Why Gravity is NOT a Force

9. okt. 2020
3 548 847 Ogledi

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 SLworlds 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
slworlds.info/wiki/ILl8ozWuxnFYXIe2svjHhg

Komentarjev
  • 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.

    VeritasiumVeritasiumPred 7 dnevi
    • Sierz-Pauli action

      Ricardo MVRicardo MVPred 2 urami
    • Maybe you could do a video on how Space time is a concept rather than a tangible thing? - Briefly, spacetime is not a thing, it’s a concept, a talking point. Things happen in spacetime. Spacetime doesn’t happen because it isn’t a thing, it’s a guiding concept, a mental construct, an idea. Those who have invested a lot of energy into the narrative that treats spacetime like a real thing are going to resist being reminded that spacetime is the mathematical linking of two venerable, quantifiable, abstract concepts, and linking them together like that doesn’t magically transform those concepts into tangibles. Nor does bringing Riemannian geometry into Minkowski spacetime convert these ideas into concrete realities. This is called reification, the act of attributing realness onto imaginative thought structures like abstract concepts.

      Quantum BaboonsQuantum BaboonsPred 3 urami
    • We are always near a large mass (the rest of the Galaxy/matter in the universe) and always in curved space time, it's just the layers of space time that differentiates from point to point, no?

      Quantum BaboonsQuantum BaboonsPred 3 urami
    • @K.L. It's the friction of the air that creates the "blown" effect. In the spaceship, since everything is moving (including the air) at the same speed, their is no friction.

      hallux20hallux20Pred 3 urami
    • muh electric universe theory

      Uncl DolanUncl DolanPred 7 urami
  • Hold on... if this guy crashing into the planet is actually moving in a straight line in curved spacetime, and astronauts orbiting Earth in a circle are also moving in a straight line in curved spacetime, how come light jumps the rails of this curved spacetime and fails to orbit Earth in little circles? I've always understood that light bends slightly when passing by a massive star, and no doubt very slightly when passing by the Earth, and I've understood that this was due to the distortion of spacetime, but what we are talking about there is on a radically smaller scale of bending compared to the effect gravity has on ordinary physical objects. The Earth is not a black hole, where it can bend spacetime into circular orbits. I can appreciate that light is moving at a much higher speed than an orbiting spacecraft, but if the spacetime it travels through is already so sharply pre-bent, how can speed alone allow light to cut across lanes?

    FuzzybeanerizerFuzzybeanerizerPred minuto
  • so we are always accelerating?

    Bright SpaceBright SpacePred 3 minutami
  • If gravitational fields and forces don't exist, then observed gravitational waves from colliding black holes are simply "waves" in space time, and not waves in gravitational fields--and therefore the notion of finding theoretical gravitons is misguided. Yet many physicists continue to work on Grand Unification theories and devise experiments to detect gravitons--when it seems to me that, based on the very notion of perceived gravity as simply the bending of spacetime, it would suggest that General Relativity *specifically precludes* force/field/particle-based theories. Doesn't this just mean that physicists pursuing GUT research are wasting their time on a misunderstanding of GR? Or worse, they're "GR heretics"?

    demongo2007demongo2007Pred 10 minutami
  • Fantastic video. Why are scientists still hunting for the "graviton" then?

    Scott EganScott EganPred 13 minutami
  • You are teaching this wrong. From where did you learn this. You talk only about about the falling observer. By the principle of equivalence an observer in a inercial frame subjected to gravity will see the guy falling due a gravitational field to which he is subjected.

    Sergio MaiaSergio MaiaPred 19 minutami
    • An observer on earth will see the light bending You are confused about frames.

      Sergio MaiaSergio MaiaPred 13 minutami
  • So things that aren’t moving are actually accelerating and the things that are falling are stationary?

    jessejames1999jessejames1999Pred 20 minutami
  • So if we don’t use the correct framework of physics we would never approach our destination.

    jessejames1999jessejames1999Pred 21 minuto
  • If gravity is not a force then are there only 3 forces of nature?

    anthony mananthony manPred 22 minutami
  • So I am what’s holding me back?

    jessejames1999jessejames1999Pred 25 minutami
  • A straight path is not a straight path if you are on a curve that will run you into each other

    ryublueblankaryublueblankaPred 32 minutami
  • Albert Einstein knows nothing about physics or gravity. He copied the theory of relativity from a French physicist and said it was his theory. Type in youtube search:

    Ka HeKa HePred 34 minutami
  • If I felt weightless I'd be floating not falling like a sack of bricks

    ryublueblankaryublueblankaPred 34 minutami
  • The intro to this video would give the younger version of myself a panic attack with the fear of falling into space by making up down.

    jessejames1999jessejames1999Pred 37 minutami
  • Remember how people say: I'm too old for this sh*t? Well, I'm too dumb for this sh*t.

    Alejandro RodriguezAlejandro RodriguezPred 45 minutami
  • how do orbits work then, if the earth is not expanding but it is then why do things stay in orbit and why don't distant orbiting objects crash into the planet like the iss, one could argue that its because its moving so fast around the planet ,but there is not energy being put into the system so this cant be the case. and why do inertial observers experience the expanding earth but the iss doesn't? how does interplanetary travel even work? the standard Newtonian theory is for more comprehendible, one would argue that the laws of physics don't and shouldn't conform to our perception of the universe, but maybe it should. maybe its better to understand the universe as we see it and most easily comprehend it. please answer, someone.

    Nolan JoslinNolan JoslinPred 48 minutami
    • and how does reentry work

      Nolan JoslinNolan JoslinPred 33 minutami
    • and if I cant travel in a geodesic why can the iss. In curved spacetime you have to accelerate just to remain stationary, how does this work

      Nolan JoslinNolan JoslinPred 37 minutami
  • Why has the charged particle test mentioned at the end of the video logistically not been possible yet?

    Bearrito42Bearrito42Pred 54 minutami
  • this is wrong because the earth is expanding. and everything else along with it including us which is the whole point of a relative view. point.

    george hincklegeorge hincklePred 55 minutami
  • So we are all Thor’s hammer... the universe just moves around us.

    Go away I have comments to makeGo away I have comments to makePred 56 minutami
  • This video is the perfect example why people need to go to school. Is there a part 2 to this video that actually proves that Gravity is not a force?

    worldofazerothworldofazerothPred 57 minutami
  • Does the spacetime around me varies as my velocity varies?

    Haidar BazzounHaidar BazzounPred 58 minutami
  • Watched this video many times. Its a masterpiece..

    Vineet TalashiVineet TalashiPred uro
  • thanks for the video, didn't get a thing of what you explained

    arie bronsarie bronsPred uro
  • Question: why are the orbits elliptical and not round.

    Alexander WerdichAlexander WerdichPred uro
  • Matter tells spacetime how to curve, Spacetime tells matter how to move. 🤯 yet?

    V MCV MCPred uro
  • I probably didn't understand this video completely, because despite the great explanation, it's kind of hard wrap my head around it. but does this explain why black holes are so immensely powerful? If gravity doesn't exist, what is it then.

    Thomas NonameThomas NonamePred uro
    • Extreme spacetime curvature. At the event horizon all geodesics point inwards.

      Narf WhalsNarf WhalsPred uro
  • The son of Carl Sagan!

    TheokondakTheokondakPred uro
  • If the earth is pushing up at 9.8 meters squared and if objects don't fall but the earth moves up to meet it then why does the earth meet the feather and brick at the same time?

    david baileydavid baileyPred uro
    • @Narf Whals just thought this right now, is this correct? So the earth moves at 1000 miles per hours. So objects on earth are moving at the same speed. When something falls it is no longer attached to the earth therefore no longer going earth's speed. The objects acceleration slows down based on air resistance, that's why when. The earth catches up to the objects they hit different because each object has a different speed...

      david baileydavid baileyPred 28 minutami
    • @Narf Whals if you drop a brick and a feather at the same time in a non vacume the brick hits the earth first , I guess because of air resistance..... But if it's the earth actually pushing up on everything and meeting the objects why would air resistance matter? Because when you drop the objects they are stationary right...so if we're all coming to it then it should hit both no matter the wieght. That's what I'm getting from the video. But I'm a idiot so eh.

      david baileydavid baileyPred uro
    • Of the object stand still and the earth moves to meet them, why wouldn't it hit them at the same time?

      Narf WhalsNarf WhalsPred uro
  • So then everyone on the ISS is just taking the scenic route?

    Ichirou KoorinoIchirou KoorinoPred uro
  • Bois, veritasium has joined the flat earthers squad

    Mir MohsinMir MohsinPred 2 urami
  • A future idea for a video; Why do sweets give off an electric charge when hit with a hammer? Destin tried to cover it but there appears to be no explanation!

    MarkMarkPred 2 urami
  • What is the name of this guy's twin brother?

    Mason GilbertMason GilbertPred 2 urami
  • Really unique

    Dheeraj KumarDheeraj KumarPred 2 urami
  • Is acceleration on an electron getting attracted to a positive charge also a deviation from a geodesic?

    Subhrodeep SahaSubhrodeep SahaPred 2 urami
  • Sierz-Pauli action

    Ricardo MVRicardo MVPred 2 urami
  • Plz do sauce. No sauce, no believ for many ppl

    XaverderschnitzelfanXaverderschnitzelfanPred 2 urami
  • Gravity sucks.. 😂

    sikandar shahsikandar shahPred 2 urami
  • Frick you riley!

    Anonymous Waffles • 9 years agoAnonymous Waffles • 9 years agoPred 2 urami
  • so If a person is trying to jump from a 10storey bilding ....are we suppose to say ..please dont do it ...the earth will accelerate to you with g and you may suffer serious damage ?????? Really ..this will help that person from not jumping ..lets think twice

    Aarush ChhatriAarush ChhatriPred 2 urami
  • One question I have is how you can use this in a static equilibrium equation? Of course in school you are taught sum of forces = 0 and you have to include gravitational force when summing the forces. I'll use a box sitting on a level surface as a example where m is mass, g is acceleration due to gravity and N is normal force. N-mg = 0 Here we treat gravity as a force, so how would this work if we only treat it as an acceleration? Would you just say the box is actually acceleration and put N = ma?

    Teach'EMTeach'EMPred 2 urami
  • 10:52 Me change my "space coordinates" I need to accelerate but, why when I'm in out in space, with no influence of any massive bodies, not accelerating I'm still changing my coordinates? In theory I'm in a flat space-time.

    Vitor DruzianVitor DruzianPred 2 urami
  • Well this would explain why we dont have a carrier particle for gravity

    Skin Is deliciousSkin Is deliciousPred 2 urami
  • Didn’t know gravity can be rhis exciting again

    Carlos Dala ICarlos Dala IPred 3 urami
  • Something that is confusing to think about is the solar system is moving at 200 kilometres per second 🤯 presumably in a straight path toward a supermassive black hole

    McPhazerMcPhazerPred 3 urami
  • I totally understand this

    Debraj RudraDebraj RudraPred 3 urami
  • Well, if anyone can devise a way to remove the illusion of gravity from everyone's life and experience, interplanetary travel, and possibly trans-light speed interstellar and intergalactic travel as well. Unfortunately, without the illusion of gravity many people would fall fatally to the ground.

    John WilsonJohn WilsonPred 3 urami
  • Can you explain to people how a centrifugal force out in deep space without being near any body of mass, would NOT hold you down to the floor. If you jumped, you would move away from the floor. And despite its spinning, and not moving forward, there’s no gravity, or downward motion. So you would basically tumble violently as it moves around you while you float away in space. Everything around you is still without gravity and only the floor is spinning. But nothing to hold you against the rotation. Now if it was moving in addition to, then it would have a force to react upon and pull you down. Make sense?

    Jason HartsoeJason HartsoePred 3 urami
  • I liked the idea of promotion videos being at the end...

    deiz007tyagideiz007tyagiPred 3 urami
  • So if spacetime is curved and objects which are in an orbit of a planet are still travelling in a straight line then why does speed of the object alter with the orbit. For example, if space station turns its thrusters on then it will eventually fly out of orbit into outer space and if it slows down then it will fall back to earth which should not happen because the space time is curved around the planet and if an object is in stable orbit then it should remain on the same line. Why does the space rime change with change in object's speed??

    Chaitanya BhardwajChaitanya BhardwajPred 3 urami
  • This video blowed up my brain

    Adam KurentAdam KurentPred 3 urami
  • I failed physics exam because of this video.

    Aleaf BanzaiAleaf BanzaiPred 3 urami
  • People do whatever it takes 5o get youtube views.... For money..

    Tony MindTony MindPred 3 urami
  • 2 types of mass are the same or else the inertial dampers on the USS Enterprise in Star Trek wouldn't function.

    HouseofRecordsTacomaHouseofRecordsTacomaPred 3 urami
  • So ur saying Made in Heaven isn't possible?

    Afiq Zul-StarAfiq Zul-StarPred 3 urami
  • I originally saw your ad for this video in which you said this was the best explanation of relativity that you’ve ever seen. I said to myself, “that’s cocky” haha so I watched it. I definitely will say I finally feel like I somewhat grasped it this time! Very good job! Thank you for the hard work in teaching this concept. One additional question I have that always confused me is how the speed of light works and time dilation. I think in light of this unique explanation, it would be good to hear how those concepts are addressed.

    Victor FragaVictor FragaPred 3 urami
  • Relativity is the single most beautiful human achievement in history!

    otiagomarquesotiagomarquesPred 3 urami
  • Greatest and simplest explaination ❤️

    Nasima KhanNasima KhanPred 4 urami
  • Excellent. Could gravity be a "medium" we're in?

    GobbledygookGobbledygookPred 4 urami
  • I listened very carefully and I cannot answer the final question. Derek's point is the free falling charge does NOT give off electromagnetic energy. Is a magnet less magnetic during freefall?

    Exist64Exist64Pred 4 urami
  • Gravity IS a force; Einstein is a FARCE and Nikola Tesla is the greatest inventor and genius of ALL TIMES !!!!! case closed

    ITILIIITILIIPred 4 urami
  • what you was saying about geodesics and two people starting a thousand miles apart walking towards the north pole like some force pulling them together it doesn't matter how far apart you start your journey if you both have the same destination point it is inevitable that you will reach the same point? Also I have a question which is; If in 1687 Newton had known about Electromagnetism, The forces of energy like the Electron and Resonance and electricity Ac and Dc and things like Ohms and Lenses Law and Flemming's L/hand rule would he not have used electromagnetism instead of Gravity?

    Gary DickinsonGary DickinsonPred 4 urami
  • quanta of electromagnetism is photon a quanta of gravity is love gravity is a property of infinity ultimate relaity is infinity omnipresence newton and einstein describe the manifestation of this property of infinity in manifest material realm as a force . in the unmanifest infinity the omnipresence gravity is a field of love thats what god is love means

    stefan stossstefan stossPred 4 urami
  • Counterpoint, all mass has gravity (or curves spacetime). Scientists were able to measure the attraction between two bowling balls suspended in proximity. We have OBSERVABLE and REPEATABLE evidence that the two objects are pulled together with a constant force of km1m2/r^2 newtons. Even the atom of oxygen (atomic mass of 32/(6*10^23) grams) in the water molecule in the cytoplasm of a bloodcell in the smallest capillary of your big toe is exerting a gravitational force on every other atom that makes up your body. We can never NOT be under the "Curved spacetime" of another mass because we are not one single mass. Please remember that Einstein never left the planet. He also never fell off a roof. He died before we ever put an object in orbit around our planet. He died before we standardized how many atoms were in a mol.

    Metrion77Metrion77Pred 4 urami
  • God The Father. Pray this before voting; "Eternal Father, bathe my heart in the Truth. Assist me in voting the way You would. Help me to decide according to Your Divine Will." God The Father. (This coming election PLEASE Say this prayer before voting) Publicly September 22, 2020 ·PLEASE SAY THIS PRAYER BEFORE VOTING Share on FacebookTweet about this on Twitter Once again, I (Maureen) see a Great Flame that I have come to know as the Heart of God the Father. He says: "Children, prepare your hearts in advance as you go to vote in this* or any election. Pray ahead of time saying:" "Eternal Father, bathe my heart in the Truth. Assist me in voting the way You would. Help me to decide according to Your Divine Will." "If you pray this prayer from the heart, all the pretentious promises of the candidates will be seen for what they are. The Truth of the impact of your votes will be made clear. I desire very much that no one is tricked by the flurry of untruths surrounding this election, which are supported by mass media. This includes the results of certain polls."" "I am entrusting the Holy Angels with propagating this prayer quickly, as some ballots have already been cast." Read 2 Thessalonians 3:5+ May the Lord direct your hearts to the love of God and to the steadfastness of Christ. + Scripture verses asked to be read by God the Father. (Please note: all Scripture given by Heaven refers to the Bible used by the visionary. Ignatius Press - Holy Bible - Revised Standard Version - Second Catholic Edition.) * U.S. Presidential Election on November 3, 2020,, St. Thomas More* says: "Praise be to Jesus." (Ex-chancellor of England St Thomas More came to warn us about the fake DNC, don’t vote for it) "The New World Order is based upon lies. Proponents of this lie see the U.S. Constitution** as a threat to their agenda. Therefore, they go about trying to destroy national pride and promote anarchy. An agenda of the New World Order is to take down civil authority - the police - so that their own form of law and order can move in." "Children, this election*** is for or against the New World Order. Do not allow democracy - so long fought for - to be shredded. Spread this Truth." * Ex-chancellor of England beheaded by Henry VIII along with St. John Cardinal Fisher. He is the patron of adopted children, lawyers, civil servants, politicians, and difficult marriages. ** The Constitution of the United States - see: constitution.congress.gov/constitution/ *** U.S. Presidential election on Tuesday, November 3, 2020., ,,,,,,

    2coryman2corymanPred 4 urami
  • 4:26 kira!!! (Death note ref)

    Samarth Singh ThakurSamarth Singh ThakurPred 4 urami
  • 12:30 got beat by the old man lol

    Davi FagundesDavi FagundesPred 4 urami
  • This video is the best explanation of gravity I've ever seen. Keep up the good work.

    Brett CarrieBrett CarriePred 4 urami
  • Another issue: the problem of a charge radiating in curved spacetime is not "unexplored", it's solved, and the math is pretty clear. Overall I'd say this video is pretty misleading and I hope it will be retracted or corrected.

    John SmithJohn SmithPred 4 urami
  • yawn

    Joseph D'BennidettoJoseph D'BennidettoPred 4 urami
  • ...so why does space/time distort around large objects (e.g., planets, stars, etc.)?

    Aquarion H2OAquarion H2OPred 4 urami
  • And another issue, quite major: the visualization of curved spacetime around Earth is very wrong. It implies that if you look out into the direction of the velocity of the orbit of the International Space Station with a very powerful telescope, you will see the back of your head, because spacetime warps completely around Earth - this is wrong. This is obviously not the case and the ISS does not follow a geodesic around Earth, it simply accelerates very slowly because the curvature of spacetime is less "deep" than on the Earth's surface. If you shine a laser in the direction of the orbit, it will not wrap around Earth and come back from behind you. The geodesic does not curve all the way around the Earth.

    John SmithJohn SmithPred 4 urami
  • At least you show the math. Most of these posts don't.

    tastyfrzz1tastyfrzz1Pred 5 urami
  • Another, more minor, correction: general relativity has not passed "virtually all" empirical tests, it has passed ALL empirical tests. This is in contrast to, say, quantum mechanics, which suffers from the graviton problem, proton radius problem, and vacuum catastrophe. Unlike quantum mechanics which we know is empirically imperfect, general relativity is, as far as we know, empirically perfect.

    John SmithJohn SmithPred 5 urami
  • The terminology in the video is inaccurate. There are no "inertial frames of reference" in general relativity.

    John SmithJohn SmithPred 5 urami
  • I just feel bad for EdwardCurrent.

    MarcSylexMarcSylexPred 5 urami
  • Wrong

    Rob DuncanRob DuncanPred 5 urami
  • *QUESTION* Do photons not follow geodesics? If they don't, why not? If they do, why don't they follow the same path as a rocket following a geodesic curving towards a planet? A rocket would curve much more towards a planet than a photon, why is that if they both move along geodesics and never actually accelerate because of gravitation?

    eskil forsbergeskil forsbergPred 5 urami
  • What the hell is this, then how can you explain the magnetic field (magnetosphere) that protects Earth from a solar storm which creates auroras? And why are we accelerating then down horizontally towards Earth if the Earth is moving on it's own axis and revolve around the sun counterclockwise then the motion of acceleration is not horizontal but diagonal. So, if I jump at atleast a 100 feet up a building, that would be enough to see if I fall horizontally or somehow diagonally. As the Earth moves not upwards but sideways then I would not fall directly just below the location where I jump off if I just stay still but I'm pretty sure I'm gonna hit the ground at 90° from where I jump off a 100 ft. up. Gravity and that acceleration you're talking about both exist.

    Natsui DragneelNatsui DragneelPred 5 urami
  • Free falling man: I don’t feel any weight. Tidal forces: Am I joke to you?

    GDarGDarPred 5 urami
  • To explain it in simpler way: Imagine you and your friend (objects of same mass) are driving a car on different paths. You are driving on a curved path and your friend is driving on a straight path but distance from starting point to end is same for you both. Your friend is going to go with constant velocity and therefore if to reach at end point together you will have to accelerate as length of your path is longer due to curve Now according to general relativity heavy objects bend space time around them (consider it like bent sheet 6:10 but only that sheet is not on one side but all the sides) So in our example you are near a heavy object say earth and your friend is in outer space. So your path is stretched (i.e. longer). But you and your friend both are not moving in real for our analogy but you are near heavy object so not only space but even 'Time' is bent (i.e. stretched or slowed). So even if you are not moving you are accelerating from your friend's frame of reference (constant velocity your friend travelling with here is 0) The force for this acceleration is provided by Normal reaction. As a free falling body is not acted upon by Normal reaction it's state is essentially same as that of your friend (object in space with no acceleration) Only difference I see between a free falling object and object in space is free falling object is in the need of acceleration as it is in the curved space time to prevent collision

    Govind DaheGovind DahePred 5 urami
  • As long as you are near or on a large mass (earth), there is indeed a GRAVITATIONAL FORCE and gravitational field of force. In the video you had the illusion that you proved there isn't !!!

    giuseppe3010giuseppe3010Pred 5 urami
  • According another video I saw Einstein claimed we are not accelerating. We, the entire universe, is already traveling at the speed of light which is why we can't travel faster than the speed of light so square one again.

    John ConnorJohn ConnorPred 5 urami
  • Yes, yes Einstein proved gravity doesn't exist as a force but what you missed is the GREAT UNANSWERED QUESTION: how/why does baryonic matter curve spacetime? Or dark matter for that matter.

    longlakeshorelonglakeshorePred 5 urami
  • You literally said it at 9:00 in this video! It's the same thing, because space is accelerating downwards, it's amazing how dumb you smart people can be! Or. iRobot you are the dumbest smart person I've ever met!

    James BruntonJames BruntonPred 6 urami
  • I think this is really neat, and certainly wasn't taught in my engineering physics class, bit this raises two questions: 1) explain gravitational waves (which have been detected), and the baseball example where putting two balls, 1m apart, with no acceleration, will very slowly, over time, come together. "How Earth Moves" by Vsauce is another really good video. Still having a hard time picturing how, given we're a sphere, moving through space-time, people on the other side of our line of motion should experience a slightly deceased force of attraction than those between the path of intended movement and Earth.

    Tony F.Tony F.Pred 6 urami
  • Do you know why accelerating up and standing on the earth are the same or equivalent? It's cause space is accelerating down! These SLworlds channels LOVE using the term "misconceptions when they are the epitome of misconceptions! What science asylums video on black holes! He shows the perfect graphic of space falling in and says it's wrong, but in fact it's correct and he is wrong!

    James BruntonJames BruntonPred 6 urami
  • So what you're sayin is, if I jump of a building then I am an astronaut? Awesome, I'll be right back guys...

    FriarTuck104FriarTuck104Pred 6 urami
  • This guy deserves a Nobel for this explanation

    Liam Joubert VlogsLiam Joubert VlogsPred 6 urami
  • So i think i get it now. I only have one question: if space time wasn't curved around massive objects, then we would've just been moving in a straight line through space time. Right? But why are we moving in a straight line in the first place? What force would be pulling us towards the center of earth even if space time wasn't curved around us?

    Matstoen BeatsMatstoen BeatsPred 6 urami
    • @Narf Whals thank you very much!

      Matstoen BeatsMatstoen BeatsPred uro
    • @Matstoen Beats because at some point there may have been a force on it. When the force is gone the thing wont just stop moving but keep going in a straight line. That's just inertia. It's a bit more subtle in spacetime because everything is always moving. When something isn't moving through space it is moving through time.

      Narf WhalsNarf WhalsPred uro
    • @Narf Whals ok, thanks for the reply. So i was wrong saying things would move towards earth if there was no curved space time around it. But still, why would anything move anywhere when no forces act on them?

      Matstoen BeatsMatstoen BeatsPred 4 urami
    • Moving in a straight line is just what things do when no forces act on them. If spacetime wasn't curved we wouldn't move towards earth unless that was where we were going for some other reason. There would be no gravity.

      Narf WhalsNarf WhalsPred 6 urami
  • Ironically, this explanation is best showcased by the video game Gravity Rush 1&2. Where you essentially ignore the curvature of spacetime and you basically plummet in specific directions

    Frosty GingerFrosty GingerPred 6 urami
  • *As a Harvard Neuroscientist, here's another mind-bending gravity-related thought. When you rotate your head, you are NOT in control of the primary directionality of your eye movements under most circumstances.* Try this. Keep your head still and look at your finger while you shake your finger left and right; your finger will look blurry due to motion blur. Now, instead, keep your finger still and look at it while you simultaneously shake your head left and right, which will demonstrate - in this situation - that you are still able to maintain a stable image of your finger. This is because your gravitationally-influenced sense of your head in space - your vestibular system - has a hardwired reflex to move your eyes in the opposite direction of your rotational head movements. This vestibular-ocular reflex (VOR) ensures automatic dynamic stabilization of images during head movements. You are not consciously doing this, and you can not consciously override it. The VOR is truly a reflex and, interestingly, does not depend on vision. During head movements, you will still have a strong VOR if you are in the dark or if you have your eyes closed. Your VOR originates from your vestibular system, which is located in your inner ear right next to your cochlea - your organ of hearing. Your vestibular system for rotational head movements consists of a series of three fluid-filled semicircular canals that have little "hair" cells inside the canals. When your head moves up-down (pitch), left-right (yaw), or shoulder-to-shoulder (roll), fluid inside the corresponding semicircular canal flows. This head motion-induced flow bends the hair cells within the canal to ultimately send electrical impulses to your hindbrain. These electrical impulses - encoding head movement - then talk to parts of your brain controlling eye movements, which connect to your eye muscles to reflexively move your eyes in the opposite direction of your head movement. So be thankful that your sense of your head in space - your vestibular system - takes care of maintaining a stable image of the world even when your head bobs around as you walk. Otherwise, walking would be a blurry journey of craziness. Videos coming soon.

    Aaron M. Lambert, Ph.D.Aaron M. Lambert, Ph.D.Pred 7 urami
    • @Charles Bosse Ha, well it was scary ,went to bed normal and woke up like that , ambulance,brain scan etc . I'm sensitive to motion sickness anyway so VR I avoid like the plague :)))) I'm a Luddite ...

      Paul NewmanPaul NewmanPred 9 minutami
    • @Paul Newman I don't know whether to thumbs up or thumbs down. It's really interesting, but... ouch. Closest I have ever gotten to this is VR sickness, which... well, it's still not fun, but at least it wasn't the whole deal.

      Charles BosseCharles BossePred uro
    • Brilliant , I think this helps explain also why in January this year a horrible episode of Vestibular neuritis made me have flickering vision left to right when moving my head and I was the sickest a person can be without dying ! Like the worst motion sickness in the world !!!

      Paul NewmanPaul NewmanPred 3 urami
    • That was incredible. Thank you so much for writing this. Subbed.

      Suggs GumptianiousSuggs GumptianiousPred 6 urami
  • The falling molecule yields it's elector magnetic radiation suddenly when it hits the ground, (squish)… the one on the shelf very slowly, then light pink , then white, depending on the pigment of course…

    1324 ARCH1324 ARCHPred 7 urami
  • Einstein's equivalence principle is not general, it only applies locally because spacetime is always flat in some coordinate system if you look at an infinitesimally small region. But gravitational fields give rise to tidal forces, if you are freely falling close to a black hole different parts of your body will accelerate differently and you will be torn apart. Free falling observers are never inertial if they have a nonzero size because of tidal forces. You will always be able to tell if you are in a gravitational field because the metric will be different for different parts of your body and you will experience a stretching that you would not feel if you were in a flat metric. Einstein's field equations relate these tidal forces (represented by the Ricci tensor) to mass and energy

    BirefringentBirefringentPred 7 urami
  • He changed the thumbnail and title again

    ShiJie 12311ShiJie 12311Pred 7 urami
  • veritasium : why gravity is not a force me a dumbass : THEN EXPLAIN SUN!

    EucenorEucenorPred 7 urami
  • So this is why time seem to go faster the older we get , because we have been accelerating through time our whole life And calling it gravity

    Erron BoswellErron BoswellPred 7 urami
  • best explanation ever!! finally able to get an idea of relativity

    srijith unnisrijith unniPred 7 urami
  • 12:31 headkick!

    João AlcântaraJoão AlcântaraPred 7 urami
  • so u mean gravity is psuedo force

    Shubhang WalavalkarShubhang WalavalkarPred 7 urami
  • wish you could show graphically how in curved spacetime one needs to accelerate in order to stand still. how earth as a globe smacks all of the people standing around the globe from the bottom up evenly, as opposed to the linear circumstance that happens to a person inside a rocket

    Paolo dela VictoriaPaolo dela VictoriaPred 8 urami
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