Death of Stars - Walter Lewin

[@Gabaruga]

Such a great man. It hurts to watch how old is he now.

[@lecturesbywalterlewin.they9259]

next year I will be 80. I will give this year 8 more lectures in Europe!

[@Gabaruga]

Lectures by Walter Lewin. They will make you ♥ Physics. It's an honor to have a reply from you, Prof. Wow. Thank you very much for the great stuff, you've done. Live long and prosper!

[@lecturesbywalterlewin.they9259]

Gabaruga Thank you \\/\///////////

[@shchpendrop]

+Lectures by Walter Lewin. They will make you ♥ Physics. Awesome! Will those lectures be available online?

[@VeganSemihCyprus33]

+Gabaruga He doesn't sound old, I think this is the important thing :D

[@StaticBlaster]

I first discovered Walter Lewin years ago in the summer or spring of 2008- 2010. One of those three years in the MIT opencourseware videos. I wish this guy could live forever. He's one of the most effervescent, passionate physicists I've come across. I've learned more from him than all of my physics college professors combined.

[@ekalavyain1131]

Nobel prize for the best teacher category physics.Nominees are Richard feynman and walter lewin.

[@DaytakTV]

My favorite professor!!!

[@pakistanigodam5149]

Professor you deserve Noble prize.

[@tammymcinerney1486]

YES

[@Phymacss]

Y E S

[@ajitreddy2382]

He makes u see supernova infront of u with his explanations!! Such a great man

[@oracleofottawa]

By far the best explanation of the death of stars on the University of You Tube. Love the mans conviction on his subject, and he has the rarest gift of transmitting that passion. That is the true greatness of the man.

[@lecturesbywalterlewin.they9259]

***** thank you \\/\///////

[@samarattia7347]

I fall in love with physics since I have watched your lectures. I am watching your lectures by hours professor , i don't feel the time . May be it's a part of Einestin theory . Time is constant with your lectures professor

[@leszekwalinowicz5795]

Dzięki wykładom profesora Lewina, zmieniłem swoje spojrzenie na świat. Choć dalej Świat jest dla mnie pojęciem nieogarniętym.

[@dougspurell2387]

Wow Walter Lewin, what an amazing, shining gift you continue to be for Physics, for MIT, and to the many thousands of fans, who, thanks to you, love physics.

[@VegasNit]

This should be taught daily to our younger generations, such underrated yet essential knowledge.

[@m.muthupalaniyappan.7842]

hi sir, good night.... it's 22.45(10.45pm) is the time here in India, Just now I seen your video so I think I will not go to sleep for another half an hour.... (Thanks for giving reply to all our messages...you are simply awesome & thanks to God/Physics for having you..)

[@jacksonsmith8554]

Wow amazing! I was always interested in astronomy. I wish there were more lectures by this professor on the subject

[@walterlewin85]

Thanks for the interview!

[@MATHEKANAL]

I have worked through Walters Physics 8.01-8.03 lectures back when they first became avaiable on OCW in the early two thousands. He is easily one the best physics educators i have ever seen. 👍

[@zvpunry1971]

1:08 And now I know how it sounds when a star is born. :)

[@tuckasamms]

Absolutely brilliant- just couldn't stop listening Feel blessed just to listen to such an awesome genius.

[@danondler8808]

Walter was born to teach. He is such a gift.

[@maryammanzoor2267]

look at how happy he is talking about this, it gives me so much motivation and drive to learn more

[@samarattia7347]

You are a great professor Dr Walter . a lot of Nobel genius stars had been born by your lectures . Congratulations to Dr Andrea ghez for Nobel prize in physics 2020

[@VinayChembil]

His Passion says it all. Such an incredible person.

[@soroushm9820]

my favorite human

[@bmw1553]

Setting the foundational knowledge on Physics in the key for exploration. I wish the young kids gets a teacher like Walter. If so, I'm pretty confident that one such kid will find what Dark matter and Dark Energy. I wish you live long healthy to see that kid win Nobel prize.

[@scanurasiri1]

I want to listen to him for hours never feel tired

[@scroxydrums]

That's just ENORMOUS!!

[@itsiwhatitsi]

Walter Lewin The Legend

[@tammymcinerney1486]

Yesss

[@trungac2414]

Thanks you Professor Walter Lewin. You are the best

[@readingaddict]

I cannot love him anymore than I do now. I am devoted

[@naisot2174]

one of the greatest physicists of the 20th century.

[@kumkumpandey4377]

We need more teachers like him to explore the universe

[@shikhachaudhary5152]

I have written theory would you help me?

[@M10-e1d]

Sir lf the higgs boson from a black hole is again converting in to a new star by using the large quantity energy , then how is the universe still expanding.

[@zosimus_99]

Thanks to all.

[@trungac2414]

Thanks for your knowledge

[@rijumukherjee5409]

Sir it is brilliant a bright topic and a brilliant discussion. I also have some idea in mind I have been thinking about the presence of dark matter and energy which I want to share with you.Though my thought will be a little lame one but I believe you will be thoughtfull after reading my thoughts.

[@lutpulla7183]

How can Prof. Lewin talk about matter in a black hole being squeezed into a point with no size, when we don't know what is beyond event horizon? Or am I wrong and we know about the size?

[@ffggddss]

We can only talk about what our best theories say about it; no black hole has been directly observed. Yet. And what he's expounding, is based on Einstein's General Theory of Relativity (GR). And we know what GR says; the Prof. is giving you the straight dope on that. [I speak from having taken a graduate-level course on GR at U. of Md. under Prof. Charles Misner, about 40 yr ago.] But we still can't reconcile GR with quantum mechanics (QM), so the existence of singularities is still in some doubt. We do know that QM says that, at sufficiently small scales (Planck units), spacetime can no longer have continuous properties, due to the Heisenberg Uncertainty Principle; it is postulated that it must take the form of a sort of 'quantum foam.' This in itself, precludes the existence of a spacetime singularity. But we just can't say yet, what the final theory will look like, that will bring GR and QM together. It is currently a very cutting-edge frontier of theoretical physics; and the mathematics involved, makes the math of GR seem like a walk in the park.

[@arturogonzalez6184]

I wish I could meet you one day

[@arturogonzalez6184]

I think I'm crazy for physics as much as you are

[@supahsekzy]

I need that shirt.

[@RanjeetSingh-pp1tu]

sir please make video on gravitational waves discovery

[@abcdef2069]

after super nova to become a neutron star, what is the star mass ratio before and after? after super nova to become a blackhole, what is the star mass ratio before and after? how much gets to be sucked in and how much gets ejected? what is the becoming neutron star's implosion time lapse? what is the becoming blackhole's implosion time lapse? at lesst i heard, 10 sec to 100's second gamma ray burst then the real implosion,. where do all the W+ bosons come from all of sudden to become a neutron star, in which W+'s are the hardest to make in a normal star? all the anti neutrinos just come out of nowhere? are we saying we dont know because quantum mech and general relativity do not communicate? so it gotta be that so much space time squeezing make these particles? to conserve something in the long run?

[@AdhamMagdy]

The more we know, the less we seem to know

[@subhrajitnandi5447]

The billion dollar sentence "It all come down to Physics"

[@KalyanBanerjee]

That energy how he express :)

[@born13611]

It was already mentioned in holy Qur'an 14th centuries ago. Chapter 77, verse 8. فَإِذَا ٱلنُّجُومُ طُمِسَتْ (Then when the stars lose their lights)

[@edmondedwards6729]

I would disagree of thinking that the black hole has "infinite" gravitational energy. I would refine that to say that a black hole has the largest measurable gravity force within the confines of this universe, or another one that is built upon the logic structures that underlies ours. Instead of infinite, read practical maximum. thanks walter

[@ValMartinIreland]

A large star is made up of atoms irrespective of what element those atoms are. When such a star is compressed by gravity into small object, what happens to the atomic structure of the atoms. I presume the nucleus is compressed and the electrons are forced into a smaller obit. So what happens?

[@ronaldderooij1774]

+Val Martin The electrons are forced into the neucleus, changing protons to neutrons. Hence the name of the star. There is no plus or minus charge in the material anymore. No protons, no electrons, just neutrons.

[@ffggddss]

+ Ronald de Rooij Right; well said! It can be added, though, that those neutrons are composed of quarks that *do* have electric charges. (A neutron does, e.g., have a magnetic moment.)

[@lightningnetwork]

favourite teacher :D !

[@dennish72]

The ultimate question of course is what is the meaning of all this.

[@stargazer7644]

There is no meaning. It is simply how physics works.

[@plabonborthakur4572]

If we can meet someday

[@omsingharjit]

but i heard iron not carbon when star stop its fusion ???????

[@AndDiracisHisProphet]

depends on the mass of the star

[@stargazer7644]

Stars around the mass of our sun will stop with carbon. It doesn’t have enough mass to get to the temperatures to fuse higher elements. Only the big stars make it all the way to iron.

[@paritoshjadhao5352]

sir how sun burns in vacuum ,not in presence of atmosphere

[@GH-oi2jf]

He is using the term “burn” loosely. Nuclear fusion is not ordinary combustion.

[@sywaddr11]

I want the price😂 Dear Sir. I want to prove that dark matter is only the size difference. It just like the nano to us, and many much smaller. Can you recommend, what I should do? And the dark energy is the magnetic fields interacted within that small fields. And particle aggregation forming the universe. Thank you!

[@subhashmaurya3023]

according to me... dark energy or matter exist in the space but i would like to share my thinking.... 1) it exist but it is moves/travels in space so fast....that is faster than light....it cannot be possessed or seen or observed.... 2) the dark energy is so powerful....so powerful....more powerful than infinity....beyond our thinking.....that the energy cease to exist....it is present in our multiverse/ universe but we cannot define its presence....it gives energy to another part of unknown objects or dimensions... 3) the dark matter is also provided energy by the dark energy.....the energy and matter may show similar properties hence the amount of enerfy received by the matter would be so great that it becomes infinitely energetic and thus like the energy it also cease to exist... i may be wrong at all....but anyone else could explain me if im wrong....

[@subhashmaurya3023]

@FREDDYFUZBEAR yeah you're right.......that was my brother.....now according to u anything that travels faster than light can achieve unlimited power.....thats where youre wrong sir......our universe is also expanding....and its expanding faster than the speed of light and according to scientist the fastest thing to go is light in the whole cosmos and nothing is faster than that.....and tychon is not yet discovered or known to us.....what assurance could you give us that this* object is travelling faster than the speed of light and having infinite power and so called tychon...... 2) i think dark matter is the negative of our universe's matter....idk about that much

[@subhashmaurya3023]

@FREDDYFUZBEAR now you're talking😊

[@Lokesh-bo1zl]

if supernova explosion took place at a distance of 6000 light years, wouldnt we see it after 6000 years

[@Kugelbliz]

That is correct. That light from the super nova from walters example took 6,000 years to get to the earth in 1,054.

[@arnavjain7566]

@@Kugelbliz yeah it was exploded 6000 years before the year 1054.

[@nirmalbalamurugan1678]

great

[@kingjeremysircornwell7847]

Giant ball of methane, and earth is the gas tank, magnetic fields can strip and transport the methane particles.

[@kingjeremysircornwell7847]

I'm talking about earth sun. If a star does not have a fuel source, it burns out.

[@gourabghosal2841]

but why do not a star directly turned into a black hole/

[@alexandrugheorghe5610]

Gourab Ghosal it needs enough mass that when it collapses due to gravity it becomes a black hole; you could say that when gravity collapses it, this event will punch a "hole" in the fabric of space time (due to the huge mass) you can refer to his pen example: when you drop it, gravity takes over and pulls it down to the center of the earth, now imagine enough mass that is so high that it will go through the earth and through spacetime into a single point

[@floreign]

Gourab Ghosal While gravity contracts the mass of the protostar indeed toward collapse, at some point, when temperature becomes just right, hydrogen fusion starts in the core of the star. This creates an outward pressure that balances the gravity push. This condition is called hydrostatic equilibrium and dictates the size of the star. For as long as fusion can happen, gravity does not squeeze the mass of the star any further. But when fusion can no longer occur (when all the fusion fuel has been depleted), gravitational contraction resumes. If the mass is enough, then the result of this compression is a white dwarf and it cannot compress any further. If the mass is even larger, and is over a certain minimum mass, then the result is a neutron star but compression cannot push any further. But if the mass of the star is even above another limit, then nothing can stop that contraction and then you have the black hole.

[@NondescriptMammal]

Just because the sun is nuclear energy, doesn't make it not clean, nor does it follow that all nuclear energy is clean as that from the sun.

[@greatsea]

+Nondescript asperger's much?

[@guarapo66]

11:33 the power of the ring

[@jatinbhatt7826]

The 96 percent is space . One day scientists will realise this .

[@muhammadismail2300]

Professor. The sun emits heat through nuclear fusion. This means that it constantly loses its mass according to Einstein's famous equation E = mc2. According to Einstein's general relativity, gravity is proportional to the mass. This means that the sun's gravity is constantly decreasing because its mass is constantly decreasing. The Earth's Earth orbit will also increase and lead to an increase in the duration of the year, but the Earth has existed for 4.5 billion years. and that doesn't happen why?

[@StormCentre88]

One related reason is that it takes an enormously long time for a photon (100, 000 years) to make its way out of the Sun to the surface; so the Sun emits energy very slowly if you look at the entire reaction chain. So, (within reason) currently the Sun's thermonuclear reaction is reasonably stable. Also, consider the sun's radius is not perfectly stable due to rotation and other effects; even when the Sun is reasonably stable. These slight changes in the Sun's radius when it is stable probably swamp the gravitational changes (due to lost mass) during the Sun's stable lifetime. All this plus the fact that gravitational force is proportional to the distance between the Sun and Earth also plays a factor.

[@hibiscusenigma]

energy and mass in e=mc^2 is not interchangeble but proportional meaning if energy is increasing the mass is not increasing but the momentum is increasing. It's unimaginable that if I aprroach the speed of light I gain more particles/atoms causing me to become more massive? The only thing that a matter can loss/gain mass is if you take away or add some atoms or particles (like if you boil a water then the mass inside the container will change because some atoms evaporated in the air or if you split the nucleus of an atom then the mass will decrease) not because there is a decrease in energy.

[@muhammadgultasifkhan1951]

what will happen to the earth if the sun dies??

[@stargazer7644]

When the sun puffs up in its red giant phase, it will consume the earth and other inner planets.

[@yo696]

He probably is the reincarnation of Richard P. Feynman

[@GH-oi2jf]

He was born long before Feynman’s death.

[@abcdef2069]

i like to believe dark matter things and big bang more if one can show me where the center of universe is, which is the violation of relativity. big bang and dark matter completely violates the conservation of energy, as if we have someone pushing some kind of inter- galactic sized piston to pump energy into our universe. even all particle spins are relativistic effect. charges are conserved, only because some kind of symmetry exist SU3. or they may use words like things are cononically related.

[@andrerousselsapet5219]

No one can prove GRAVITY 😬😬😳

[@manolo1130]

Also, he is my favorite teacher. On December 8, 2014, MIT announced that Lewin engaged in online sexual harassment of an online MITx learner in violation of MIT's policies. As a consequence, MIT revoked Lewin's professor emeritus title and indefinitely removed Lewin’s online lectures from its online learning platforms.

[@SeriousScience]

We are not going to delete Prof. Lewin's videos.

[@AdivingShamWow]

I do not believe you Monolo. and your nothing on this internet. not even a single atom. compared to Walter. unless your IQ is even at least 100 point away from matching his, no one cares about your facts. Walter has formulas, and explanations for all of his teachings. I advise you just shut it :)

[@MaryMsB]

manolo martinez Manolo, Thanks for the info. I was wondering why I couldn't find him on MIT's Open Courseware site. I have only just discovered him on You Tube. It is a disappointment MIT has removed his work, as it must be for you since he is your favorite teacher. I am grateful that SeriousScience will be keeping his videos.

[@MaryMsB]

manolo martinez In addition to SeriousScience, it turns out his lectures can also still be found on iTunes University.

[@manolo1130]

Advising ShamWow i dont understand your point, but are not my facts, are from MIT, just read: newsoffice.mit.edu/2014/lewin-courses-removed-1208

[@andrerousselsapet5219]

You see a great factor To know In the Bible John 12:24 24 Verily, verily, I say unto you, Except a corn of wheat fall into the ground and die, it abideth alone: but if it die, it bringeth forth much fruit. 25 He that loveth his life shall lose it; and he that hateth his life in this world shall keep it unto life eternal. Die is mentioned x2 So life comes out of DEATH 😂 THIS IS the deepest part of God

[@akshaymutha5933]

Ohh cmon!! Scientists talk about their “observations” with such confidence as if they were facts. They are just correlating. Thats it!

[@MKMKrueger]

didatico

[@dinysanchez]

He is the best physics teacher I ever had, even tho I have never physically sit in any of his classes. :)

[@muhammadfawadabbasi9021]

@lecturesbywalterlewin.they9259 what Quran says about this 1450 years ago is 9:00 "Then I swear by the setting of the stars," (56:75) "And indeed, it is an oath - if you could know - [most] great."