And think even beyond that, the blast of radiation from supernovae can cause mass extinctions in *nearby* solar systems.... So check out those iron pots again, it could've cost the destruction of entire civilizations to make the materials that we casually use every day.
dacypher22 The same star, in it's dying gasp, that cast out the iron for your cast iron pots also expelled the iron in our blood, which we can't live without. So, instead of asking your pots that question, ask that question the next time you look in a mirror. Whatever the answer, it happened many millions of years ago & we owe it our gratitude for making our lives possible.
These videos are absolutely wonderful. Especially the narration. I normally hate the talking head-type videos, but: *a.)* Phil clearly knows what he's talking about. *b.)* shows such an infectious enthusiasm for it. *c.)* Has the demeanor of that favorite teacher we've all had at one time or another.
The ending of this episode is my most favorite thing ever. It's so touching and almost made me wanna cry. XD "That star blew up more than 5 billion years ago. But parts of it go on: In you."
Um, that's "more than 5 billion years ago". The universe itself is only (only?) about 13.7 billion years old. Not only did all the heavy elements originate in the cores of stars, the atoms in your body originated in several different stars.
Wizard Suth I was going to set him straight myself but you did a fine job at it. With that being said, I wonder what the catalyst was that spurred the creation of the universes that particular time. Why 13.7 billion years ago and not 50 billion years ago? What took place at that moment that did not take place prior to that? I have pondered that question for years. Any thoughts on that subject?
@@afterburner2869 That's a good question. I just wonder how some scientists are so willfully ignorant towards the fact that there is a divine engineer, a creator in all of this. God. How everything in this universe works. How the earth is so specially put that life would not exist if it were a little closer or farther away from the sun. How absolutely complex our DNA is alone. When has an explosion ever created such a magnificent order? It's one of the basic laws of thermodynamics. Something can't come from nothing. I too have many questions.
New science suggests that neutron star collisions are responsible for most heavy elements in the universe, with supernovas representing a relatively minor contribution. No gods needed.
@@vealck Betelgeuse won't explode until the next 1 Million years, Scientist's are watching the sun and we will see it. But it technically is exploding. And has been proven it is still too young to go Supernova.
Space is so absolutely amazing. I know this is kind of a dank meme, but honestly... "Born too late to explore the world, born too early to explore the universe" kinda rings true with my feelings. I want to go to these places, I want to see the andromeda nebula with my own eyes out of the window of a spaceship, I want to walk on these planets. I don't think we will be able to travel through space, but maybe the evolution of Virtual Reality will one day in my lifetime reach a point where I can experience something that feels just as real. One can dream. Besides that, CC: Astronomy is by FAR one of my absolute favorite series on RUclips. Phil is an immensely likeable person and can really deliver information so well.
Phil shows us how tiny, and I mean TINY, we are in the universe. The stars that we see at night may seem like a tiny speck of dust but it is really a gigantic ticking time bomb waiting for its time to collapse and become a black hole. It really puts a lot of things into different perspectives. I learned a lot from this, so thank you Phil.
+minshwan tang if they reach $40,000 on their Patreon, CC Physics might become a thing. www.patreon.com/crashcourse?ty=c PBS Spacetime comes close though. It's not exactly a physics course, but its got more theory than CC Astronomy.
***** Because PBS has been grossly underfunded since the 80s, and the reason it gets money from the government because it is PUBLIC Broadcasting. It's not as simple as throwing 30-40 grand into a project that may or may not make its money back. Streaming is a popular way to view video, but it is not a great investment because right now streaming video is not very lucrative. That's why Creators turn to things like Patreon so fans can help them make money. CC already barely breaks even as it is.
FINALLY! THANK you for TELLING US THE ACTUAL NUMBERS of HOW LONG given events (e.g. time it takes for a star to fuse all its silicon = 1 earth day). Absolutely 0% of all other physics videos EVER give these numbes.
The reason they rarely give exact numbers is that there are several factors at play namely the preexisting amounts of heavy elements(known as metallicity) and mass of the star which significantly alter the result. To give an example you need to note the mass and metallicity. Of course in the most massive stars with masses over a hundred times that of the Sun it gets even more complicated as several extreme outcomes can upset the usual process described above. For low metallicity ultra massive stars such as the first generation of stars that formed in the early universe the uncontrolled energy production goes out of hand and the energy supporting the core against collapse starts producing matter antimatter pairs robbing the star of energy before it even reaches the late phases resulting in the complete annihilation of the star as in no remnant of the former core in an absurdly luminous supernovae far brighter than a typical supernovae resulting in some calling them by the term hypernovae. On the other extreme ultra massive stars with high metallicities can become dominated by what is known as the CNO cycle which is a catalyst cycle involving Carbon Nitrogen and Oxygen which is far more efficient and faster at high temperatures than normal proton proton chain fusion. This results ins a strong enough energy imbalance that the star begins to become convective again increasing the amount of fuel at its disposal meaning these massive stars burn through their entire mass worth of hydrogen in only a few million years and or blowing much of their mass away which takes away much of the stars angular momentum as the stars never actually reach hydrostatic equilibrium instead rotational torque helps gravity hold the star together against the sheer luminosity of the star which would otherwise radiate itself apart as it exceeds the Eddington limit for its mass (i.e. its luminosity is larger than the gravity holding it together). When the most massive of these stars die the star has lost all of its angular momentum which normally allows matter to somewhat resist the pull of gravity since angular momentum must be conserved. In these stars there is barely a shock wave and if one forms at all it will be super weak having barely escaped the gravity of the core that instantly collapses into a black hole without the support of fusion. For those with too little angular momentum remaining the shock wave might never form as it too becomes trapped behind the event horizon of the newborn black hole. To an observer watching the process thousands of light years away the star would simply wink out of existence. These are just two extremes from a whole menagerie of exact ways high mass stars can die depending on the stars initial conditions which makes things far more complicated. What Phil did here is he plugged in a specific mass and metallicity in order to give that particular results as an example. I don't know exactly why but people rarely bother to do that but it probably has to do with the governing system of partial differential equations being hard to solve even if it is well understood.
No. Having subtitles makes it so that foreigners don't have to learn English. This would be bad because everyone must adapt to English now that it is undeniably the global language.
+Kenrick Brown While English is undeniably a lingua franca of the world (Or a strong contender), it would be better if these videos got around more and weren't limited by a language barrier.
Dindono Acularius Okay, I'll admit that subtitles would be good. In fact, they could learn by comparing the subtitles to what he said. BTW, I am bilingual (English and Mandarin)
The fact of iron fusing resulting in a net loss of energy reminds me a little of why it’s bad (for humans) to drink seawater to parch thirst - because our body needs to exercise the use of more bodily water to evacuate the salt in the seawater than it gains in water.
"Every atom in your body came from a star that exploded. And the atoms in your left hand probably came from a different star than in your right hand. It really is the most poetic thing I know about the universe. You're all stardust. You couldn't be here if stars hadn't exploded, because the elements ( the carbon, nitrogen, oxygen, all the things that matter for evolution) weren't created at the beginning of time. They were created in stars. So forget Jesus. Stars died so you could live."-Lawrence Krauss
Your astronomy/ cosmology series is outstanding, Dr. Phil. You provide a wonderful information in an interesting and easy to comprehend manner and your delivery is impecable. Thank you for sharing such interesting information and for making knowledge of science fun and entertaining. You're the best!
Pronoy Dutta It goes even beyond that...life is a more efficient way of processing complex carbohydrates in ways that stars cannot, perpetuation the flow of energy from a useful state into a useless state. We are a link in the chain of entropy. So don’t ever let anyone tell you that our existence is meaningless. We are a natural consequence of a progressively more chaotic universe. :)
This is amazing. I always wondered about the life of a star after the hydrogen was used up. What an amazing sequence of events with so much variety depending on mass. Stars are so cool.
I am now really curious who the hell click the "thumb down"..... this is such a heroic effort to make complicated things easy to beginning astronomy learner. Show some respect!
+Fraser Henderson You aren't supposed to learn anything at all...? I think that's a shortsighted look at the series. Star Trek is a good way to teach ethics and philosophy. Both those subjects are based on opinion, but it does teach one to critically think about them.
+Mat G It's just as well. Star Trek is great for morality plays, horrible for astronomy. They did once put the ship in "Geostationary orbit over the South Pole."
+fmlAllthetime Startrek is mainly entertainment not all of it is fact ..some is purely made up..You could say. It has inspired many to be Astronauts tho
+rlrsk8r1 Why do you consider imposible that a ship whith warp capabilities would have a problem in moving thru space at the same speed and direction as a given planet?
I am now officially addicted to Crash Course: Astronomy since I've checked to see if this new installment came online far more times than I have for anything else on RUclips (or Netflix, for that matter).
Life Cycle of the Massive Star: Protostar > O, B, or A type main sequence star > Red Super giant > Helium Burning Super giant > Second bigger Super giant > Type ii Supernova > Neutron Star > Pulsar or Magnetar or stellar Black hole > X ray emission.
If what they are saying about the fusing of iron is true, well that's a clear sign that the there is intelligent design in the universe, because the process of fusion would have otherwise gone on unabated. Iron gets the star ready to die and thereby release all the elements it created. Nicely done.
UY Scuti is the largest...sometimes. It’s actually a variable, meaning that it can change physical size almost at will. There’s also a hefty margin of error when it comes to defining the “surface” of stars as large as UY Scuti and VY Canis Majoris because their densities are extraordinarily low.
Rolling Kneebar i dont think its by will, but philosophical things aside, i would also add that the gas and dust around the stars also makes for more error in measurements
Just about every other video I've seen on the fusion process in stars, they literally skip the middle man and explain in extensive detail the hydrogen helium side and why iron sucks. Though the onion analogy is often brought up they give scant detail on how the onion forms, or the steps involved. Thank you for going that extra mile.
Despite the fact I know that for many and many years, I'm still stunned in a moment of awe every time I think about the fact that we are made of dead stars.
+BaTBaiLeyS They thought it was but last I heard there is a margin of error when it comes to its size so it might actually by smaller. There are also stars that are pulsating so they are constantly getting larger and smaller
+Schnitzel Strike Yeah, apparently it was once thought it was so large it defied the supposed laws of stellar evolution. It shouldn't be that large, and it probably isn't, though it could still be the largest star without breaking this limit.
+Schnitzel Strike That's irrelevant since even if we assume the worst of our measurements, the order is UY Scuti > VY Canis Majoris > NML Cygni VY Canis Majoris loses no matter what happens.
It was at one time the largest known star. It's possible the script was written before more recent measurements brought it down to size (if that's an applicable term for something over 1400 solar radii). It's a weird star, and it's hard to define where it's surface is.
@Cuzeg Spiked It somewhat depends one how you look at it. The energy in those nuclear reactions stems mostly from the mass defect, so .. it's "created" from matter. Sometimes matter is just seen as another form of energy therefore, but if you don't .. energy IS actually created here.
@@ScareSans No. You don't. The sun created it from the mass defect during fusion in its core. Those fusion is part heat, part kinetic energy of the products. Those products are slowed down be collision though, so they also just heat up the core. That heat travels to the sun until it reaches its "surface". This surface is still quite hot, so it emits radiation (it glows). Part of that radiation is visible sunlight. Part of that light reaches earth. Then that sunlight is absorbed by plants which turn it into chemical energy via photosynthesis. Those plants are eaten be you (or by animals you eat later, maybe after they were eaten by other animals) and the chemical energy is deposited in your body (blood sugar / fat deposits) now. When you rub your hands together, at first your muscles turn those energy into kinetic energy, and the friction between your hands converts it back to heat. The energy was always there after it came from the mass defect during fusion in suns core, it just was converted around between different forms of energy. And some people say mass/matter is just another form of energy, if thats the case, it has been there since time existed. What was before that .. well there wasn't even a before since a before needs time to exist. (And yes I'm quite aware that this explanation is pretty inaccurate and incomplete, but it gets to the point).
@@ScareSans no. You are now a little tired. The energy comes from your own internal body energy reserve and the energy in the muscles of your hands and arms
All the elements... that were once fused in the very heart of hypergiant stars... make us up... We are star dust. Our terrestrial bodies are the remnants of a huge celestial body.
I don't know if anyone else has mentioned this, but my wife noticed that Mr. Plait only said "Betelgeuse" twice. She counted. Very subtle and nicely done, Mr. Plait!
Anyone else sad that we didn't get to see little Star-Phil go bang? Also, very very interesting series you've got going on here, I hope it continues to cover some of the more exotic aspects of astronomy!
You're amazing! I knew it all for last 15 years or so, but I enjoy listening to it so much! And I can show it to my friends without degree in physics, and have something to talk about. Good job!
Just think. It takes billions to millions of years to form the elements all the way up to iron, but every things above it, was formed in the fraction of a second of a supernova There's something truly mind boggling to think about how all the material around me, that makes me, was all formed in the hot forge of a massive dying star. It's both inspiring and humbling
"My god it's finally happened, he's gotten so massive he's collapsed into himself like a neutron star!" ... Family guy actually taught us something with a joke, holy crap.
All the Crash Course Astronomy episodes are very good, but this one was the best. It was even the best among all other astronomy videos I ever watched.
+Guillermo Garcia Viesca A neutron start does not fuse anything, its basically a really small ball of pure neutrons, barely a few dozens of kilometers in diameter, at that point there are no elements on the star just neutrons so fusion is just impossible
+Guillermo Garcia Viesca The process of fusing elements to release energy ends with iron. From there fusion absorbs/stores energy, which you can release again by splitting those atoms. The process of splitting atoms i known as fission, and is what the fuss with uranium and plutonium is about.
+Guillermo Garcia Viesca Stars don't fuse heavy elements during their regular life time. Like iron, any element heavier than iron also uses energy to fuse instead of creating it. The main place elements heavier than iron get created is during the supernova event itself. During the tremendous explosion fusion kicks off again and all the elements heavier than iron get produced.
Wonderful Phil. You've explained the genesis of material stuff from matter now here. Next, please, Tell us about how everything came from nothing in an instant. I can hardly wait.
very good and informative video. Heavier elements means those naturally occurring i.e. up to Uranium are produced in SN? this is mindboggling. Are we able to trace the location of the SN which created our solar system and us?.
+Prakash Kamath This is something I've wondered about. Now considering that the early universe had a lot of enormous stars that may have lived a few million years , we could be made of multiple overlapping supernova remnants that occurred eons ago . And the background radiation from them is probably long gone .I would also guess that most of the matter has been integrated so completely into the galaxy that it would be hard to trace back to its origin . The one thing that we may likely find could be the black hole or neutron star remnants of the suspected SN's . I'm not an astronomer though, so some intelligent feedback would be appreciated .
I don’t think we could chiefly because there is a stellar life cycle gap between a SN and the creation of a protostar: nebulae. It’s almost certain that the creation of the Sun took place in a nebula chock full of hot, molecular hydrogen gas that began to gravitationally collapse into a protostar. But these nebulae are seeded with hydrogen by many (possibly thousands) of supernovae over a long period of time. These interstellar clouds become the cradles of infant stars. :)
The elements composing your right hand probably come from a different star than the ones on your left hand. Multiple SuperNovae were necessary for us to exist. Stars died for us to exist. We’re all made of stars, literally.
+Reagen Lionel From what I understand, there's just a lot and they (hydrogen/helium) came from the big bang. I don't think any new ones are being created though.. so yeah it's probably a finite supply, but I don't think the universe will run out in any amount of time we can calculate
monkeytrollu No, I'm talking about after this. There will come a time (many trillions of years from now) when every star has exhausted every possible source of fusion. Google '5 ages of the Universe' (we're currently in the Stelliferous era- the age of stars) for more information, or read Dr. Plait's book.
You've basically gotten your answer at this point, but I'll summarize. The lightest elements, hydrogen and some helium, were formed at the Big Bang. Because the amount of energy, and thus the amount of stuff, in the universe is constant, it will eventually run out. About 100 trillion years from now, it's estimated that the Degenerate Era will begin, as stars can no longer form from free hydrogen, because there is none. Everything will be brown dwarfs, white dwarfs, neutron stars, and black holes. It's possible that some brown or white dwarfs will merge occasionally, temporarily igniting some fusion as type 1a supernovae, carbon stars, helium stars, or even (if two brown dwarfs merge) a long-lived red dwarf, but that will be rare.
Besides Venus this is one of the best episodes. Even though i technically knew all this stuff and have been looking up this like a thousand times, no one has ever, Ever! taught me this super super complex mechanics as understandable as well as in this epiode. Plus, these superlatives are like the best in like the universe. Thanks a lot for this episode! Greets from Germany!
Are you serious? Why does a video from September 2015 claim that VY Canis Majoris is the largest known star? That's been given to UY Scuti a LONG time ago.
Indy The Great A peer-reviewed publication says that VY Canis Majoris is the largest known star, because possibly larger stars are less accurately measured.
+Fourth-Dimensional Quasar To what degree? Would it break apart to Protons, Neutrons and Electrons and then just stop, or would it break down further? Perhaps all the way to qwarks? And, building on that, what would happen to a qwark not fused to any other? And how would that effect surrounding matter?
+rubikfan1 if enough heat is being pushed into this single atom system, it will most likely break apart. depends on how much heat you want. eventually, temperatures could be high enough so that even the quarks that make up the protons and neutrons can't hold on to each other. similar conditions were present when the big bang happend. ever heard the term 'quark-gluon plasma'? that is what you would get at the highest imaginable temperature.
Supernova are almost beyond the ability for human minds to grasp. XKCD did a great What If on this subject: what-if.xkcd.com/73 One of the things covered there is that given any comparison between things, the supernova is always reliably more powerful. There was a comparison between the brightness of a supernova if the sun were to suddenly explode as one vs the brightness of literally sticking your eyeball against the casing of a hydrogen bomb when it explodes. The supernova is brighter. A billion times brighter. And the light and heat that are released are only 1% of the total energy. 99% goes into the neutrino wave that is released.
Just the idea that neutrinos, the absolute epitome of smallness, are the main reason why the largest stars explode is about as poetic as reality can get.
I already know most of the stuff they talk about in these videos, but hearing it again in a very easy to understand and engaging format makes it enjoyable anyways.
Every time I hear about iron being the death of a star, it always makes me look at my cast iron pots and think "What worlds have you destroyed?!"
I must ask mines now.
dacypher22 oh no lol
And think even beyond that, the blast of radiation from supernovae can cause mass extinctions in *nearby* solar systems.... So check out those iron pots again, it could've cost the destruction of entire civilizations to make the materials that we casually use every day.
dacypher22 The same star, in it's dying gasp, that cast out the iron for your cast iron pots also expelled the iron in our blood, which we can't live without. So, instead of asking your pots that question, ask that question the next time you look in a mirror. Whatever the answer, it happened many millions of years ago & we owe it our gratitude for making our lives possible.
@@renaissanceman7145 Good point. (looks at own body) "What worlds have you destroyed?!"
These videos are absolutely wonderful. Especially the narration. I normally hate the talking head-type videos, but:
*a.)* Phil clearly knows what he's talking about.
*b.)* shows such an infectious enthusiasm for it.
*c.)* Has the demeanor of that favorite teacher we've all had at one time or another.
soviet!! when will the next csgo random bullshitery be released? xD
Womble is a.... What was the word?
Couldn't agree more.
This series of episodes is the best of any kind on the whole of RUclips.
d.) his shirts are awesome.
"Relax, something else will kill you."
This series is just great. Thank you all so much for producing it!
one lees thing to worry about
+Grillpanzer Death and taxes gets us all
if you havent died yet, just give it some time
Blah Cga, that was dark yet true.
Buhahahhahahahahahahhahahahaahahahah!
The ending of this episode is my most favorite thing ever. It's so touching and almost made me wanna cry. XD
"That star blew up more than 5 billion years ago. But parts of it go on: In you."
Um, that's "more than 5 billion years ago". The universe itself is only (only?) about 13.7 billion years old.
Not only did all the heavy elements originate in the cores of stars, the atoms in your body originated in several different stars.
Wizard Suth I was going to set him straight myself but you did a fine job at it. With that being said, I wonder what the catalyst was that spurred the creation of the universes that particular time. Why 13.7 billion years ago and not 50 billion years ago? What took place at that moment that did not take place prior to that? I have pondered that question for years. Any thoughts on that subject?
@@afterburner2869 That's a good question. I just wonder how some scientists are so willfully ignorant towards the fact that there is a divine engineer, a creator in all of this. God. How everything in this universe works. How the earth is so specially put that life would not exist if it were a little closer or farther away from the sun. How absolutely complex our DNA is alone. When has an explosion ever created such a magnificent order? It's one of the basic laws of thermodynamics. Something can't come from nothing. I too have many questions.
Dan Caban The more learn, the more questions I have.
New science suggests that neutron star collisions are responsible for most heavy elements in the universe, with supernovas representing a relatively minor contribution. No gods needed.
"We are made of star-stuff. Our bodies are made of star-stuff. There are pieces of star within us all."
-Carl Sagan
+The Curious Noob thats one heck of a true
"Luminous beings we are, not this crude matter."
-Yoda
"We may be made of star stuff, but that also means we are made of nuclear waste."
-Veritasium (i think)
My shit looks like a nebula - me
You should probably get that checked out
"On onion with multiple layers" Sounds familiar.
Onion routing?
_Betelgeuse will certainly explode some day, but it's too far away to hurt us._
Just don't say it's name three times.
It might have exploded already. Or just might be exploding in this very moment. If it does, we won't know for 600 years.
@@vealck Betelgeuse won't explode until the next 1 Million years, Scientist's are watching the sun and we will see it. But it technically is exploding. And has been proven it is still too young to go Supernova.
Betelgeuse
Betelgeuse
Betelgeuse
Fight m3.
@@envi.3901 it's showtime
@@pearl3scent this is why i like my life
Space is so absolutely amazing. I know this is kind of a dank meme, but honestly... "Born too late to explore the world, born too early to explore the universe" kinda rings true with my feelings.
I want to go to these places, I want to see the andromeda nebula with my own eyes out of the window of a spaceship, I want to walk on these planets.
I don't think we will be able to travel through space, but maybe the evolution of Virtual Reality will one day in my lifetime reach a point where I can experience something that feels just as real.
One can dream.
Besides that, CC: Astronomy is by FAR one of my absolute favorite series on RUclips. Phil is an immensely likeable person and can really deliver information so well.
so you must play no man's sky as me
+joel Pallaroso Nonone hell no .
I m 7 year old
You will. Honestly, whether you believe it or not you will.
Totally agree!
AND PEOPLE SAY ASTRONOMY IS BORING!
eXCUSE THEM WOW I AM SO OFFENDED WHOEVER SAYS THOSE THINGS TO ME
+SeaBiscuit Who dares propose such heresy???
+Beastinvader Heretics, I guess? I dunno. But they're lame.
+Beastinvader Heretics, I guess? I dunno. But they're lame.
+SeaBiscuit I've never heard anyone say that though!
This was one of my favorite episodes so far! Maybe it's just the child-who-loves-gigantic-explosions part of me, but either way, great episode. :D
>Sun has layers
>Shrek has layers
>Shrek is the eternal light and life giver = confirmed.
Shrek is iluminatti
shrek is love
+AlterBridgeSaint The Sun is an onion! :O
+Robert vdHill The sun is an onion? That means Shrek is an onion. Shrek maks u cri evrytim cunfermed.
+AlterBridgeSaint The sun stinks.
Phil shows us how tiny, and I mean TINY, we are in the universe. The stars that we see at night may seem like a tiny speck of dust but it is really a gigantic ticking time bomb waiting for its time to collapse and become a black hole. It really puts a lot of things into different perspectives. I learned a lot from this, so thank you Phil.
Quasar and Blasar Episode PLEASE PLEASE PLEASE PLEASE!
+Damstraight68 maybe they'll be touched on in the Neutron Star episode next week?
+Damstraight68 Magnetars!
+Damstraight68 They have their own schedules, highly unlikely they're gonna change it to consumers' tastes
+Tommy Vercetti ....
Yell yes!
I'm British, and American accents usually irritate me but I could listen to this guy all day. Enthusiasm rocks!
I love this series so much
can we use the energy of a supernova ???
"Vy Canis majoris is the biggest star we know of"
UV Scutti: "hold my hydrogen"
Also if a gamma ray burst is close enough it could do damage to us
I think “damage” is a complete understatement.
@@TheBeast12567 yup
Crash course physics pls
they need more money for that
+minshwan tang if they reach $40,000 on their Patreon, CC Physics might become a thing. www.patreon.com/crashcourse?ty=c
PBS Spacetime comes close though. It's not exactly a physics course, but its got more theory than CC Astronomy.
yess
***** Because PBS has been grossly underfunded since the 80s, and the reason it gets money from the government because it is PUBLIC Broadcasting. It's not as simple as throwing 30-40 grand into a project that may or may not make its money back. Streaming is a popular way to view video, but it is not a great investment because right now streaming video is not very lucrative. That's why Creators turn to things like Patreon so fans can help them make money. CC already barely breaks even as it is.
Yes please
3:18 the sun is me and VY Canis Majoris is ONE of my classmates
@Soumil Yarlagadda Yessir one of my classmates is 7'4 lol
I love this guy. I have seen all episodes of Crash Course Astronomy (I think) and I sometimes watch them again just for fun of it.
FINALLY! THANK you for TELLING US THE ACTUAL NUMBERS of HOW LONG given events (e.g. time it takes for a star to fuse all its silicon = 1 earth day). Absolutely 0% of all other physics videos EVER give these numbes.
The reason they rarely give exact numbers is that there are several factors at play namely the preexisting amounts of heavy elements(known as metallicity) and mass of the star which significantly alter the result. To give an example you need to note the mass and metallicity. Of course in the most massive stars with masses over a hundred times that of the Sun it gets even more complicated as several extreme outcomes can upset the usual process described above. For low metallicity ultra massive stars such as the first generation of stars that formed in the early universe the uncontrolled energy production goes out of hand and the energy supporting the core against collapse starts producing matter antimatter pairs robbing the star of energy before it even reaches the late phases resulting in the complete annihilation of the star as in no remnant of the former core in an absurdly luminous supernovae far brighter than a typical supernovae resulting in some calling them by the term hypernovae.
On the other extreme ultra massive stars with high metallicities can become dominated by what is known as the CNO cycle which is a catalyst cycle involving Carbon Nitrogen and Oxygen which is far more efficient and faster at high temperatures than normal proton proton chain fusion. This results ins a strong enough energy imbalance that the star begins to become convective again increasing the amount of fuel at its disposal meaning these massive stars burn through their entire mass worth of hydrogen in only a few million years and or blowing much of their mass away which takes away much of the stars angular momentum as the stars never actually reach hydrostatic equilibrium instead rotational torque helps gravity hold the star together against the sheer luminosity of the star which would otherwise radiate itself apart as it exceeds the Eddington limit for its mass (i.e. its luminosity is larger than the gravity holding it together). When the most massive of these stars die the star has lost all of its angular momentum which normally allows matter to somewhat resist the pull of gravity since angular momentum must be conserved. In these stars there is barely a shock wave and if one forms at all it will be super weak having barely escaped the gravity of the core that instantly collapses into a black hole without the support of fusion. For those with too little angular momentum remaining the shock wave might never form as it too becomes trapped behind the event horizon of the newborn black hole. To an observer watching the process thousands of light years away the star would simply wink out of existence. These are just two extremes from a whole menagerie of exact ways high mass stars can die depending on the stars initial conditions which makes things far more complicated.
What Phil did here is he plugged in a specific mass and metallicity in order to give that particular results as an example. I don't know exactly why but people rarely bother to do that but it probably has to do with the governing system of partial differential equations being hard to solve even if it is well understood.
The whole series is made so well, you should make subtitles in French, Spanish or German lovely CrashCourse Team!
No. Having subtitles makes it so that foreigners don't have to learn English. This would be bad because everyone must adapt to English now that it is undeniably the global language.
+Kenrick Brown no
+Kenrick Brown Nice way of saying fuck you to half the world
+Kenrick Brown
While English is undeniably a lingua franca of the world (Or a strong contender), it would be better if these videos got around more and weren't limited by a language barrier.
Dindono Acularius Okay, I'll admit that subtitles would be good. In fact, they could learn by comparing the subtitles to what he said. BTW, I am bilingual (English and Mandarin)
The fact of iron fusing resulting in a net loss of energy reminds me a little of why it’s bad (for humans) to drink seawater to parch thirst - because our body needs to exercise the use of more bodily water to evacuate the salt in the seawater than it gains in water.
dude i'm so stoned this is better than a good blockbuster
I love Phil's excitement when he talks about space. It's so true and inspiring to hear someone talk about something they love so much.
"it's like an onion. with multiple layers" sooo Shrek is a star. got it.
Mya you beat me to the comment
Somebody once told me the world is Gonna Roll me
4 years on, Phil Plait is still the best guest presenter Crash Course has ever had. He has a seriously genuinely gift for imparting information.
"Every atom in your body came from a star that exploded. And the atoms in your left hand probably came from a different star than in your right hand. It really is the most poetic thing I know about the universe. You're all stardust. You couldn't be here if stars hadn't exploded, because the elements ( the carbon, nitrogen, oxygen, all the things that matter for evolution) weren't created at the beginning of time. They were created in stars. So forget Jesus. Stars died so you could live."-Lawrence Krauss
This is by far my favorite series CC has done. Phil is positively amazing, great teacher. Haven't missed a single episode.
This episode is the best thing on the internet! I've been waiting for this one in particular, and you guys did not disappoint.
I've always wondered how Gamma Ray bursts work. Thanks for the videos Phil and CC.
Hi, I'm from Thailand and crazy to interest everything relevant to the universe.
FINALLY an explanation on why iron is the last element made.
Sun-*Dies in a Nova*
Betelgeuse-*laughs in Supernova*
VY Canis Majoris-*Laughs in Hypernova*
the sun isnt gonna explode
No.. Sun will go out in a whimper
Black hole- devours them all
White whole- throws all of them out
Galaxy - hurts them all
Your astronomy/ cosmology series is outstanding, Dr. Phil. You provide a wonderful information in an interesting and easy to comprehend manner and your delivery is impecable. Thank you for sharing such interesting information and for making knowledge of science fun and entertaining. You're the best!
cosmic bodies living on through our building blocks...... feeling we're somewhat cherished here..... humbling and inspiring
Pronoy Dutta It goes even beyond that...life is a more efficient way of processing complex carbohydrates in ways that stars cannot, perpetuation the flow of energy from a useful state into a useless state. We are a link in the chain of entropy.
So don’t ever let anyone tell you that our existence is meaningless. We are a natural consequence of a progressively more chaotic universe. :)
This is amazing. I always wondered about the life of a star after the hydrogen was used up. What an amazing sequence of events with so much variety depending on mass. Stars are so cool.
10:45 - "We are stardust, we are golden; we are billion-year-old carbon..."
I am now really curious who the hell click the "thumb down"..... this is such a heroic effort to make complicated things easy to beginning astronomy learner. Show some respect!
2:13 "Silly confusion creates iron"
Thats what I heard lol
Silly confusion creates irony
Silly confusion confounds moron
Finally! This is the episode I most wanted to see the moment Crash Course Astronomy started.
3:18 *UY SCUTI WANTS TO KNOW YOUR LOCATION STAT!*
I love how he speaks in both English and ASL
I learn more in this episode than all of the Star Trek series combine.
+Mat G You are not supposed to learn anything from Star Trek, it is supposed to inspire you to invent stuff.
+Fraser Henderson You aren't supposed to learn anything at all...? I think that's a shortsighted look at the series. Star Trek is a good way to teach ethics and philosophy. Both those subjects are based on opinion, but it does teach one to critically think about them.
+Mat G It's just as well. Star Trek is great for morality plays, horrible for astronomy. They did once put the ship in "Geostationary orbit over the South Pole."
+fmlAllthetime Startrek is mainly entertainment not all of it is fact ..some is purely made up..You could say. It has inspired many to be Astronauts tho
+rlrsk8r1 Why do you consider imposible that a ship whith warp capabilities would have a problem in moving thru space at the same speed and direction as a given planet?
I am now officially addicted to Crash Course: Astronomy since I've checked to see if this new installment came online far more times than I have for anything else on RUclips (or Netflix, for that matter).
2:37 So blue stars turn red when they get bigger?
Also UY Sucti is now the largest star. I know this video is a bit old.
I didn’t know that UY Scuti is smaller than *UY Sucti*
Qualifium Gaming LMAO 😂 😆
Life Cycle of the Massive Star:
Protostar > O, B, or A type main sequence star > Red Super giant > Helium Burning Super giant > Second bigger Super giant > Type ii Supernova > Neutron Star > Pulsar or Magnetar or stellar Black hole > X ray emission.
My mom told me I was a star. :)
+drink15 I bet she had a great figure ... of speech....
Probably because any one that gets near you ends up in orbit
+daniel117100 Calling drink15 fat!!
+drink15 I guess we can safely say she was not entirely wrong!!!!
Only because you achieved critical mass!
If what they are saying about the fusing of iron is true, well that's a clear sign that the there is intelligent design in the universe, because the process of fusion would have otherwise gone on unabated. Iron gets the star ready to die and thereby release all the elements it created. Nicely done.
UY Scuti is the largest star we have discovered so far though.
"That star blew up more than 5 billion years ago, but parts of it go on in you."
I can never think of something more profound than that
Isn't UY Scuti the largest, and VY Canis Majoris the most massive?
R136a1 is recognised as the most massive known star currently
UY Scuti is the largest...sometimes. It’s actually a variable, meaning that it can change physical size almost at will. There’s also a hefty margin of error when it comes to defining the “surface” of stars as large as UY Scuti and VY Canis Majoris because their densities are extraordinarily low.
Rolling Kneebar i dont think its by will, but philosophical things aside, i would also add that the gas and dust around the stars also makes for more error in measurements
I really hope they're doing an episode on variable stars! They are one of my favorite things in astronomy
This was a mighty fine episode - really well produced and well spoken. Thanks folks, love your work
Thanks Phil, your explanation is terrific. I'm sharing this with my kids and they'll love it too. Nice to know how the periodic table came to be
Easily the best episode you've made. I'm riveted.
Just about every other video I've seen on the fusion process in stars, they literally skip the middle man and explain in extensive detail the hydrogen helium side and why iron sucks. Though the onion analogy is often brought up they give scant detail on how the onion forms, or the steps involved. Thank you for going that extra mile.
loving this series. keep it up!
Despite the fact I know that for many and many years, I'm still stunned in a moment of awe every time I think about the fact that we are made of dead stars.
But VY Canis Majoris is'nt the largest know star. Is'nt it UI Scuti?
+BaTBaiLeyS They thought it was but last I heard there is a margin of error when it comes to its size so it might actually by smaller. There are also stars that are pulsating so they are constantly getting larger and smaller
+Schnitzel Strike Yeah, apparently it was once thought it was so large it defied the supposed laws of stellar evolution. It shouldn't be that large, and it probably isn't, though it could still be the largest star without breaking this limit.
It's still a red hypergiant even if not the largest known star by diameter.
+Schnitzel Strike That's irrelevant since even if we assume the worst of our measurements, the order is UY Scuti > VY Canis Majoris > NML Cygni
VY Canis Majoris loses no matter what happens.
It was at one time the largest known star. It's possible the script was written before more recent measurements brought it down to size (if that's an applicable term for something over 1400 solar radii). It's a weird star, and it's hard to define where it's surface is.
It’s crazy how now UY Scuti is the largest known star ( year 2020). I’ll be back in 5 more years to disclose the biggest star discovered in 2025.
He says "Energy is created". He should have said "Energy is released".
@Cuzeg Spiked It somewhat depends one how you look at it. The energy in those nuclear reactions stems mostly from the mass defect, so .. it's "created" from matter.
Sometimes matter is just seen as another form of energy therefore, but if you don't .. energy IS actually created here.
something i don't understand: when you rub your hands together, your hands heat up. therefore, you've created energy o.O
@@ScareSans No. You don't. The sun created it from the mass defect during fusion in its core.
Those fusion is part heat, part kinetic energy of the products. Those products are slowed down be collision though, so they also just heat up the core. That heat travels to the sun until it reaches its "surface". This surface is still quite hot, so it emits radiation (it glows). Part of that radiation is visible sunlight. Part of that light reaches earth.
Then that sunlight is absorbed by plants which turn it into chemical energy via photosynthesis. Those plants are eaten be you (or by animals you eat later, maybe after they were eaten by other animals) and the chemical energy is deposited in your body (blood sugar / fat deposits) now. When you rub your hands together, at first your muscles turn those energy into kinetic energy, and the friction between your hands converts it back to heat.
The energy was always there after it came from the mass defect during fusion in suns core, it just was converted around between different forms of energy. And some people say mass/matter is just another form of energy, if thats the case, it has been there since time existed. What was before that .. well there wasn't even a before since a before needs time to exist.
(And yes I'm quite aware that this explanation is pretty inaccurate and incomplete, but it gets to the point).
@@ScareSans no. You are now a little tired.
The energy comes from your own internal body energy reserve and the energy in the muscles of your hands and arms
@androkguz yes, i did research after saying this. i'm now aware of how this works
Best lecture on this subject I ever had. Very well explained, Phil!
just teasing us with future episodes. I want it now!
One of my all-time favorite science videos. Informative and more thrilling than the best crime fiction.
"in a fraction of a second, these neutrinos carry away 100 times as much energy as the sun produces IN ITS ENTIRE LIFE!"... OMFFGGG
The star is pumping iron until it gets a pump. It's like someone is blowing air in to it. It feels fantastic!
All the elements... that were once fused in the very heart of hypergiant stars... make us up...
We are star dust. Our terrestrial bodies are the remnants of a huge celestial body.
abloogywoogywoo explains why the nickname of the girl from Rogue One is "Star dust"
Oh, Sagan
Phil,
Your videos are truly awesome, educational, well written and narrated and intelligently presented. I love your work.
thoroughly enjoyed this episode !!
I don't know if anyone else has mentioned this, but my wife noticed that Mr. Plait only said "Betelgeuse" twice. She counted. Very subtle and nicely done, Mr. Plait!
+Christian Conkle Does it count that you said it once more?
Nope, it only counts if *I* say "Betelgeuse" three times. Uh, now I've said it twice. Looks like I'm cut off.
8:38 "The energy release is so huge, they can be seen halfway across the universe." Dude... No edge?
agree
the visible universe....
Clotilde Vivier i gess he was talking about the visible unisers
it was... a joke...
Anyone else sad that we didn't get to see little Star-Phil go bang?
Also, very very interesting series you've got going on here, I hope it continues to cover some of the more exotic aspects of astronomy!
I have my own scientific law.
Any time black holes are mentioned, the phrase "not even light" will always follow.
You're amazing! I knew it all for last 15 years or so, but I enjoy listening to it so much! And I can show it to my friends without degree in physics, and have something to talk about. Good job!
Waitwaitwaitwait, so Rigel is pronounced like "Nigel"?
What the fu-
Just think. It takes billions to millions of years to form the elements all the way up to iron, but every things above it, was formed in the fraction of a second of a supernova
There's something truly mind boggling to think about how all the material around me, that makes me, was all formed in the hot forge of a massive dying star. It's both inspiring and humbling
10:58
So... The ending of Super Mario Galaxy is true after all.
I get excited when Phil says "we'll cover this in a future episode". Love this series!!!!
"My god it's finally happened, he's gotten so massive he's collapsed into himself like a neutron star!"
... Family guy actually taught us something with a joke, holy crap.
All the Crash Course Astronomy episodes are very good, but this one was the best. It was even the best among all other astronomy videos I ever watched.
How big does a star have to be to fuse elements like uranium in its supernova?
Also: does fusion continue within black holes or white dwarves?
+Guillermo Garcia Viesca At least 5-6 miles around.
+Guillermo Garcia Viesca
A neutron start does not fuse anything, its basically a really small ball of pure neutrons, barely a few dozens of kilometers in diameter, at that point there are no elements on the star just neutrons so fusion is just impossible
+Guillermo Garcia Viesca They don't fuse unstable elements.
+Guillermo Garcia Viesca
The process of fusing elements to release energy ends with iron. From there fusion absorbs/stores energy, which you can release again by splitting those atoms. The process of splitting atoms i known as fission, and is what the fuss with uranium and plutonium is about.
+Guillermo Garcia Viesca
Stars don't fuse heavy elements during their regular life time. Like iron, any element heavier than iron also uses energy to fuse instead of creating it.
The main place elements heavier than iron get created is during the supernova event itself. During the tremendous explosion fusion kicks off again and all the elements heavier than iron get produced.
Wonderful Phil. You've explained the genesis of material stuff from matter now here. Next, please, Tell us about how everything came from nothing in an instant. I can hardly wait.
very good and informative video. Heavier elements means those naturally occurring i.e. up to Uranium are produced in SN?
this is mindboggling.
Are we able to trace the location of the SN which created our solar system and us?.
+Prakash Kamath This is something I've wondered about. Now considering that the early universe had a lot of enormous stars that may have lived a few million years , we could be made of multiple overlapping supernova remnants that occurred eons ago . And the background radiation from them is probably long gone .I would also guess that most of the matter has been integrated so completely into the galaxy that it would be hard to trace back to its origin . The one thing that we may likely find could be the black hole or neutron star remnants of the suspected SN's . I'm not an astronomer though, so some intelligent feedback would be appreciated .
+Prakash Kamath Probably not. Interesting thought though!
I don’t think we could chiefly because there is a stellar life cycle gap between a SN and the creation of a protostar: nebulae.
It’s almost certain that the creation of the Sun took place in a nebula chock full of hot, molecular hydrogen gas that began to gravitationally collapse into a protostar. But these nebulae are seeded with hydrogen by many (possibly thousands) of supernovae over a long period of time. These interstellar clouds become the cradles of infant stars. :)
The elements composing your right hand probably come from a different star than the ones on your left hand.
Multiple SuperNovae were necessary for us to exist. Stars died for us to exist. We’re all made of stars, literally.
"RELAX, SOMETHING ELSE WILL KILL YOU" How encouraging, I feel so much better! Thanks, CrashCourse! xD!
“Silly confuses”
All massive stars go out with a big bang, we all started with a big *BANG*
This show is what Discovery Channel wants to be but fails at.
This Crash Course episode is absolutely astonishing. Unbelievable.
If stars are what create heavy elements. Where do the lighter elements come from? Will the universe eventually run out of lighter elements?
+Reagen Lionel From what I understand, there's just a lot and they (hydrogen/helium) came from the big bang. I don't think any new ones are being created though.. so yeah it's probably a finite supply, but I don't think the universe will run out in any amount of time we can calculate
+Boredness It's definitely finite, and the last stars will die out trillions of years in the future. Then, Heat Death of the Universe.
+Slaphappy007 Perhaps pure Helium fusion stars will form, or pure Carbon fusion stars.
monkeytrollu No, I'm talking about after this. There will come a time (many trillions of years from now) when every star has exhausted every possible source of fusion. Google '5 ages of the Universe' (we're currently in the Stelliferous era- the age of stars) for more information, or read Dr. Plait's book.
You've basically gotten your answer at this point, but I'll summarize. The lightest elements, hydrogen and some helium, were formed at the Big Bang. Because the amount of energy, and thus the amount of stuff, in the universe is constant, it will eventually run out. About 100 trillion years from now, it's estimated that the Degenerate Era will begin, as stars can no longer form from free hydrogen, because there is none. Everything will be brown dwarfs, white dwarfs, neutron stars, and black holes. It's possible that some brown or white dwarfs will merge occasionally, temporarily igniting some fusion as type 1a supernovae, carbon stars, helium stars, or even (if two brown dwarfs merge) a long-lived red dwarf, but that will be rare.
Besides Venus this is one of the best episodes. Even though i technically knew all this stuff and have been looking up this like a thousand times, no one has ever, Ever! taught me this super super complex mechanics as understandable as well as in this epiode. Plus, these superlatives are like the best in like the universe. Thanks a lot for this episode! Greets from Germany!
Are you serious? Why does a video from September 2015 claim that VY Canis Majoris is the largest known star? That's been given to UY Scuti a LONG time ago.
You are correct sir.
Indy The Great A peer-reviewed publication says that VY Canis Majoris is the largest known star, because possibly larger stars are less accurately measured.
I love this! You’re a great presenter and teacher, Thankyou!!
what whould happen if you heat up a single atom? so it has no other atoms to fuse with.
+Fourth-Dimensional Quasar To what degree? Would it break apart to Protons, Neutrons and Electrons and then just stop, or would it break down further? Perhaps all the way to qwarks? And, building on that, what would happen to a qwark not fused to any other? And how would that effect surrounding matter?
hmm... interesting... what are the thresholds?
Fine, the laser "excites" them, whatever, pedantic, pants. Just kidding, I actually found what you said to be helpful and interesting.
+rubikfan1
That's what atom smashers do and study.
+rubikfan1 if enough heat is being pushed into this single atom system, it will most likely break apart. depends on how much heat you want. eventually, temperatures could be high enough so that even the quarks that make up the protons and neutrons can't hold on to each other. similar conditions were present when the big bang happend. ever heard the term 'quark-gluon plasma'? that is what you would get at the highest imaginable temperature.
As ever, an excellent presentation. Well done, Phil and the team.
Supernova are almost beyond the ability for human minds to grasp. XKCD did a great What If on this subject: what-if.xkcd.com/73
One of the things covered there is that given any comparison between things, the supernova is always reliably more powerful. There was a comparison between the brightness of a supernova if the sun were to suddenly explode as one vs the brightness of literally sticking your eyeball against the casing of a hydrogen bomb when it explodes.
The supernova is brighter.
A billion times brighter.
And the light and heat that are released are only 1% of the total energy. 99% goes into the neutrino wave that is released.
This guy knows his stuff and LOVES his job. Very excited to talk about the cosmos. No doubt you would need a washcloth if you sat ringside.
“We will never know anything about the chemical composition of stars.” - Auguste Comte, 1835
'1835'
Just the idea that neutrinos, the absolute epitome of smallness, are the main reason why the largest stars explode is about as poetic as reality can get.
2 Billion Kms across...what the fuck?
Malcolm Pagett ~1,24 billion miles in American.
I already know most of the stuff they talk about in these videos, but hearing it again in a very easy to understand and engaging format makes it enjoyable anyways.