Learning Physics in a nutshell: Grade school: here are a bunch of concepts that make intuitive sense and line up with how you naturally perceive and think about reality High school/College General Physics: here's some relatively complicated math (mostly algebra and trig in high school, more calculus in college) that you can use to express the basic physics you already understand on an intuitive level and make predictions that make intuitive sense. Maybe it gets a little weirder with the field dynamics towards the end, but still not too bad. Relativity and Quantum: everything you know is a lie, here are some ridiculously complicated equations that prove that nothing is what it seems. The deeper down the rabbit hole you go, the more we will fuck with your mind.
This is one reason I think we need to find ways to teach Relativity and Quantum to kids, at least conceptually. I mean, Einstein's concept of gravity can be illustrated with spandex, a steel hollow drum, a weight, and metal marbles.
@@tristanband4003 Actually, all attempts to explain Einstein's "gravity" are effectively useless because they rely on the gravity of the Earth to be done. It's bloody hilarious when someone does the weighted ball example --- what's making that ball stretch the sheet?
I'm still backtracking through the "Watch this video first". This is my fifth video so far, and this video is one of four videos I was told watch first in the previous video. This content is like a backtracking treasurehunt of information.
Try reading Wiki on quantum mechanics, each term being explained has at least 10 other terms highlighted I do not understand to explain the term being explained, then I click on one of those and that has at least 10 more terms I dont understand and that loops...finally by the time you get back to the original term you started with you still have 9 times 10 to the 10th number of terms to go through to finish "understanding" 1 term.
This is the only channel on RU-vid I actually watch to the end. The responses to viewer comments are great especially since the channel doesn't take up a defensive stance against them.
The Curious Noob I think a lot of that has to do with the serious quality of this channel and its commenters. I almost selfishly wish this channel could stay a (semi) hidden gem but obviously that would not be best for these wonderful content creators and I hope more like myself discover it.
The Curious Noob What I enjoy equally about this channel is the positive and constructive responses by all the viewers. It's good to see a place on RU-vid not ruined by negativity.
A good thing to realize when talking about this stuff is that, from a space-time point of view, NOTHING is stationary. Everything is moving forward in time, so even without gravity or forces, every object is constantly moving along a path from one point in space-time to another. When you curve space-time, the time and space directions get bent into each other and "stationary" paths (geodesics to you geometers) get bent into paths that travel through space as well as time. In the case of a spherical gravity source like Earth, all these paths get bent just a bit towards the centre of the planet. They're still MOSTLY just going forward in time, but they gain a tiny bit of curvature from the curvature of space-time that bends them inwards. "Stationary" paths (that aren't orbits) all end at the centre of the earth at some finite time in the future. To avoid ending up there itself, the ground has to accelerate outward just to stay where it is. That's why we say that the ground is accelerating, even though the planet is not expanding. The force needed to provide this constant outward acceleration is the compression force from the rest of the planet. Amazing show guys. I'm loving every episode so far. Let me know if I got anything wrong.
Are all these vectors, when your accounting for space and time, of the same magnitude? Can we add velocity to the growing list of terms that only exist as mathematical conveniences?
rngwrldngnr For every point in space there is a bit of information (the metric tensor) that describes how space is bent at that point (or if you like, what the distance covered going through that point would be, except that this isn't a good definition from a math POV) Using partial differential equations you can integrate the length of a line through space, and the shortest of these two lines between spacetime events is the geodesic that describes inertial motion. As for velocity - i think that's fair to say for all of physics to some extent... But that's a question for philosophy ;-)
Cannot watch either There is a belief that if you talk fast, either people think you’re smart or people will follow your lead. It works for business negotiation or sales pitch, but not for teaching.
NIST WTC FAQ 31 says the top of the twin tower in NYC fell essentially in free fall because as the floors failed from the top down the weight added as each floor became part of the collapse got heavier and heavier even though free fall means weightless. And then there is building 7 ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-LJPuWy9utss.html
Amit kumar Gravity does not push or pull. It is the curvature if spacetime, you fall towards an object with mass because it bends space. Gravitational waves do not travel faster than light, they travel at the speed of light. I don’t know what you mean by “the gravitational field is the area that space time tries to even itself out”. It’s like the laws of thermodynamics but for gravity. Which we know doesn’t apply to gravity. Space time doesn’t try to even itself out, unless the actual fabric of space time acts like energy.
"How can geometry and straight lines possibly work the way I said?" Being an actuary didn't prepare me at all for physics, but this is something I actually understand! Thanks random masters-level topology course I took so I could graduate early!
Lutranereis I can recall thinking in undergrad physics that both calculus AND topology should have been prerequ coursework rather than just calculus. Basic topology is well within the range of a HS or freshman student and really makes a lot of the later coursework simpler to grasp.
neeneko ...we must have taken very different topology courses, because that stuff nearly kicked my ass. I made an "A" in the class only because I was graded on a scale that was shifted down 5% due to the fact that I was an undergraduate. I just don't see how most high school students would fair with the course, especially considering most have never had to write out proofs. Unless there's some other way of teaching topology that isn't exclusively proofs.
Lutranereis I had a pretty good HS one that introduced proofs as part of the class under the assumption that students would not have had them yet. It was about on par with Calc I in terms of depth and difficulty.
I clattered down the stairs in a train once because it stopped rather violently when I wasn't expecting it. There was nothing illusionary about the painful lump on my head I can assure you.
I am thinking thingzz and I am thinking it nowww. Yes, now it exists, this is real because I'm perceiving it and that makes it something that exists because I can perceive that I exist at all. At the very least, all as I perceive it becomes because I can even perceive my act to define. I probably make no sense, but my arms feel wobbly and I feel sort of happy. Ugh I made no sense. But everything is beside the point when there simply is existence. Existence is. Existence
Basically, you hit the ground and got the lump BUT it was not because a FORCE acted on you backwards that cause you to accelerate towards the ground. It might have seemed that way but this illusionary force was precisely that - an illusion. And all because your frame of reference was on the moving train and not the stationary ground outside.
If the ground is rushing to meet a falling ball, and it does this at all points on the surface radially outwards. Doesn't that mean the Earth is exploding?
Another way to ask this might be to wonder where the real acceleration that creates a fictitious gravitational force might be. Mass curves space (and time), fine. That defines that a a straight line might actually be an orbital circle around a planet, fine. But sitting still on the surface and not moving, what do I still feel a force?
Mastikator Good point, if I had to guess,it might have something to do with curved space/time and maybe radially outward from our point of view is something completely different in space/time ( Can someone answer this question because I want to know)
Mastikator Im just guessing, but it might have something to the rotations of the earth and its athmospheres, which dont let its matter fall apart, and this force just so turned out to be 9.8 m/s^2
I read something a while ago that gave me a WHA? moment: something that made perfect sense, after years of 'understanding' something, that was clear I didn't really understand. All you smart people will will just say, "well, d'uh." Anyway, it was concerning the idea of universe expansion. My original understanding was that planets, solar systems, galaxies etc are moving away from each other. In typical human centric chauvinism, I assumed everything in my vicinity was static while everything else just moved away. The article I read, from a legitimate scientific source, stated that EVERYTHING was expanding. Everything from galaxies down to particles. The article explained it with the example that if we were to compare a 1 cc block now to what would have been considered a 1 cc block several billion years ago, we would perceive "our" block as larger than the older one. So, I'm asking then (because I really don't know), could this "expansion' be (maybe partly) the outwards movement described as gravity. As we are near a very large mass, the earth, that perception of gravity would seem greater. This along with space-time in some way I'm not capable of understanding. Sorry, I know: TL:DR.
Irritable Jon Syndrome neural activity is how you feel pain in the first place. If the feeling of pain is caused by neural activity then can you see how an irregularity in neural activity could create pain?
@Jon Dillon when you are stressed/irritated/hyper-focused, a lot happens in your body and blood pressure that can cause a headache you pretentious tool.
This is one of my favorite videos ever, it challenged my conceptions in a manner that makes me come back to it again and again, I'm not gonna act like I understood everything, specially the last part, the curved space-time part, I'm just not at that technical level but as I progress in my engineering career I swear some day I'll teach this to my kids, it's just too damn interesting. PS: Bring back this guy for other videos and don't slow down, you speak like you want to speak bro!
Hi Mario, I might be able to help. Instead of thinking of space as curved, imagine all the atoms of the earth expanding. We are made of the same atoms so we're expanding too - we don't perceive the expansion because everything around us is also expanding.
NIST WTC FAQ 31 says the top of the twin tower in NYC fell essentially in free fall because as the floors failed from the top down the weight added as each floor became part of the collapse got heavier and heavier even though free fall means weightless. And then there is building 7 ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-LJPuWy9utss.html
Christopher Willis Imagine if everything moved at a constant speed relative to everything else the universe would freeze in motion. if everything moved at the same speed the universe would not exist. light would never reach us because space would cancel it out. if the space between two objects traveled at the speed of light then light would virtually freeze and hence the universe would cxease to exist. velocity does effect the existence of reality who would have thought. Imagine if your food ran away from you, making it impossible to eat and hence to exist. or imagine if your bed was moving away from you at the same speed so it appeared that you were both standing still.
Tethloach1 Though I realize this is pure speculation, it's worth noting that light _would_ reach you, since it moves at the same speed compared to every inertial reference frame. So even if you're moving away from it, it will still move towards you at its regular speed.
rango3526 If space moved at the speed of light than it could not reach you. if the space between objects moved away. galaxies expanding apart will reach a point where light from other galaxies will not reach us. Dark energy supports this. the space between galaxies will eventually reach light speed.
I've been watching this video for almost 3 years now, and after countless hours of research and other videos, I finally got it xD The best space and physics channel in existence !!!
So, gravity is an illusion, and acceleration is actually zero. Therefore, no gravity. What about force between two charged object? You are telling me no electric magnetic force? Because you see, gravitional force and electric magnetic force are fundamentally the same thing, they follow exactly same law.
@@seanleith5312 Agreed. This is what I don't get in all those "gravity is not a force" videos. How is it different from a "real force" "like when you push a chair", if that's just electric repulsion acting over distance? What's the definition of a real force anyway? Nobody seems to give it. Especially the Veritasium's video talking how "gravity is not a force because YOU don't feel it in free fall" - of course I don't, because I don't have a gravity sensor in my brain! If you replace Earth with something that has a big electric charge but zero/small-enough mass, and fill your body with electric charge, you won't "feel a force" that's attracting you (in a free fall), the same way you don't "feel a force" with gravity. Having said that: - does the fact that light gets bent by gravity but not by other "forces" give an argument to this "gravity is not a force" argument? You could replace all the massive objects with electrically charged objects in experiments and get the same conclusions (I think), but since light is not massive and thus doesn't have an electric equivalent, you couldn't say the same about light, so the equivalence principle doesn't hold. What do you think?
The nice thing is that despite constantly arguing with each other about apples and boxes, Newton and Einstein were really good friends and liked hanging out together and have fun.
+Robeon Mew smh no..Everything is relative, so everything that is moving at a constant speed relative to another object is an inertial frame of reference. smh Like you are when you sit in a plane, or a car that is moving at a constant speed, all the laws of physics are normal in those cases even tho you are moving. Its ONLY when you ACCELERATE that you are no longer in an inertial frame.
How to become a flat-Earther: 1) Understand some of this video. 2a) Fail to understand all of it, _and_ fail to notice said failure. OR: 2b) Simply reject bits that don't make intuitive sense. 3) Deduce that the world is a flat plane accelerating upwards at 9.8m/s^2. 4) Everything that would contradict your newly deduced cosmology (finer points of physics, photographs of a spherical Earth)? IT'S A CONSPIRACY! OPEN YOUR EYES, SHEEPLE! 5) Shape shifting Lizard Alien Illuminati. They fill in all those supposed "gaps" in your hypothesis, right? They even explain why your car wouldn't start this morning!
tbone martinez Nope :D Was this video really necessary? Or RU-vid? Or intelligent life? Or the universe itself? Nothing is _really_ necessary, it just _is!_ Mind blown, right? :D
pixel girl not really tho, if nothing is necessary or intentional then that means reality isn't necessary and thus we cannot be sure its not an accident. :( mind blown, unnecessarily.
tbone martinez I'd... _like_ there to be some kind of deeper, spiritual meaning to all this. But reality doesn't have to conform to my wishes or expectations. I guess I'm a hopeful agnostic?
pixel girl If there is no deeper meaning to life or reality, then it is truly pointless. Everything is an accident and thus everything we have grown to love, enjoy, and look forward to is an accident. No meaning to it other then what we assign, and since we are accidents it is utterly meaningless in the grand scheme. That is a truly dark way to believe and live :(
Drop an apple at the north pole. Have a friend drop an apple at the south pole at the exact same time. Earth accelerates in opposite directions at the same time, apples are stationary. You've just levitated two apples.
Except it's a great way of guiding someone through the logic, a path of learning, questioning and then learning more. Rather than just splatting out everything, like reading Wikipedia. Soo much more helpful and engaging for curious minds. I mean I know it was probably at least 50% joke, but that was for how ever much part of it might not have been.
When you're on the surface of the earth, "down" means towards the center of the earth and "up" means towards space, right? So how can the earth be accelerating upwards (to be exerting gravity) in the whole earth at once? I know i probably got something pretty wrong, but the whole thing seems illogical.
It's not illogical, and you got nothing wrong. The issue is that you are trying to analyze the entire earth with one reference frame, which can't work in general relativity.
electrocat1 Dude, i would burn you so bad if we were in the middle ages. Nothing personal, but this thing you just said about "frame of reference" sounded like some warlock spell straight from hell. But seriously, i tried to watch the rest of the series on relativity yet i can't figure why, if the earth is expanding in all directions at once, it doesn't explode. It is probably because i don't understand this frame of reference thing. Do you have something on the subject that i could read/watch?
Djanck000 yeah, look up frames of reference on RU-vid and watch the old black and white one. I hear it's good. It's pretty much just coordinates you can put around the planet. The earth isn't exploding, nor is it accelerating in all directions. They explained this in one of the relativity videos. Because spacetime around earth is curved, trying to use one reference frame to analyze the entire planet doesn't work, so trying to say reference frame on the other side of the earth is a conclusion you can not make.
+electrocat1 So in the frame of reference of the apple...the Earth is moving towards it, while in the frame of reference of the Earth...the apple is moving towars the Earth? It´s all basically a matter of perspective then.
Overdose Divided yes. But, if you had a box full of apples in free fall, they would look the same as if they were in outer space (inertial frame) thus making it the preferred frame of reference.
I watched the other video and it gave me a frame of reference by which to observe this man is talking way too fast. I like how in olden days people spoke with deliberation and people had time to process information.
I know I’m late to the party... but this was such a great, simple and interesting explanation! The editing and visuals are fantastic and help to understand what you’re explaining 👏🏻👏🏻👏🏻
NIST WTC FAQ 31 says the top of the twin tower in NYC fell essentially in free fall because as the floors failed from the top down the weight added as each floor became part of the collapse got heavier and heavier even though free fall means weightless. And then there is building 7 ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-LJPuWy9utss.html
1:21 He says that the video about Frame of Reference is from MIT but on the picture to the link it says "University of Toronto". Could it be a difference in our frame of reference?
Americans always take credit or ownership of what Canadians do and or accomplish, I.e. The movie Argo where the CIA take all the credit for getting the 6 on the run Americans out of Iran when it was the Canadians who housed them and fed them and broke our own passport laws to give the Americans Canadian passports to get them out, but the best one so far is an article I read where they said Wayne Gretzky was the greatest American born hockey player haha ohhhh jeez
After watching videos describing these concepts, I'm always confident I understand everything well. But when I try to explain them to someone, it becomes clear that my understanding is tenuous at best.
That is because these videos are still superficial. If you want a detailed understanding you'll have to get deeper into the math. If you're interested in that, I highly recommend the channel Eigenchris. They have detailed videos on the required math and its application in Relativity. This video also lists some resources for self study ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-cP2uVarXi1A.html
Too much caffeine, please have your energy drink, your coffee after your presentation, not before. Try some Buddha mind meditation before. Like they say in Montana, take the time to watch the grass grow. If it is all relative, why are you trying to squeeze time and destroy space?
0:30 That's not really correct. The idea of Einstein's is that both the apple and the Earth are free-falling in a spacetime that's _curved_ in such a way that the paths of free fall of the apple and the Earth are getting closer and closer together. When they finally touch (the apple fell to the surface of the Earth), the Earth keeps FAPP free falling while the apple is now being _pushed_ by the Earth _off_ its path of free fall (this push is felt as "gravitation", it's what pushes you in the chair while you are reading this). The reason the Earth continues free falling while the apple gets pushed off is that the Earth is much more massive (i.e., much more _inert_) than the apple. It is only in the above sense that one can reasonably say that "the Earth jumps up to the apple" (it's still misleading).
JanPBtest the earths surface has forces from the layers below it. If it was also at rest, it would be orbiting the center of the earth, which it's not. Each layer of the earth is being pushed by the layer below it.
A different point of view: ....... What about the earth is stationary and and the apple is stationary..... Resulting in the space field in which the apple is sitting, being stretched by the earth mass..... Resulting in the apple being pushed down the space itself.... Not the earth accelerating up... But the space is moving toward the greater mass, dragging the apple along (not the sun around the earth, but the the earth around the sun...... :D) .... And in the black holes case..... The universe is loosing mass, gaining space instead And in the case of dark energy.... All the BH's in the universe streaching the space (in all directions there are BH's) in such way that it's seems to us that space is expanding faster than light over long distances.... But there are a lot of BH's that are dragging each other expanding space faster and faster
A few people have been commenting on the importance of time being a dimension, and that nothing is stationary. This is more invaluable than any idea in relativity. "The earth is really accelerating upward." How the hell is that possible? Well, it isn't accelerating upward in space, but in time. Locally, the temporal direction in spacetime is being warped much more so than the other three spatial dimensions; one can show this using a weak-field approximation. This causes "free fall" to occur according to the mathematics of differential geometry even if space is not itself curving. That time is a dimension is the biggest and most important assumption relativity makes and there would be no general relativity, or gravitation, without that assumption.
I’m 31 years old and I just finished a grade 12 university-preparation physics course... after learning all of the Newtonian formulae and how to apply them, General Relativity is mind shattering. This Einstein dude is seriously a mf’er... couldn’t he just leave well enough alone? I’m going to stay here, in my comfortable inertial frame of reference. Get the heck away from me Einstein, you the devil and, gravity is REAL and REALLY SIMPLE: things fall through the ether because of magical faeries, don’t @ me
I never understood why gravity must be quantized if according to General relativity and Einstein's fields equation it's just a curvature of spacetime. Why graviton is necessary if is the stress-energy tensor that stretches spacetime?
All the other forces have been successfully quantized. And, there is a drive to unify all of physics. The incompatibility of qm and gr is what stands in the way, though there are already serious similarities mathematically.
@@josephpark3949 Man, I happened to finnish a bachelor's degree in Physics and start a master degree in Nuclear Physics in the meantime of my comment and your answer. But thank you anyway
I smoked a joint last night and with a few replays of couple minutes I finally understood the whole concept of gravity is an illusion and the curved space time, I was so blown away.
I believe that you have just stumbled upon a hole new universe. Welcome in the other side of knowledge. Watch some more of the videos these guys make, and you will understand how the world works ;)
Until we get away from this nonsense about bending and stretching Spacetime (THERE IS NO SUCH THING AS SPACETIME = SPACETIME IS ALWAYS EVERYWHERE ) we are going nowhere.
Damn! Every time I drop an apple, Earth accelerates toward my apple, meaning I float people on the other side of the earth for a second or two!!! I am sorry Madagascans.
Ok, so the earth accelerates upwards (which must mean radially outwards) how about if two meteorites fall, both on opposite sides of the earth. huh? the earth would have to accelerate towards both those meteorites as the same time, stretching the earth into an oval, and tearing it apart!
Also, what i don't get is... if Earth is accelerating at 9.8 m/s2 ... after less than a year it would reach the speed of light, or thereabouts... But now how can it KEEP accelerating? :-\ Or is that what you meant by "must mean radially outwards"? That the speed isn't really constantly increasing due to the acceleration?
yes, I thought the same, but you don't even have to go that far, right know thousands of objects are falling to the ground of the earth in all parts of the world, everytime every second, so yea, that way of explaining general relativity sucks.
if our gravity worked on the concept that earth is accelerating upwards and we are stationary....the earth would have to be constantly accelerating upwards to keep up the "fake gravity"...(if the earth were to slow down or have a constant speed....we would already be floating or flying away).... it also needs an infinite amount of energy to be accelerating "upwards" and all points on earth would literally be exploding outwards into space since the earth is a sphere
It's so cool watching this in 2022 with the JWST actually in operation! Still a bit away but were closer to realizing the results from the questions they are asking
Why such an idea doesn't work (and Einstein didn't necessarily think of it like it was explained): -If you have two planets of equal mass in contact with one-another, then each should expand with centers of mass diverging, which means that gravity would be stronger on either side of this system than if the balls were not in contact. This violates conservation of energy. -If all objects are expanding, then to match gravity equations, they must be expanding at an exponential rate, which does not match the expansion of the universe.
Conservation of Energy doesn't have to work in small regions of the universe according to general relativity. And the expansion of something like a planet would have nothing to do with the expansion of the universe because the object is held together by gravity and gravity is stronger than dark energy. Universal expansion only really becomes noticeable at intergalactic scales.
Clay Eickemeyer no, never did it once say that. It says that the ground appears to be accelerating toward freely falling objects, and since it's obviously not expanding, then there must be something else going on here. Welcome to general relativity.
electrocat1 They did say that there is something missing, I remember now (thanks). But in the first place they still gave the idea and said what I said. I completely disagree with it, and I am aware of (conceptually, not mathematically) how gravity works in Relativity. All I mean in the OP is that gravity is _not_ the expansion of objects into one-another.
A different point of view: ....... What about the earth is stationary and and the apple is stationary..... Resulting in the space field in which the apple is sitting, being stretched by the earth mass..... Resulting in the apple being pushed down the space itself.... Not the earth accelerating up... But the space is moving toward the greater mass, dragging the apple along (not the sun around the earth, but the the earth around the sun...... :D) .... And in the black holes case..... The universe is loosing mass, gaining space instead
Added to my playlist of confuse gravity explanations. This is the kind of videos that confirm flatearthers in their beliefs. The consecutive "gravity isn't..." starting by the title, the speed, and not mentioning that the subject is still under study and not totally understood.
Did the numberphile Sports in Hyperbolic space inspire this video? I've always been intellectually aware of curved space-time but considering the consequences of it makes me think of that video.
Darth Stuticus I've seen that video too. I think it's fun to try to visualize different spatial geometries. But I think PBS Space Time has had this topic in mind as a goal---or at least a stepping stone---for some time now.
If this works for gravity does it also work for other forces such as the electromagnetic field? If not, why not? If so, does that mean that all fields are illusions? If so then do we expect to see particles like photons and gravitons? In short, which is correct, relativity or particle physics?
Gareth Dean I think that is one of the major problems in Physics right now, that our model for 3 of the forces (strong, weak and electromagnetic) is quite different from the model for the remaining one (gravity) and both models pass with flying colors at any experiment we throw at them. Only model I know that seems to correct that is string theory but we can't test it yet.
Gareth Dean Congratulations! You just found: *"Unsolved Mystery Of The Universe That Every Physicist In The World Is Trying To Figure Out Right Now"* use it with care...
Gareth Dean There's two types of mass: gravitational mass (the _m_ in _G = mg_) and inertial mass (the _m_ in _ΣF = ma_). While these aren't conceptually different, no experiment has yet proven any difference between them. This is different from the other fundamental forces; for instance, electromagnetic charge is a quantity independent of inertial mass, meaning that two initially stationary objects in an electric field may accelerate differently. However, there are other forces that, like gravity, are also proportional to the inertial mass: fictitious forces, such as the centrifugal force or the Coriolis force, that occur in an accelerating frame of reference. This is probably what inspired the idea that gravity is also a fictitious force.
frxstrem So there needs to be a relation to inertial mass for this treatment to work? Because as far as I can tell you should be able to model the electromagnetic force as a distortion of spacetime and- Wait no, I just got it now. Differing acceleration would imply different geometry for different masses, which is nonsense. Very good, thankyou.
Thats funny!! I have to watch a minute of it, then back up and listen to it again, all the way through. Great stuff, especially with a Bourbon on hand. :)
I love how this guy speaks so rapidly as if we all have degrees in physics. It's like a native Japanese person teaching Americans Japanese by demonstrating how well he speaks it.
I appreciate the rapid flow of information. If I miss something I can back up the video. At least what he says in this video, in contrast with many U-Tube videos, is not endless grandstanding about the dog, the wife, the fish he caught, etc. Highly trained or very intelligent people tend to speak rapidly about that which they are familiar with. By speaking rapidly, he respects the time I have to spend watching his video.
The image shown at 9:05 is just sooo misleading. As a visual orientated person, I see this "gravity well" image everywhere, because every science channel is copying the idea. But if you think about it, showing that space time is curved like a well when near massive objects, and other objects "fall" inside the well, its just like trying to explain gravity with .... gravity. There is no "falling" because there would need to be a force. This visual analogy is just so wrong... :(
'Wojciech Mazur I fully agree with you, and we specifically addressed this point in two other videos. Here: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-D3GVVkPb3OI.htmlm17s and then again here: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-AwhKZ3fd9JA.htmlm40s. Our episodes are not intended to be self-contained. They all refer to one another and make much less sense when viewed in isolation. You may want to watch our whole Relativity playlist: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-YycAzdtUIko.html
Life is Eternal, Life have a Life-side and a Stuff-side. Will is the Life-Force, Gravity is the Stuff-Force. Stuff-side appears as an illusion, but, it is a Real Illusion, a Eternal Miracle.
(Sorry if you're seeing this twice, sometimes I have troubles with comments working). I recently gave a lesson to a high school physics class about inertial vs non-inertial reference frames and how that affects whether the centrifugal force is "real" and I'm embarrassed to say that I learned a few things from this video and I realize that mislead my students on a certain point. I posted a video of the lesson to my youtube channel (see how to get to the video below) and I'm now going to annotate my video to reflect this, and I was wondering if you'd be alright with me linking to this video for a more nuanced explanation of non-inertial reference frames? Thanks -Marco (It seems like when I try to post a link to a video the comment doesn't show up, so if you're willing to, search "Marco Alatorre Centrifugal Force is REAL ...sometimes")
If gravity is an illusory force, and is just a causal implication of the warping of space time by the presence of objects of mass then why are physicists looking to merge the force of gravity into the frameworks of theories such as String Theory and Loop Quantum Gravity in order to develop a theory of everything which would unify the force of gravity with the electromagnetic, weak nuclear and strong nuclear forces? Why is gravity thought to be a fundamental force which must be united with the others, because if it is just a causal implication of warped space time it would not need to be unified with the other fundamental forces and would not need a guage boson like a graviton to carry its force. If gravity exists merely because objects being present in space time cause a force which must be described, then why can it not be simply viewed as being unique in this fashion and be seen as distinct rather than coupled into being part of the fundamental forces group? Am I being too simplistic here???
Too simplistic... not to me buddy! Unification of the theories will be like seeking pots of gold at the end of a rainbow. For me gravity is not an actual thing (force, particle... leprechaun!) I prefer to think of it as the term used for the transfer of energy into or through the four dimensions that we exist in.
It's a matter of description. Gravity is described to amazing precision by GR but it's not the only description. There may also be an equally accurate particle theory of gravity as well. An analogy is the orbit of the moon. From the top down it appears to move in a circle with a centripetal force. But from the side on, it looks like a spring moving back and forward obeying Hooke's law. Both models like accurately predict the motion of the moon at all times. We're in the same spot, we need a new description of gravity that include quantum mechanics.
Was also thinking something very similar and then read this. Great question. The reason why scientists are trying to do this is because GR doesn't say that gravity is an illusion. That is actually just clickbait bollocks for cool RU-vid videos. Gravity is definitely not an illusion. It is simply that GR shows us that the nature of gravity is much deeper than what we think it is. Similarly the nature of time is much deeper than we think it is. What is the principle of the all attractive gravity? What is the nature of time? I think this is where the line between physics and philosophy becomes blurry. I don't think you can answer these questions with empirical tests, because you're starting to ask intrinsically non-empirical questions. There are paradoxes. For example, is space infinitely divisible? What is infinity? Does infinity exist? What is the beginning of time and does it even make sense for there to be a beginning? What is consciousness and does it exist beyond temporary beginnings and ends? These are ontological and metaphysical questions. I don't think anyone is ever going to find answers to these questions in a particle accelerator or any physics lab. People generally either end up giving up entirely or they take up a philosophical/spiritual journey of self realisation. The chase for that "Grand Unified Field" is the same chase that practitioners of yoga are on, because the Unified Field is just another name for the same God that has attracted the hearts of all people for millennia. It's a rabbit hole which most people tiptoe around the edge but never jump into. Personally, I jumped in. I was for a while, but I'm not afraid of God anymore.
I think that "gravity is an illusory force" looses his real meaning without "is just a causal implication of the warping of space time by the presence of objects of mass". It doesn't mean that gravity doesn't exists and is just a fake illusion, it's only that it can be explained in a different and better way from a different point of view (or frame of reference to say it with physics). We still need to find the unification theory that can explain all the 4 fundamental forces of nature at the same time, because we must answer to the questions: why masses create distortions in space-time? and how it happens? Thanks to GR we can explain many observed phenomena like Mercury orbit precession, curvature of light due to mass, black holes and gravitational waves. All things that Newton's gravity could not explain and GR instead even predicted before any experimental evidence. Excluding the Mercury orbit that was already known before GR and in fact has been the nightmare of physicist and astronomers for many years, and also the reason why it was supposed to be another planet near the Sun. GR also gives a whole new perspective on fundamental concepts like space, time, mass and energy. Anyway, this doesn't mean that Newton's was wrong. His theory is still valid for most application on Earth when is acceptable to assume that we are in a non accelerating frame of reference and space and time are constant and absolute. When we have to deal with astronomical distances, big masses, very high velocities or simply we need an incredible level of precision we can only use GR. I think GR can also have the effect to open the mind of people because it makes you realize that what makes sense at the level of everyday life is not enough to explain the universe and what makes sense in the universe frame reference can appear as a paradox for our common sense. It's astonishing how many truths can be hidden in a paradox. T.
This Video: "Gravity is an illusion (an effect/byproduct)." Other Science Videos: "Gravity is one of the four main forces that govern our universe. We have detected gravitational waves and may soon discover gravitons." Me: "I think the mainstream scientific communities to reconvene about what they say gravity is in textbooks and news reports." This Video: "Huh, that's a good point. ...It turns out that there's a loophole that makes Einstein's viewpoint self-consistent." Me: "Sounds like almost every part of our current 'model' only works at all, because of loopholes."
This video doesn’t properly explain why “gravity is an illusion”. I prefer to say gravity is not a force. There is no denying that what we observe and call gravity is real, not an illusion. What gravity is though is still up for debate, kind of like what is time. I think the term “gravity is an illusion” really should be stated as “gravity being a force is/maybe an illusion”. The fact that it may not be a force is irrelevant to the current laws of physics and how we do things. Whether one uses GR or Newton. To fly and navigate rockets and space ships in our solar system, for the most part doesn’t make any difference. Both work just fine, except maybe near the sun like where mercury is. According to Newton’s laws gravity must be a force. If gravity really is a force then Newton’s laws should cover the orbit of mercury, but it doesn’t. If Newton’s laws don’t cover the orbit of mercury, then we can’t believe what those laws say about the nature of gravity. The laws none the less are still true for 3D space, but may not hold true for 4D space time in all cases. GR tells us what Newton saw as a force for gravity is really to objects travelling straight lines through curved space time. Think of it like this. Two planes ( piloted by flat earthers) 100 miles apart start at the equator and travel north (true north, not magnetic north). As far as each are concerned they are travelling in a straight line parallel to each other. They check in with each other every hour, and find that even though they both have been travelling in a straight line, they are no longer 100 miles apart, they are closer together. The longer they fly the closer they get. They conclude there must a force pulling or pushing them together. They do a bunch of experiments and tests and conclude the force is relative to their speed, as the faster they go the faster they come together, and the slower they go the slower they come together, and if they do move at all the force is zero. They work out a formula ( something like F = v* d) that can be used to predict and explain what they observe. One day while doing an experiment (with the planes on auto pilot) the pilots fall asleep and do check in for quite a few hours. When they wake up they find that the planes are on opposite sides from each other, and now the force is pushing them apart. (Fortunately they were not flying at exactly the same altitude). They are also no longer flying north, but south. Long story short after much more experimenting over longer flights. They come to the conclusion that the earth is a sphere, not flat and the force they thought existed is not a force at all, but the result of a curve in the 3rd dimension. Their straight line flights were only straight in 2 dimensions, but not in 3. Just as a curve in the 3rd dimension brings 2 objects together traveling in straight lines in 2 dimensions without a force, so does a curve in the 4th dimension (time) bring two objects together traveling in a straight line in 3 dimensions. One might say well it is not quite the same. If the 2 planes do not move, then they don’t get closer together, but 2 objects not moving (in 3D) still get closer together. This is true, but look at what causes the movement in the curved dimension in each case. For the planes, only movement causes movement in the curved dimension. For our objects time never stands still, (never stops moving) they are always moving in the curved dimension. I personally am not saying gravity is a force or not. There is not enough evidence to determine one or the other. Though I am leaning to not. If that be the case there still could be a force that mass exerts on time to cause it to curve.
Yes I understand this simplify logic, but here is a question. Why gravity apply to all sides of earth? If I drop an apple at Japan and the earth currently moving forward through USA, then, why the apple don't just be left behind in space. And a less rediculous question. How the earth succeeds to keep its air and atmosphere if there is not gravity. Can someone simply explain?
i am not a scientist but I will try my best to explain, so here goes. You have a huge 10 foot by 10 foot piece of cloth, you stretch out this cloth and suspend it in mid air so that it is completely straight. Now you take a toothpic and place it on the cloth, nothing changes right? So now you put a bowling ball on the cloth and it sinks in and the toothpic assuming is frictionless and free floating gets drawn towards the bowlng ball. This looks like the work of gravity when in reality there is none, it is the force of attraction. The bowling ball attracted the toothpic not gravitate it, becuase if it generated gravitational force then the bowling ball would be considered a planet which sounds crazy. Unless your hand, an external agent stops the toothpic from going towards the bowling ball the fore of attraction does its work. Thus proving that gravity is not real.
Michael Fastbender I am sorry the example may be good but I still not get it. Even we assume that there is not gravity but only "spacetime stretching" (I think that your example was all about this), then, there is still a force that make small objects attached to heavy objects. The bowling ball cause the stretch not the toothpic. The earth cause the stretching and that's why the apple is attached. The video says that the apple is stable and the earth moves forward to attach it, and my question was about that specific claim.
Just imagine all the stuff from earth floating in open space: air, water, apples etc. And then there comes an infinite accelerating plane, what would happen? Exactly, everything will be attached to this plane like there is a gravity: objects will stick to it, air will condense etc. In earth case it's the same, but instead infinite plane there's a sphere.
fritt wastaken Pfff no the opposite. Everything will go away from the plain, even the air will become blast wave... Sorry but you don't get my question. Even if your example is wrong, STILL, the plane will cause the "attachment" not the apple...
Earth moving towards apple . Ok. Explain this, what if 2 people stand on opposite sides of the earth and drop 2 apples at the same time. Which way, would the earth move ?
Exactly! Two apples falling at antipodes would then both be "inertial" reference frames that are accelerating toward one another. Same with two spacecrafts in separate orbits around Earth.
@@carultch Inertial reference frame accelerating towards one another?? They are suppose to be references to other how can they accelerate wrt each other??
@@Sarthakz99 Ok, that was bad vocabulary on my part. Change that to two objects, each within an "inertial" reference frame. Object A is accelerating toward Object B in Object B's reference frame. The point still stands. How can they both be in inertial reference frames, if one is accelerating toward the other?
@@carultch I saw this video again and I think the solution is that inertial frames can accelerate if space-time has a curved geometry. Example: A satellite is actually moving on a straight path with constant velocity but its curved wrt us maybe?
@@Sarthakz99 Still seems like a contradiction of terms. I think the only true inertial reference frames by strict definition, are in deep space of truly zero gravity, and not accelerating.
Ok, this one I get. The earth is physically preventing my free motion in accord with the curvature of space time ,which constitutes an acceleration. The satellite, is allowed to ,being above the ground, and so constitutes a proper inertial frame of reference. The earth is not pushing by expansion, it's resisting my free fall constantly, equating an acceleration. Bass ackwards but ,I think that's the point.
Tides are the effects of earth. moon , electronic connections . Whenever the moon electronic connections is strongest the earth heaves upwards out of the ocean leaving a low tide behind , the moon connection weakens and the earth settles back into normalcy with a high tide , all of this is coupled with earth rotation and it's allinement with the sun and moon which is responsible for the amount of energy it receive at any one time to carry Out its tidal duties . The moon electronic connections to the earth is very strong ,its holding on with all it got , while the earth connection to the moon is very weak , this is because the earth is not dependent on the moon to mentain its orbit .Still , they both need each other for the preservation of life , case in point , without the moon strong electronic connections the earth would not have a tilt to suffice life as it does today .For More proof of zero gravity , visit RU-vid SUNLIGHT ELECTRO RAY'S with visible proof of planetary orbits powered by sunlight energy lol .
Money JattDepends what you mean by "very less gravity". Actually the gravity is relatively constant around the globe. You will measure 9.8 meters per second squared all over the globe. The differences around the globe are there, but very slight. Your downward foce is also affected by your latitude and the force of the spinning at the equator slightly lifting you. That effect diminished as you get to the poles. Effective gravity on the Earth's surface varies by around 0.7%, from from 9.7639 m/s2 on the Nevado Huascarán mountain in Peru to 9.8337 m/s2 at the surface of the Arctic Ocean. The tides come from the gravity of the moon. Just Google it for a description and illustrations. Most people understand the high tide that faces the moon, what confuses most people is the high tide OPPOSITE the moon.
@Joe Lusk - Because the Earth is SOOOOO big from our humanly perspective, that it appears flat, which is how we get a horizon. Oh, and because they're idiots. Ask a flat Earther why it's daylight in China while it's midnight in America??
ahah I am a physicist and believe me, it is impossible that you understood the general relativity after watching this video ;) It takes years and you would need to read several books about theoretical physics and mathematics.
