Why Gravity is NOT a Force
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The General Theory of Relativity tells us gravity is not a force, gravitational fields don't exist. Objects tend to move on straight paths through curved spacetime. Thanks to Caséta by Lutron for sponsoring this video. Find out more at: www.lutron.com/veritasium

Huge thanks to Prof. Geraint Lewis for hours of consulting on this video so I could get these ideas straight in my own brain. Check out his SVsoft channel: ve42.co/gfl or his books: ve42.co/GFLbooks

Amazing VFX, compositing, and editing by Jonny Hyman
2D animations by Ivàn Tello
Filmed by Steven Warren and Raquel Nuno
Special thanks to Petr Lebedev for reviews and script consultation
Music by Jonny Hyman and from Epidemic Sound epidemicsound.com

Rocket made by Goodnight and Co.
Screen images in rocket by Geoff Barrett

Slow motion rocket exhaust footage from Joe Barnard at BPS.Space
svsoft.info/glo/ILl.html...

Kommentarer
  • Veritasium
    Veritasium

    Here's a question I've seen a lot in comments: OK, I'm accelerating up but then shouldn't someone on the other side of the globe fall off? No, here's why: Either watch again from 8:28 or read what I've written below... Spacetime is curved - it curves the opposite direction on the other side of the Earth. Neither us on this side of the Earth nor they on the other side are changing our spacial coordinates - we're not moving up, they're not moving down - Earth isn't flying into one of us. BUT we both ARE accelerating. In curved spacetime you have to accelerate just to remain stationary. The traditional definition of acceleration is something changing its velocity. In general relativity you have to embrace a new definition of acceleration: it means deviating from a geodesic - not going on a straight line path through spacetime. Near the Earth a geodesic is a parabola so unless you're moving in a parabolic arc (like on a zero-g plane) you are accelerating. This definition is the same as the old one so if you're accelerating in deep space then your velocity is changing. *BUT*... if you are near a large mass you are in curved spacetime, now acceleration your velocity is changing. You can stay stationary relative to Earth's surface and still be accelerating. This is because your acceleration should be measured not relative to the Earth's surface but relative to free-falling objects - they are inertial observers. Imagine this - I'm in deep space and I make horizontal rows and rows of stationary golf balls. Then I hop in my rocket and accelerate up through them. Just think about what that looks like. Now my rocket is back on Earth just sitting there. I freeze time for a sec and make horizontal rows and rows of golf balls up into the atmosphere. Now unfreeze time. What do you see? If you just look at the golf balls and the rocket ship it looks the same as the situation in space where the golf balls were stationary and the rocket was accelerating. Einstein's point was the golf balls have the better claim as the "stationary" thing since their experience is just like the golf balls in deep space - no forces experienced. The rocket on Earth is just like the rocket in space. It feels a force and hence an acceleration.

    • Rich Munson
      Rich Munson

      E

    • adorable
      adorable

      h

    • xiao99 xiao99
      xiao99 xiao99

      @T F Rubbish. You are claiming that a permanent Magnet is NOT attracting metal objects, pulling them across space, doing WORK, because where is the Energy coming from? The magnet has no Fuel, so Magnets do not work right? Anyway, Where does the Energy come from when the Earth curves SpaceTime? It must be a massive amount of Energy, as SpaceTime is so dense, solid or something, able to make the Moon go in circles..... SpaceTime, and having no Gravity caused by the Earth is a moronic claim. Unsupported by the direct observations. All this complexity of the otherwise simple, just to try to keep the MYTH that Einstein is some sort of Genius, and that his nonsense ideas are somehow rational.

    • Stanford Luk
      Stanford Luk

      @Veritasium we attribute the weight of our body to gravity. And astronauts weigh different depending on the planet they're on according to Newtonian physics, which also tells us the difference in gravity is due to the difference the planet's size(mass), but if gravity is a function of acceleration through spacetime, shouldn't that right weight therefore be calculated based on that planet's acceleration through spacetime? For instance, the moon orbits earth, logic would argue the moon needs to accelerate faster than earth through spacetime in order to remain in orbit, therefore astronauts should be subjected to higher gravity on the moon than on earth, yet the opposite is observed? Could you please do a follow up to reconcile this? Thanks heaps

    • Aditya Vikram Singh
      Aditya Vikram Singh

      @Des Troya your 'clear defination of acceleration' is not right for the curved space time. Simply answered

  • spiderman7330
    spiderman7330

    I think you should make it clear that this is all THEORY.. and not FACTUAL.

    • Narf Whals
      Narf Whals

      A scientific theory is a set of rules that explains observations and makes predictions based on evidence and experiment. It is pretty much the gold standard of knowledge. It doesn't actually get any more "factual".

  • John Yang
    John Yang

    The overwrought canvas unequivocally fence because retailer differently bolt except a lamentable step-sister. average, chunky attempt

  • sol3au
    sol3au

    How does the rocket know it should bend its path towards the planet? The answer that space-time is bent and it is falling towards it does not answer anything, then how does the rocket know the space-time time is bent? There is something missing! All these answers are just abstract approximations of that something.

    • Narf Whals
      Narf Whals

      How does a rocket usually know to go in a straight line? It's just newton's first law. The rocket doesn't even notice spacetime is bent.

  • T-bone Tyrone
    T-bone Tyrone

    I'm confused about the bit where he says that to an outside observer, the light in the acceleration spaceship looks the same as it always would. Whereas when perceived by the observer inside the accelerating ship it appears slightly lower. Why wouldn't the light appear lower for an outside observer as well?

    • Narf Whals
      Narf Whals

      @T-bone Tyrone exactly. Though that's only a correlation, not actually an explanation. It goes more like this. We know from Special Relativity that light will seem to bend in an accelerated reference frame. The equivalence principle demands that it look the same under gravity. Spacetime curvature is the mechanism that allows that.

    • T-bone Tyrone
      T-bone Tyrone

      @Narf Whals Oh that makes things much more clear. So because an accelerating frame of reference is indistinguishable from the influence of gravity, the light bends the same as it would following a curved path through space time.

    • Narf Whals
      Narf Whals

      He is unclear about that. The outside observer sees the light move in a straight line but the rocket accelerate up. The light hits a lower spot on the opposite wall. The inside observer sees the light bend downward to hit a lower spot on the opposite wall Both observers agree which spot the light hits.

  • Alexander “Peaceful swiss Guy” Gilomen
    Alexander “Peaceful swiss Guy” Gilomen

    Question: If Mass doesnt create a force, how can it bend Space-Time?

  • Blue Flask
    Blue Flask

    so the point your making is that instead of gravity its just curved spacetime ?, wich would br correct to a certain point but viewing a person falling from a building will not be caused by that curved spacetime as that would make no sense, its in out atmosfere. thats why we have gravity

    • Narf Whals
      Narf Whals

      The atmosphere has absolutely nothing to do with gravity. All it does is provide air resistance. We fall off buildings because spacetime is curved.

  • Aaryan Upadhyaya
    Aaryan Upadhyaya

    don't use a marker on paper next time and don't play its sound

  • Sir Aaron
    Sir Aaron

    According to this video, anyone experiancing freefall isn't passing through time, at all. Meaning, in their own frame of reference, they'd never hit the ground. Can we debunk that?

    • Sir Aaron
      Sir Aaron

      Your change in position equals your your spacual acceleration minus the curvature of spacetime times temporal velocity squared. From your own frame of reference this would look like 0 = 0 - z Where z is the portion of the equation that deals with curvature and temporal velocity. By mathematical law, one of those terms has to be zero. frames of reference are about how things move relative to itself. So technically in *all* frames of reference you're only moving through time

    • Narf Whals
      Narf Whals

      Where did you get that from? In their own reference frame they are actually *only* moving in time.

  • ask
    ask

    5:42 Astronauts in the space station are not weightless, not even close. They are quite a bit lighter than they are on the surface of Earth, but they're not anywhere near weightless.

    • Narf Whals
      Narf Whals

      ​@ask The point is that you are always weightless in free fall. And an orbit is free fall motion. They aren't weightless because of the altitude, but because of the falling.

    • ask
      ask

      @Narf Whals Yes I only mean to say that Earth's gravity is only somewhat reduced at the distance of the ISS. Of course, if you move fast enough around anything, you can counteract . But I was a bit thrown off by the suggestion thay objects at the altitude of low earth orbit are weightless. But maybe I was the only one who read it that way! I think I gave it a quick watch and didn't let the segment finish!

    • Narf Whals
      Narf Whals

      They are weightless as long as they fall. You can put a scale under their feet that is at rest with the space station and it won't show any weight. If you try to stop them from falling, that is when you get weight. And indeed their weight would be an appreciable portion of their weight on earth.

  • AlphaCent007
    AlphaCent007

    Didn't LIGO show gravitational field? I am confused

  • Tennis Fun
    Tennis Fun

    This video made me happy today....

  • Dyaus Varuna
    Dyaus Varuna

    Question. If i understood correctly, earth is accelerating and affects us the same way. But in the video he says "there is no weight". Then what are we measuring when we stand in a scale?

    • Narf Whals
      Narf Whals

      Weight is the force required to accelerate you to a standstill in the curved spacetime.

  • trah subedaar
    trah subedaar

    Masterpiece!

  • Patricia Lorentzen
    Patricia Lorentzen

    So now that my understanding of physical force (completely reinforced by observation within my non-inertial perspective) has been totally shattered, how long will it take to begin to re-evaluate my spatial interactions in these new terms? It's understandable how Einstein's "man falling off a roof" scenario was such an epiphany and why he referred to it as his happiest thought.

  • Raven Master
    Raven Master

    Hate to burst your bubble, but accelerometers are affected by gravity. It is how your phone knows it is upright, or face down or sideways.

    • Narf Whals
      Narf Whals

      Only when you keep your phone still. In free fall your phone won't register an acceleration(unless it is rotating).

  • Eightshot
    Eightshot

    sorry, but my brain cannot compute the concept of curved space time.

  • Fırat KARA
    Fırat KARA

    İhtiyacı olan şeylere baksana.

  • Mihai Ciocoiu
    Mihai Ciocoiu

    Don't we know we are accelerating?

  • vamshidhar reddy
    vamshidhar reddy

    *THIS EXPLAINS IT ALL.* time slows down when we move through space and it also slows down under the influence of gravity so if gravity causes us to accelerate through space, it is moving through space which is causing the time dilation under the influence of gravity. This automatically proves that general relativity's picture of gravity is correct. Hence the stationary charge will give off electromagnetic radiation.

  • Justin Fliss
    Justin Fliss

    The human brain is currently working on mastering the 4th dimension. Memories are a form of 4th dimension information. You could even argue that dreams or visions could be flashes of a possible future moment in time.

  • Pet Dog
    Pet Dog

    9:32 blew my mind

  • Manuel Menapace
    Manuel Menapace

    I somehow struggle to understand the example with objects falling with the same speed on the surface of earth. How would an accelerating surface towards these 'falling' objects consider air resistency, like with a feather? If not the objects, but the surface of earth is accelerating? Can anybody explain?

    • Narf Whals
      Narf Whals

      The earth's surface accelerates the air. The air in turn pushes against the falling object. The effect of this push depends on the shape and composition of the falling object and that is what air resistance is.

  • Debarshi Raj Basumatary
    Debarshi Raj Basumatary

    @Veritasium from your video I understood that gravity is not a force but curvature of space-time and its the earth that is moving not a free falling object. But there I have a question, I saw a physics demo video, there they kept some objects on trampoline when someone jumps on the trampoline those objects stays in same position in air for sometime before moving down, the commentator said its an example of inertia. If the there is no gravitational force , and its the earth that moving up then there should be no inertia on those objects and they should start moving down immediately. Please answer? anyone?

    • Narf Whals
      Narf Whals

      It isn't that the earth is moving and the falling object is not. Both are moving depending on your point of view. But the falling object is not _accelerating_ . And it is basically inertia that is causing things to fall back down after bouncing on the trampoline. That is what "inertial frame of reference" means. It is moving with no forces on it. In a curved spacetime that means falling. So they do start moving down immediately. But they have an upward velocity they need to get rid of first. So they move up, get slower, and then move down. And all of that is inertial motion.

  • wackywankavator
    wackywankavator

    Remove all mass and energy from the universe. Place two objects at zero velocity within a foot or two of each other. Will they stand perfectly still or pull towards each other?

    • Narf Whals
      Narf Whals

      If you put two objects into the universe you are introducing energy again. That energy curves spacetime and the objects will start moving. And there is no such thing as "perfectly still" in spacetime. If the objects have no velocity in space, relative to each other, then they are moving through time. Spacetime curvature turns this motion through time into motion through space.

  • Adrian Duty
    Adrian Duty

    I will agree with you. Therefore my preference will be to express the gravitational constant in terms of acceleration. I do not know if there is a mathematical formula for such. It is that acceleration of the earth along with its elliptical curvature, that creates differences in distance from its centre, as it rotates on its axis that will account for: 1. variations in gravity/ weight at higher altitudes and 2.a projectile falling to the ground in a perceived arch when launched as the curved earth moves to meet the ball that is in an inertia frame of reference. The projectile quickly moves out of such as it's acceleration is less than the earth's.

  • Braneloc
    Braneloc

    Time is an illusion. Lunchtime, doubly so.

  • aleethan one
    aleethan one

    don't really know how to explain it myself but i'm opening up to the idea. i think it feels like it would be helpful to think more about the situation we are in on earth. like visualizing being on a orb that's spinning and orbiting and moving through space and all that.

    • Narf Whals
      Narf Whals

      None of that spinning and orbiting is very relevant for gravitational attraction. You can take the earth to be stationary and non rotating and gravity will look almost identical.

  • MAKER
    MAKER

    Feel that's matter

  • MAKER
    MAKER

    Then what if we made a whole in earth .From north pole to south pole. Does we get out of our plane according to Einstein's theory

  • Wayne Adams
    Wayne Adams

    Constant velocity is constant speed in single direction. It is incorrect to say constant velocity in a straight line. In fact, to be really picky, any good mathematician will tell you that lines are defined as straight, everything else is a curve. The correct terminology is constant velocity. His constant use of straight lines along geodesics is just plain bad terminology. Objects falling with the same acceleration regardless of mass can be explained using Newtonian mechanics without writing a single equation. I used this kind of explanation many years ago when I was asked to do a series of science workshops for elementary school teachers who had very little science training. I also have used it in my class. Here we go. Imagine we have two objects, A, and B. B has twice the mass of A. We place each on a cart with wheels and push them so they have the same acceleration, that is, they stay side by side as they accelerate. What would we observe? Obviously, the more massive object B requires more force, in the same way it takes more force to push a large truck as compared to a small car. In fact, we would find that it takes twice the force to accelerate object B. Now what do we find when we weigh the two objects? Well, duh, obviously object B weighs twice object A. What does that mean? It means object B experiences twice the downward force of object A. But wait a moment, didn't we just determine that object B needs twice the force of object A to have the same acceleration? There you have it, Object B experience twice the gravitational force of Object A which is exactly what it needs to have the same acceleration. So all objects will fall with the same acceleration regardless of mass. All of tis assumes that air resistance is small enough to be ignored. No equations, no math, just simple intuitive concepts that can be grasped by an elementary school child, or teacher for that matter. Here is a nifty, easy to do demonstration you can do right now in your home. Drop a sheet of paper and a book so it lands flat, at the same time. The book falls to the floor with a thud, and the paper flutters down. Now put the paper on TOP of the book, being careful that none of it hangs out over the edges (you may have to trim it to size). Now drop the book-paper combination. The paper falls with the book as though it were glued in place. As soon as the effects of air are removed by having the book push the air aside, the sheet of paper falls to the floor with the same acceleration as the book. I like to use this demonstration in my class for two reasons. One, it really illustrates the point because the book is so much more massive than the paper. Two, I use the biggest heaviest book I can find so that the loud thud wakes any students who may have been dozing off. Wayne Y. Adams B.S. Chemistry (ACS Certified) M.S. Physics

    • Dyaus Varuna
      Dyaus Varuna

      2 questions from an outsider's point of view: Is this an explanation of why newtonian laws work to explain that there is in fact a gravitational force? Does weight affect in any way what the author of this video says about general relativity?

  • MAKER
    MAKER

    Thanks for clearing doubts and misconceptions about gravity . 🤩🤩

  • BraveScience
    BraveScience

    I really need an answer to this. If the planets and stars and other bodies are falling through space, like a diver with weighted boots sinks in water, why are there stars and planets beneath our solar system? I thought in a vacuum an anvil and a feather would fall and be next to each other?

    • Jay R
      Jay R

      This is an intersting question, but i don't think things in space are falling or rising. i think what he meant was that planets are accelerating instead of gravity pulling things towards them. i don't really know

  • srussert28
    srussert28

    From high school...(80's ish)The way Skylab corkscrewed through space while the astronauts were "weightless" bugged me the same way you could "toss" a baseball around the planet. Scientist may have got this question down to one part in 10 trillion. But in my head Kentucky windage would play a roll in hitting a target. Now this explained the same idea. If it was 50 feet shooting a .22 or a quadrillion light years trying to hit another planet. You would have to take into account the curve or "wind" to hit your target. OK so now the gravity funnel I always could not quantify is a bit backward but the idea of it being a force or "wind/curvature" actually makes this easier. I can now understand the idea of hitting a target a quadrillion light year from here. Getting the idea of our solar system spinning through our galaxy with a message from us hitting another galaxy and a specific planet...this answers a lot of questions.

  • Ryan Francois
    Ryan Francois

    Me: *crashes into a parked car* The car owner: dude you just hit my car Me: AcTuAllY you hit me bozo learn how to drive still

  • Andrei Cristian
    Andrei Cristian

    I like to question stuff that make no sense to my human brain. Before being able to conclude it's curved, I must first be able to understand wtf a "spacetime" is. If I focus too much on me falling onto Earth, sure I might conclude the Earth is falling on my face (which would be a very narrow minded thing to do really, I mean my mind would probably be flatter than a flat earther's brain for me to entertain such a thought). But wait, on the other side of the Globe, the Earth must then be falling onto someone else's face at the same time. Thus one can only reach the conclusion that Earth is expanding to hit both our faces at the same time! Or maybe people tend to be stupid, and curved spacetime is an abstract idea where you make a graph, you put time on the abscissa, you put distance on the ordinate axis and you should get a straight line if distance travelled is a linear function of time, or a CURVE if distance is a nonlinear function of time, meaning the rate of change of distance is not constant, which Einstein tried to prove. I bet Einstein "faceEarthed" really hard when people started using "spacetime" as an actual thing that is curved, making you fall onto planets and stuff.

  • KSloyan
    KSloyan

    Is that a mask for sawdust or scary cold virus? lol

  • SagyCatopOlis
    SagyCatopOlis

    no matter how to try and play it off, you will always be able to tell when you are accelerating relative to the space time that surrounds you, whether you can see it or not. so the guy who is falling would not feel weightless, he would feel like he is moving very fast in a relatively downward direction. as a man who has fallen from greater than average heights, I know a thing or two about how it feels. this is a great thought experiment, but like many great thought experiments, in practice, it's almost completely different

    • Narf Whals
      Narf Whals

      @SagyCatopOlis You can't. You can feel a _change_ in motion, aka acceleration. But not motion itself. From the inside you don't notice that a plane moving straight through calm air is moving at all.

    • SagyCatopOlis
      SagyCatopOlis

      @Narf Whals explain how you you can feel movement inside of a falling falling air tight object(be it a high a plane or another vehicle/object that can be sealed) and still feel movement while in free fall even without air movement.

    • Narf Whals
      Narf Whals

      @SagyCatopOlis The difference is air resistance, which is the major thing we notice when falling. The suit is falling at exactly the same rate you are. You won't press against it. The same is true for everything inside your body that usually notices acceleration. The difference in falling is that we're not used to that. Usually our organs hang and push against our body. In free fall they start to float. That is a thing you can notice. But that is exactly the same feeling you get when floating in outer space. Movement is not absolute. Movement is relative. If you can't look outside the suit to see the thing you're moving relative to you won't notice.

    • SagyCatopOlis
      SagyCatopOlis

      @Narf Whals no, but I don't see how that matters in the slightest. movement is movement no matter how you try to define it. you're body(so long as you are an average human with no major health problems) is capable of noticing a change in acceleration relative to you're surroundings. beings as you'd be in a bulky suit inorder to survive in a vacuum, if you were to start falling into a planets atmosphere, before you ever made it there, you'd feel yourself press against the suit. let's say that just for arguments sack we didn't need to use equipment and could float in space nacked. you'd still be able to feel your organs move around in you're body as that would very likely be the only thing you could feel at all

    • Narf Whals
      Narf Whals

      Have you ever fallen through a vacuum?

  • liveuk
    liveuk

    I love this as my favorite thought has always been the galaxy we are in moving relative to everything we observed numties think is everything moving away from us lol stuff moving to a point gravity is simply being blocked, contained by other stuff such a fun thought since a kid when people say g1 in a lesson I always just smiled after crashing into a wall for the first time on my trike aged 5 just sat there smiling for a bit as the wall is gravity in the book I reads model Der Hu.

  • Infine Myself
    Infine Myself

    As I always like to explain to myself is that in a curved space-time light travels bigger distances (curved lines from As to Bs) with the same time it takes to travel the smallest distance (straight lines from As to Bs), so it’s kinda like the speed of light is bigger in curved space-time, thus every speed is bigger, and to stay in rest we have to accelerate to negate this additional speed

  • Sami zafar
    Sami zafar

    That hit the mind awesome 👍

  • Twisted Code
    Twisted Code

    gravity isn't a force and the speed of light can't be measured. Next I expect you'll tell me you have a working TARDIS

  • rkt31 rkt31
    rkt31 rkt31

    Free fall on earth is akin to moving in space with constant speed. Similarly standing still on earth is like standing in a accelerating rocket. In both the cases in earth and rocket, the person who is observing the other in acceleration himself experiencing no force. An accelerometer in free fall does not record any acceleration hence no force. Brilliant ! Now please do video how quantum entanglement retain information until observation is done and gravity is all about creating new information ( change in entropy ) along with time ie gravity is responsible for time or vice versa or time is nothing but increase in entropy.

  • kub1x
    kub1x

    So it is not gravitational force pulling me down, it is spacetime speeding up around me downwards at 9.81m/s/s? The spacetime has some sort of friction on me, so the ground has to push me up to stay at the "same spot"? I feel like what I'm asking in previous question, e.g. the mental model in my head is the same thing as the gravitational force, just explained backwards. I think I'm just half way to understanding this. I would very much like to improve on it. So more thinking... Where does the spacetime go, when it reaches earth's (sun's, black hole's) core? I think it goes nowhere. It just "stops moving" when there is mass all around. It is just regular coordinates, like X, Y and Z. Lines of X==1, X==2 etc. Only they are not stationary. The paper the coordinates are drawn on is moving when it gets close to mass. But they constantly move with what we eventually perceive as gravity. Ok, NOW I see the golf balls analogy. How does spacetime behave inside of large objects? Does it "get confused", or just stop as there is mass all around it? When earth (or other massive object) is moving does it "change coordinates"? So as it moves through spacetime, the curvature shape of spacetime moves with it? Like today spacetime curves towards x==1, y==1, tomorrow it will curve towards x==1, y==2 since earth moved by +1 in Y direction. But this is weird. How do I distinguish between spacetime shifting towards gravity and actual move of an object? Earth is moving around Sun. This move helps it to stay on the orbit. So it does change coordinates. It goes in a straight line, but the axis in which direction it moves is curved around the Sun. Like, the Y axis is no longer a line but a shrinking circle. But the earth is not going in circles but in ellipses (ignoring the spiralling part). Does it mean the earth's trajectory is not a straight line along the Y axis which is bent around the sun, but some sort of sinus trajectory (only wider on top where we're further from the Sun). PS: Sorry, for being wordy. This IS interesting and it made me think (well procrastinate, but in a non regretting way). PPS: If I point my rocket to the perceived point of the star behind the Sun and press go. Will I hit the star? Does the spacetime bend the same way for me and the light coming towards me? Would I have to go a speed of light to follow the same path as the curved light? I don't really expect any answers. Still many thanks. This was fun. And mind blowing. But starts to hurt a bit now. Back to work ;D

  • Force_A_Nature _KZ
    Force_A_Nature _KZ

    And in the future it's turns out that Gravity is just a 4D path through space-time

  • ABHINAV MAYANK SINHA
    ABHINAV MAYANK SINHA

    6:15 - This is exactly what my toilet flush do.

  • John P
    John P

    The standing wednesday cranially wander because secretary apparently support times a spiffy lip. elfin, bewildered dentist

  • Tarocalypse
    Tarocalypse

    11:14 Crikey that's the University of Sydney there! Looking rather young too lol

  • Scott Birch
    Scott Birch

    Can time not be taken out of the equations though?

    • Narf Whals
      Narf Whals

      Not at all. On the contrary it is actually almost entirely the curvature of time that is responsible for keeping us on the ground and the planets in orbit. It is always necessarily spacetime that curves.

  • Mohammed Alharbi
    Mohammed Alharbi

    I didn’t know that flickering 3 switches lunch a rocket. 😂😂😂. I love it

  • SuperHamSniper
    SuperHamSniper

    11:01 well you say that but it doesnt really answer my questions or explain it so i can completely know what every part is.

  • SuperHamSniper
    SuperHamSniper

    10:43 i will worry about the details and you cannot stop me

  • SuperHamSniper
    SuperHamSniper

    why is there an r on the a ?????? 10:25

  • SuperHamSniper
    SuperHamSniper

    9:24 so are you saying the earth is constantly expanding? so that the floor is always accelarating towards you at 9.81m/s or are you saying that im the floor, or are you saying that space time is the floor or are you saying that there is no up and we are all just moving one waythrough space, or are you saying that space is moving towards us from all sides making it seem as if the floor is moving through space by expanding without expanding, because this video leaves me with alot of questions and the most important one of those, completely unanswered except for "oh well its this formula here and thats why"

    • Jay R
      Jay R

      "are you saying that there is no up and we are all just moving one waythrough space" ????

    • Jay R
      Jay R

      he never called you a floor xD he tries to simplify it as much as possible, if you want answers do more research on general relativity

  • SuperHamSniper
    SuperHamSniper

    you say "they arent falling they are just going straight" then what stops people from just jumping and following the straight line of curved space that goes directly "up" relative to them out into space, why are we then stuck to the ground instead of just being able to jump directly into space??

    • Jay R
      Jay R

      because the ground is accelerating into you

  • SuperHamSniper
    SuperHamSniper

    this video leaves me with several questions unanswered and i dont like it, like, why do you move towards earth if there is no force? why would you say that that in a sphearical space it takes energy just to stay still and then just saying "you dont need to think about why but it just is like that".

    • Jay R
      Jay R

      he says that you do not move towards earth, earth accelerates towards you

  • DeejayF
    DeejayF

    "Gravity doesn't exist!" Flat earthers: I knew it!

  • LB Joum
    LB Joum

    I get it for my first time. Curved space is changing around me and the earth is pushing me through it. Thanks you for blowing my mind. Thought? If the earth wasn't pushing me where would I fall to?

  • Solomon Lepcha
    Solomon Lepcha

    Flat-Earthers assemble

  • Science Wolf
    Science Wolf

    I just think of gravity as a force and not a force

  • niraj mondal
    niraj mondal

    It's not us accelerating on surface of earth but space that is moving through us is

    • niraj mondal
      niraj mondal

      But energy required to make space particle very small so very small amounts is added to matter that's the reason no matter how we try we fail to produce absolute zero temperature as amount of energy added to matter by space particle cant be stopped no matter were we try because space is everywhere . I came to this realization by thinking about fact every matter in universe radiates energy as radiation just you need is sufficiently cold observation device

    • niraj mondal
      niraj mondal

      Then another problem arises if space particle moving towards matter (earth) is converted to energy then net energy of earth is increasing the answer is yes

    • niraj mondal
      niraj mondal

      If space particle is being eaten up by matter then it must be violating law of conservation of mass and energy I will say it's not because we know a way around it e=mc² energy mass equivalence if normal matter can be converted into energy then space particle can be also converted into energy.

    • niraj mondal
      niraj mondal

      Then by looking at interaction between space particles and normal matter we can say matter acts like vaccum cleaner and space particle like air.

    • niraj mondal
      niraj mondal

      Problem is space is not like air but very similar thing made out of particle say space particle that can interact with two things only other space particles and space sub particle in normal matter

  • Dale Welsh
    Dale Welsh

    I need an answer to this question if gravity doesn’t exist. If gravity doesn’t exist then why would you weigh more at certain areas on earth and weigh less on others if gravity was relative to a curvature in space time then how would this be a probability?

    • Narf Whals
      Narf Whals

      Curvature is proportional to the massdensity of earth and related to your distance from the center of mass. But the earth's mass density isn't constant and neither is the distance on the surface. Earth's rotation also plays a role. You weight about 1% less at the equator than at the poles.

  • John Marks
    John Marks

    So one question. Assume 2 people on opposite sides of the Earth. Each falling off of a building simultaneously in time. From their frame of reference, both observe people in the respective buildings traveling at 9.8 m/s up, yet, in complete opposite directions. Travel through space is still directional, but direction is then absolute due to the square of the velocity through time. Is this the correct hypothesis? Then I foresee a problem, where 'vt' is velocity through time, as stated -vt^2 = +vt^2 = |vt|^2; however velocity to the first power is still directional and '+vt' is opposite '-vt' . In the frame of reference the falling people, the Earth must either must be experiencing a velocity of either +vt or -vt regardless of curvature and cannot be traveling both directions simultaneously.

    • Narf Whals
      Narf Whals

      He talks about that in the pinned comment. But one important note is that the equivalence principle specifically states that "in a small enough region of spacetime" you can't tell gravity from acceleration. If you compare people on two opposite sides of earth, that region is just too big.

  • patman0250
    patman0250

    If you keep saying frame of reference gravity has nothing to do with frame of reference, just how you see it. Something that looks or feels the same doesn't necessarily mean they are. And people floating in space maybe you didn't know but they actually are speeding up. Which is probably the cause of dark matter. That's neither here or there, you said you were going to prove that there are no gravitational fields but you didn't prove anything. All you've done is explain your theory on what you think gravity is. Congratulations you're like all the other thousands of people who think they know what gravity is with absolutely no proof or evidence whatsoever. This is probably one of the worst explanations I've ever heard. And PS, Einstein is in always right.

    • patman0250
      patman0250

      @Narf Whals Maybe you didn't know this but a theory will always be just a theory. In other words we really still don't know you might need to do a little more reading up on what Siri means. No technology has ever been invented or discovered solely on a theory. And don't try to go on sing with gravity is and what it isn't considering no one knows what it is dude. To say gravity isn't a force listen to yourself dude it's like trying to say what dark matter is but having absolutely no idea on what it actually is. You're not making a whole lot of sense here dude. All we could do is observe effects gravity just might be a byproduct of what's really going on. That's the problem though nobody knows. Just like nobody really knows what photons are. Sure we know what they do but what they're made of waves or particles. It's the mysteries of quantum mechanics relativity and reality stop working. Based on our physical knowledge anyways. Never heard of the double slit experiment how results can change whether the simple act of observing or not observing. How particles of light act a certain way only if you're watching. Thems just the mysteries of the universe dude. PS what makes you think we achieve this technology? Like we didn't have help. we know extraterrestrials exist the military knows they exist we can see them the damn clearly. Military has claimed they've been in contact with them and reverse engineered down UFOs since the early years of the 1900s, where the technological boom really started. Don't you think that would explain the thousands or millions of years we've been on this planet but the last 200 it exploded with technology. Doesn't make sense does it.

    • Narf Whals
      Narf Whals

      @patman0250 Sorry but "just a theory" is not a good argument. A scientific theory is the gold standard of our knowledge. We will never have anything "better". Being able to be proven wrong is the whole point of it. Of course our theories are limited by our understanding of physics, but that is what they seek to push further. But relativity is about the very simple observation that the laws of physics, whatever they are, should be valid for all observers. I can absolutely imagine technology that seems like magic, that doesn't mean gravity is a force or relativity is wrong. Gravity is demonstrably not a newtonian force and pretending Newton was right all along and Einstein was a hack is holding us back from achieving this technology. Our scientific advances of the 20th century have shown us that forces _don't even exist_ and have lead us to technologies that would have seemed like magic just 100 years ago. Why would you kling to outdated science that could never have achieved this?

    • patman0250
      patman0250

      @Narf WhalsI mean don't get me wrong I know we're advancing towards understanding more and more about this universe and the unknown everyday. All I'm saying is whatever gravity is made of or the mystery behind gravity is still just a theory. Relativity is a little fickle because it's only relative to our understanding of physics, or to the extent of our limits of understanding. But I will say that our theories today are more advanced and closer than anything we could have imagine 200 years ago. It's true we're not even close to becoming a type1 civilization yet. But just imagine the thing's we could achieve once we start scaling that ladder. Anti-gravity spaceships questions about thing's once thought supernatural, like spirit's and the amazing forces they control. Like what are they made of, what dimension do they reside. Even though people might see that as supernatural or spiritual. I see it as another category of science and technology. But that discussion is for a whole another day. Just imagine technology almost indistinguishable from what we perceive as magic. What kind of spiritual technology powered by interdimensional forces we never could have imagined existed. That right there will graduate us to a type 3 civilization and beyond. Maybe call it hyper technology? Oh man I hope I didn't lose you, yeah I probably did oh well.

    • Narf Whals
      Narf Whals

      We want laws of physics that are valid in all frames of reference. To achieve this forces have to be measurable in all frames of reference(they are vectors). If gravity vanishes in a frame of reference that means our force description does not give laws that are valid in all frames of reference. Instead, like the coriolis effect, it is a fictitious force that comes from comparing two different kinds of reference frame. This is not his theory. This is General Relativity, our best theory of gravity for over 100 years. It gives us laws of physics that are valid in all reference frames by letting gravity be an effect of spacetime itself that everyone can agree on rather than a force that they can't.

  • gabriel gauchez
    gabriel gauchez

    in standard newtonian physics im not a stickman, im a point in a vacuum

  • DFSOUTLIER
    DFSOUTLIER

    A person falling off a building is not in an inertial frame of reference, they 'feel' weightless because they are falling at the same rate as the pull of gravity. if gravity did not exist planets and suns would not form because the matter would not be attracted in the first place. if you place two objects in a vacuum near each other they will eventually move together until they touch and no outside force is required. It seems like every video you make is the exact opposite of Occam's razor, you appear to be looking for the most complicated solution to any given issue.

  • peronkop
    peronkop

    Isn't spacetime a field?

  • Lloyd Nicholls
    Lloyd Nicholls

    So it seems for matter to exist, it must have caused a massive distortion of space-time every single time any particle came into existence... ... I guess this adds to the theory that matter is nothing more than a deviation of space-time; a wrinkle in the fold, so to speak.

  • Muthulingam Ramiah
    Muthulingam Ramiah

    Finally, they start moving in the right direction... I always knew Gravity was greatly misunderstood... Imagine the archaic days when they were looking for Gravitons... This offers a glimmer of hope on our path towards Warp Speed and Interstellar Travel....

    • Narf Whals
      Narf Whals

      This is General Relativity and has been our best theory of gravity for over 100 years. It still needs to be brought together with quantum mechanics and the graviton is one attempt to do that.

  • Cpt Adama
    Cpt Adama

    Two Parachutists go out for a jump. They jump out of a plane and one tells the other my chute won't open. The other jumper tells him "not to worry", "gravity is an illusion".

  • MAKER
    MAKER

    Newton ,just sell that apple and start business 😂😂

  • Wanderers
    Wanderers

    Why do "everyone" think that general relativity is the final piece of the puzzle!? Why do you telling it as a fact, instead of saying that it's the our understanding by far. It's misleading and I hate it.

  • Wanderers
    Wanderers

    What bends the space-time? What made the earth a sphere? Gravity. And because we don't understand gravity, we can speculate. Otherwise if we understand it, we would know how to bend space and travel faster than light.

  • Norma Snockers
    Norma Snockers

    Gravity is opposing force of the expansion of the universe via dark matter my granny said.

  • mindstormmaster
    mindstormmaster

    In order to keep a charged particle "stationary" relative to the earth, you would need to apply forces on it, which is accelerating it, which would cause it to emit photons, as it would if it were accelerated in a particle accelerator by magnets.

  • Dumii Cris
    Dumii Cris

    i never liked about you the simple observations

  • If only See thru my eyes
    If only See thru my eyes

    awesome...I think I've got it :)

  • Dumii Cris
    Dumii Cris

    i like your title why gravity is not a force means u want to know more and you say is not a force cause is not what u understand in school .. :)

  • Old Blind Darby
    Old Blind Darby

    What about the gravity waves detected in the inferometer experiment whose name escapes me?

    • Narf Whals
      Narf Whals

      Gravitational waves are waves of spacetime curvature and predicted by this theory.

  • → to the knee
    → to the knee

    I can tell if I'm in an accelerating in a rocket vs being "stationary" on Earth by measuring the Newtonian acceleration of objects at the top of the ship vs near the bottom; they would be identical. But on Earth, the Newtonian acceleration changes closer to the surface of the planet.

    • Narf Whals
      Narf Whals

      This is why the equivalence principle specifically states that 'in a small enough region of spacetime' you can't tell gravity from acceleration. Small enough would in this case mean that you can take the acceleration to be the same at the top and the bottom. Many communicators leave this out and it often leads to confusion.

  • divya lattoo
    divya lattoo

    Even the sponsor section at the end is interesting

  • Paras Mehta
    Paras Mehta

    So does that mean that all the planets around the sun are travelling in a straight geodesic path? What about centripetal force?

  • demi clay
    demi clay

    bull

  • Ely Gurren
    Ely Gurren

    So the earth is flat and moving upwards 😅 /s

  • mutantgenepool
    mutantgenepool

    Is Vacuum a Force?

  • Gordon Freeman
    Gordon Freeman

    I have so many other questions I could ask but here's a couple of them... If someone jumps from a roof and accelerates towards Earth, and then suddenly the Earth was removed such that the Moon would then be the closest large mass, what would happen to the person? And what would they experience? I assume that their direction of travel would change, from where Earth was to the Moon, but how quickly - instantly or gradually? Secondly, would the person experience any perception of force as they change direction? Based on the video explanation, I feel like the answer to the second question is that they would not experience any force - but I find it hard to understand how someone could completely change the direction that they are 'falling' in without experiencing any force. For the first question, I have no idea what the answer would be.

    • Narf Whals
      Narf Whals

      For a very short time they wouldn't notice at all as the information that the earth has vanished moves through spacetime at the speed of light. Then they would just be falling towards the moon with some "sideways" velocity. If that is the right velocity they will orbit the moon, otherwise they will hit it eventually or escape into the solar system. It will be just like falling. If you throw an object up there is no force on it as soon as it leaves your hand. It is in free fall until you catch it again and can not measure an acceleration (as usual ignoring air resistance) You see the object change direction relative to yours, but the object doesn't notice. The same thing will happen. All that happens is that the direction of "down" changes. But the falling person never knew where that was in the first place.

  • Waddup Mayne
    Waddup Mayne

    Dang it! Im not smart enough to understand this...

  • Sophrosyne
    Sophrosyne

    Wait a minute...this disproves the ether theory.

    • Sophrosyne
      Sophrosyne

      @Narf Whals what is it anyway?

    • Narf Whals
      Narf Whals

      Aether theories have been disproven many times over since Michelson-Morley did it the first time in 1887. There is no aether.

  • Sophrosyne
    Sophrosyne

    Einstein was sponsored by masons

  • tonybaby100
    tonybaby100

    I'm pretty sure Gravity exists and nothing in the universe with mass moves in a straight line except for light unless it's course is deflected by a stars gravity. I don't agree with this space time crap or big bang or expanding universe, The universe has been in existence for ever and is infinite and red shift means nothing because light traveling from billions of light years away is obviously going to slow down.

  • J T
    J T

    2:21 "There are no gravitational fields." 11:50 "m is gravitational mass, the property of an object that creates and experiences a gravitational field." Makes perfect sense lol.

    • Narf Whals
      Narf Whals

      If you listen he says "was" gravitational mass. As he describes an outdated formula.

  • Austin Ortega
    Austin Ortega

    I have been lied to my whole life?

  • Flyn Valighn
    Flyn Valighn

    Why is gravity always shown as a 3 dimensional object on a 2 dimensional plane. When it affects a 4th dimensional area?

  • Shane Garrison
    Shane Garrison

    The zippy haircut premenstrually suppose because resolution rapidly appreciate out a soft saw. melted, mature fairies

  • The90forts
    The90forts

    Then why does light warp around a black hole?

    • Andy
      Andy

      Because a black hole bends spacetime, a lot.

  • Alex Oja
    Alex Oja

    It is not the fall that kills, but rather the sudden transition from an inertial frame of reference.

  • Andy
    Andy

    There are far easier sensors of acceleration to measure than whether or not radiation is emitted from a stationary charge versus a falling charge. Buoyancy is one for example. Mixtures of objects with varying density will not float or sink relative to eachother in free fall. That proves they are not accelerating.

  • Diana B.
    Diana B.

    Hmmm, similarly to how light behaves both like a particle and a wave, depending on the method of observation, I think it's possible scientists may discover that both charges might emit electromagnetic radiation, depending on how they're measured. Here on Earth, I think the falling one will surely with emit it. If not, my mind will blow. 🤯

  • Andrew Osiris
    Andrew Osiris

    Ive been thinking about this a lot and I have some problems that lead me to believe that gravity must be a force. If it is just an illusion caused by curved spacetime, then why do stars glow. Why would the elements just peacefully stack on them at the bottom of the hill. No, it is the force of gravity that attracts them to each other, a force grinding them together, ultimately fusing them and creating heat and light. The same force can be seen on our own planet, though less extreme the force of gravity pushes the core together and liquefies the rock. Sure space is curved, but that has no meaning unless a force causes things to slide down the hill.

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