I am saddened that the lecture Q&A videos have moved behind a pay wall. It seems counter to the RI mission of "connecting as many people as possible with the world of science." I hope they will reconsider.
I don't mind the ads, I think donating a few seconds of my attention in exchange for a little money flowing to the RI is a good trade. But effectively blocking access to a part of the lecture experience feels contrary to RI principles. I love the work they do. I hope they can find a better way.
A superb talk on a topic very rarely discussed with the public. Lucidly explained, with engaging examples - e.g. of neutrino oscillations. Much thanks to James Riordon and RI.
@@jamesrriordon5955 Your talk opened my already wide-open eyes, to even more complexity. Rhetorically, I wonder: If/since neutrinos seem to oscillate between their 3 flavors (and between their lepton/antilepton states), does it suggest all leptons oscillate within their species? Related is the idea of baryons probabilistically oscillating between particle/antiparticle forms (and between 3 or more odd-count multiples of quarks), creating the "quantum foam" we call "empty" space. _Combining both:_ As a lepton traverses "empty" space, does it/how does it perturb the quasi-particles in the quantum foam?
I thought it was quite interesting, to watch this lecture, the point of view of a journalist, a man that shows to be very passionate about this like us all. In a way, he mirrors our desire to know more, our, us,we the people that the destiny didn't lead into scientific research, but nevertheless, marvelled by it. Saying this man should never been there, should sadden us all. We love science, seeing this mans passion right there, it could be us, amongst our family and friends. If one spoken word is not accurate, and we know it so, we think to ourselves, that was not accurate, but... realize I knew that! We could be that Man right there, using his passion, to spark ours. Love to all, happy holidays! 😽
Thank you for mentioning Ray Davis and John Bahcall. I saw a documentary on their experiment decades ago and have wondered why they were never mentioned again as neutrino science advanced.
How could you ever communicate with a system with such high error rates? Only 1 data bit would be detected for every 100,000,000,000 misses? Even just turning off and on ala binary would never work because of missing bits. Great speech.
I really enjoyed going to Homestake Mine Visitors Center in Lead, SD a few weeks ago. They have exhibits about Dr. Davis and the current experiments that are going on in addition to the history of the mine.
39:10-46:10 in theory there could be sections of the universe with matter and other sections with antimatter, with empty space in between. And from what I know you can't distinguish matter and antimatter from afar. In this case we wouldn't observe any annihilation. Or is there a reason to rule that out?
Very good point! You are correct, matter and antimatter would be difficult to tell distinguish, if they exist in separate parts of the universe and are far enough apart that there is little interaction with the opposite variety. It could certainly solve the matter/antimatter asymmetry problem, if it happens. (Because there would be no asymmetry to explain!) And neutrinos wouldn't need to be involved. Then the big puzzle would be why the matter and antimatter separated. Which would also be exciting to work on!
Yes, and now you need an explanation how these large amounts of matter and antimatter got separated so neatly that it didn't leave any x-ray signals at all. ;-)
Are neutrinos waves, like photons are EM waves? And how do we know? Note: The neutrino-oscillations seem similar to how light "oscillates" from electric to magnetic and back.
all quantum particles have wave properties. the lighter the more pronounced. wave like behaviour has been observed up to giant C60 molecules showing interference in a double slit experiment
@@S1nwar I know Quantum-mechanics. But the way neutrons behave, it looks more like another version of light. The neutrino-oscillations are just like EM-waves change from Electric to Magnetic and back.
a photon has both electric field and magnetic field at the same time, perpendicular to each other. they both oscillate at the same time, they dont replace each other.@@zyxzevn
Could be longitudinal electrodynamic waves... basically the far-fields of divergent current sources which are omitted by the coloumb guage in classical electrodynamics, and subsequently omitted by quantum electrodynamics through enforcement of the same kind of guage freedom that has been assumed valid in the classical domain. Good luck getting physicists to question maxwellian electrodynamics though.
One Alien to the other Alien when looking thru their Neutrino Telescope at the people who constitute the Government of the Most Powerful Country in the History of the World: "Waaa, not's let go there"
I always laugh when people say, ' it shouldn't be here'. Mistaken the map or model for reality. The proper observation should be. 'Hey this is here, where did my idea go wrong, let's do it again!'. Unfortunately I don't have a degree, only common sense.
How good are we now at judging the directionality of neutrinos? It seems like 3 or more big detectors could be used to locate the general location of nuclear reactors. Especially reactors that aren't supposed to exist.
neutrinos interact with electrons.. speed up the electron so that it becomes a muon.. some of the energy is stored as neutrinos.. we could call it neutrino capture... when the muon decays, it releases those neutrinos..
Hi Sir, I have a simple question. Inside a factory at the end of the shift a supervisor and his co-worker are counting the produced objects, the objects are approximately the size of a tennis ball. It is their daily routine,the worker counts the objects as he takes it from the production lot and puts it inside a bag. The role of the supervisor is to keep watch so that there is no mistake while counting. One fine day, before starting the counting process, the supervisor looks at the lot and writes down some random three digit number as quantity of the produced items, in short he assumes that the actual quantity would probably match with that number. Now the question is what are the chances of that actual quantity matching exactly with that random number?
It depends on the distribution from which the random number was drawn. For example, suppose you roll a six-sided die whose sides are numbered 0-5 (slightly unusual, but bear with me). Each of the numbers 0-5 is equally likely to come up. Suppose, instead, that you toss a coin five times and count the number of heads. Now, you'll get 0 and 5 about 3% of the time each, 1 and 4 each about 16%, and 2 and 3 each about 31% of the time. So the choice of distribution can very much alter the probability that the supervisor guesses a particular number and, therefore, the probability that they're right. Now, I guess the reason you're asking the question is that a lot of physics experiments take the form of "Measure some random events, then announce that they agree exactly with theory." The point here is that, first, they're measuring a huge number of random events. That means that they're very likely to see close to the average number of such events, rather than some fluke. Second, "agree exactly" actually means that they're extremely close to the theoretical value but not necessarily exactly equal to it. For example, suppose our theory is that coins are equally likely to come up heads and tails. Our experiment is to toss a coin some number of times and count how many heads. If we toss the coin ten times, it's fairly likely that we'll get 3 or 7 heads, so we don't learn much. But suppose we toss the coin a million times. It's still very unlikely that we'll get exactly 500,000 heads -- even if we have 499,999 heads out of 999,999 tosses, there's only a 50/50 chance that the last flip will give us the result we need. But it can be calculated that the chance of seeing either less than 49% heads or more than 51% heads is about one in nine million. So, in that experiment, the supervisor is very unlikely to guess the actual number of heads but, if they guess 500,000, they're almost certain to be within 1% of the true answer. Or, to put it another way, the actual number of heads when you flip a million coins is almost guaranteed to be between 495,000 and 505,000. And it has about a 97% chance of being between 497,500 and 502,500.
Skittering - move lightly and quickly or hurriedly. And a Sean Carroll reference. So no nuclear furnace and the earth is part dark matter? Whaaaaa? Hmm lets see what Anton Petrov says. 😉
@@jmjawors Dark matter, as far as we can tell, pervades the universe. so there is some in the earth. (There's also some in you.) Neutrinos could be used ot measure the non-dark matter portion of the earth, while gravitation-based measurements tell you about the combination of matter and dark matter in the earth. The difference between the two measurements will tell you how much dark matter is in the earth.
No matter if you are or are not a particle physicist, please try to remember this: A neutrino is a quantum (small amount) of energy. This energy comes with some other properties attached which show the internal symmetries of the vacuum, but at the end of the day it's "just" energy.
"For the very first time in history, as far as we know, we have the ability to look at the universe with something else". I am being picky I know, but gravitational waves are also a new window on the universe and are not made of electromagnetic radiation so neutrinos are not completely unique in this regard.
Very good point. But you can't yet produce images of the Milky Way or any other structure with gravitational waves. They reveal individual events, so it's more like listening for car crashes in a city than mapping the structures in a city. Someday, gravitational waves will produce images comparable to the ones we get with light, and which we are now starting to get with neutrinos, but we're not there yet.
very indepth talk,a pleasure to listen to.ouestion ; as neutrinos alter mass with spin, ie lower and higher,then ether e equals mc su is at play or they interact with the higgs field alter this to change their mass as opposed to having a fixed mass determined by the higgs ?
@@Marrss____666 I get that, but I also don't understand, heh. Like, when it was all the size of a football or something, and the universe expanded, faster(?) or slower(?) than now, does that mean that the universe has to loop, cuz wouldn't the neutrinos that were flying around back then have reached the "edge" if it doesn't loop?
Wow.❤loved this. Who's James Riordon again? Thank you very good lecture.. Super informative. And I'm buying that book asap. Putting all other books on full stop.
Would the vast majority of neutrinos from the early universe inside you be non-relativistic? An item not mentioned is the handedness of neutrinos and antineutrinos. The talk was very informative, especially about the very early work on neutrinos. Do neutrinos pile up in the universe over time is what I wonder about.
Yes, they could be non-relativistic. The temperature is approx. 1.95K, which corresponds to 0.1mEcV/c^2. At least the upper bound is three orders of magnitude above that. Could some neutrinos collect in gravity wells? Without any calculation just off the top of my head... probably very few. I don't think the scattering cross section in ordinary matter is nearly large enough for them to thermalize. I could be wrong. Some (also very few) would get caught in black holes, of course.
Current estimate is that primordial neutrinos have red-shifted (slowed down) due to expansion of Universe to the velocity of about 1000km/s at present time. > Could some neutrinos collect in gravity wells? No, with vanishingly rare exceptions. 1000km/s is too large velocity for gravitational capture.
We need to stop trying to touch ghost particles and start trying to look. E equals m c two should mean we can see them through Gravitational wave detector. There should be small static. That is them.
Подход к анализу процессов рассматриваемых в лекции вызывает сомнения, причём, на первоначальном этапе. Анализируя материальные процессы, механику берём которую знали от исследователей 19 века. Однако, попробовать по другому представить сам процесс. Говоря о частицах но не разбирая среды в которой эти частицы, всё равно, что кипятить воду ядерными реакциями добывая электричество. Странно всё это.
If i were a neutrino ,i would be in the dark and alone ,tgere would be nothing for me to identifying that i was actualy moving , sometimes something hits me 😮😮😮😮
I realize you said that those who "Knew" only "Knew" about 40% more but only after directly admittimg limited knowledge that you "weren't going to get into". This seems quite a bit like spiritual elitism (I cannot understand your faith). I would appreciate a chance to try. Whether to agree or deny. Otherwise how do you even back up the 40% ?
It's not spiritual elitism because it's not spiritual and it's not elitism. The reason he doesn't give you the "chance to try" is that the talk would be literally thousands of hours long if he tried to explain everything that is known about neutrinos -- searching arXiv for "neutrino" gives 35,899 papers.
Molecular hydrogen line appears in cold molecular clouds. (Otherwise - dissociation). Atomic hydrogen line appears in hot areas of the Milky Way. > then why images are not inverses of each other? Because we project 3d space to 1D map. Along your sight there might be cold and hot objects.
We could shoot them at the sun no problemo. Using that to learn about the insides would be tricky though, because we would need a neutrino detector on the other side to look at them...
@@SwingingbellsGood point! (The lady of the house ask me to point out that it's "el problema." I said that was being snarky. However, she won -- as usual!)
there's no need tho... the nucleus of the Sun produces a whole ton of neutrinos per second and they are already coming our way. Studying solar neutrinos is already one of the main tools we use to study the nucleus activity.
Ask AI how much recognitive memory it has retained since it's conception and how much outside contact information has it received and from whom it got it from. Then you will have given it a processed order in which it must know. Dustin Normand and I approve this question for ai. 😮😮😮
Называют, как это будет странно. Есть даже теория "Эфиродинамики" изложенная Владимиром Акимовичем Ацюковским. Довольно таки интересная механика процесса в той теории.@@EnergyTRE
I don't see why the matter/antimatter, how can the universe exist at all thing is a problem. Sure, if the universe was created with _exactly_ equal amounts of matter and antimatter, it would all have annihilated by now and there'd be nothing left. But if you start with the slightest imbalance, say 50.1% matter, 49.9% antimatter, then all the antimatter annihilates with most of the matter, leaving us with 0.2% of the original amount of stuff, which is everything we see today. The same argument applies for any split that's not exactly 50/50.
@@clwho4652I guess there is no requirement for them to serve a purpose but would the physics of reality and life be different without them? The subtle interactions we observe may not seem like much but on a universal scale they probably have profound effects.
@@MrHerrjon With out them thermodynamics would be wrong and we could have perpetual motion machines. I think neutrinos has been rules out as dark matter. Beyond those they might not serve anything. Like Sir Arthur Eddington said: "Not only is the universe stranger than we imagine, it is stranger than we can imagine."
@@clwho4652because, so far, everything we've discovered so far it connected to everything else and consequently serves a purpose. Things that don't serve a purpose would just mess things up. That's fine but it would be a whole new universe that went against all the things we've observed so far, which is a big ask. That's not the end of it though. Relativity was a big ask that changed the entire way we understand the universe because, so far, everything we discover backs it up. So it's not impossible but a lot of evidence is required to counter everything we already have and so far all the evidence sides with the status quo on this matter.
Попробуем взглянуть на всё происходящее с точки зрения анализа ситуации. Кто то сделал открытие и сформулировал своё виденье процессов в изложении для нас, мы теперь смотрим на процессы его формулировками ( каждый из нас процессы не открывал, а брал как учили). Так что " О сколько нам открытий чудных, готовит просвещенья дух".@@woofbarkyap
Very good question! It's not sensitive to the low energy neutrinos coming from submarines. Other neutrino detectors that use other detection methods, could, but they aren't good enough yet to be practical.
The neutrino flux of a reactor can be detected out to maybe a couple of miles, but that's probably it. Even then the event rates would be way too small to track a moving reactor. It's also not necessary. We have very effective ways of tracking submarines.
@@jamesrriordon5955 it is not hard to believe that $ is not a limiting factor while talking of finding nuclear submarines or communicate under the sea. Governments have spent trillions doing this!
Nobody ever called neutrinos that. Physicists don't call the Higgs that, either. We call it the Higgs. After all, Christians also don't call Jesus "Flubber". ;-)
At 1min 13sec why claim "probably before that" ? Are there betting odds your not letting on to? Probabilities can be discussed in ratios, correct? What is the probability? Do you mean "possibly" or do you just mean to encourage those unfamiliar in psycho/lingual debauchery not to look further?
The Wardaman people named the artwork "Sky Boss and the Rainbow Serpent," so you'll have to take it up with them. I'm not sure "serpent" is strictly synonymous with "snake." Merriam-Webster says a serpent is "a noxious creature that creeps, hisses, or stings." Snakes don't sting, and there's no mention of legs (or a lack of them) so, it seems, "serpent" has a broader meaning than just "snake."
An answer comes from information theory (of which I am not an expert.) There are methods of differentiating between noise vs. information (i.e. meaning.) The receiver may not speak English, however, they would know that its sender is intelligent.
He was referring to the core. it takes 200k years for light to escape then 8 mins to reach us, so if the core disappeared, we wont know for 200k years but if we look at nutrinos we will know in 8 mins since nutrinos escape without interacting.
I aasume that the escape time is distributed statistically. While the average photon might take 200’000 years to ooze out, there will be some that make it out much quicker. We will therefore see a dimming of the sun presumably with massive freezing of earth long before that time.
The problem is not thermodynamics, it's probability. Since probability works (apparently) at a macroscopic level, it doesn't at a microscopic level (remember the collapse of Schródinger equation).
It's tough when you're talking about historical events, and the units have meaning in the historical context. Cowan and Reines specifically set their experiment ~137 feet from the detonation tower as an homage to the fine structure constant. Crane didn't buy a 0.907 kg bag of salt; he bought a bag of salt labeled 2 pounds. While Cowan and Reines themselves eventually changed their diagrams to say 40 meters, they chose ~137 feet for a very specific reason that using metric units would obscure in this context. Just to beat a dead horse, Jesse Owens ran the 100-yard dash in 9.4 seconds in 1935. He didn't run the 91.44 meter dash.
