The Biggest Ideas in the Universe | Q&A 18 - Atoms

[@seancarroll]

Erratum: around 20:00, trying to explain why it's okay for the muon to decay via a virtual W, I had it eventually decaying to a tau, which is completely not allowed (the tau is heavier than the muon, and not supposed to be virtual in this example). Thanks @Valdagast.

[@KaiHenningsen]

@Christian Because the branches don't interact, we can only see the branch we're on.

[@recurrencetheorem4264]

@Christian The other branches are "copies" and are potentially asking the same question you are. The branches are independent histories and do not interact.

[@davidjamesovens2320]

Thanks so much Sean, wonderful videos, sometimes over my head, but this has forced me to do further research. For instance Hilbert Space, Hamiltonian, Gauge theory, Vectors, Scalar, Tensors, Particle spin, the Schrödinger equation etc I have learnt so much without having to do a maths degree!! Thanks again, your time is much appreciated!!

[@marcos49888]

I love this! I love when you and the science/astronomy/astrophysics cast show up on history channel etc haha. That's TV! That's the kind of stars we need!

[@Valdagast]

20:00 The tau is heavier than the muon, so how does the moun decay into something that decays into a tau?

[@seancarroll]

Oops, you're right, that was a mistake.

[@paulc96]

Thanks again Professor Sean, for the best show on air, anywhere, on a Sunday evening. . . . One question - I thought “Neutronium” was the name given to Neutron Star material ?

[@paulc96]

At 55:20 What ! - I am always gravitating towards my refrigerator !!

[@rhondagoodloe3275]

Thank you Professor Carroll- Ready for class to begin!

[@chaoticstorm8145]

Sean I really love your videos! I'm going to school right now and getting my bachelor's in computer science, but after finding yours and many other scientists talking about physics it really makes me wish I could go back and switch lol. I'll probably stick with computer science and have physics as my curious interest for the time being, but I just want to let you know that this series is great and highly appreciated 👍🏽👍🏽👍🏽

[@SanjayShashikantJosh]

Nice to see an early entry of Schrödinger's cat! ;-)

[@cesteres]

Bond villain.

[@JohnDlugosz]

At the end: a new force will not be able to build a hovercraft, but subtle short-range effects might be useful in building computer chips. Also, interactions are not all about "force", the Weak being a case in point. Harnessing it might be useless for making motors, but might enable completely new abilities, such as efficient power generation, fabrication, or scanning/imaging.

[@SkorjOlafsen]

I love it when you take the time to clarify sloppy terminology. It really does help! I'm sure between experts everyone knows what is meant, but it's really confusing to the novice.

[@pamelacollins1153]

I love your online lectures.Dr Carrol ! I just got your “Deeply Hidden” book and am reading it now. . I read your book about the Higgs a few years ago, and I’m really glad I found your channel

[@JoeHynes284]

ive read it three times and am still digesting :)

[@tonib5899]

2 atoms walk into a bar, only 1 shows up.

[@paulmichaelfreedman8334]

Great to see you also answered my question about where the photons went. I had already worked out that the CMB was a definite candidate but was not sure. Thank you for long answer!

[@nibblrrr7124]

Trying to follow the references for the plot shown at 53:45, I found a couple similiar but not identical graphics: - _Long et al (2003) Upper limits to submillimetre-range forces from extra space-time dimensions_ doi.org/10.1038/nature01432 (You can use sci-hub (dot) tw to get access.) A newer, high-quality graphic can be found in _Antoniadis et al (2011) Short-range fundamental forces._ doi.org/10.1016/j.crhy.2011.05.004 There are also similar sets of variants in earlier publications by _Antoniadis_ (et al.) but in potato quality (both in preprints & paywalled final publications): - (2003) _Physics with large extra dimensions and non-Newtonian gravity at sub-mm distances_ doi.org/10.1007/978-3-540-45230-0_9 and (2007) _The Physics of Extra Dimensions_ arxiv.org/abssch /hep-ph/0512182 - (2003) _Brane to bulk supersymmetry breaking and radion force at micron distances_ arxiv.org/abs/hep-ph/0211409

[@volaireoh883]

Excellent stuff, I've learned so much... many thanks Sean.

[@robertshirley2645]

I have Never been answered neither for my essay nor for my questions directly but, it is like every thing proves that my theory is right as rain! About forces and matter and dark energy and dark matter

[@SomeGod]

That's amazing! You should publish your works, submitting them to peer review!

[@robertshirley2645]

@@SomeGod it is almost impossible.I have sent it to more than 30 physicists but no one responded back. A physicist would not take that much of great risk to review and credit it!

[@wolfyklassen]

Could you speak a little about CPT conservation, and why that might come out of the standard model? What are the origins of discrete symmetries like this?

[@Johncornwell103]

So close to 100k subscribers. Congrats

[@coastwalker101]

Oh many thanks. I have been wondering what physicists mean by "on shell" and "off shell" interactions for ages and you just nailed it for me. Virtual particle interactions where the mass is more likely given the energies involved is on shell and the ones that are not are off shell. Brilliant! (Edit, I assume that this could also involve virtual particles that are much lighter than the input energy would equate to as well as much heavier ones).

[@mellertid]

"Therefore, neutronium cannot exist". Neutron stars left the chat.

[@w6wdh]

Fascinating description of how the u u d quarks (2 MeV) fit inside the proton (938 MeV). Thanks, Professor Carroll! Q: Does Heisenberg’s uncertainty principle imply that the quarks’ momenta must be huge because they are tightly confined? It sounds as if the interior of a proton could be a seething mass of quarks and gluons, whizzing around at a significant fraction of the speed of light.

[@msanguanini]

How would you define the differences of condensed matter and states of energy below it?

[@stephensonal4082]

I'm trying to understand why what you say is so understandable, thank you. Now the big Q. is there a conceptual idea of an inverse atomic structure reflecting a black hole?.

[@OBGynKenobi]

How does combinatorics work into the discussion of atoms in the universe. Ie, there is only a finite number of atoms in the universe, so how does that affect the evolution and outcome of the universe?

[@ProfessorBeautiful]

34:40 or so.... explanation of relationship between virtual particles, the "mass shell", and interaction rates. Aha! That's a whole lot of "aha"! ... but hungry for the math to really understand.

[@brandonlewis2599]

@ ~ 19:30 ... Wait, a muon can decay into a W- boson, but then that boson can decay into a Tau?? I thought the Tau was heavier than than the muon...

[@TheMemesofDestruction]

35:00 - Fascinating! ^.^

[@tonib5899]

Does the compton wave length increase as we squeeze the particles down.Thankyou.

[@JohnDlugosz]

No. You would not be able to say that they were squeezed if that were the case! It's what you measure against.

[@tonib5899]

@@JohnDlugosz Thankyou.

[@w6wdh]

Is the Pauli exclusion principle enforced at the speed of light or is it enforced instantaneously everywhere? I guess enforcement would be instantaneous, just as entanglement causes quantum state changes to happen instantaneously over arbitrary distances. Or wavefunction collapse. That’s instantaneous everywhere when a measurement is made, right? (Whatever a measurement is.) I have no idea how you would ever unify quantum mechanics and general relativity. They have different notions of causality. Perhaps I should just shut up and calculate, but I really want to know what’s actually going on.

[@TheD4VR0S]

I have a question about superposition: As you know when multitasking on a single core cpu it runs programs one at a time but switches between them so fast it looks like multiple programs are running simultaneously. So could particles be switching between spin up and spin down so fast it just appears like a superposition ?

[@JohnDlugosz]

No, that's not what is happening.

[@TheD4VR0S]

@@JohnDlugosz How do you know ?

[@JohnDlugosz]

@@TheD4VR0S I've read a number of books on the subject, up to and including actual text books. Read up on "Hilbert space" and separable wave functions. A good book, which I do believe Sean also recommends, is "Quantum Mechanics and Experience" by David Albert. (Chapter 1). I believe you can find a PDF on-line. Superposition is categorically *not* switching between two things very quickly and you happen to catch it in one or the other. It is a state that does not correspond to a classic measurement. The quantum state is a matrix full of numbers, and a classical measurement corresponds to the eigenvalue of one of the eigenvectors of that matrix. But a matrix has much more possible state to explore and is much richer than the classical regime.

[@TheD4VR0S]

@@JohnDlugosz Thanks

[@paulc96]

@@JohnDlugosz Hi John, how are you keeping ? Thanks for that - and the book recommendation. I used to think of Superposition in the same way as David - rapid switching between the 2 states. Could you please tell me - is there a lot of Maths in the David Albert book? (Sorry, but I am a bit of a Maths dimwit I'm afraid.) All the best, Paul C.

[@Grasuggan22]

Does the stong force and gravity have something in common?

[@davidhand9721]

Why are we multiplying little psi to form big psi? Calling it p, I'm looking at P(x1, x2) = p1(x1)p2(x2) - p1(x2)p2(x1)? Why are they multiplied, then subtracted? If they're parts of a whole, not factors, then shouldn't they be added? Why not?

[@josephpaoletti2435]

Has anyone ever considered if electrons going in and out of existence while producing and emitting photons is actually fractal iterations?

[@johnp1]

Can't wait to hear about a thought experiment with Sean Carroll's cat :-)

[@protoword10]

Thank you profesor!

[@junacebedo888]

Ideas from a mind. A mind of a Person. A Creator person. An Almighty Person

[@tonydarcy1606]

Sorry Sean, but I just do't get the difference between the "wave function of the universe" and the one where measurements are made on particles.

[@stevesastrohowardkings2245]

Does decay act different in space Verses vacuum on earth thoughts

[@kimoothe1st]

What about dark matter axions

[@markcoffey9437]

I want to make bubbles inside bubbles to strengthen our magnetic field. I'm working on a design that will help redirect and reverberate the Earth's lost magnetic fields back into the larger magnetic field lines. In my personal opinion I think the larger lines will absorb the energy and transfer it into the lines it's making...pretty much creating a mini amplifier, by creating multiple tiny electromagnetic Infinity loops to help us stop getting punk'd on by the Sun.... Help me achieve a device that could possibly let us determine how big the green zone is in our universe? (Technically it would be reverberating ionized light along with some electromagnetics)

[@fubarbazqux]

Viewers: Hey Sean, can there be negative mass things? Sean Carroll: Let me tell you about the article we wrote...

[@rickharold7884]

So cool. Thx

[@ThuannguyenN-gp2vp]

The Universe based on the concept of our ideas or It based on Itself. For example compared how big a balloon Vs tennis ball ? The biggest idea when the balloons fullest with air or no air ? Samething the universe is possible ability: Every space in Universe is expand or contract? Some space in Universe is expanding and some space is contracting ? If you fired a Canon towards from the front of your face strong enough around 3.6 km per second then after 3 hours you will see canon ball reaching your back. How about if you send a laser beam to the night sky then after billion of billion years; the same these light beam return back to your head after travel around a full trip to the Universe ? Believed or Fact ?

[@peterq1978]

ive a Tabby too, hey Kerry, ill tweet you a pic of Pheoniz, i also have Servilan

[@jalalkhosravi6458]

Thanks 🙏

[@James_Stewart]

The easiest way to lighten the hearts of any final year undergraduate student is to include the term 'non-degenerate' in your exam question!

[@tonydarcy1606]

When on a diet, I eat virtual meals.

[@ccarson]

Ghost meals if you want to lose mass.

[@tonydarcy1606]

@@ccarson Ingested energy is instantly repaid to the vacuum !

[@teddybrow]

Just make sure you don't eat any anti-meals!

[@stridedeck]

There is a possibility that there is a new force that is larger than the gravity's force, as well as, the gravity's range. For example, with Sean's multiworld theory, when the world is split into another, isn't there a force created that makes the split? Another example, is that the forces observed are all from the matter in our 3D existence. What if, just like in Flatland, we are exposed to another dimension outside of our observable physical matter? How can we then detect this other dimension's force? Prof. Michael Manfra's experiment, as reported in ScienceNews, that: "physicists have 'braided' strange quasiparticles called anyons", and was concluded ayons were created when the electrons' two paths in the 2D material were reunited after their one path was split into two by a device and then measured the resulting electric current having acquired an extra phase. Perhaps, it was not a creation of a new ayon particle, but a shortcut, via. another dimensional force, cutting through our 3D space?

[@DaveMuller]

I like the videos that have cat. Video liked.

[@ytinformes2]

"You don t feel the gravitational force of your fridge." Plz remind this to any teenager boy hanging around in the kitchen field.

[@davidhand9721]

Not enough of an answer for neutronium. If indeed 2 neutrons could form a nucleus, yes, it would rapidly decay into a deuteron, but the overall reaction would be neutron-neutron fusion. There would be tons of energy in it, right? There's no electrostatic repulsion between neutrons, so the energy barrier to fusion would be next to nil. One can imagine 2n + 2n fusion into He4, or arbitrarily higher, at low temperature. If you can create 2n at all, there would be massive profit in it. We don't see this, so what gives? Why can't we generally sneak protons into a nucleus as neutrons exothermically? I know it kinda happens in certain fission reactions and neutron star collisions (R-process elements). But why isn't it more useful for low energy fusion? Why do we need protons for exothermic fusion?

[@sarojinichelliah5500]

Hi Ariel !

[@cdgt1]

What do we call an electron floating upside down in a swimming pool ? Bob.

[@notmyrealnameful]

Personally I think I do feel a gravitational force from the refrigerator in the kitchen. Particularly about 3am.

[@Petrov3434]

Q#3 -- no idea what really was the Q nor what was the A ;-((

[@JasonWalsh-b4n]

👍✌️❤

[@cdgt1]

We should get rid of those pesky quarks and concentrate on the three electrons and the kinetic energy they produce when confined.

[@pistitoth1363]

Kevés vagy!

[@christianfredh]

I'm not only learning physics here but also that I'm a nit-picky person 😅

[@Sixstringman]

I come from the mainstream news section. There were no signs of intelligent life anywhere.

[@kagannasuhbeyoglu]

👍

[@quahntasy]

*Hey Sean I found first 100 page of Something deeply hidden book very boring, but you ignored me on twitter so here I am*

[@DeezNutz-yg8io]

ALL BOLD IS OBNOXIOUS! Just...don't

[@seymoronion8371]

The odds are strongly against Senpai noticing you, when you post negative comments, and yet you persist. To what end?

[@quahntasy]

@@seymoronion8371 oh he will notice me some day. I found the rest 200 pages actually good with some new 'information'

[@CorwynGC]

en.wikipedia.org/wiki/Neutronium

[@barissannan2731]

well, its maybe the nature that is sloppy, not our language.

[@AndrewKroll]

Cat is in heat 😂

[@joshua3171]

he was using a Yves Klein IKB 79(I cheated and googled it....guilty)

[@AtomFA]

THINK UR SO SMART

[@johnqpublic2718]

Nocka botch!

[@benkel7528]

Tongue twisters with a scientific equation. I will use this to meditate along with. It's a metaphor of nothingness.