Why Time and Space swap in a Black Hole 

I have a question when a ball fall from top, we can't reverse it . Which is similar to dropping ink to water which we can't able to reverse due to increased entropy. But when ball is falling down where can we see "disorder"? Could you please make a video about it or answer my question

Yes! I do. Or in German: Ja, tu ich. Danke. Thanks.

Gracias!

Shiwn the topic in a very nice way, though I cant really see the switch to tine behaving as space and vice versa. Another German video tells, that movement through space now only allows one direction to the center (instead of 3 freedom grades outside) but time might be more freely moved through now 🤔 However I dont see any ohysical reason why a black hole should be an empty sphere, but massive. How do we know if our physics still work right below the horizon, and does not only break in the very center (unlikely beeing of infininte density)?

@@Dr.RiccoMastermind So there is no sudden transition, space and time are continuous and curve smoothly. A falling observer doesn't experience anything weird: if they are inside a small box with no windows (and assuming the black hole is much bigger than this box) they have no idea that the box is falling at all. So they can still move in 3 directions inside the event horizon. There actually is no single direction of time or space, there are multiple coordinate systems that are all valid. Like you can say the +x direction is your left and I can say the +x direction is your right, and both can be correct depending on how we draw the axes. A direction for time describes the world line of some observer. You can say the time direction follows your world line and therefore you move purely in the time direction, while someone in a fast spaceship can say that the time direction follows their spaceship and you are therefore moving backward and not purely in the time direction, both are correct depending on how the axes are drawn. Outside the event horizon, the direction that results in hovering at a fixed distance is a valid direction for time because observers can move in such a way. Inside the event horizon it's impossible to hover so no valid time direction points perpendicular to the radius. But it is in fact possible for observers to move directly in the radial direction so that becomes a valid direction for time. If chosen so, the other 3 directions: east-west, north-south, and past-future, would be the corresponding directions for space. So the event horizon marks a boundary where the intuitive coordinate system stops working and the weird one with time and space swapped starts working. But it's also just as possible to gradually change coordinate directions while getting closer, resulting in no sudden change at the horizon. Such are how the coordinates the video used work (if you're curious, the video uses Eddington-Finkelstein and later Kruskal / Penrose. The coordinates that have a sudden change at the event horizon is called Schwarzchild coordinates).

Yes! Beautifully captured the irresistible dark power of a black hole

Truly terrifying, but also fascinating to say the least

This must be how the Bene Gesserit in Dune feel

@@electriceyeball L

Doesn't that mean we are currently falling towards a singularity?

Good visualization is not just important, it is often the key to understanding something. Visualization can in most cases make the difference between understanding a concept and not

@@f1reflam3 I agree completely

All gravity well graphics are wrong. The bottom of the well in in the center of the mass, not under it. See corrected gravity well model.

If this was all taught to me only in math form, I’d understand absolutely nothing. But an A.I. would understand everything!

@@rupertchappelle1089 Well, if the corrected gravity well model is correct, that would mean *most* gravity well graphics are wrong, not all 😉

Stupid consumer, why would you ever give someone on RU-vid money.

Thank you very much 🙏

Couldn't agree more

EXACTLY

I still hit pause and uttered a loud *bruh* when he said the event horizon was no longer a place but an event in our past

RU-vid ads : we have more pauses

And having great visuals and background music also helps fill it out.

I'm glad you liked it! I also think it's easier to understand this way, Penrose diagrams are great but not really intuitive

Agreed. I’ve never really understood what was meant by “they flip” this was a definite “ah ha” moment for me. So many other channels, such as Sixty Symbols are wonderful, but too often the scientists on there are like, you can’t explain these abstract concepts to a layman. Science Clic is like, hold my beer bruv and I love it.

Roger Penrose is a genius!

yeah, visualized this way it was so obvious and simple that i feel like a two year old would get it. yet up until now I've really really struggled with this concept! bravo science clic. truly the best relativity/cosmology channel.

Einstein is a genius!

That's cause your a do'er not a dreamer . They have absolutely no idea what's going on it no doubt it will all change around in a few years time and then again a few after that. The only way to change the future is to do something . To act, not just sit there with your tongue hanging out the side your mouth drawing lines in the air.

​@@Greenfist007what tf are you talking about?

I dont' know@@yngtylrdrdn

@@yngtylrdrdn you see you are a dreamer not a do'er. They have absolutely no idea what's going on it no doubt it will all change around in a few years time and then again a few after that. The only way to change destiny is to absorb it yourself, then to combat it. To do, not just sit there with your tongue hanging out in space time tracing curves. That, is how one attains destiny.

@@toastycrystaleclxpse3423consider yourself a smart man do you

Even if I already understood how and why that happens, this added a beautiful interpretation to it, really really perfect explanation

When in the video does he say about the apple had its "future point downwards"?? This wouldn't work on normal earth gravity (except black hole) as its future is not certain from the point of motionless in the air. It could be hit back upwards with something.... (your comment sounds like the apple's future was certain) I would state that the structure of space near a massive object distorts, constantly.... Continually going straight line to curve towards the center of the earth. Its this that starts the apple falling down. Time is the process of it falling. I don't think your idea of time in your comment is accurate.

@@davem1658 But then do you think the idea of time presented in the video is at all accurate? I am directly quoting it starting at 5:50.

@@igbaccin Oh ok, you've directly quoted it. I've missed that.... I really have no idea, and I defer to your assessment. ... What I like to know is; the very exact moment the apple is motionless in space, what starts its trajectory on the curvature of space of falling down? What gives its initial push from 0 acceleration?

@@davem1658 don't quote me on that since I am not at all an expert but I think the apple does not require any push because it is already has a trajectory through time. The apple, and everything else for that matter, is continually moving through time. It would only remain "floating" if it was in a region where spacetime is not distorted. I think this is the mind bending thing! You do not need to be pushed towards the earth if you are motionless within a region of spacetime that is distorted by earth's gravity. By virtue of moving through time (and of course always forward in time) your trajectory through time will meet the earth's trajectory through time. I think this is the rationale behind the quote at 5:50. You can even see the author displaying "stacking earths" at the bottom of the screen during this particular explanation to denote earth's movement through time (already illustrated at 0:54). I may be getting this all wrong, but this is what I understood from the video and from whatever else I consumed on the topic!

In the incredible chance that we were to learn how to move backward in time, I wonder if this means we will be able to escape a black hole

@@JoseAndCode I am pretty sure at the time we discover how to travel back in time, we will simultaneously be able to discover of a way of escaping block hole

@@studypurposeonly69 true

@@JoseAndCode or maybe forward in time ? Since time slows down and is supposed to stop at the centre of the black hole. Meaning if we calculate correctly, we can enter black hole or stay close to the event horizon at one point in time and escape it at another point in the future ?

@@JoseAndCode by this analogy, since the light cone is turned towards the black hole, you could move backwards in time within the event horizon

it can come, there is a disease from a black hole named HM-248, it causes liver failure

Pay good teachers more!!

a real teacher will teach regardless of compensation. @@Emc4421

In the EU there is the Science Communication Prize.

Nice.@@Anolaana

Absolutely, more concepts have clicked for me from watching this channel than any other of the great physics channels.

Most definitely!!! ScienceClic is In a Nutshell on steroids!!!

Thank you very much it means a lot 🙏 I hope you'll enjoy the next videos!

i dont agree. there are too many good channels on this topic. Its a fantastic channel to visualize the concempts and get new insights. But its not that simple as some videos of this channel might suggest. general relativity is so weird that you can interpret it in a thousand ways and alot seem right and wrong at the same time. to really understand more, you inevitably have to lean the calculations. There are some beatiful lectures on that on youtube.

@@ScienceClicEN definitely will. Thank YOU

Thank you very much! Very glad you liked the visuals, it was a tough challenge to represent light cones in a video!

@@ScienceClicEN seriously...I watched PBS which is good at visuals....but everyone representa the cones directly on space time grid and then reveal the Penrose diagram immediately....it doesn't give viewer the time to get the concept and visualise that its a 2d representation of a 3d sphere expanding....now it feels really really easy...

@@ScienceClicEN visuals were as clean as one could make them... amazing mind you have got👏👏

imagine you're walking in a dark place while holding a light torch and walking forward, you can't walk outside the lightcone of your torch

Yes this is by far lightyears away from channels like PBS spacetime where they confuse people instead of clarifying things to them!

@@-_Nuke_- AGREED, PBS SpaceTime videos can be easy to get lost very quickly sometimes but this ?? my god-- this should be taught in all schools around the world, imo

@@-_Nuke_- PBS doesn't confuse people, it just doesn't have nice visuals

​@@AverageAlien yeah visuals can really help grasp a concept as hard as these!

Perfectly put!

it can come, there is a disease from a black hole named HM-248, it causes liver failure

Thank you very much 🙏

Yeah under general relativity, gravity isn't a force at all and that distinction is actually important for the definition of an inertial frame.

Just to rephrase what the video already said: the reason why objects fall to earth, is because more future paths point towards earth than away from it. So an object with random movement will always fall towards the center.

Gravity is a force, and very observable, thanks redditor.@@MrCmon113

"huge force that drags us to center" it's because gravity pulls on time and space. Like obviously you're going to crash into something if it has gravity, this video is trying to make it way more "big brained" than it is.

And if it were the case that it's because "oh time is just pointing there dur hur" that breaks the whole speed of causality thing. I feel like science is just being made up at this point.

Keep putting Ukraine flags in your name, makes spotting idiots much easier

Zelensky had the deaths head emblem on the other day, they got all our baby formula too

​@@kyleflanagan8410 why do you comment this on non-political videos, kremlin bot?

This video says it's 45 degrees because light speed is constant but that's not really the answer, any constant speed draws a cone of some fixed angle. It's only 45 degrees because we choose the scale of spatial and time axes such that light goes at 45 degrees.

It's rather that light travels the same distance through space as it does through time, using natural units. In 1 year of time, it travels 1 light-year of distance. It can be considered an arbitrary choice of units, but it's not so arbitrary, it's the only choice of units that is "natural", in the sense that nature specifically gives us something invariant such that we can measure time and space with a same unit : light

@@ScienceClicEN I recently discovered that the fact that " light travels the same distance through space as it does through time" is just a convention ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-pTn6Ewhb27k.html

@@thedeemon Well, in order to do angles, you need to take arctan (y/x). But this only works if y/x is unitless, and if your y axis is in meters while your x axis in is seconds, well... it doesn't work. Instead, we label the x axis as "ct": the distance light travels. And because the distance light travels is equal to the distance light travels... arctan(y/x)=arctan(1)=45 degrees.

@@user-cj9jk1pd4g Nope, this way you'd get 45 degrees only if c=1. This is the natural units the author mentioned.

🙏

yep 100%

The greatest revelation I got is that the singularity isn't a place. It's an event, much like getting old or becoming father. So, one will not see the singularity as a point ahead of them, just as one doesn't see their older self sitting ahead of them. Rather, once past the event horizon, it will feel like the whole world is weirdly twisting, stretching and collapsing from all side, until everything is collapsed to (by GR*) a single point of nothingness. * GR = General Relativity.

Yeah, channel has been blowing up steadily for a while. I distinctly remember it hovering around 10k subs even I first watched the general relativity visualization vid for the first time. It's been awesome seeing the channel grow.

Yeah

Very glad you liked it! 🙏

🙏

Many science channels have been doing for a long time so I guess with patience he will be up there also, his content is very good

@@ScienceClicEN Hello Mr ScienceClic, I was wondering if it would be worth making a video related to your GR and Gravity Videos about “how spacetime curvature behaves INSIDE planets”. Is there still a gradient inside when you have mass in all directions? I’m not educated enough to understand it but i can’t help but feel there must be some interesting things going on in there. LOVE your videos please never stop blessing us!

@@literallybiras True

Because people don't care about stuff like this.

I think this was one of his very best so far, mind = blown!

Haha send me an email when you're done I'd be curious to try it

@@ScienceClicEN Service is spotty. I sent it tomorrow, you should receive it last week.

Jim Wang - when you get to learn some more physics you'll start to realize this video is a pile of crap

it can come, there is a disease from a black hole named HM-248, it causes liver failure