What are special and general relativity?

[@Mutantcy1992]

Special relativity is relatively easy in general and in general, general relatively is especially difficult.

[@jasonbatmanrogers]

+Mutantcy1992 Brilliant.

[@zbzb-ic1sr]

That was is general, relatively clever.

[@jestekine5892]

I

[@ishworshrestha3559]

Yes

[@jona5820]

Set c=10km/h and we would be able to see length contraction just by running. Could be fun and extremely confusing.

[@DrPepper776]

+Jong Fuu that is hard to think about. what would happen in reality if the speed of light changed, would there be no light or would time slow down or speed up for us relatively?

[@Mandragara]

+DrPepper776 We would all die as chemistry would not behave the same way.

[@Muck006]

+Jong Fuu You would not be able to move faster than that speed though, because you would be moving blindly ... and into things. Just think how long it would be to go from A to B ... moving at a walking pace more or less.

[@jona5820]

Muck006 True. However. That wasn't really the point of my comment. I think it would be cool to see the effects of length contraction, but I wouldn't want to live in such a universe. That's crazy.

[@MrDpsc]

+DrPepper776 there is a video game out there where you can do just this, run around with relativistic effects. They only include relativistic aberration and doppler shift but it gives a reasonable idea. Might be able to dig it up if you don't find it

[@ElectricityTaster]

It may be that constants are changing. For example, the rate at which time flows relative to some other universe may change, but for us and our measuring devices, it will remain constant. But I have no idea if you'd even consider that a constant.

[@sixtysymbols]

@thelleht I honestly don't know... I have footage of the the team answering another 10 to 20 - will probably to another 3-4 videos from these! Have a few more symbols we want to do soon though!

[@Sneakytoke]

i must admit is there was one thing in this world that i would want it would be to become a physicist, to have a true bsic understanding of the universe around me and see the beauty in things that no one else can see.

[@raymondbanton9365]

you sound like a physicist toe already 😌

[@DaredewilSK]

Get a bag of weed. Same result.

[@Zerviscos]

be an engineer. it's the closest you can get without actually doing hardest math. We usually tackle more on mechanics, but once you atleast get the basic gist of it, and physics, you can work your way up to atleast more advance ones.

[@hjembrentkent6181]

Mix meth and heroin with glue. Same result

[@robinswamidasan]

"... and see the beauty in things that no one else can see." Come on, surely you would share it with us. Even if your see it first.

[@bobby132231]

I just want to say that i really enjoy watching this channel and that I have learned a lot of interesting facts thanks to you. Keep up the good work!

[@jjkul1]

Dear Sixty Symbols, I have been watching your videos ever since the channel started and frankly i have learnt more than anyone at school could teach me from the books there. An Arabian saying is "Whoever taught me a letter, I would be their slave". Thank you for you have taught me much more than a letter.

[@CivilNL]

@sixtysymbols Great to hear, always fun to see these videos in my subscription box.

[@TessaEe888]

Man. Whenever I see a new sixtysymbols video, it will totally make my day. And this is definately, my favourite video yet. Especially, because I'm totally in love with researching about Einstein's Theory of General and Special Relativity. :)

[@sixtysymbols]

@Terrayeah thank you... we do some other science channels... check out periodicvideos or nottinghamscience or wordsoftheworld or favscientist

[@BibleBurnr]

Finally a highly scientific video. not just descriptions of stuff but a very analytical and scientific video. this style is the best and i think should be the basis for all your videos

[@Nilguiri]

It would be interesting to go into more detail about what they think would happen if the fundamental constants, like the charge of an electron, etc. were changed.

[@rogerdotlee]

> (which is ok since it means you`re thinking) This phrase, more than any other, shows just how much of a success these videos really are. I could die a happy man if someone could say "He made me think" about me.

[@DaScribbler]

Even proffesionals pull all nighters before a dealine. VINDICATION. 5:40 This guy. He thought of a genius little troll.

[@kaloneh2315]

i guess you could say... he did a little trolling, he was a little sus. 2021 will be the end of us all.

[@PrimusProductions]

Please do a video on the precession of mercury's orbit and how it relates to general relativity.

[@Cosmalano]

I believe it is because mercury's orbit is more elliptical.

[@jona5820]

electrocat1 Well no not really. There is just a angular correction do to it being so close to the sun. I don't think that Sixty Symbols will make a video on it, but it could be fun. However as it was stated in the video, it's a bit tricky math. Using GR you get an equation for the energy of the orbit which is familiar to what you would get using Newtonian mechanics. The difference is a term: -R/r(l^2/2mr^2) Where R=2MG is the Schwarzschild radius and the term R/r goes to zero for large r, i.e. this correction is most apparent for orbits close to the sun. The Schwarzschild radius for the sun is about 2.96 km. For Mercury this means that it does not return to its perihelion at 2pi, but more like 2pi + 3piR/((1+e)r_p), where e is the eccentricity and r_p is the distance at perihelion. Thus the perihelion advances for each trip around the sun.

[@jona5820]

Jong Fuu Oh, not to confuse, I used that c=1. So the Schwarzschild radius is actually 2MG/c^2.

[@mikaeljensen4399]

Jong Fuu Also the correction to the orbit of Mercury that GR predicts is not very large. Perturbation theory makes pretty precise predictions for Mercury's orbit.

[@KevinVanOrd]

Yes, Kai Tale , I am sure that you, random KZbinr, have figured out what thousands of physicists over the last century have been unable to do. I would be interested to see the equations you used to "work this out," though I already know that there are none. I love when New Age-y folks hop on physics videos with unsubstantiated, provably false claims, declaring they have figured out the answer to life, the universe, and everything. Everything you typed is just--it's just nonsense. I wouldn't even know where to begin.

[@lewisner]

Is the answer an Invisible Man In The Sky ?

[@TheKrisowski]

Great example of special and general relativity is GPS. A clock in a GPS satellite runs slower than the one in your phone because the satellite is moving faster than you (special relativity) but on the other hand the clock runs faster because it is higher in the gravitational field (general relativity). Both effects are not equal and they have to be taken into account when determining the exact location.

[@jezzbanger]

Ladies: "Don't change anything, it's dangerous". Gentlemen: "Change EVERYTHING, just to see what happens"

[@freyja5800]

it would be perfect if we could change the constants in a finite volume, e.g. a laboratory or something

[@uhRoid]

This is why very few women are in chemistry/physics but rather in biology.

[@hjembrentkent6181]

First you need an education dingus

[@surendervenkata7025]

jezzbanger it is the other way the dialogues should put in, ladies: changes everything and gents: doesn't want to change anything

[@robertwc82]

@puncheex so what your saying, is it does not actually slow down in the traditional sense? im not sure i understand. when they say constant, do they mean reletive to the medium it passes through? it will only travel at 1 speed through water and another through air?

[@TheTrumanZoo]

why was it slightly suspect? id love to know.

[@Alittlewhitewave]

Did Moriarty say 6.63 by 10 to the 34th of june 2nd?

[@NoActuallyGo-KCUF-Yourself]

Ha, now I can't not hear him say that. it was "joule-seconds" - the units of h, Planck's constant, but it does sound a lot like June 2nd!

[@MidnightSt]

If I understood correctly, the thing about changing planck's constant was not about being able to see atoms, but that it would "increase" the quantum effects such that they would propagate at the scales visible to us, e.g. instead of atom tunneling through a solid object, a book would tunnel through the table and so on.

[@dipi71]

I first watched this 7 years ago? Unbelievable, how time flies. Explain that, Einstein!

[@jeebersjumpincryst]

AWESOME AWESOME AWESOME!!! Definitely the best part of my day also, when a new Brady/Nottingham vid pops up in my subs box! And this one was EXTRA good. Thanks again to all involved - youre all science superstars! :)

[@KevinVanOrd]

The best part of reading comments on any physics videos on KZbin is that there is always at least one self-important, unpublished, unknown, combative "expert" with no calculations to show and no corroborated experimental evidence, and yet who professes to know more than the combined intellect of educated and brilliant physicists the world over. One of the immutable laws of science is that there must be at least one such individual. I am glad to see the law remains intact here.

[@IX0Ahmed0XI]

"Special relativity is relatively easy"

[@Mbfrmdao]

Compared to general relativity

[@Bodyknock]

Re: the second question in the video, which constant would you change, I think it would be interesting to ask what would happen if energy weren't quantized and could take on any arbitrarily small value, effectively making Planck's constant zero. Or similarly ask what happens if you make Planck's constant significantly smaller. Considering what effects that would have could be fun (and probably dire for life as we know it.)

[@SchrodingersPet]

@sixtysymbols PLEASE do infinite symbols!!! i love your videos sooo much and get so excited when a new video appears under my subscription box!!!

[@BXBZ88]

Again,great to watch.One of the best KZbin channels.

[@MozartJunior22]

If I could change a constant, I cut down the speed of light by 5 orders of magnitude, to 3000 m/s. Just to make special relativity more significant in our lives.

[@alexgilbert2315]

I think I would increase it. It would make it easier for space travel in the distant future (it wouldnt really affect us now at the relatively slow speeds ahaha)

[@CharlieHofigan]

Alex Gilbert Well, if it were slower, than it would be easier to get close to, and therefore greater magnify the effects of time dilation, making space travel seem shorter to the astronauts even if it actually takes longer.

[@libalchris]

I can't post them on youtube, but look up the Einstein Field equations. They are a set of 10 partial differential equations that describe the curvature of space-time as a result of matter and energy.

[@MoltenMetal613]

The Ives-Stilwell experiment has already shown that time dilation does occur. This, however, does not contradict the idea of velocity. Velocity can only be measured relative to another reference frame, as all inertial reference frames are mechanically equivalent. Special relativity says that IRFs must be optically equivalent as well, which leads to time dilation to keep the speed of light constant.

[@robertwc82]

@puncheex thats what i meant by "slow down in the tradtional sense". really it does not slow down in the sense that the photons change speed. decelerate. they just take longer to reach your eye? thanks for taking time to explain

[@CetraTJ]

I liked that he touched on the fact that the constants may not have always been constant. I think this idea of a slowly changing Newton constant or Planck constant helps explain how the universe is formed.The theory of Relativity lends to the idea that gravity affects time so our understanding of the age of the earth in relation to the age of the universe could be way off. Also the rate at which the earth vibrates and in fact our bodies vibrate has slowly been increasing, an indication perhaps?

[@Muck006]

The one constant I would change is the "constant of stupidity and greed" in our politicians. That is about the only one holding humanity back.

[@Kavetrol]

+Muck006 Did you mean constant of stupidity and greed of people who put politicians in power?

[@adamlees1720]

Something about the older fella with the deep voice makes me happy to be doing science. I'm doing pharmacy, i really would be looking for something more theoretical or more pure chemistry, turns out i hate most people so being a primary healthcare provider may not be the best career path for me

[@pyro5050]

Found your channel.... about 2 weeks ago and i am loving it so far. your interviewed persons are extreamly intelligent, something your dont get to see online tht often, as well they seem to have a good sense of humour as well... so far i love the video of the solar eclipse, and the god question. as well your LHC video was humourous as no one fully knows what can happen there but the theories are amazing...

[@mortenlu]

@puncheex Ok, I have absolutely no idea what that means, so I'll just try to grasp this in mortal language. After watching a lecture on Lorentz Transformation, I think the reason for my confusion is that I forget to account for length contraction. So taking my example above, when traveling at 200 000 km\s, and each second is 50% longer, the distance is also 50% shorter, meaning the speed would be exactly the same. So a star 50 light years away, could be 1 light year away, when moving close to c?

[@Goproflying]

Where was part 3?

[@EclecticSceptic]

The idea that the constants might not be constant is the most exciting idea I've heard at least all week if not longer.

[@Nokkenbuer]

It makes sense to me, since it fits in with cosmological natural selection and the increasing realization that there are no "laws" of physics, only behaviors according to certain probabilities.

[@zbzb-ic1sr]

Even 'c' might be changing.

[@MoltenMetal613]

In your video, you seem to be saying that because observers in the rest frame are not in the moving frame, they cannot measure relativistic effects. However, these effects are observed in muons. Classically, muons would decay before reaching Earth, but because of time dilation, they do reach Earth and can be detected. From the muon's point of view, its time coordinate is unchanged; it is Lorentz contraction that shortens Earth's atmosphere so that the muon can reach Earth before decaying.

[@mortenlu]

Love how you mix it up with different people answering. About the speed of light though, I've been wondering. If you travel (very) close to the speed of light you can pretty much get to anywhere in the universe in moments, because of time dilation (and space contraction?), right? That means that if you measured your own speed from your own perspective, how high would it go? Infinite -1? cont.

[@ZoeTheCat]

GR is certainly more difficult than SR, but the math (Differential Geometry + Tensor Analysis) CAN be mastered. Even Einstein grappled with it. He had to consult with David Hilbert to understand it. The GR Tensor equation says two basic things: 1) Matter determines how Space-Time curves 2) Space-Time then determines which direction Matter should go (ie: along the Geodesic) It blows my mind that we are warping space-time as we travel through it.

[@gpcrawford8353]

Zoe TheCat I thought that Einstein’s erstwhile nerdy classmate Marcel Grossman taught the not so wise Einstein Differential geometry and tensor calculus / analysis. Marcel also found him a job at the Swiss patent office. Although Einstein spent 10 yrs on general relativity it was in the last 4yrs or so that he learned the mathematics to complete it. David Hilbert was competing with Einstein to finish general relativity during the 4 weeks of Einstein presenting the final paper Einstein was having none of it he had devoted 10years of his life and a broken marriage to it . Einstein had got lost in tensors but had already gone down the right path and rejected it now he retraced his steps and arrived at the final Theory. Apparently Hilbert was staggered at Einstein’s speed not realising that he had been this way before. Hilbert did finish his version and it became known as the Einstein-Hilbert action not that I can understand any of the mathematics involved.

[@LeconsdAnalyse]

Given a material particle moving along its worldline with 4-velocity u(τ) (where τ is its proper time). At each τ the particle has a frame defined by an orthonormal basis, (u(τ),e₁(τ),e₂(τ),e₃(τ)). This is the most general scenario in SR. Most textbooks dwell on the case u(τ)≡u, eᵢ(τ)≡eᵢ, i=1,2,3. But in general, (du(τ)/dτ,de₁(τ)/dτ,de₂(τ)/dτ,de₃(τ)/dτ) can be split into a Fermi-Walker component and a spatial rotation component.

[@HeyHeyHarmonicaLuke]

@LeconsdAnalyse Ah so it's the warping of space time that is considered an accurate description of reality, and gravity pulling on the mass-energy of light is a thought experiment/an easy to visualize approximation model? (is 'parametrized' to determine parameters/model something's properties?) I have another similar question; Is gravity seen as a warping of space time similarly mutually exclusive with the idea of gravity as an exchange force via gravitons?

[@LeconsdAnalyse]

@HeyHeyHarmonicaLuke NO. In GR the motion of a massive particle is parametrized by proper time, whereas the motion of light (a continuous stream of photons) is parametrized differently. Imagining that the energy content of light has a mass equivalence is what`s known as a `gedanken experiment`.

[@apeek7]

I have a question... If an enclosed space experiences an accelerating force, like either pure acceleration or gravitation, it should be easy to differentiate between them using either two clocks or two plumb lines. Just hang the two plumb lines on either side of the enclosure. If they are parallel the force is pure acceleration, two lines, non parallel, will point toward the gravitational center. Two clocks, one on top and one on bottom. will keep different time. Where am I wrong?

[@HeyHeyHarmonicaLuke]

@LeconsdAnalyse yar I know gravitons haven't been demonstrated, what's been on my mind is- wouldn't proving that gravity is a warping of spacetime disprove the idea of gravtions? They seem to be two mutually exclusive explanations for the same process

[@metabog]

@AlohaBay We went through the math, I'm sure we didn't go through it to final year undergraduate level, but I do remember exams with things like light cones Minkowski space and inertial reference frames. Come to think about it, it was probably only special relativity, since we didn't do any partial differential equations if I remember correctly. Our final year physics was getting ridiculous though with superfluous content that we were going to do in university anyway.

[@BlueCosmology]

Things like E²=p²c²+M²c^4, E=Mc² or γ=1/sqrt(1-v²/c²),e.t.c are pretty much only used in the general public. Actual physicists define c (among other things) to be 1 so they become E=p+M, E=M, γ=1/sqrt(1-v²)

[@LeconsdAnalyse]

What`s commonly referred to as `black hole` is a 3D representation of a 4D object. Every solution of the Einstein field equations (NONLINEAR pde`s) lives in 4D spacetime. You are trying to make an analogy by using an exercise in calculus (which is ok since it means you`re thinking). However, underlying Newton`s law of gravitation is Poisson`s equation, a LINEAR pde whose solutions live in 3D Euclidean space.

[@saemj]

I would like to change Pi to 3. Exactly 3. Not that messy endless number we have now :D Anyway, great video as always. Thanks a ton for making these, and thanks a ton to all the professors for taking the time to make these. You have one of the best projects here on youtube !

[@ChrisGJ700]

@Ichibaz Uh, I'm pretty sure that nowhere in the video did it say that they couldn't chose the speed of light. If the opposite is true then please point out where.

[@postbode30]

"that'd be fun, change the charge on electrons a little bit and see what happens" Love this comment!

[@Nilguiri]

You can think of Special Relativity as a special case of General Relativity where nothing moves relative to anything else. All measurements are made in a fixed frame of reference where relative acceleration is zero. General Relativity explains what happens when something is accelerating relative to something else; that's where the difficult maths comes in. So the Special case of no acceleration is Generalized to explain what happens in frames of reference with relative acceleration. Cheers.

[@CastorQuinn]

I love Roger. What constant would you change? Some scientists want to experiment, some want to keep the universe as it is. What does Roger want to change? "H-bar because it would drive everyone else crazy". Don't ever change Roger.

[@pikuorguk]

@bozy99 so explain why i can spin a bucket of water around my head, without getting wet... When you're in a lift which is going up, it takes time for your body to accelerate to the same speed as the lift and that's what we perceive as an increased feeling of gravity.

[@libalchris]

This is why that quote is important, because F=ma does not pertain generally to K, (as Einstein clearly states: "If the electron be at rest at any definite epoch..") and applies only when the object IS AT REST IN K. Einstein is using the Lorentz transformation to derive the laws of motion in the general case that the object is moving in K. If we postulate (as Einstein did) that F=ma is only applicable at negligible velocities, then it is clear there is no contradiction, as lim_(v->0) (β^3)ma=ma

[@MDK1867]

Because as the guy explains at 1:20, energy (like mass) can be attracted by gravity. Photons, though indeed massless, do have kinetic energy as they travel around space and hence are affected by gravity themselves. Hope that answers your question :)

[@robertwc82]

@puncheex i see. and you are saying the speed is constant, relative to the medium it passes through. water always travels through water at a constant speed?

[@HeyHeyHarmonicaLuke]

I hear them describe how light is affected by gravity as both because energy is equivilent to mass, making it subject to gravity, and also as light as travelling in a straight line but going through a curved space. Are these two ideas mutually exclusive? Aren't these two different explanations of the same thing?

[@ThePinkus]

My personal take on the difference 'tween special and general relativity. The first is local, as in local interaction, it's about the structure of physics occurring at each point of space, it's about symmetries and groups, it's about particle interactions (which are representations of the symmetry groups of special relativity), and as such it has all the structure of the tangent space of general relativity. Well, it is literally the tangent space, at each point, to general relativity. But I'm also reversing the perspective that led from special relativity to quantum field theory, by considering that special relativity is the phenomenology resulting from the structure of particle interactions, as in QFT and the standard model (and beyond...). General relativity is extension, and it is metric and geometrodynamics (meaning that extension is dynamic). This suggests that going from the tangent flat space of special relativity to the curved manifold of general relativity should correspond to going from the parametric representation of groups, i.e. QFT-SM, to the actual extension. The suggestion here is that the word 'actual' is not just emphatic, but, in QM perspective, the non-trivial part of the passage. The extension we observe in this universe is actual, not potency, and this suggests that extension might be at stake as well as, or together with, act, and that going from parameters to extension is part of the QM (interpretation) problem of going from potency to act. If, for QM interpretation, act is (dynamically) emergent within potency, and if extension is part of the same problem, then the geometrodynamical nature of general relativity is expected and explained.

[@thaandiesel]

@sixtysymbols keep em coming, loving your vids!

[@LeconsdAnalyse]

@HeyHeyHarmonicaLuke 2. "..is 'parametrized' to determine.." The future-pointing trajectory of a material particle is parametrized by its proper time. Just as in Newtonian kinematics you`ve seen expressions like: da/dt, dv/dt, dr/dt, where it`s tacitly understood that r=r(t), v=v(t) and a=a(t), in which `t` (absolute time) acts as the parameter. Since ds² = 0 for light we cannot use proper time, so we use an unrelated `affine` parameter `σ` (say) s.t. ds/dσ=0.

[@talmiller19]

1:11 is a wrong, REALLY wrong, you CAN describe accelaration, special relativity is about dynamics in minkowski space, dynamics can be any kind of space time trajectory .

[@nawedy]

The singularity is such a strange concept! For what I understand (disclaimer: very little) all the mass of a black hole is concentrated right at that point. So if you were to find the volume of that point, would it be 0? If so, how can mass occupy no space at all?

[@arnoldduran4953]

@3:16 that is a amazyingly helpful anology to visualize!

[@nawedy]

So basically, it doesn't make sense for a black hole to have volume but it doesn't make sense for it to not have any volume either (with our current knowledge). Physics is awesome. Thanks for answering!

[@sixtysymbols]

@Stickalas don't blame me... blame the scientists! Hope you haven't found periodicvideos yet - that'll take even longer!

[@LeconsdAnalyse]

@MrIamSamIam2 What do you mean by, "..`discrete` units of electromagnetism.." ? Renormalization is a very technical subject that cannot be summed up in a sentence. Too difficult to accomodate all `energy scales`.

[@U014B]

Is it (im)possible for there to exist an electromagnetic wave with a wavelength of less than/equal to one Planck length? What properties would it potentially have?

[@Kavetrol]

+Noel Goetowski Uncertainty principal would not allow it.

[@vorpalneko]

Another way of thinking about is that mass is not intrinsic to gravity at all. The gravitational charge is energy, not mass. ALL energy gravitates. It just so happens that mass has a certain amount of energy associated with it, which for ordinary matter under typical circumstances is much greater than all other forms of energy (mc²), but it isn't the fundamentally important quantity. In general, what affects gravity is energy, momentum, and stress, cf. stress-energy tensor.

[@roguemale57]

In essence, what relativity says is that space and time are not absolute but both are relative to the observer and the thing being observed, and the faster one moves the more pronounced these effects become. For example, Cosmonaut Sergei Avdeyev travelled 0.02sec into the future when he was onboard the Mir space station.Because, he circled the earth 11,968 times over the course of 748 day at 17,000 mph.

[@feartheglosshh]

3:35 does anyone know what video he is referencing here about changing Newtons constant?

[@sixtysymbols]

@humanprototype we're trying!

[@libalchris]

Go back and read it again, the paper clearly cites two different systems: uppercase K(the stationary system), and lowercase k(the system in which the particle is stationary). The first set of equations were given for that in which k and K were the same system) In system K, F=ma applies only to stationary objects, F=(β^3)ma applies generally to all objects (even to stationary ones, since (β^3)ma=ma when v=0) There is no contradiction here. It may seem weird to you but that doesn't make it wrong.

[@HeyHeyHarmonicaLuke]

@LeconsdAnalyse well isn't the just over the border of fact into hypothesis, the best place to discuss and explore?

[@agentHMX]

thanks for sharing these videos and of course the other science channels you provide.... my respect for the field of science has attained a new level... hopefully in the future I can be as enthusiastic and excited if someone asked me such questions... thnx again and keep the videos coming

[@gulllars]

@sixtysymbols regarding Brady getting a nobel prize, i don't know if that would be fitting, but it would be interresting. I would however be happy to see him recieve some sort of prize or honor, f.ex. for work related to innovation in public understanding of science. I don't know if you need it, or it would be any help, but i think it could be interresting if Brady were given a grant or funding to expand periodic videos, sixty symbols, and nothingham science (possibly with dedicated staff?).

[@Madzarzour]

Brady, could you make more on this topic?

[@TheRealTaco87]

Is it possible that the constants are not only changing but are different in differnt parts of the universe?

[@MoltenMetal613]

Lorentz transformations are simply a method of keeping the speed of light constant. They may not be noticeable within a single frame, but observers in their respective frames will notice relativistic effects in the other frame. You may not have day-to-day experience with this, but atomic clocks are accurate enough to detect such discrepancies, which is why the atomic clocks in GPS systems require relativistic corrections.

[@Cronuz2]

i dont have a specific space, it is defined by three dimensions which we know things happen within (some would say 4). photons is within space. same as your couch not being your house, but it is within your house. hope this helps.

[@MalcolmAkner]

The notion of light bending in a gravitational field hasn't really got to me. I thought that gravity could only interact with mass and seeing that a photon does not have mass, how is it affected? And thank you guys for replying, this channel has taught me more physics than all my highschool classes put together.

[@LeconsdAnalyse]

@MrIamSamIam2 Hello. Yes. QMs is compatible with special relativity (but not with general relativity). Quantum Field Theory has Special Relativity built into it. :)

[@sixtysymbols]

@odaymustdie I just walk into offices and ask questions - then pick the best bits and post them on KZbin.... I can think of a few hard-working and clever scientists that would be pretty cheesed off if I got a Nobel Prize for that!

[@lahadc]

it's funny, i just found out about plancks constant yesterday for the first time and here it is again.

[@youtubehandlesareridiculous]

Nice number, eh?

[@Odin029]

I've watched this video before, and I've always liked Professor Bowley, but now that I've noticed that Miles Davis poster on the wall, I really like him. Its too bad he retired.

[@MoltenMetal613]

The only video of yours that mentioned E=mc^2 is your video titled "Einstein's 'Theory' of Relativity Must Be Removed from Science," but it never mentioned Ampere's Law or even bothered to derive E=mc^2 from it. Plus, you told me that Ampere's Law can be multiplied by the electric field vector E to give E=mc^2, but this doesn't give the right units (kgm)^2/(A^2s^5) instead of kgm^2/s^2). Plus, E and m are scalars, while c^2 is a scalar conversion factor. Your "derivation" would give a vector.

[@MikeG0042]

What about changing the value of Pi from Pi = C/d to Pi = C/r ? This way, one rotation around a circle would be Pi as opposed to 2 Pi, and would make a lot of math much easier

[@legendpawan]

if light travel in curve at high gravitational field then is there any great interaction of gravitational field and photon?what particles of gravity cause so...or vice versa?

[@Starchildcasanova]

i have to ask, what do you guys over at nottingham think about colonizing the moon?

[@Fenrakk101]

As for changing constants, what are the risks of making the speed of light faster?

[@rgudduu]

Super enjoyable interviews

[@CanalTALL]

Plz put english subs on sixty symbols videos

[@DougBanks470]

@ADizezedCrow Light does go slower in denser mediums for the simple reason that a denser medium is...denser, haha. The slowing down process happens so quickly, it's easier to just say light travels at different velocities in different mediums, a vaccuum being the fastest medium to travel in (that we know of)

[@MoltenMetal613]

I double checked my work; I still got the same units. Besides, c doesn't appear at all in Ampere's Law or the electric field vector. Multiplying the units that result from Ampere's Law (N/A) and the electric field vector (N/C) reduces to the units that I already derived.

[@sirsideways]

Thank you very much for uploading such interesting content to youtube!

[@ilikechess1]

can someone please link me to the all the other viewer question videos? I'm trying to find them all but i'm having a difficult time = /

[@dooterino]

Correct me if I'm wrong, but wouldn't bringing quantum mechanics into the visible world not really let us observe them still? Wouldn't observation still collapse the probabilities?

[@jasonbatmanrogers]

+John Huddleston Yes it would. The question is just meant to be one of Einsteins's famous thought experiments. It's fun to kind of think about it...