If someone has a really hard time explaining something. It might just be because they don’t actually understand it, and they are trying to figure it out as they go. Often I think I understand something... then I am asked to explain it.

This guy is like the Teddy Atlas of science with his analogies

well i guess its all math its like explaining things in french

An even better analogy is this: why is North the Arctic, and not Antarctica? Why is Australia not at the top of maps, but on the bottom? The answer is - it doesn't matter.

Awww... you heard Weinstein say it was confusing so you came on here to post this comment. Cute

Best explanation, what i do not undestand is what does it mean a change of phase in wave equation, i mean psycally. It is said that locally the phase of a electron can change but what does it mean physically . Sorry for my english 🙏

@@elizabethreyna8354 When I wrote that comment I was thinking about classical electromagnetism. In quantum physics, a vector potential can change the phase of charged particles even when the electric and magnetic fields are zero, and in such a way that if each of these particles gets a different phase they will create an interference pattern when they are observed. It is a real effect known as the Aharonov-Bohm effevt.

@@elizabethreyna8354 Copy&paste from ChatGPT There have been several experiments that have demonstrated the Aharonov-Bohm effect. One of the earliest and most well-known experiments was performed by Yakir Aharonov and David Bohm in the early 1950s. In their experiment, Aharonov and Bohm used an apparatus consisting of a solenoid (a coil of wire) with a small opening at each end, and two paths that led around the solenoid. They sent a beam of electrons through the two paths, one on either side of the solenoid, and observed the interference pattern that resulted when the two paths were recombined. What they found was that even though the electrons never passed through the magnetic field of the solenoid itself, the interference pattern was still affected by the magnetic field. This interference pattern was dependent on the presence of the solenoid and the magnetic field it generated, indicating that the electrons were being influenced by the vector potential of the magnetic field. Since then, many other experiments have been conducted to demonstrate the Aharonov-Bohm effect, including experiments with other types of particles such as neutrons, and with more complex geometries. These experiments have confirmed the predictions of quantum theory regarding the influence of vector potentials on charged particles, and have furthered our understanding of the fundamental nature of electromagnetic interactions.

@@orbifold4387 tha is what i want to undeerstand, what does it means "different phase", does it mean that the electron change from positive to negative particule, ?

@@elizabethreyna8354 Imagine an electron moving between two points A and B. In classical mechanics, the electron would move along a fixed, unique trajectory determined by the equations of motion (Newton's laws). In quantum mechanics, there is no fixed trajectory. An electron will take all possible paths between A and B. To compute the wave function of the electron one has to sum over all possible paths with a coefficient (weight) that is a complex number. This coefficient is called a "phase". It is just a complex number that tells you how much the partial wave function along a path contributes to the total wave function.

Seems pretty simple to me but maybe that's because I'm looking at it simply, often good advice when trying to understand the complicated

@@michaelfarrell4824 teach me if you understand it

@@abd6169 Begin by imagining that at every point in spacetime there is a circle affixed with it... it shoots off in some direction that you can't really determine, but can still imagine there is that circle attached to each point. Now imagine all those circles are rotating through a determined angle, it then becomes clear that the nature of space will not change, consisting of all the circles and the underlying spacetime, that we've imagined. It's clear that any observation will seem synonomous. But all of the circles will have been rotated through a fixed angle So we now have a space with a global symmetry, the rotational symmetry of the circle above spacetime .... If a charged scalar field is allowed to exist on the underlying spacetime, which transforms by a certain phase when the circles are rotated through any given angle, include only pairings of that charged scalar field to itself that are invariant under the phase change, then we can correlate a maintained current with this global rotation symmetry, and we could construct from that current a maintained charge. In a gauge theory, one would promote the global symmetry to a local symmetry instead - so we would still have circles above each point in spacetime, but allow each circle at every different point above the spacetime to be rotated through a different angle, but an angle that changes evenly from point to point and in a way that we can say how that angle is varying between different nearby regions. The charged scalar field will still pick up a phase related to the rotational angle of the circle, but this phase is different at each point in spacetime. It would then turn out that we can describe that rotation angle by means of one of these 'gauge fields', which just lets us transfer the charged scalar field from one point in spacetime to another, always considering how the rotation angle of the circle is changing. That's the basic principles of the idea... . With the "gauge" as a kind of coordinate system that varies depending on the location with respect to some underlying space.

​@@michaelfarrell4824 Wait, so global symmetry and gauge theory can both be described by a phase shifting scalar field whose shift is defined by a rotation of a bunch of spheres that are defined at different points in spacetime, and global symmetry is when the function that determines the rotation of each of the spheres is defined as a constant, whereas gauge theory is when the function is defined as any continuous function of spacetime? I'm a math undergrad, so I don't see how any of this has to do with physics (What do the spheres represent? What does the phase shifted scalar field represent? What do you mean by "circle that shoots off in some direction that you can't really determine" and what is that supposed to represent?) but the visualisation itself sounds pretty easy to grasp. I've been messing around with Manim and I'm pretty sure I could whip up an animation of this if you gave me enough time (I probably won't since I got assignments to do). Also, how're we supposed to imagine spacetime? I've been imagining it as a 2d plane with each axis representing a point of space and time, but I've been told to imagine it as a coloured 3d space with each (x,y,z) coord representing a different point in space and each colour representing different points in time. I'm fine with assuming that spacetime can be imagined as 2d plane, but I don't see how you can transform a point in 3 dimensions (the x,y,z coords in the coloured space) to a point in 1 dimension (the space axis on the 2d plane) without compromising a layman's ability to understand it.

Notnilc space time is 4D

Then your cat food also smells like a cat.

@@rickhunter17 cats smelled differently before packaged cat food/

Let's help each other out. You explain what that effect is, and I will teach you basic grammar.

@@jacobgalloway9123 hahahahaha

** these, its

@@professorboltzmann5709 Thanks.

When u try to be smart

That’s not gauge symmetry, that’s just relabelling.

Great takeaway, but yea, Gauge symmetry is something completely different. After hearing his explanation, I don't blame you for interpreting it like this though. I must also add that everything you state is entirely correct; it just isn't gauge symmetry

I think there's less depth though

It's like where clothes only purpose is to cover u not what kind of shirt or colr

Thank you. Finally someone with intelligence.

I think I just located intelligent life forms in the KZfaq comment section... sir how did you get here?

I totally understand it and plenty of other areas of science

Labels being arbitrary should be common sense. I wish he didn't spend so much time trying to explain that concept lol

EDTGO1 He is not just saying labels are arbitrary but electrons and protons are interchangeable in Maxwell's equations, right?

“If you can't explain it to a six year old, you don't understand it yourself.” Albert Einstein

Now look here You!! Joe did just fine! He said a couple times he didn't understand! You probably love Alex Jones...

@@sheriffakhry9084 I definitely do not agree with that. Science builds up....

This is a perfect summary of what he was trying to say. He just never got the real point of his argument very well.

Isaac Schmitz no... That's not what he was saying

what? where? finally a smart subscriber

what? where? why didn't he just say that then? all he was saying was that us observing things and naming them doesn't change their behavior, Wich is obvious

He sort of did say it, just not in one self-contained analogy. As to why... have you ever done a live broadcast? Theres very little time to think.

congratulations you just outsmarted a theoretical physicist, give yourself a pat on the back man

Lol same

He is trying to simplify it in a way that only confuses him :)

16 minutes and you didn't understood the point. Your comment is like a scientific r/whoosh. You completly missed what he was trying to explain. I would explain it, but I don't have the words for it.

Do you understand fiber bundles though? Idk why he'd talk about fiber bundles to the general public on a podcast but still they are good for describing the redundancies you see in Guage theory.

It's useful in understanding physics

We can experimentally derive laws of physics like momentum, OR we can find the symmetries and the math falls out. It's a double-check, or a way of finding laws that are hard to configure experiments for, or a way to hypothesize new laws.

That's not what he said, you obviously didn't pay attention

thx for not being insulting while explaining clearly what was missed.

JoshReflek But he actually wasn't insulting so the sarcasm isn't as funny :/. If you weren't sarcastic then I am deeply sorry and want to apologize for misunderstanding you.

I think thats exactly what he said.

JoshReflek yeah I don't get what's so complicated, it seems very obvious that the name for a thing doesn't matter

This comment is underrated.

Bob West not everyone is a super genius who got hired as vice chairman to tesla like you

@@D1sc0rd- No, I have very little knowledge of physics and shit but as long as you listen to what he says it's pretty easy to get what he is talking about the first time. Weirdly enough I've had this thought separately that language and our definitions are irrelevant but I thought everyone knew this. I'm glad I watched this though because now I know what to call shit like that.

Exactly

RENILO You haven’t actually understood what gauge symmetry is then, as what you’re talking about is just relabelling.

It's not about sematic....If the universe treat positively charged and negatively charged non symmetrically, then positive and negative are still labels....but the symmetry will not exist (similarly if the rule for black and white are different in chess...black and white are still labels, but they are not symmetric). So it's not just about semantic...it's about the symmetry of the universe.

That doesn't help people who don't understand mathematics, though. A better analogy, is that if you flip a map upside down, and rename North to South, nothing really changes.

Michael Sims Even if life only exists in 0.0001% of the universe that would mean that there's life on other planets. That's why i don't think the idea of it being randomly created would be impossible. Kind of like winning the lottery, the chance of winning it is very unlikely, but someone is still getting the random numbers right. Maybe not the best comparison but i think you get the point :)

ZaiLeNZe D Yea man. i agree. Did you somehow get that i didn't believe it was possible from what i said? Because as crazy as it's going to sound, ive actually seen a giant UFO that was totally silent fly right over my head, while my brother was stranding next to me seeing the same thing, confirming it wasnt the residual effects of mushrooms I'd eaten several weeks before or something. The thing was so alien in appearance & behavior that there is no possible way it was made by man, so I'm actually certain w/out a doubt in my mind that there is life out there somewhere & it's WAYYY more advanced than we can ever imagine. It's also visited our planet in at least 1 instance. Did i come off somehow as if i didn't believe life on other planet's or in other parts of the multi-verse was possible?

Michael Sims No man, not at all. I just replied on what you said about the odds of life happening randomly. The fact that the conditions needs to be perfect for life to form makes it unique to us because we never discovered life outside of our own planet. But it may not be unique to the universe so I'm just saying maybe life is random. I only replied cause I agreed on everything else you said :). The universe is a fascinating place. Wish we had more answers.

Still trying to understand his actual point, because there is no way that it's this simple. Your answering your own question. Why would Laurence Krauss tell everyone that words don't change physics? He wouldn't. The point was missed. By you, me, and many other people.

What he's saying is, if suddenly for example the electromagnetic charge of every particle flipped, there would be no way of knowing, because the 'positive' charge is exactly the same as the 'negative' charge. It's not to do with what we label the charges, it's the fact that the things we're labeling could change and we wouldn't be able to tell. Another example is how intense gravity strongly warps space. If you had an object that was exactly 1 meter long on Earth, and then took it to the surface of a neutron star, it would be significantly shorter in length. However, since everything you could have brought with you to compare with the meter stick would have ALSO reduced in length, you wouldn't be able to tell the difference. Then if you left the neutron star and landed back on Earth again, your meter stick would once again be one meter long. A symmetry in physics has to do with how if you change a fundamnetal aspect of a system it is impossible to tell what changed from within that system. If you could step outside the universe and look in, you may discover for example that time is constantly slowing down, and it takes twice as long for things to happen than in did the time previously, etc. Thus a second would start off taking one second, then two, then four, eight, sixteen, etc, from your perspective outside the universe, until eventually trillions of years would need to go by before even one microsecond of time occurred inside the universe. From the perspective of an observer INSIDE the universe, however, time would appear to flow continuously and with no changes.

Rothpol X thanks for clarifying, he didn't explain it that well.

Rothpol X If this is a correct explanation of gauge symmetry you've done a fantastic job of clarifying it in my dumb mind, thank you.

RothpolX is pretty much correct from my layman understanding of symmetries. Basically, take any system in physics, and if there is a way you can change that system and and the system is identical to what it was before, then you've found a symmetry and that symmetry requires a conservation law in order to exist. A classic example of of this is if you shifted the entire universe ten feet to the left. Nothing changes about the universe if you do this, so we've found a symmetry. This particular symmetry is translational symmetry, and it implies the law of conservation of momentum. The charge symmetry, that the positive and negative charges can be flipped at any time, gives you conservation of charge. Krause went one further, and said the universe has a rulebook that keeps track of what charge does what to what other charge, and that rulebook is the electric and magnetic fields. So then we should be all kinds of fields related to different forces and symmetries and conservation laws, and we do. I dunno if every symmetry has a field, but I know there are at least several of them. Unfortunately, his explanation of all that was rushed and rather jumbled together and pretty hard to follow.

Andrew Bellinger that’s why he also mentioned that the board would need to be rotated 90°.watch that part again