You all prolly dont care but does any of you know of a trick to get back into an Instagram account..? I somehow forgot the password. I appreciate any tricks you can give me!
@Khalid Alonso thanks for your reply. I got to the site on google and Im trying it out atm. Takes a while so I will get back to you later with my results.
Have you seen my videos on General Relativity: An Introduction (parts 1 and 2) and Curved (Warped) Spacetime. They deal with the nature and effects of gravity.
A neutrino is an elementary particle. Billions are produced by the sun when protons are converted to neutrons as the first step to making Helium. A proton changes to a neutron, a positron and a neutrino. You can get more info about neutrinos in my video on the Standard Model.
The process is called Deep Inelastic Scattering (DIS) and involves firing very high energy electrons at a nucleus. High energy electrons have low wavelength so are able to probe the proton. Some of the energy of the electrons is used to create new particles which results in meson production. And you are right that electrons will be attracted to protons. But they can still deflect (just as a comet is deflected around the sun by attractive gravitational forces). I haven't done a video on this.
You could use either. A W+ in one direction = a W- in the other direction. But a tip I am offering is to take the W away from the baryon and towards the lepton. Whether it is a + or - will be determined by whether a proton is changing to a neutron (needs a W+ away from the proton) or the other way round in which case its a W-.
This really is impressively done. Admittedly, I was first looking for a video with lots of fancy graphics having enough of the collegiate approach. This video reminds us that giving the student "insight something an insightful professor can relate counts for a lot. Having finished college a good number of years ago, it reminds me what the best professors always do. They know what is essential for everyone to learn and help tweak one's world-view of a topic.
The general position is that baryon number, lepton number and charge are always conserved. And in the case of leptons it has to be the lepton type (eg electron, muon or tau). For particle interactions governed by the strong or electromagnetic forces, the total strangeness must remain the same. For interactions governed by the weak force, the strangeness can change by one unit.
Well this is partly what string theory is all about. At present the standard model contains what are known to be the most fundamental particles, (quarks, electrons, neutrinos and bosons). We have no experimental evidence to suggest that these are made up of anything smaller, but who knows what the future may bring.
" Three quorks for muster Mork, sure he has not got much of a bork, and sure any he has it's all beside the mork."( Written in chark by a leg of park that could not tark except he could wark.)
A level is the exam taken by British (and other) students at 6th form college when they are (usually) 17-18 years old. It is the exam level immediately before students go to University.
If, say, an electron and a positron were created by pair production, then angular momentum would have to be conserved. But if you take a random electron and a random positron they can have a spin in any direction and there is no requirement that one has the opposite spin to the other.
The key point is that no pair production will occur unless there is enough energy to provide at least the rest mass of the particles concerned. Excess energy will go to kinetic energy. But there is no way of determining in advance which particles will be produced. That is the nature of quantum mechanics. In practice, of course, billions of protons collide and produce a whole range of particles which enables us to calculate the statistical probability of their production.
so fascinating and awesome. Before seeing this video, I've always struggled with actually understanding what the weak interaction did, and why it happened. Now it makes perfect sense. Thanks Doctor!
Thanks for comment. Do you mean gravity waves (eg waves on sea) or gravitational waves - the consequence of massive objects moving in curved spacetime?
No. It's just that no-one has discovered such a gauge boson for gravity. If it were there it would be a graviton. The Higgs Boson isn't there either for the same reason.
Yes. A proton decaying to a neutron requires an energy input (I think it is 1.29MeV ie the mass energy difference between the proton and the neutron - the neutron is about 0.2% heavier than the proton). A neutron decaying to a proton produces energy (about 1.29MeV). And yes, the total energy of all the particles has to be taken into account. Indeed it is this calculation which showed that there had to be a neutrino to balance the equation.
It can indeed be measured but I do not know the details of how. You cannot, of course, isolate an individual quark so the measurement of the charge is going to involve measurements of other factors with a deduction of the appropriate charge.
I think it must be an error. The Up, Charm and Top quarks have charges of +2/3. The Down, Strange and Bottom quarks have charges of -1/3. The anti- quarks in each case have the opposite charge, either -2/3 or +1/3.
Thankyouthankyou! You make the material manageable and relatively easy to understand. Now I'm off to binge on all your particle physics videos before my final exam.
Thank you. Good luck with your studies. My degree is in physics. I'm not sure which energy equation you mean, but if it is the Schrödinger equation, have a look in my playlist on quantum mechanics and you will find a simple derivation.
12:45 The Mesons are combined by 2 quarks (a quark and an antiquark) so the total spin is not semi-entire... and consequently, I think they are Bosons, not Fermions. Very well explained all, thank you very much for your effort
Why when a quark and anti-quark come together they do not annihilate - why, how can they live together? By the way thank you for giving your time in creating these videos, you are helping to educate they world.
Nice, but the gluon are the ones that hold the quarks together and the strong nuclear force are the ones that hold the protons and neutrons together to make it balanced.
Fantastic summary of the standard model. I feel like mesons are the most mysterious. Does the model assume that there is no gauge boson for the force of gravity?
When you're talking about what is being conserved towards the end. Is this only in the weak interaction? Because I thought the Strangeness is not always conserved?
omG!! talk about a personal eureka moment for me yesterday when i realized the electrons in the shells are ENERGY MOVING IN SINEWAVES instead of staying a fixed distance from the nucleus....... or am i understanding this correctly? i've got a thorough understanding of this vid now.. can you recommend which one to watch next? i feel like ive just entered a new dimension of science that i cant wait to explore! amazing work, btw, and how anyone could give a thumbs down is beyond me lol
@ 19:02 You spoke of things conserved in weak interaction. You mentioned the lepton number but the last part did not really answer my own question (which is, "Is the lepton number conserved?") Also, what is not conserved during interactions and what is the difference between the "W+" and "W-" bosons? Please reply soon, Thank you.
I thought you said, if matter 'meets' their respective antimatter, they annihilate each other. How can an up and anti-quark coalesce to form a (Pi 0) meson? Surely, they would simply be converted into photons. Does this mean there needs to be certain conditions for annihilation to occur?
Doctor, not to nitpick, but you tell us that quarks should pronounced as rhyming with "forks", then you pronounce them as rhyming with "parks." I really enjoy your presentations, so I don't really give a fark.
I'm glad someone else noticed- but he does insist we should pronounce it that way- then continues the entire demonstration pronouncing it the wrong way. Absent Minded Professor Syndrome? What do you think?
When a Proton decays into a Neutron does this only happen when energy is inputted? And is this why the extra matter of a Positron and Neutrino occurs? Due to the energy being converted into matter?
Hi I have 2 questions. During electron scattering I understand mesons are produced, I don't understand how, I get how they're produced when you separate quarks but not when you fire electrons at a nucleus. I also don't understand why the electron is deflected, surely it should be attracted to the nucleus due to opposite charges. I don't think you've done a video on this but if I'm wrong please direct me to it :) Thanks.
At 14:30,if all the mesons are positive quark,anti positive quark then why k` is positive positive,like strange and up positive ? Apart from these very well explained , this video is an amazing guidance for me at my peak time of examination.
DrPhysicsA, the atom was found to be form of another more elementary particles; do you think this discoveries of subdivisions can go on indefinitely or will phisycs find 'the' most simple particle? if so, why that one in particular? can all matter be reduced to energy?
I appreciate the attempt to clearly explain the topic. The Sky is blue but why is it blue? It would have been better if the reasons behind why so is so had also been told.
Hi, for the paired production, how do you know what kind of "pair" it will produce during the separation of quarks in a proton? Such as a up and anti-up, down and anti-down or even strange and anti-strange,etc....
where's the Higgs boson in the standard model? Or it's an entirely different "particle"? My bad, this video was before the discovery of the particle. It's now part of it.
Yes the Higgs is very much part of the standard model. I made most of my videos before the Higgs was formally confirmed. But it has been added to the standard model diagram.
@@ARavingLobster It is a 17th particle and goes adjacent to the photon. However, it is in a category of its own. Photon, gluon etc are gauge bosons whereas the Higgs Boson is a scalar boson.
Im am doing GCSE physics at a young age. I think you are ver good at particle physics what is your degree if I am not concerned. Also can you do a video on the energy equation because my father is working on it.
Particle physics and cosmology should not be an examinable part of school physics. Physics A level in 1978 was entirely corroborated by simple experiments that the kids actually perform and see for themselves. Atomic structure down to electrons and even protons and neutrons and elementary quantum mechanics is clear from experiments in chemistry, gases,, Brownian observations, vacuum tube rays and simple radioactivity experiments. It all hangs together and basic physics science is also essential for engineering and medicine. High school kids should not think of science like some kind of religious scripture that is to be memorised but particle physics and cosmology are very close to this because those experiments are not doable in schools and one just has to believe what you are told. Also the level of theory required to argue and analyse really is pretty advanced and kids just aren't equipped yet. The kids when presented with this dummies version of particle physics should be ripping it to pieces as it really doesn't make sense without more sophistication . There is just to much stuff that can't be explained yet.Also it is completely unnecessary for 99.9% of anything that goes on in the real world and so for engineers and chemists and medicine is basically a waste of time memorising useless stuff. It should be a non examinable option or Christmas project type thing.
Actually I have partly changed my mind. I guess anyone doing physics should at least need to hear about this stuff, but the examiners and curriculum setters just need to make a very clear distinction between stuff the kids are having to take on faith versus stuff that they can verify for themselves
I would agree that it should not be included in an average classroom, however when it comes to higher education I believe that it is still something that could be benefited from studying, as it is still gaining a greater understanding of our world. And I believe that as we start to discover more about this area of science in particular it will begin to become more and more practical. Quantum computers, for example could greatly help in creating more advanced simulations for other areas of science. But again, I do think it wouldn’t be beneficial to try to teach highschoolers a still rapidly advancing topic. If we want to be able to teach it in that manner, we will need more concrete information that isn’t likely to change too often.
This is a great video.. But can you make 1 video on the behavior of charged particles in a Magnetic and and Electric field please.. and also about crossfields
How come the quarks in the neutral pi meson do not annihilate each other and go off as radiation, as they are a quark and its respectve antiquark, up and anti-up or down and anti-down?
The s or strange quark is a quark that's heavier then the down quark but has the same charge. Scientists found that particles that with an s quark exhibit strange behaviour like half-life that's too long for what theory suggests the particle half-life should be, hence they called the quark responsible a 'strange' quark. Particles with the strange quarks have a strange number of -1, or +1 for the strange antiquark. Another strange thing about the strange quark is that unlike Baryon or lepton numbers the strange number doesn't need to be conserved in particle decay or reaction. However take what I say with a grain of salt as I myself am quite new to this subject and this is what I think I learned, but could be slightly inaccurate.
