Animation vs Physics - An Over-Analysis

"Even I don't understand what this means" is the most terrifying thing you can hear from a physics professional

1:54 I had a conversation with my sister and we realized that this “ice floor” is actually the slippery, frictionless plane we often find in highschool physics tests. “Assuming there is no friction” type of problems, so when an object recieves force, it gains 100% of it, just for the sake of clean numbers for practices.

Did no one notice how TSC literally ran almost as fast as the average speed of Usain bolt, at 10m/s? Dude could run faster than most of us as a stick figure

There's some touching on String Theory going on in this video. The basic, VERY basic summation is that the dimensions of space we can see are only part of a larger group of dimensions. Space and time are just the 'expanded' dimensions, while there are more that are 'compacted' or folded in on themselves. But the scale at which the compacted dimensions exist is down at the Planck length, more or less that distance that was getting infinitesimally small as TSC 'swam' towards the singularity near the end. In these folded dimensions, small 'strings' of energy vibrate, being forced into open or closed one-dimensional patterns. Now, the last time I read a book on this was the 2000s, but it went on to discuss how all these string constructs, in combinations, are the most basic form of all the matter an energy in existence. The Calabi Yau Manifold is the name of the shape of the compact, folded up dimensions the strings are vibrating around in. That is why the quantum apple briefly morphed into it. The reason it is called a manifold is because, quite literally, it is a manifold. A series of dimensional 'tubes' folded in on itself. Of course, quantum mechanics and string theory are something to take with a salt mine. You're at the far end of theoretical physics when you get to them. The part where physicists get into fist fights, and mathematicians drink themselves under the table.

its refreshing to see that when someone doesn't understand something, they admit it. it made me laugh that after the newton's law stuff you were just like "i have no idea what is happening" felt like we are learning together! i haven't learned a thing but maybe you have, i'm still trying to understand the math one

You know the team did a good job when even the one that’s trying to explain doesn’t actually know what’s going on

Physics is life. Physics is everything.

4:34 "Gravity is so weak!" Black Hole: "Hold my beer."

this is my best interpretation of the video from 11:36 11:36 starting from here, TSC is falling through a red cylinder. This is a worldsheet, which is a one-dimensional enclosed string (a circular shape) stretched into a cylinder. The height dimension of the cylinder represents time. Essentially, worldsheets describe the path a string will take over time. TSC has shrunk to the point where he is falling through one of the quarks, since quarks can be represented as strings. Neutrinos are also seen flying by, which makes sense since they are much smaller than quarks. 11:45 Now TSC has shrunken to the point where he leaves the quark. My guess is that the worldlines represent the light cone of the singularity at the center. There are two light cones that emanate from an object. One cone represents the past possible light paths and one cone represents the future possible light paths. Anti de-Sitter space (AdS space) is a type of space where no points in space or time can be told apart from one another, and it has a negative curvature (aka hyperbolic geometry). Conformal field theory is a type of quantum field theory that remains unchanged when its lengths and curves are changed but its angles are kept the same. SInce the video directly mentions Anti de-Sitter space and a conformal field, this implies that the video is referencing AdS/CFT correspondence. I don't really know too much about it though. This also implies that the black hole that TSC entered was an AdS black hole, which is a black hole with a negative cosmological constant. A black hole with a negative cosmological constant approaches AdS space. Maybe AdS black holes have some special properties. AdS space is probably why hyperbolic space is mentioned at 13:17. 12:02 In the bottom right, there is a diagram. The diamond on the right is our universe, and the diamond on the left is a parallel or alternate universe. Black holes that are connected to white holes have a special property. The black hole region can contain particles that fell in from either universe, and particles in the white hole region can escape into any universe. White holes are a region of the singularity's past, while black holes are a region of the singularity's future. That's why there's a "future singularity" and "past singularity" in the two circles that TSC is approaching. The distance meter that is on the screen displays a distance close to a planck length, or the smallest possible length possible in the universe. Also, keep in mind that I am not an expert in quantum physics and most of this is speculation, so I might be extremely wrong about most parts. (And unfortunately, in real life you can't use black holes and white holes to cross between universes. It is impossible to enter a white hole, so you can't enter the other universe throught the white hole side. Meanwhile, if you try to enter through the black hole side, you will reach the singularity and die.)

I love how accurate everything in the animation is! Taking physics now and man, if it doesn't feel like I'm using an education for something finally! Really though, its fun how everything is logical and reasonable up until the black hole, where quantum mechanics go "Eh... probably!"

11:45 By the time you reach this point, we get into string theory, meaning everything that happens after this point is not absolute. Only what is believed with current science of 4d mechanics.

Even though you didnt understand it as much as your math one, you still did a great job! Loved this video when it came out!

As a student of black hole physics and having some research in the area of black hole, I've endeavored to explain each physics concept presented in this absolutely amazing masterpiece by Alan Becker. I'd greatly appreciate your comments on my review, "Black Hole Physics Student Reacts to Animation vs. Physics by Alan Becker | Comprehensive Analysis," as it would enhance our mutual learning experience. I started working on my review just an hour after the video was released, and I feel fortunate to have stumbled upon your review after posting mine. Much respect from my side. cheers!

Not bad! Though I have a nitpick with the displacement definition at 0:40 -- displacement is the distance between TSC and some starting position (so the distance between d1 and d6), not total distance accumulated. I don't blame you however, since the animation confusingly presents displacement with the sum of distances traveled for some reason. Since I'm a college physics student and I have no life, I'll write down some more detailed notes for the underexplained parts of the video just for fun: 6:06 - Gravity assist equation: U = planet's velocity, v_i = initial velocity of TSC before entering the planet's gravitational field, θ = angle between the planet's velocity U and TSC's initial velocity v_i. 7:29 - "H = (B/μ) - M" is the equation for the magnetic field strength (also called "magnetic field intensity"; SI units are Ampere/meter), where: * B = magnetic field (more specifically called "magnetic flux density" since "magnetic field" is a very vague term; SI units are Tesla) * μ = the magnetic permeability, which describes how easily a material can become magnetized in a magnetic field. In a vacuum (empty space), the magnetic permeability is μ0 = 4π x 10^-7 Henry/meter. The animation doesn't write the subscript 0 next to μ, which is a minor mistake. * M = magnetization, which describes how strongly a material is magnetized (SI units are Ampere/meter) 7:29 - "B = (μI)/(2πr)" is the equation for the magnetic flux density (B; SI units are Tesla) produced by a circular loop of a wire (circumference 2πr) with current (I) flowing through it. 7:29 - The vectors for force (F), current (I) and induction (B) are all perpendicular to each other. This is in accordance to the equation for the magnetic force experienced by a wire with a current (I=dq/dt) in a magnetic field, F = IL × B, which involves a cross product (×) that makes all three vectors perpendicular to each other. This equation is derived from the more general magnetic force equation F = qv × B = q(dL/dt) × B. Here, L = length, distance traveled by charges in a current, q = charge, and v=dL/dt, velocity or change in distance. 7:31 - "F = ∇(m⋅B)" is an equation for magnetic force (F). The upside down triangle "∇" (called "nabla" or "del") tells us to take the gradient (partial derivatives for each x, y, z component) of (m⋅B). "(m⋅B)" is the dot product of magnetic dipole moment (m) and the magnetic field (B). The magnetic dipole moment (m) is a measure of the object's tendency to align with a magnetic field. The dot product (⋅) of two vector quantities (m and B have magnitude and direction) produces a scalar quantity (magnitude only, no direction). The gradient essentially means that F = ∇(m⋅B) =〈∂/∂x (m⋅B), ∂/∂y (m⋅B), ∂/∂z (m⋅B)〉; the partial derivatives (∂) for each direction (x, y, z) tell us what is the rate of change of (m⋅B) is depending on the position (x, y, z). Also note how the gradient turns the scalar quantity (m⋅B) into a vector. 7:34 - The animation shows the symbol ∇ with parentheses enclosing a bunch of horizontal arrows pointing left. I honestly don't know what it means exactly, but I'm guessing it's a visual way of writing out the magnetic force equation "F = ∇(m⋅B)", where (m⋅B) probably represents the horizontal arrows. I don't know if this is accurate, but it looks cool! 7:36 - "Φ=BAcosθ" is the equation for magnetic flux (Φ; SI units are Tesla * meters^2), which is a measurement of the total magnetic field (B) passing perpendicularly through a surface area (A). The cosine part of the equation (cosθ) just tells us to include only the component of the magnetic field vectors (B) that are perpendicular to the surface area (A). 11:33 - A proton is made up of 2 up quarks and 1 down quark. The quarks are colored red, green, and blue, which visualizes their property of "color charge". The quarks are stable under the strong force since their red, blue, green colors cancel out. Note that the word "color" in "color charge" has nothing to do with actual color that you see with your eyes; it's just an analogy (because physicists suck at naming things). 11:34 - A photon collides ("interacts") with an up quark to produce a quark-antiquark pair. The antiquark which has opposite electric and color charge to its normal quark counterpart (the antiquark is colored green, which I assume means "antigreen" to pair with the green quark?). I'm not sure if the photon-quark interaction shown here is accurate, because electric and color charge should be conserved in a particle interaction---if the quark-antiquark pair is a green-anti-green pair, then their colors would cancel out, leaving only red and blue in the proton, which wouldn't be stable to the strong force. 11:42 - Worldsheets = similar to a worldline, but in two dimensions: a worldsheet is a 2D path (like a sheet of paper or ribbon) traced out by a 1-dimensional string (objects that make up the fundamental particles like electrons according to string theory) moving in 4-dimensional spacetime (3 dimensions of space and 1 dimension of time). 11:49 - The worldline is a 1D path (like a line or curve) that is traced out by a point-like object moving in 4-dimensional spacetime. 11:49 - (3+1) conformal field = A conformal field theory (CFT) is a quantum field theory that does not change under coordinate transformations that preserve both angles and shapes, but not size or curvature. 11:49 - 5-dimensional anti-de Sitter space = An anti-de Sitter space describes a universe that has a constant negative curvature, kind of like how a 3D saddle shape has negative curvature. An anti-de Sitter space universe would have a decelerating rate of expansion. I think the "5-dimensional" part of the name refers to 4 dimensions of space, and 1 dimension of time. For further reading, I'd like to direct you to "Simplified Guide to de Sitter and Anti-de Sitter Spaces" by Bob Klauber. 12:01 - The diagram shown at the bottom right is called a Penrose Diagram, which graphs space horizontally and time vertically. The black hole's event horizon or point of no return is represented by the top triangular region bounded by the two solid diagonal lines that separate the "parallel universe" (left) and "universe" (right) region.

I have not got a Theoretical Physics PhD or degree. But, I think: The Wormhole thing they were messing around with was an Einstein-Rosen Bridge. Or, a wormhole. As an aside, any Mass moved via the Einstein-Rosen Bridge must be taken out of it, but due to a Black Hole having Infinite Density, this can be avoided. But as Space and Time are linked (Space-Time) it can also affect Time too, by creating Tipler Cylinders as seen in the video. Those 1-D Strings come from String Theory. Everything is made up of them. That's the extent of my knowledge there. The Apple turning into a 6-D object was likely due to, at this unfathomable, Physics-Breaking gravity inside the Singularity, the several hidden dimensions (from M-Theory) of the Universe can act on objects here.

After 11:45 where majority of the stuff gets Theoretical physics and some quantum physics stuff. After a somewhat "ok-ish" understanding from google/wikipedia here is what the terms I think means: Worldsheets: Worldsheets are basically a part of string theory, where basically it is a 2D surface which shows how a string (from the string theory, is 1 Dimensional so that the traced path thing becomes a sheet) is embedded in spacetime. It basically shows the properties it is currently exhibiting. World line: World lines are kind of similar to worldsheets. It is basically the same, showing the properties of a particle (0-Dimensional so that the traced path thingy becomes a line) over space time Conformal Field: This is yet another Quantum Mechanic + String theory thingamajig. Basically in this, it is a field where you can change the size of an object, while maintaining its shape. For example, in a 2D Conformal field, A quadrilateral's size could increase but the angles of each sides would remain the same. In a 3D one, the apple size would be increased, while the shape of the apple remains the exact same, down to the minute details Anti-De Sitter space: (AdS) is basically like a solution to Einstein's equation of general relativity if we were to apply negative cosmological constant (determines the shape of spacetime). It basically suggests that the universe is shaped like a Pringle's shape (or like a Horse saddle, where all points curve away from each other) (12:02) Penrose diagram of blackholes: Basically this is a pretty complex (took my like 1 hour to understand) diagram/concept. In the simple diagram, it is just the sheet of spacetime in a diamond like shape, with the left-right vertice being space-infinity (space-like infinity bcuz if you were to calculate the distant between the starting point of your journey to this vertice it would be infinity), and the top-bottom vertice being time-infinity (top being the infinite future and the bottom being the infinite past). The side between the timelike infinity and spacelike infinity is called lightlike infinity. Basically the simple one is a down-scaled graph showing the path of an object in space and time as its axis. Now for the diagram shown in the video, it is the Penrose diagram for blackholes & singularity. In this the angles of the sides are 45° because photons (light) always travels at a 45° angle (thus why that side is called lightlike infinity) (Google Light cones for more info). And so when TSC enters the blackhole region of the diagram, his trajectory shifts towards the center, because in the horizon, space and time axis swap, making space unidirectional (only move in one direction, while time you can go forward and backward). Because of this he ends up where his future self would end up, where basically all of his versions are going to end up (kind of making like a destined fate once he entered the black hole). Calabi-Yau Manifold: What Gallium-Gonzollium said was not exactly correct. Basically it is a geometric space (like a sheet of graph) which is a very complex manifold (fancy way of saying another dimensions. Like basically it is telling us the shape of the dimension its referring to). This Manifold has features such as having Ricci Flatness (basically flat everywhere) and Vanishing Chern Class (basically Chern Class is a measurement to display the value of the curvature of one point to the other on a geometric space. Its like a tool rather than a object, but pretty sure its used here for Visualization and entertainment form. (13:24) Outside of the whitehole side of the penrose diagram: Basically it is showing how due to TSC once he entered the horizon, he went downwards in the Penrose diagram (depicting him going back in time) and so he can view him at the start of the video. Also a fun reference to that scene from Interstellar... i think. (13:55) neat representation as to how in string theory, the way those 1-D strings vibrate can make different matter. here the close looped one made the big heavy ball and the open one made the rope, and the third one Future TSC configured it in such a way it represented a rocket (altough in reality if string theory is true, the strings would represent the subatomic particles not entire objects) (14:57) Reminds me of the Oppenheimer soundtrack "can you hear the music?". Lol (15:20) No idea why it came back, most definetly bcuz of Entertainment purposes. (15:33) Just like I said before in the penrose diagram of blackhole, current TSC we have been following is now the future TSC for the past TSC we were looking from the Hyperbolic disk, basically fate is destined for TSC. Basically the bootstrap paradox. (15:38) Probably the future TSC going to parallel universes (exiting the blackhole region of the penrose diagram on the opposite side). (No idea I could be 100% wrong) Thanks for reading :)

I like how once it got into quantum mechanics and string theory, you just went blank, just like every one of us pretty much.

I like how all the parts where magic is introduced just go unexplained

There is one thing i'd like to ask to Alan, when did TSC had the time to carry all those things to his "past" self, or it could maybe be the original TSC at the very start of the first timeline where there was basically no predetermined future or past, where TSC hasnt met his "future self" in the singularity and had to offer his past self the items needed Tbh, thats the only valid explaanation i could think of

Bro calculated 1 million times my brain in just 6 hours meanwhile my ass just sittin there watching, knowing 25% of this sht Nice job