno na stakleni zid i ako budem dovoljno pažljiv da ga pustim s nultom brzinom klatno neće razbiti staklo.


So, the book signing will start. 	 Sad ću da potpisujem knjigu.


3 gunana 1 jukta 6 gunana negative 1/6 2 sahita saman. 	 3 puta 1 plus 6 puta minus 1/6 jedanko je 2.


You don't even have to look to the sun. 	 Čak ne treba ni da gledate u sunce.


Art. 	 Umetnost.


If it is, if the particles are as large as half a micron, then there is no longer Rayleigh scattering, there is no preferred scattering for the blue light. 	 Ako se svetlost rasejava na česticama prečnika pola mikrona, nema više Rejlijevog rasejanje. Tada nije više prioritetno rasejanje plave svetlosti.


tikie late hoi gala, au tikiye confusing bi hoi jauchhi. kahipariba ki y-axis cut ra bhagata kete? 	 Kasno je, postajem malo umoran. Pa gde je presek na y osi?


So white light comes in and you are standing here but what is the light that comes to you? 	 Bela svetlost prodire ovako, vi stojite ovde. Ali koja svetlost dolazi do vas?


OK, now you count. 	 OK. Sad vi brojite.


You can do it with a light like that. 	 Možete da gledate u svetlo kao ovo ovde neko vreme.


They are now being viewed daily on average by 6000 people all over the world. Which is 2 million per year. 	 Dnevno ih pogleda, u proseku 6000 ljudi širom sveta, što je 2 miliona godišnje.


Mote copy and paste kariba ku diya. just move kara. 	 Samo da kopiram i nalepim nekoliko sledećih zadataka.


I derive in class that, that period equals 2 pi times the square root of l over g. 	 Videli smo da je period jednak 2 pi puta koren iz L kroz g.


Just take that off. 	 Samo uklonite to.


But, since l only shows up as the square root, it means the uncertainty in the time that we predict in only half of a percent. 	 Pošto period zavisi od korena iz L to znači da će greška za period biti samo pola procenta.


We need a table. 	 Treba nam sto... Priredio:


That is rather well defined. 	 To je prilično dobro definisano.


It is my love. 	 To volim.


I had my training in Nuclear Physics and then I had some offers for a 1 year post doctorate to the United States. 	 Ja sam se obučavao u nuklearnoj fizici. I onda sam dobio ponudu za jednogodišnji postdok u Sjedinjenim Američkim Državama.


Now, comes an experiment which is emotional and the most difficult for me, of the whole evening. 	 Sada dolazimo do eksperimenta koji mi je emotivno najteži na ovom predavanju.


If you put too much sulfuric acid in it the whole process goes too fast, and if you put too little in it then you will become impatient. 	 Ako se stavi malo kiseline postaćete nestrpljivi.


It's on. 	 Uključeno je.


Also why are they brown? 	 Kupite knjigu.


Because when you look at a pendulum, and when you see it stand still. That is really well defined, plus or minus 0.02 seconds. 	 Kad gledate u klatno lako uočite kad se ono zaustavi, što je dobro definisano plus ili minus 0.1 s.


OK Ya! 	 U redu.


Y-axis cut bhagata sete bele 0. 	 Presek na y osi je 0.


When you are swinging yourself, however, then you can only do it by sensing the moment that you think you stand still. 	 Kada se ljuljate na klatnu možete samo da pokušate proceniti kada ste se zaustavili.


And I am going to demonstrate that to you in two complete different ways. 	 I sada ću vam demonstrirati tu pojavu na dva sasvim različita načina.


Because building in demolishing you take a huge mass, you lift it up over distance h, and then you put your target, which is your house, or whatever it is, right at the bottom,where all this potential energy is being converted to kinetic energy, and so this object is hit with enormous energy! 	 Da biste srušili zgradu, treba vam velika masa. Podignite je na visinu h. I onda usmerite na metu, kuću koju rušite, ili nešto drugo, što je ispod, pa će potencijalna energija biti pretvorena u kinetičku energiju.


Audience Member - I was just wondering like, what inspired you to become such a great professor? 	 Pitam se šta Vas je inspirisalo da postanete tako dobar profesor?


So from day one, my lectures were always different from the mean. 	 Zato su od početka, moja predavanja bila drugačija.


Audience Member - As a youngster I read a book that told me to stare at the sun then I could change things by staring at things. 	 Kao mlad, čitao sam u jednoj knjizi da kada gledam u sunce, pa pogledam u neku stvar ona izgleda drugačije.


And so there is no heat loss because it doesn't hit the floor. 	 Tu nemamo ni gubitak toplote pošto klatno ne dotiče pod.


Well, have you ever gone to a Thanks Giving dinner? 	 Da li ste ikad išli na večeru na dan zahvalnosti?


It is going to be RED! 	 Tako je, biće crvena.


I have given in this lecture hall about 800 lectures. 	 U ovom amfiteatru održao sam oko 800 predavanja.


It's true. 	 Gledate brm-brm-brm.


And physics cannot explain that. 	 Vidite, to je neurologija.


We associate with the position of that object. That energy has a name. We call that Potential Energy. 	 Energija koja zavisi od položaja tela naziva se potencijalna energija.


A few days ago I had a book signing. And I didn't ask them for a piece of paper. 	 Pre par dana sam potpisivao knjigu i nisam tražio papir.


Thik thak rasta dhara. Sabu thik thak fit heuchhi. 	 Možemo samo da pomerimo... budimo konsistentni. ...


What that means is that if you have an object and you drop it from a very large altitude, very high, few hundred meters high. 	 Šta to znači videćemo ako razmotrimo telo koje je na velikoj, ogromnoj visini od nekoliko stotina metara i pustite ga da pada bez početne brzine.


It is very interesting thing. 	 To je vrlo zanimljivo. Ali fizika to ne može da objasni.


No, I really cannot say anything. 	 Zaista ne mogu da se opredelim.


Jeun ta ki choice B. Para question ta heuchhi kau point ta line 3x plus 6y equal to 2 upare paduchi? 	 Što je ujedno izbor B. ...


Audience Member - Which I actually use myself when I was a professor for some number of year. 	 To sam koristio dok sam bio profesor pre nekoliko godina. To je vrlo korisna stvar.


OK, one more question. 	 Dobro, nemamo pitanja.


So after an hour that thing is about 2,000 meters in the sky. 	 Nakon jednog sata, takva stvar bi skakala nekoliko stotina metara.


But now as time goes on we will get more and more, and more, and more of those 0.1 micron particles. 	 Ali kako vreme prolazi biće sve više i više i više čestica od 0.1 mikrona.


Y sete bele 2 unit badhi jauchhi. 	 Pa onda se y povećava za 2.


I will tell you that just before I puff it out and you will see the light smoke. Just before I do that I will remind you of the color that you see now. 	 Dakle, pre nego što dunem i pokažem vam beli dim, podsetiću vas na boju koju sad vidimo.


Here is the floor, here is the object. 	 Ovde je telo, visina h.


And so here we have a situation which is extreme. 	 Takvu situaciju imamo kada posmatramo, izlazak ili zalazak sunca.


And no book signing afterwards! 	 I neće biti potpisivanja knjiga posle.


So, when the object is here on the floor, it is zero. 	 Kada je telo ovde na podu, h je 0.


Take your seats, please. 	 Sedite molim.


What is it? 	 A koliko je?


Audience Member - What is your favorite lecture out of all of them. 	 Koje predavanje Vam je najdraže?


If you have a pendulum. This is a pendulum, mass m, length l. You can derive, which I do in class, but I won't bore you with that. 	 Ako imate klatno evo klatna, mase m, dužine L, može se naći, što sam učinio na predavanjima, ali neću ovde da vas zamaram s tim, koliko vremena je potrebno klatnu da napravi jednu oscilaciju.


Y-intercept ta 0. 	 Znači odsečak na y osi je 0.


And that means in Rayleigh scattering, blue light has a 5 times higher probability to scatter than red light. 	 To znači da je pri Rejlijevom rasejanju, verovatnoća rasejanja pet puta veća za plavu nego za crvenu svetlost.


At that time I told the class, my reaction time was is a 10th of a second. 	 Vreme moje reakcije bilo je 0.1 sekund.


You stared at the sun at sunset? 	 Na zalasku. Na zalasku.


Because if it goes the first time higher it will do that the second time. 	 Ako je odskočila više prvi put, to će raditi i drugi put.


I predict, using this equation, that's all I do is put in 5.21, I put in 9.80, multiply by 2 pi, and I make the prediction that the period of pendulum is 4.58 + or - 0.02 seconds. 	 Stavim L=5.21 m. Stavim g=9.80 m/s/s. Pomnožim sa 2 pi i dobijem predviđanje da je period klatna 4.58 sekunde plus ili minus 0.02 sekunde.


The dependence of the power of scattering, which I'll give that P, the power, is proportional when we have Rayleigh scattering, this is the only equation which may bother you. 	 Zavisnost intenziteta rasejane svetlosti zvaću to P je određena na osnovu formule za Rejlijevo rasejanje. Ovo je jedina jednačina s kojom ću vas gnjaviti, 1 kroz


I don't have a favorite. 	 Nemam najdraže predavanje. Nemam.


And i dropped it zero speed, after 1 second it will have a speed of 9.80 meters per second, but after another second it will add to that 9.80 meters per second. 	 Nakon jedne sekunde, telo će imati brzinu 9.8 metara u sekundi. Ali nakon sledeće sekunde, brzini tela će se dodati još 9.8 metara u sekundi.


There is a 2 minute video tape which someone made; someone looked at all the dotted lines that I ever drew in 8.01 and put that in one video tape. 	 Postoji jedan video snimak, traje dva minuta. Neko je složio sve tačkaste linije koje sam ovde napravio i napravio jedan kratak filim.


Well I do not know! 	 Pa, ne znam.


So what color do you think the sun is going to get? 	 Koju boju će Sunce tad imati? Crvenu.


Because, you simply sit down and you watch the ball game. 	 Jednostavno, možete sesti i gledati kako loptica odskače.


I cannot move any further back, so there is no cheating. 	 Ne mogu da se pomerim nazad ovde nema varanja.


If the sun is 5 degrees above the horizon, then the sunlight has to travel through a lot more atmosphere. 	 Ako je sunce na 5 stepeni iznad horizonta, tada svetlost prelazi veći put kroz atmosferu,


And if you don't see the reason why the 1% equals half percent, that's ok, just forget about it. 	 Ako vam nije jasno zašto greška od 1% u dužini pravi grešku od pola procenta, za period, nije važno. Možete da mi verujete na reč.


At least MIT students would. 	 Bar će studenti MIT-ja postati.


If you sit all the way there, you don't see it so well. 	 Ako sedite sa strane, nećete ovo dobro videti.


I make every student, and not only at MIT, but all over the world. I make them to love physics. 	 Ja sam uspeo da svaki student ne samo ovde na MIT-ju, već širom sveta, gledajući predavanja zavoli fiziku.


Here we have a glass plate. 	 Ovde imamo staklenu ploču.


So, if it is for your daughter, and your daughter is Emily. You write for Emily. Even though your name may be Peter. 	 Ako je to za Vašu ćerku Emili napišite "Za Emili." Čak i ako se zovete Piter ja ću napisati "Za Emili" i potpisati se.


Let's face it. Isn't this incredibly romantic? 	 Budimo iskreni, nije li neverovatno romantično?


Ya, 	 Da?


Because you are now into Mie scattering. All colors scatter equally. 	 Pošto smo u oblasti Mijevog rasejanja, sve boje se jednako rasejavaju.


Now I am going to add a litte sulfuric acid. 	 Sada ću dodati malo sumporne kiseline.


I always have a back up if this takes too long. 	 Uvek imam rezervu.


I am going to release it right from my chin. 	 Pustiću klatno tačno od moje brade.


Suppose, it could come after one bounce, up here. 	 Pretpostavimo da će nakon jednog odskoka doći ovde gore.


Now, I have one request. 	 Imam samo jedan zahtev.


And so you get ideal Rayleigh scattering. 	 I imamo uslove za Rejlijevo rasejanje.


Audience Member - Hi, how do you prepare your lectures, how much time do you take? 	 Zdravo. Kako pripremate Vaša predavanja? Koliko vremena potrošite na pripremu?


Audience Member - I know, I agree. 	 Saznao sam to na teži način.


I think of that as being the sunlight away. 	 Uzgred, ovo posmatramo kao Sunce.


In general the lecture is then a little bit too long so I have to do some surgery. 	 Uglavnom, kad tako probam predavanje je predugo. Zato moram neke delove da odstranim.


And if you have a question, raise your hand. 	 Ako imate pitanje, podignite ruku.


This is not to scale. 	 Ovo nije u razmeri.


How accurately am I able to make that measurement. 	 Koliko sam u stanju da uradim precizna merenja?


This gentleman, oh,also. Ya 	 I ovog gospodina takođe.


And you see, comfortably within the prediction. 	 Kao što vidite, merenje je u skladu sa predviđanjem.


"Crowd Counting" 	 Jedan, dva, tri, četiri,


But, if my hands shake a little, and they give it a little push, then of course it can come back, and may want to go higher than this. 	 Ali ako mi se ruke zatresu i malo ga poguram, klatno će se vratiti s brzinom i moći će da dostigne veću visinu.


So in other words, when it bounces back, the total energy is no longer the full energy h but is a little less and so it won't bounce this high. 	 Drugim rečima, kada odskoči teniska loptica nema više početnu energiju koju je imala na visini h, već nešto manju energiju tako da će odskočiti manje.


Audience Member - Hello. 	 Zdravo? Treba li ovo da uključim?


Clouds consist of very small water drops, surely larger than half a micron; which is Mie Scattering. 	 Oblaci se sastoje od vodenih kapljica, koje su veće od pola mikrona tako da na njima imamo Mijevo rasejanje.


Audience Member - So I sat in on your lectures here, I think about 20 years ago. I had forgotten that the one thing I had learned from you was how to draw dotted lines on chalk boards. "Audience Laughter" 	 Sedeo sam na Vašim predavanjima pre 20 godina i zaboravio sam da sam od Vas naučio kako da pravim tačkaste linije na tabli.


I'm going to start it when it comes here. Ya! 	 Počinjemo kad klatno dođe ovde.


So, please write very carefully the name to whom I should address the book. 	 Dakle, lepo napišite kome želite da posvetim knjigu.


Some of you may think, well isn't that a waste of time, 10 periods if you can get away with one. 	 Neki od vas će pomisliti, zar nije gubljenje vremena da se meri 10 perioda kad nam treba samo jedan?


Because the red light more or less goes through. 	 Crvena svetlost manje-više prolaziti bez rasejanja.


You realize as you have just seen that the slightest push and this will be my last lecture! 	 Jasno vam je da će ako malo gurnem klatno ovo biti moje poslednje predavanje.


Two complete courses. 	 Dva čitava kursa: prvi kurs za brucoše, drugi kurs


There is something weird about this equation, something that must go against your intuition, and you shouldn't feel bad because it also goes against my intuition. 	 Postoji nešto čudno u jednačini za period T, što se protivi vašoj intuiciji. I ne treba da se osećate loše zbog toga, jer ni meni ova pojava nije očigledna.


Here is the ground. You are here. 	 Ovde je tlo a vi ste ovde.


You can now understand that the more pollution there is in the air, the more beautiful sunsets are! 	 Treba da shvatite da više zagađenja u vazduhu pravi isti efekat i dovodi do lepog zalaska sunca.


The difficulty with this is experiment is always. 	 Problem s ovim eksperiment nastaje ako se stavi previše kiseline, jer se sve desi brzo.


That was the discovery of X-ray astronomy. 	 Radi se o otkriću nebeskih izvora x-zraka.


There is a question right here. 	 Imamo pitanje ovde.


I don't have more time. 	 Hajde.


Initiated by Professor Bruno Rossi who was at MIT. 	 Bruno Rosi.


Now you will see how I am going to do that. 	 I sada ćete da vidite kako ću to da učinim.


Physics is my life. Art history is my love. 	 Fizika je moj život, istorija umetnosti ljubav.


Look at it! 	 Pogledajte ga.


But, now we bring it out only this far, it doesn't have to travel very much at all. 	 A sada, stavimo ga u ovaj položaj. Sada ne mora da putuje tako daleko.


Buy my book. It is explained in my book. 	 To je objašnjeno u knjizi.


And I am going to demonstrate to you that within the uncertainty of the measurements, that I get the same numbers of all 3 cases. Within the uncertainty. 	 I sada ću da vam pokažem da ću u granicama greške, u svim merenjima dobiti isti rezultat, u skladu s našim predviđanjem.


So the white light of the sun scatters off the clouds, white remains white. 	 Bela svetlost sa sunca, rasejava se na oblacima i ostaje bela.


Ei case re ama pakhare 3 gunana 0 jukta 6 gunana y jukta chhaa gunana 6. jeunta ki 9 jukta 36. seita 2 sahi ta samana nuhe. 	 U ovom slučaju, imamo 3 puta 0 plus 6 puta y. Plus 6 puta 6. Pa to je 0 plus 36.


So, you have seen in front of your own eyes, Rayleigh scattering. 	 Tako ćete pred svojim očima videti Rejlijevo rasejanje.


I have a feeling that if you want to be kind for a change let us assume that my reaction time at age 75 is now 2 tenths of a second. 	 Ali ako želite da budete dobri prema meni pretpostavićemo da je moje vreme reakcije sada 0.2 sekunde.


That has nothing to do with our lack of knowledge the exact length. 	 To nema veze sa našim nepoznavanjem tačne dužine klatna.


And in fact nobody knows why. 	 I zapravo, niko ne zna zašto.


Aw, we have 10 more minutes, so can handle quite a few questions. 	 Preostalo nam je 10 minuta, pa mogu da odgovorim na još nekoliko pitanja.


As long as you realize that if I release if from a certain location with zero speed, it can never when it comes back be higher than that location. 	 Zaključimo da klatno pušteno s neke visine sa brzinom 0 nikada neće doći na veću visinu.


If I don't do that I will not be able to convince you that the period is independent of of the mass. 	 Ako to ne uradim neću moći da vas ubedim da period klatna ne zavisi od njegove mase.


There is a person there. 	 Imamo zainteresovanog tamo.


Those of you who do not see blue say NO! 	 Oni koji ne vide plavo neka kažu: Ne. Ne.


1 over lambda to the fourth, and lambda is the wave length of the light. 	 lambda na četvrti, a lambda je talasna dužina svetlosti.


Terrible demo! 	 Užasna demonstracija.


If you are a good physicists, you'd will say, if you are going to sit on that ball, then actually you bring the mass of the ball up so the length of the pendulum will shorten, so you will get a shorter period. 	 Ako dobro znate fiziku primetićete da kada sednem na klatno efektivno podignem centar mase klatna. I zbog toga je dužina klatna manja. Pa će i period biti kraći.


Good, bhala dekha jauchhi. 	 Ok, svi su stali.


I can't change that. 	 To ne mogu da promenim.