The s-Process - Sixty Symbols

Stars can forge elements using two important methods - the slow and rapid processes of adding neutrons to an atomic nucleus.
Featuring Professor Mike Merrifield.
Extra footage: • The s-Process (extra f...
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Sixty Symbols videos by Brady Haran
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[@Eric_Pham]

The Astronomers periodic table is LOL

[@casacara]

"which means I need to venture alarmingly close to chemistry" ah the physicist's dilemma

[@EugeneKhutoryansky]

Nice explanation.

[@ashtondrye9375]

YYYEEEEEEEEEEE

[@martinvonheland1749]

"There are lots of everything in supernovae, it's a complete mess." This is one of my favourite quotes from this channel.

[@tarnvedra9952]

This channel is just great. Each video is a treat.

[@fuffofuffino2017]

yeah! if only the videos weren t upload 1 every 2 f****in months

[@rikschaaf]

+fuffo fuffino If you want more videos, go look at brady's other channels. There is almost a video per day, sometimes even multiple on one day.

[@ruawhitepaw]

A very educational video, I was really interested to learn about this! I didn't know these processes existed before.

[@nagualdesign]

(7:53) Great use of the word 'bimbling'. bimble v. walk or travel at a leisurely pace

[@N05K177]

I like how you have "human-made" just sitting next to supernovæ, cosmic rays & big-bang.

[@HeavyMetalMouse]

It's a little mind-boggling to think that we as a species are the 'reaction' necessary to create ultra-heavy elements.

[@garethdean6382]

TO be fair those elements are pretty much definitely made in supernovae too, the video even mentions it, but making them ourselves is the only way WE can get them.

[@Ripcode2233891]

Earth, and the human race as a whole is it's own little supernovae, if you look at it like that. Which is nice

[@rationalmartian]

Those heavier elements are also made too, I'm reasonably sure. It is just that as the element gets heavier it becomes more unstable and therefore will break down sooner into lighter elements and hence not stick around for long.

[@N05K177]

+rationalmartian Oh I'm not disapproving here, I also think it's probably the case. But the fact that we are somewhat comparable to those events makes feels nice ^^

[@theonetojump]

5:21 - I love how he says "It's a complete mess". Just something about that line made me lol

[@IamGrimalkin]

One point you didn't mention is the possibility of neutron star mergers producing some of the elemnts instead. Maybe we'll find out more about this when advanced LIGO boots up again later this year.

[@mussalo]

Part 2 please! With updated info based on neutron star merging.

[@TheGamblermusic]

So it takes two stars to make a samsung galaxy that doesn't work.

[@noahwood2394]

A galaxy consisting of two stars is no galaxy at all.

[@eddielong96]

you mean lithium?

[@8nayrb]

A bit judgemental, or two judgemental.

[@8nayrb]

Artem Borisovskiy You're certainly determined.

[@lastsilhouette85]

I like how I always feel smarter after watching these videos. Too many other youtube videos just give you the basics, but you guys get into detail.

[@EmanuelsWorkbench]

It would be nice to see that periodic table distinguishing by colour elements created by the s- and r-processes.

[@TobyGarcia]

Since the s-process cannot result from supernovae, it would seem all of the green beyond Fe must be s-process.

[@ragnkja]

It would also be nice to see it distinguish between elements that can be made in first-generation stars and those that can only be made in later generations.

[@jamez6398]

+Toby Garcia Wrong. Some of the heavier elements beyond Iron are formed in the core of stars beyond a certain mass. In fact, I think all of them. I think that some of them are formed by s process or r process only, plus nuclei being smashed together directly during supernovae. As far as I know, the only thing that is affected the s and r process is the abundances of the various elements throughout the universe. In fact, that would mean to say that the bigger the star, and the longer it spends in the iron state before all elements lighter than iron are used up to make iron and beyond, then the more elements beyond iron it gets, and the further beyond iron it gets. That means that some elements, during supernovae, only get made by smashing nuclei together, so more elements are made during supernovae that can be made by the r-process rather than s-process only because those ones can be made by both r-process and nuclei smashing whereas the other one can only be made by nuclei smashing alone.

[@spoonikle]

Excellent topic, Thank you Professor Merrifield and thanks Brady.

[@mikedowns7650]

Any word on the Nobel videos for this year?

[@aiman4036]

I look forward to a video on that, too.

[@Nilguiri]

Bob Dylan Live at The Shrine Los Angeles 2016?

[@Jeffrey314159]

1:25 Plutonium is man made, as well as Technetium

[@livedandletdie]

Technetium can actually form in stars. Sure it doesn't have stable isotopes, but it is formed naturally here on earth in uranium ore. The most stable isotope has a half-life of roughly 4.2 million years.

[@tobyhallidie1498]

That was unnecessary.

[@Laborejo]

I would like to have an aesthetically pleasing, well-designed version of the "origin of elements" table. Maybe even with the traditional chemical properties incorporated. As vector graphic with non-converted text, so we can translate it in different languages (the few English words at least) and print it in big sizes for classrooms and privates joy all over the world.

[@JeSuisUnKikoolol]

upload.wikimedia.org/wikipedia/commons/3/31/Nucleosynthesis_periodic_table.svg

[@__w__o__w__]

I think you missed the well-designed, aesthetically pleasing, part.

[@JeSuisUnKikoolol]

wow! I have to agree it is not a masterpiece but it is probably the only image that fulfill 1. downloadable as svg 2. legally allowed to modify and share Feel free to create a new one and share it with us :p (btw the image's license is CC-BY-SA 3.0 and I found it here : en.wikipedia.org/wiki/Nucleosynthesis#/media/File:Nucleosynthesis_periodic_table.svg )

[@jordancarter7047]

You make it then.

[@__w__o__w__]

Jordan Carter Would it be of enough benefit to warrant doing so? I have the knowledge of PS / AI to do so. Seems like a tedious job without much value though.

[@themightygugi]

Great video and fantastic explanation. I have always been wondering exactly how the various elements were made, and now I get it.

[@Eyerleth]

"There's lots of everything in a supernova, it's a complete mess." That is such a wonderful bit of understatement.

[@FemptMurderOrgy666]

What a great video!!!! It explained the gaps in my "where those extra heavy elements came from" but the "its a long journey" really brought it home!

[@LoanwordEggcorn]

Wonderfully clear explanation. Thanks!

[@andresmlinar]

Another excellent explanation from the professor, thanks!

[@markc2494]

Love this channel.

[@fuffoon]

Great video!

[@paulmcelhinney3318]

I love the Atlas of Creation in the background! Those crafty creationists!

[@garethdean6382]

The idea of the universe being a simulation (Which requires a simulator) is gaining popularity in physics.

[@KajurinP]

He actually made a video about this explaining why he has it :)

[@EmethMatthew]

Great stuff!

[@eckligt]

I guess this video needs an update, with recent discoveries related to neutron star mergers. I'm not a phycisist, but as far as I know the two processes described in the video are augmented by a third process where neutron stars merge, which throws off chunks of neutronium -- neutron star matter. Neutronium is highly unstable when not contained in a deep gravity trap, and beta decays will rapidly turn it into more sustainable combinations of neutrons and protons.

[@jonathan.gasser]

That human made section of the periodic table really puts things into perspective: the more complex the universe gets (us!), the heaver the elements become!

[@jonbold]

Astounding! Intriguing!

[@esdev92]

This is quite amazing stuff.

[@12tone]

So if S-Process elements have to be built one proton at a time, why does the table show elements that can't be made with it below ones that can? If a star is making Barium from Iron, for instance, surely it must make Cesium at some point along the way. Unless it incorporated the Cesium directly from a previous supernova, but the way Professor Merrifield described it made it sound like it could be done directly from Iron, which would imply that all the steps in between could too.

[@maxzhao]

Having the same question here, glad I'm not alone!

[@Slithy]

Here's what i'm thinking - this table of colors shows predominant ways of forming, but those are not guaranteed to be unique. I.e. Cesium that is formed through the S-process might account for some small percentage of total Cesium in the universe, but almost all of the Barium was created this way.

[@tomdodd5442]

The whole story is almost inevitably more complex and intricate than what the professor decided to go into, so I can only imagine there are some interesting little quirks when looking at the more detailed picture.

[@philp4684]

I think both Slithereenn & Tom Dodd are correct. The s-process doesn't necessarily strictly alternate between neutron capture and beta decay. What really happens is that over some time period, a nucleus accumulates more than one neutron without beta decay occurring, until a relatively unstable isotope is formed. Then it undergoes a few beta decays, jumping up the periodic table by more than one position until it's stable again. Then the cycle repeats. That explains how certain elements are skipped over. Wikipedia's s-process article has a diagram showing this in the silver - antimony range.

[@tomdodd5442]

You're probably right Phil - as you say, a single capture doesn't strictly have to be followed by a single beta decay. You also may want to give the professor's twitter a go, if you can deal with the character limit :)

[@ericjane747]

I am grateful for this additional knowledge. How could I ever see Barium again as just another run of the mill element!

[@BattleBunny1979]

The way this man explains things is very catchy :-)

[@Perun42]

Very interesting, as always :)

[@BarchBR00KS]

this was fascinating. From this, I wonder how we are so fortunate to have all these elements on this planet. there must be many planets that only have a few elements by comparison.

[@aetherseraph]

absolutely awesome

[@ACGW]

was thinking about elements beyond Fe, got my answer now!

[@sushaminirastogi7389]

Very informative thank you sir

[@khadijah830]

very clear and informative explanation 😚 i have my physics hl exam tomorrow and i really love this topic . pls pray for me

[@ericsbuds]

Thinking about the creation of the elements in the center of stars and in supernovae is always mind blowing to me. It really puts the size and scope of the universe in perspective. Amazing to me that a large number of the atoms in our bodies were created this way. I very much like the though that we, all of us, all creatures, plants, insects, mammals, rocks, lakes, everything, are birthed from the universe much like we are birthed from the womb of our mothers. We really are one with the universe.

[@jonathanwalther]

Finally a periodic table I can recall :)

[@ronaldderooij1774]

Top video!

[@ChilledfishStick]

That's really fascinating. I've pondered the question (regarding how elements bigger than iron are made) myself a few times, but for whatever reason, I didn't look it up. What I still wonder, is if a neutron decays into a proton, the new element would be a neutron short, wouldn't it? What is it that makes them decay? And how does this occur in radioactive isotopes?

[@hephaestus1956]

Professor Merrifield always rocks!

[@bogenriederlukas]

Wow, this was so interesting! Even more exciting then draditional myths about how everything formed.

[@EmilyDeibert]

Really useful for my qualifying exam. Thank you.

[@Account-fi1cu]

Stellar astrophysics final exam is tomorrow, thank you so much !

[@0xCAFEF00D]

I knew it. I was having a discussion with my dad about this very topic and I came to think of beta decay as a means of producing new elements. He wasn't sure. Thanks for making me sure.

[@skardykats]

Mind blowing.

[@dwayne_draws]

Did we get an update to explain the role of neutron star mergers?

[@Congochicken]

Would love to see a video from you guys on the EM drive.

[@JasonBechtelTeaches]

@5:20 "cuz there's lots of everything around in a supernova; it's a complete mess." -- Mike Merrifield, PhD :D

[@FlyingCowRabbit]

Great video as always! One thing though - in beta decay, a beta particle and an antineutrino, not a neutrino, would be produced.

[@SimonSozzi7258]

That was great.

[@ds5375]

So it seems that the abundances of radioisotopes is based on neutron capture and the beta decay rate. In the R process more neutrons can be captured compared to the speed of beta decay, resulting in heavier element formation. In the S process on the other hand, less neutrons can be captured before a beta-decay event, leading to the formation of a greater variability in (lighter) isotopes/elements. It seems that this is a rate limiting phenomena. What determines the rate of beta-decay in an atomic nucleus though?

[@flymypg]

Brady- Could you add links to the Astronomer's Periodic Table and the Nucleogenesis Periodic Table? I especially want the first (I have a chemist to annoy).

[@utl94]

Yes, please! I seriously just came home an hour ago, from the exam in the course "Stellar structure and evolution", about every single thing that was mentioned in this video. Coincidence…? I would very much like to have these charts! Thanks in advance! Great video.

[@flymypg]

Found the Nucleosynthesis illustration on Wikipedia: upload.wikimedia.org/wikipedia/commons/3/31/Nucleosynthesis_periodic_table.svg

[@utl94]

Thanks! Just waiting for the other one then. I tried a few searches, but they maybe drew that themselves.

[@grandpaobvious]

Very interioresting!

[@jessstuart7495]

Elements can also be created as unstable heavy elements created during a supernova undergo fission or alpha decay. You forgot to mention that in the video.

[@nikolaos9175]

Thanks!

[@shadoah]

Awesome.

[@AndreaIdini]

actually, the production site of heavy elements, like lead, and the site of the r-process, is still under review by the scientific community. The predominant opinion is that comes from neutron star merging and releasing loads of neutron enrich material that then decays. Modern supernovae simulation disprove the r-process in the supernovae. it is intuitive to associate r-process to supernovae, is the reason why in the '60 to the '90s they have been associated with heavy elements productions, but simply does not compute. you have to go, maybe, to magneto-driven ones which are pretty rare and difficult to understand...

[@Alexagrigorieff]

I don't think neutron star merger happens often enough for that.

[@AndreaIdini]

We cannot actually know for the moment.Neutrons stars mergers are less brilliant than supernovae (denoted astronomically as kilonovae). In a few years, after LIGO and VIRGO upgrades, we will tough! They for sure happen less than supernovae, by definition, but the amount of matter released is hundreds to thousands fold. Galactic chemical evolution is not an easy field...

[@pipertripp]

And now we have a better handle on that... exciting times.

[@MK-je7kz]

Is there going to be a video about x-boson and possible fifth fundamental force?

[@murphysborounderdark]

somebody really needs to do a remix of this with him going " bing bing bing bing."

[@mazinnasralla2036]

At 8mins 30 there's a caption which says the s-process does not occur in our Sun, but WILL in the distant future. I thought that the S process requires a neutron flux, and that is usually the result of carbon burning - and the Sun is too small a star to experience Carbon burning. Is this a mistake, or am I wrong?

[@elendor3428]

Great video but I'm still wondering why the s process can continue to capture neutrons when the r process reaches a stable isotope that won't decay anymore.

[@jim40135]

Love it, but that's just how a single atom of something comes about. Can you say a bit more about how these individual atoms of "stuff" come together to form lumps (or I suppose clouds) of a common material as they drift away from their point of origin? Or have I totally missed the point (that happens a lot)?

[@MyYTwatcher]

Very, very nice video. I liked every single second of it. Any news from North pole?

[@Mr.Unacceptable]

Do elements leave any trace of the processes that formed them? Can you tell and s-type made element from an r type in the same sample?

[@garethdean6382]

To a point yes. This is complex and depends on things like the amount of each isotope of an element (Most elements have more than one stable isotope) and whether there are an even or odd number of protons and neutrons in that isotope. This works best for things like meteorites, in Earth stuff gets mixed and filtered; changing their isotopes. (For example you can tell a fake wine by looking to see if petrol-based industrial alcohol was used instead of grape-derived stuff.)

[@lorenbooker9486]

Moar videos on 4 dimensional objects like hypersphere's and hypercubes pretty please :D

[@danhei]

Where can I get a copy of that chart? I found this most interesting. Cheers

[@rockets4kids]

I recall reading not to long ago that some heavy metals (most notably gold) were only produced in the merger of two neutron stars. Do you have any comment on this?

[@sunshineo23]

wow, how come I only learned about this today!

[@Swoost]

They need to update this to reflect recent insights into nucleosynthesis in neutron star mergers

[@BrownPen_BluePen]

So can you only add neutrons to unstable isotopes of elements in star cores?

[@stz03]

Where can I find that star synthesized period table?

[@xXxMonerderDarkxXx]

Please, make a video abut the Great Attractor and Gravitational Anomalies !!!!!!!!!!!!!!!!!!!

[@clancywiggum3198]

Do larger supernovae with higher neutron flux produce heavier elements than smaller, lower flux supernovae through the R process?

[@adamprasek9640]

That would depend on specific situation but in general you have to consider fission barier - heavy elements are broken down to lighter elements.

[@wiadroman]

"How on earth do you end up with those elements?" - a nice pun right here :-)

[@ds5375]

When an element reaches isotope stability, what is it on a physical or chemical level, that prevents more neutrons from being added, or will any further addition of neutrons, just decay to that stable isotope ad infinitum - i.e. the element has reached its final state.

[@massimookissed1023]

You could have a stable isotope, and then adding a neutron makes an unstable isotope which undergoes *_alpha_* decay, which means instead of gaining a proton through beta decay, you've *_lost_* 2 protons and 2 neutrons.

[@feelingzhakkaas]

Does these S and R process achievable in the laboratory ?

[@PTNLemay]

Not only forged in the heart of a dying star, but forged in the heart of TWO dying stars.

[@robkuijer9273]

So what is all the recent fuzz about neutron star merges making large amounts of gold and other heavy elements about? Is that the r-process? or something else?

[@junkerzn7312]

I believe so, yes. When neutron stars collide the resulting explosion frees up an insane numbers of neutrons (they are no longer being crushed by gravity) which collide with outer shell and create lots of heavy atoms, far more than would be created in a supernova. That's my understanding. -Matt

[@alext9067]

It's true. I used neutron capture and beta decay to create about 50lbs of gold under my bed. The problem was the next morning they had decayed to jelly beans and were covered w/ ants.

[@elanjacobs1]

Where do the extra electrons come in to balance the extra protons?

[@Shinigami537]

Interesting that there's a book called Atlas of Creation on the bookshelf.

[@jessewright5604]

'And then those neutrons go "bing bing bing bing bing!"' lol

[@morgengabe1]

Was that first one an Astronomer's periodic table or a Cosmologist's?

[@fpm1979]

Professor Merrifield’s comment about the astronomers’ periodic table: “I’m only showing this because it really annoys chemists.” Pun intended.

[@michaelibrahim9275]

Felix Müller Where’s the pun

[@brandonjames8137]

I got this email today and Brady's voice (inside my head) told me: "Brandon, check out the latest video from your channel subscriptions for Oct 25, 2016."

[@geoffrygifari4179]

what is the mass limit of the s process?

[@zachcrawford5]

When neutron are on their own they have a half life of 15 minutes or so but when they are in an atomic nucleus their decay rate slows down or even stops. How does that work?

[@GumbootMan]

The basic rule of particle physics is that if a particle decay can happen, it does happen (with some probability). Neutrons can decay in free space because all the conservation laws are obeyed, conservation of energy, momentum and charge being the main ones. Whereas protons cannot decay to neutrons in free space because protons are a tad lighter (less massive) than neutrons, which means conservation of energy would be violated (mass being equivalent to energy via e=mc²). When neutrons are bound to an atom, there is an additional potential energy factor -- the nuclear binding energy -- the exact value of which depends on the electric and strong nuclear forces in quite a complicated way. This binding energy can easily be large enough to cancel out the mass difference between the proton and the neutron and then some. This can result in the neutron to proton decay *not* being allowed (which makes the neutron stable), and it can also result in protons decaying to neutrons.

[@zachcrawford5]

So it is sort of like how water will boil at room temperature if it is in a vacuum but won't boil if it is bound together by a sealed metal container. Cool Thanks :D

[@ObjectsInMotion]

Another way to think about it is that neutrons do decay in atoms, its just when a neutron decays to a proton, it releases an electron and neutrino which are immediately captured by an adjacent proton, turning that proton to a neutron. Effectively the decay is canceled out.

[@ProOnes123]

Is Sixty Symbols planning on doing a video for the nobel prize?

[@geoffrygifari4179]

and maybe sixty symbols can do a video on where the heat of the earth's core comes from, also with the general heat flow in the earth

[@noxim_]

Nice

[@Merto6]

Why don't the neutrons in neutron stars decay into protons and turn the star into a super heavy element?

[@aetherseraph]

Merto6 he didn't mention that beta decay occurs in radioactive isotopes. in fact, beta decay is the process of radiation

[@noahwood2394]

How about you try to decay under neutron degeneracy pressure, also the last half of your sentence makes less sense than a small off duty Czechoslovakian traffic warden appearing on the surface of a neutron star. Does that answer your question?

[@ze_rubenator]

Oh I get it, cause Czechoslovakia doesn't exist anymore. For a second I thought you mean there AREN'T off duty traffic wardens continously appearing on the surface of neutron stars.

[@TheHarboe]

For the same reason neutrons in a stabile nuclei doesn't decay. Neutrons are unstabile if they're free/unbound. Neutrons in a stabile nuclei are stabile through the binding energy associated with the strong force. Neutrons in a neutron star are a bit more difficult, but roughly explained they are stabile through the binding energy associated with the immense gravitational force.

[@breckenkeller6508]

i think merto6 is joking guys

[@rhapsoblu]

For the r process elements, has anyone tried to calculate how many different supernovae remnants are combined to form the elements on earth? If I have a lump of gold is it the remnants of hundreds or thousands or millions of different stars?

[@tman301j]

What's up with the Atlas of Creation in the background? Why is it there?

[@Abdega]

Probably for lulz

[@bovanshi6564]

What limits this from being used to create new super heavy elements?

[@garethdean6382]

Decay rates. Heavier atoms tend to decay via 'spontaneous fission', the nucleus just splitting roughly in half for no reason. This becomes more and more common until, at some point, the nucleus will be so unstable it doesn't exist long enough to acquire more neutrons. And since fission doesn't just move you a bit back but undoes half your progress that should set a pretty solid limit. Exactly where though is unknown at this time.

[@joetylerdale]

At 8:43, this explosion shows "curves" from the center to the outer circle. Why curves?

[@garethdean6382]

What you're seeing there is gas given off by a star expanding into space. It's actually more of an hourglass shape, two big lobes around the central star. *That* shape has to do with the interesting way a star's spin interacts with how it throws off gas and how that gas interacts as it moves through space. It's related to the 'jets' black holes can emit when feeding.

[@joetylerdale]

Very interesting, thanks Gareth. I'll be on the Astrophysics circuit in about 300 years ;-)

[@joetylerdale]

Forgot to ask, what is your picture of (red crystals on a white surface)? Quite fetching.

[@garethdean6382]

joetylerdale It's vanadite crystals growing on some limestone. Vanadite is a very colorful mineral.

[@scottmuck]

If not via a super nova, how would the elements reach us? I’ve always assumed those elements not blown out into space via a super nova would be trapped forever in whatever star formed them... or in the white dwarf left over.