Why Gravity is NOT a Force

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  • 게시일 2024. 04. 25.
  • 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 KRplus channel: ve42.co/gfl or his books: ve42.co/GFLbooks
    Amazing VFX, compositing, and editing by Jonny Hyman
    2D animations by Ivy 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
    / @bpsspace

댓글 • 52K

  • @veritasium
    @veritasium  3 년 전 +9156

    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.

    • @destroya3303
      @destroya3303 3 년 전 +453

      @Veritasium "In curved space time you have to accelerate just to remain stationary"
      Seems more like physicists have become so enthralled by these mathematical equations they are willing to throw out observable reality for them. I have two options, I can either call a lack of motion "acceleration" (which contradicts the clear definition of the term) or question the math / model I'm using to describe the physical world.

    • @sarthakgandhi324
      @sarthakgandhi324 3 년 전 +27

      First 😀

    • @dryjoints454
      @dryjoints454 3 년 전 +141

      @@sarthakgandhi324 not first

    • @veritasium
      @veritasium  3 년 전 +2042

      @@destroya3303 throwing out the way things appear to be is core to physics. Aristotle said an object's natural state is to come to rest. Newton figured out it was friction making everything come to rest and without that force everything would keep moving in a straight line with constant velocity. You are being Aristotle in this situation.

    • @vrnvorona
      @vrnvorona 3 년 전 +490

      @@destroya3303 You do understand that motion itself is relative? When you don't accelerate, you don't feel any force, and so far the falling object doesn't feel it (well it does feel air but it's a friction and it's a force), while you stationary - do. And you move up relative to falling object, it's just that you climb curved spacetime same amount that it curves

  • @QuiGonGinger
    @QuiGonGinger 3 년 전 +6212

    So Newton actually rammed his head into that apple. Rude.

    • @DasMc
      @DasMc 3 년 전 +981

      Poor apple was just trying go on a straight line in spacetime, minding its own buisiness.

    • @RaviPaudel69
      @RaviPaudel69 3 년 전 +64

      *@Colton Smith* Lmao you made me laugh🤣

    • @muhdizz9915
      @muhdizz9915 3 년 전 +19

      Hahahahahaha

    • @velikovskysghost
      @velikovskysghost 3 년 전 +8

      +Cotton Smith While wearing a bucket on his head.

    • @robertjones6891
      @robertjones6891 3 년 전 +45

      This is the kind of comment I live for 🤣

  • @TheBoxingNinja
    @TheBoxingNinja 2 년 전 +2312

    Mom: "son did you fall down?"
    Son: "No mom, you fell up!"

  • @niy._.
    @niy._. 8 개월 전 +551

    Love how Derek is blasting himself off into outer space so that we understand gravity better, he always works so hard for his audience 😢❤

    • @xerbud
      @xerbud 7 개월 전 +19

      He will be remembered 😢😢😢

    • @fridolfgranq
      @fridolfgranq 4 개월 전 +10

      The true mvp is the Cameraman 😔

    • @gancuber4204
      @gancuber4204 2 개월 전

      @@fridolfgranq fax

    • @smailedog657
      @smailedog657 26 일 전

      Also copped a boot to the face in that weightless simulation plane.

  • @anafps23
    @anafps23 9 개월 전 +537

    Been through college in physics and physical engineering and honestly no professor would explain in such an interesting and somehow profound way. Thank you

    • @mmoonchild276
      @mmoonchild276 9 개월 전 +2

      Could you help me with a simple question?
      What makes engineering different from physics?

    • @lew-ejones-ayres5088
      @lew-ejones-ayres5088 9 개월 전 +18

      ​@@mmoonchild276application

    • @niy._.
      @niy._. 8 개월 전 +2

      Hey if you don’t mind me asking, which uni/college did you go to for physical engineering, that is a major I’m interested in and from my research, very few colleges have that as an option and I will be applying to colleges next year so it would be great iylmk

    • @anafps23
      @anafps23 8 개월 전 +3

      @@niy._. well mine was in Portugal in the faculty of Science in Porto University

    • @KnewTherapy
      @KnewTherapy 7 개월 전 +1

      @@mmoonchild276weed out classes and corporate politics

  • @miketacos9034
    @miketacos9034 2 년 전 +6118

    At this point, Newton throws his apple at Einstein.

  • @wave8092
    @wave8092 3 년 전 +2587

    "Gravity is an illusion"
    flat earthers: "WRITE THAT DOWN WRITE THAT DOWN"

    • @ophiolatreia93
      @ophiolatreia93 3 년 전 +59

      'theyre rubbing it in your face'

    • @ophiolatreia93
      @ophiolatreia93 3 년 전 +15

      Gotta love that predictive programming

    • @alexwilson7127
      @alexwilson7127 3 년 전 +79

      Also flat earthers: chek maite, won uf yoer gais sed gravitee is faek

    • @sebastianstewart6894
      @sebastianstewart6894 2 년 전 +32

      But gravity is a lie rock climbers die annually from not being attracted to the cliff face.

    • @wave8092
      @wave8092 2 년 전 +57

      @@sebastianstewart6894 rock climbers are attracted to the earth more than they are too the rock they are climbing. ofc they'll fall towards the ground

  • @AubreyD9
    @AubreyD9 9 개월 전 +494

    Here I am watching this video for the 4th time trying to better understand the concept, while Einstein thought of this in 1915 with only a fraction of the technology available today. It is mind boggling how smart he was

    • @fabriziogiordano2405
      @fabriziogiordano2405 8 개월 전 +29

      Apart his genius, I like to remember to people that THINGS do not evolve like in movies, we are the same intelligent humans since 10k years, the only things changing are the tools we have at our disposal, 4k yo Einstein is a real thing 😂

    • @floga10
      @floga10 7 개월 전 +9

      I watch this video again and again every couple months to understand it more. Also on my 4th watch, I think I just accepted how to the falling man, everyone else is accelerating up

    • @MagusOfArcadia
      @MagusOfArcadia 7 개월 전

      ​@@fabriziogiordano2405actually wrong, contrary to popular belief, thanks to the mass utilization of ethyl as gas fuel sometime ago, our generation and at least 3 generations before are dumber than our ancestors.

    • @ampojohnfranz3836
      @ampojohnfranz3836 7 개월 전 +2

      liked your comment so you could watch it again, imma watch it for my 2nd time soon

    • @thetruth156real3
      @thetruth156real3 7 개월 전 +1

      That’s maybe why if your really clever they call you Einstein, he was really clever, your mind was boggled because you obviously didn’t realise he was really clever, and technology would not have helped him as it was mostly theoretical.

  • @siddhiwalawalkar3547
    @siddhiwalawalkar3547 9 개월 전 +19

    you make learning so very much fun. Thank you so much. You never fail to blow my mind 🙏🏼

  • @TheActionLab
    @TheActionLab 3 년 전 +30529

    This video is a masterpiece. The best explanation of gravity on the internet currently.

  • @benjamintollison
    @benjamintollison 3 년 전 +3541

    Officer I can't walk in a straight line because we all walk in geodesics.

  • @Mooon_Light
    @Mooon_Light 10 개월 전 +128

    When I asked my teachers about why two objects fall at the same rate, they said the same thing, that accelaration of both objects are independent of their masses. I was so confused as to why it only happens with gravitational force and not some other forces, this video cleared my doubt but I can't use it as I'm still in high school, so I'll keep it in the back of my head until I graduate high school and will stick to that old mathematical derivation from classical physics of why two bodies fall at same rate.

    • @PsychoMuffinSDM
      @PsychoMuffinSDM 10 개월 전 +41

      Another way to think about it is if you have two masses, one that is 1kg, and another that is 10kg. Gravity will pull with 10x more force on the larger object , because it has 10x more mass, but because it has 10x the mass it has 10x the inertia, so requires 10x more force to get going. The additional force and additional inertia cancel out, so all you are left with is the same acceleration for both.

    • @WaluigiisthekingASmith
      @WaluigiisthekingASmith 9 개월 전 +14

      Heres something cool. Its not just gravity. If you look at the equations for the Coriolis "force" or centrifugal "force" they too have a factor of m you can cancel. These "forces" are all 'ficticious forces' meaning they arise from choosing a non inertial frame of reference

    • @ajirios
      @ajirios 8 개월 전 +5

      Don't sweat it. Gravity is just space accelerating downwards into earth. Earth itself is not accelerating, but objects inside the spacetime around it collapse at the same rate (cause space is collapsing acceleratingly).

    • @Twisted_Code
      @Twisted_Code 8 개월 전 +4

      In fact you ought to be able to use any information that you can validate scientifically, but perhaps the primary school educational system is not very scientific. ;-)
      Maybe you ought to try (but don't cause TOO MUCH trouble) challenging your teachers on why these factors can be canceled. It's very clear that Newtonian physics can't quite explain it.
      hopefully their viewpoint is not completely immutable, i.e.stubbornly resistant to new information, in which case you might end up teaching them something. If not, well, you tried.
      Whatever you do, don't stop thinking for yourself, because some of the biggest problems in life come from letting others think for you, from letting others tell you what to think. Independent and verifiable thinking and experimentation is how science got where it is.

    • @voidloop8220
      @voidloop8220 8 개월 전 +1

      Show this video to your teachers.. why let them remain in the dark? It's your obligation to enlighten them if they're going to be teaching invalid information. If I were a teacher I would appreciate a student showing me new information.. it's always fun learning something new. If they're good teachers, they'll feel the same.

  • @shashankgrag344
    @shashankgrag344 7 개월 전 +12

    wow..just speechless.. You are a great scientist and even more great a storyteller ... Absolutely loved it :)

  • @morpheus6749
    @morpheus6749 3 년 전 +3797

    When mountain climbing, try not to become an inertial observer.

  • @ananyaravikumar5069
    @ananyaravikumar5069 3 년 전 +4371

    On a lighter note, this means that the apple didn’t fall on Newton’s head. He accelerated right into it.

    • @alexanderkilburg7415
      @alexanderkilburg7415 3 년 전 +195

      No, Spacetime willed the collison. The word of Spacetime is truth itself.

    • @kiranaun9593
      @kiranaun9593 3 년 전 +579

      So.... Newton's head fell onto the apple

    • @uncannyvoid81
      @uncannyvoid81 3 년 전 +45

      exactly

    • @thebrahmnicboy
      @thebrahmnicboy 3 년 전 +260

      Newton's head was in the straight line path that the apple was taking, but Newton's head wasn't itself taking a straight line path.

    • @hadeskay6091
      @hadeskay6091 3 년 전 +50

      I thought he was just calling in geodeSick to skip work.

  • @duck2701
    @duck2701 10 개월 전 +3

    You're literally the most goated youtuber, I love your content and our interests are alike

  • @Surfergeo_
    @Surfergeo_ 6 개월 전 +1

    I can confidently say that i have watched the majority of Derek's videos... but this one has me stumped, i can't wrap my head around it at all 😭

  • @DanielRenardAnimation
    @DanielRenardAnimation 3 년 전 +1952

    _"Gravity is an illusion."_
    Eugh, FINALLY!
    *[floats off, to get groceries]*

    • @howtheworldworks3
      @howtheworldworks3 3 년 전 +14

      That's not how it works. There is still an EARTH that you cannot ignore and go off floating.

    • @HassanSelim0
      @HassanSelim0 3 년 전 +55

      Reminds me of a joke in one of the ASDF Movie.
      A guy says: Screw Gravity.
      Then simply floats away.
      ... it's much better seen than written in text, the asdf jokes are mostly visual.

    • @JustinMarshallElias2
      @JustinMarshallElias2 3 년 전 +4

      Hahahaha ✌🏻

    • @samarth3957
      @samarth3957 3 년 전 +4

      Lmao

    • @takoja507
      @takoja507 3 년 전 +3

      Sorry to nitpick but he didn't say "Gravity is an illusion", he said "Is gravity an illusion?" It's a question.

  • @smartereveryday
    @smartereveryday 3 년 전 +6965

    As long as I've known Derek he's consistently asked the difficult questions. This video challenged me, and taught me many things. I want to try the eclipse photo now. Impressed Eddington did it in 1919.

    • @kvsalahuddin5
      @kvsalahuddin5 3 년 전 +35

      First one to reply...✌
      I like your videos 🤗

    • @killeroblivin
      @killeroblivin 3 년 전 +30

      You could totally make a video on that I think it would be cool.

    • @danpavlov
      @danpavlov 3 년 전 +16

      Quoting the wise Sheev Palpatine - DO IT!

    • @ilhamburger8288
      @ilhamburger8288 3 년 전 +22

      Quoting the wise Shia LaBeouf - JUST DO IT!

    • @kodakincade8063
      @kodakincade8063 3 년 전 +9

      Love to see youtubers support one another. It’s amazing!! Love your videos destin!!

  • @bhaumanshah6100
    @bhaumanshah6100 7 개월 전 +2

    Till now i saw many videos ..they just said spacetime mesh and curve and all but they could make me visualise like you did... best explained!!

  • @hhjones9393
    @hhjones9393 8 개월 전 +22

    I love this video. I've come back to it several times. When I first saw it I had to think differently about not just gravity, but spacetime as well. This video helps by putting the pieces together. And his charged particle question at the end was the icing on the cake. That's when I knew that I understood him correctly.

    • @sebaschan-uwu
      @sebaschan-uwu 4 개월 전

      I had to watch this twice to get it and use my prior knowledge from physics class but it's quite interesting. Still a lot of questions unanswered though.

    • @ronald3836
      @ronald3836 2 개월 전

      But the video makes at least two mistakes.
      1. that you "don't feel" acceleration if you are falling through space and bending towards a planet is not an argument against gravity as a force. Gravity as a force pulls at each of your particles in the same way, i.e. same direction and same magnitude, which is why you cannot feel it. But if you stand on the ground, then you do feel the counterforce of the ground on your feet because that force acts on your feet and not on every particle of your body.
      2. while general relativity may answer the question why inertial mass = gravitational mass, it does not explain why inertial mass determines the bending of spacetime. So it just shifts the question rather than answering it.
      In the end, general relativity is just a mathematical description that happens to have excellent predictive power in most situations, but that does not actually explain anything. Einstein gave no explanation as to HOW mass would bend spacetime.

    • @hhjones9393
      @hhjones9393 2 개월 전

      @@ronald3836 I disagree. When traveling along a geodesic and not feeling a force, that is the definition of an inertial observer. You feel gravity on earth not just on your feet, but everywhere. The earth is blocking your geodesic path through space.
      General relativity may not yet provide a clear answer to exactly why space curves to your satisfaction but it does explain with remarkable precision what is going on. That in itself is a pretty good answer.

    • @ronald3836
      @ronald3836 2 개월 전

      @@hhjones9393 I guess we agree that, in rest (not in free fall), we feel gravity through the earth pushing us back. If you stand, the earth presses on your feet, and the atoms in your feet press on the atoms on top of them, etc. You feel this, and over the course of a day your spine compresses a bit. At night, people typically lie flat and the pressure they experience is less.
      In free fall (ignoring air friction), we "don't feel" gravity independently of whether you view gravity as a force (e.g. Newton) or as a bending of spacetime (Einstein). It seems to me that Derek is trying to argue that "you don't feel acceleration in a free fall" means that you do not accelerate, i.e. that it shows that Newton was wrong and the Einstein is right. But this argument is just wrong. Even Newton will agree that you won't feel acceleration in a free fall (in vaccum), until you land on earth.
      Derek is not very explicit in stating that this argument is "proof", so maybe I am being unfair, but even after watching the video several times it is still what I perceive to be the intended message.
      I certainly agree that GR is a very valuable theory because of its predictive power. (And I'd like to understand whether the GR equations mandate the "bending of space-time" interpretation or whether it still allows for a "gravity is an attractive force" interpretation.)

  • @nolanbie3664
    @nolanbie3664 3 년 전 +674

    The fact that you can make videos on topics that are so out of the ordinary, and most people would never be able understand it without years of education, into a short video that is free to watch and actually understandable is amazing

    • @krassigor
      @krassigor 3 년 전 +17

      That's what we internet should have been for

    • @monotonicallyuncertain2883
      @monotonicallyuncertain2883 3 년 전 +1

      I'm high schooler from india preparing for JEE and understood everything in this video!

    • @okktok
      @okktok 3 년 전 +2

      I don’t think people without years of education will understand this video too, but okay

    • @maxodgaard1335
      @maxodgaard1335 3 년 전

      I still dont get it..... And you dont get it too.....

    • @markomitreski1182
      @markomitreski1182 3 년 전 +4

      @@okktok no I'm 14 and I understood everything I just needed to commit and re watch it 5-6 times to get every single term and to kinda start viewing things differently

  • @Technodog
    @Technodog 2 년 전 +537

    I’m starting to realize if any of these videos were elaborate April fools jokes, I would never be able to tell

    • @scottbilger9294
      @scottbilger9294 2 년 전 +9

      Rather like the relativistic principle itself.

    • @christinakinch
      @christinakinch 2 년 전 +21

      Just checked the date of the video, just to be certain

    • @MrMeeHigh1
      @MrMeeHigh1 2 년 전 +5

      @Dancing Swords Because it contradicts observable things, like things falling towards the ground, by giving new definitions to words like force, gravity, acceleration. Even if all is true you can't steal words you must invent new words to describe them.

    • @MrMeeHigh1
      @MrMeeHigh1 2 년 전

      @Dancing Swords Einstein always said atomic bombs are not possible.

    • @MrMeeHigh1
      @MrMeeHigh1 2 년 전

      @Dancing Swords So why do the army use parachutes?
      You better explain them: "There is no gravity, look at me jump without parachute."
      Link here how you explain and jump. Thanks.

  • @chantzyoder953
    @chantzyoder953 개월 전

    This video explains space/time and gravity better than any textbook, lecture or video I've ever seen

  • @theooooot9469
    @theooooot9469 5 개월 전 +2

    This video is so good and well explained that it was shown to us in our hsc physics classes

  • @jacobbishop8067
    @jacobbishop8067 2 년 전 +686

    “Do you feel weightless? No of course not” me falling off a roof: that’s what you think science boi

    • @5446isnotmynumber
      @5446isnotmynumber 2 년 전 +4

      Very edgy boi

    • @rickthebas
      @rickthebas 2 년 전 +1

      Underrated comment

    • @Lego6979
      @Lego6979 2 년 전 +3

      The dedication of this man.

    • @xexstartheyoutuber2424
      @xexstartheyoutuber2424 2 년 전

      Explain your comment I didn't get it

    • @rickthebas
      @rickthebas 2 년 전 +6

      @@xexstartheyoutuber2424 Derek says in the video that falling off a roof is one way you could feel weightless. Derek also assumes that if you're watching this video right now, then you probably don't feel weightless because you're probably sitting down on a couch or bed or whatever. So the guy who made the comment implied that he was, in fact, falling off a roof while watching the video, making him feel weightless.
      God, dissecting jokes really isn't fun

  • @ashrafulalam3662
    @ashrafulalam3662 3 년 전 +145

    Now every time that someone mentions gravity as a force,
    I'll open my mouth in preparation to correct them
    but then remember that I hardly understood this video and smile instead.

  • @andrewboone4942
    @andrewboone4942 5 개월 전 +15

    Great condensed delivery of information, as always. A few points of clarification that might be of help to viewers of this great video (and great channel):
    1.) Based on general relativity, the question isn't one of whether or not gravity is an illusion. Rather, what we have, as you pointed out, is an exact one-to-one isomorphism between gravity and acceleration. So acceleration is just as much an illusion as gravity. We have to approach this from both directions. That is, bodies in a "gravitational field" can be thought of as accelerating bodies, as you've illustrated so well here, but accelerating bodies can also be thought of as bodies within a gravitational field. It works both ways. Acceleration and gravity are two useful ways of thinking that Einstein's theory reveals as equivalent. We could say that when we think we're experiencing gravity, we're actually experiencing acceleration, but we could just as easily say the opposite. The true illusion isn't one or the other -- gravity or acceleration; rather, the true illusion is the notion that gravity and acceleration are two different phenomena. Einstein shows us that the same thing is happening in both cases.
    2.) Still, the claim that gravity is not a force isn't so easily made. Based on general relativity, it is a true statement, yes. General relativity shows us that gravity is not actually a force at all, but rather the motion of bodies through the curvature of spacetime. However, general relativity is not our only valid theory of reality. In quantum mechanics -- or, more specifically, in the standard model of particle physics, based on quantum field theory -- gravity is, indeed, a force. And we first detected gravitational waves in 2016, I believe -- several years before the release of this video, showing us pretty conclusively that gravity is, after all, a force (though no one has detected a graviton as yet, and likely never will). This is, of course, one of the many, many, many contradictions between quantum mechanics and general relativity tormenting physicists. Einstein's model is so aesthetically pleasing -- compelling, even -- it's only natural to want to believe it. But quantum mechanics tells us something else. As we know, the search for a super theory that unifies these two theories -- that is, the search for the theory of quantum gravity (or, at this point, I should say, the search for the correct theory of quantum gravity) -- is ongoing and should provide us with an answer to which of these theories is correct on the issue of gravity as a force. That said, that's probably not the right way to think about the problem. With acceleration and gravity, Einstein showed us that it wasn't about one being right and the other being wrong; it was about an equivalency -- a synthesis that allowed us to see both phenomena as facets of a larger conceptual structure, a structure in which the two phenomena are actually one. We should expect something similar from quantum gravity. The history of science is, if nothing else, a history of these kinds of syntheses of what previously appeared to be opposing, or at least separate, ideas, going back to electricity and magnetism and beyond. The fact that quantum mechanics is telling us that gravity is a force and general relativity is telling us that gravity is not a force should be a smoking gun that the entire question of whether or not gravity is a force is simply not the right question to ask. Quantum gravity, whenever it is established, will likely offer us a larger conceptual structure through which to understand these ideas, so that this apparent contradiction is resolved, much in the same way general relativity itself presented us with a larger conceptual structure through which we could understand the equivalence of gravity and acceleration, or the way special relativity presented us with a larger structure through which we could understand the equivalence of mass and energy, or the way Newton's theory of gravity gave us a larger structure through which we came to understand the equivalence of the heavenly and earthly realms -- that is, that the same laws were governing both -- an idea that would have been beyond foreign to Aristotle, and many who came long after him.
    In short, we can't simply state that gravity isn't a force, because quantum mechanics refutes that idea. Nor can we simply state that gravity is a force, because general relativity refutes that idea. And, of course, quantum mechanics and general relativity refute each other. And so we await the synthesis. It is one of a thousand key places in contemporary physics/cosmology where we hope quantum gravity will give us answers. Or, more realistically, lead us to ask better questions.

    • @stewiesaidthat
      @stewiesaidthat 5 개월 전

      Gravity doesn't exist as was shown by the hammer and feather drop tests. Both here and on the moon. How can your physics be valid if it's based on something that doesn't exist? A force so weak it can't be detected and yet it holds galaxies together? Don't piss on me and tell me it's raining.
      What is the Higgs Boson? An electrical charge? There's your 'gravity'. It's why grains of dust coalesced in space.
      When you worship at the alter of relativity, you become blind to reality. You see things backwards. How is it that relativitists believe that mass increases with acceleration and yet hot water as less mass than cold? How is it that relativitists believe time slows down with acceleration in space when objects accelerated in space are actually losing mass? And how is it that relativitists believe that Newton's apple falling from the tree is the result of gravity? But rather it's impact with the ground is because of 'gravity'. You will never find the gravition because gravity doesn't exist. Which means your theories based on gravity are baseless. But you have to keep the house of cards from falling down so let's start warping the cards.
      How much more proof do you need to at least acknowledge that the earth isn't 'flat'.

    • @ronald3836
      @ronald3836 2 개월 전 +2

      Great comment!
      As far as I understand, general relativity is really just a mathematical description (with excellent predictive power) which does not attempt to explain why nature works like it predicts. It posits a bending of space and time, but it does not explain the mechanism by which mass/energy causes this bending. To me this seems to be a very weak basis for claiming that "gravity is not a force". General relativity just happens to give a mathematical framework in which gravitational phenomena are explained without there being a true force.
      (What I have been wondering about for some time is whether the Einstein field equations allow for an interpretation in which gravity is a "true" attractive force. I do not know the answer.)
      Regarding Derek's video, I think Derek has come up with some arguments pro general relativity which aren't as strong as he seems to think:
      1. That you "don't feel" acceleration if you are falling through space and bending towards a planet is not because gravity "is not a force". Gravity as a force pulls at each of the molecules of your body in exactly the same way, which is why you cannot feel it, and an accelerometer cannot measure it. (So if we ever build an interstellar spaceship that reaches near lightspeed or beyond, we should do it in such a way that every molecule of the ship and what is inside of it undergoes the same force. Even more ideally, there would be a 1g difference in acceleration, but now I am asking for too much.)
      2. While general relativity removes the question why inertial mass = gravitational mass, it raises the question why it is inertial mass that determines curving of spacetime. It just shifts the question without explaining anything. (At least in my understanding.)

    • @stewiesaidthat
      @stewiesaidthat 2 개월 전

      @ronald3836 The simple answer to your questions is that mass has no force without acceleration. Mass is not the cause of acceleration but the result of acceleration. Or, more precisely, deceleration. As the atom's acceleration factor decreases, its mass increases.
      E=mc. Mass is stored energy unlocked by acceleration. Mass is inert. It has no functional properties other than length width, height.
      Gravity is the result of an external force accelerating the frame of reference. What you feel is that applied force accelerating you in space. The same as dipping your hand in hot water. You feel the water molecules being accelerated.
      The earth is round (curved space) because F=ma. Force equals Acceleration. As the acceleration factor increases, the mass factor decreases. Which is why the atmosphere becomes thinner as the radius increases. Because the earth is rotating on its axis, it's mass is being accelerated not only outward but forward as well creating curved space.
      The 'gravity as a force' math works because framing mass as the force multiplier creates a mirror image from reality. Mass based Relativity says the atmosphere thins because there is less gravitational attraction. In reality, the laws of motion show that the atmosphere becomes less dense because of acceleration.
      Which one are you going to believe? Newton's Laws of Motion that accurately describe the Earth, its atmosphere, its tides. Or some made-up mathemagical theory that doesn't hold water?
      What does Relativity give you? An increase in mass with acceleration? Then why does cold water have more mass than hot water?
      Time-dilation? Then why do astronauts experience accelerated heart rates and solar sails increase in temperature?
      Gravitational Attraction? Why do objects with disparate mass attributes fall at age same rate?
      Gravity is one frame of reference being accelerated by another frame of reference. When standing in line and I push you forward, what you feel is gravity accelerating you. When you accelerate yourself, take a step forward, you don't feel gravity.
      Here is something for you to ponder regarding gravity. The Earth's rotation speed currently creates a force of 1g. If the Earth's rotation doubles, it would create a 2g force. What would happen if the Earth's orbital speed around the sun where to double instead. Would you still be subjected to the 1g force as generated by the earths rotation?

  • @birjisafroz8886
    @birjisafroz8886 8 개월 전 +12

    Watching this video made me what an amazing physics teacher i had during my O levels and A levels. Even though it wasn't in our syllabus, our sir rly took the time explain this topic in great detail. Truly the best teacher I've ever had
    Ps the vdo is spectacular, as always

  • @NeuromodulatorNetwork
    @NeuromodulatorNetwork 3 년 전 +1912

    *As a Harvard Neuroscientist, here's another mind-bending thought. When you rotate your head, you are NOT in control of the primary directionality of your eye movements.* 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 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.

    • @getbehindmedemon9576
      @getbehindmedemon9576 3 년 전 +87

      Woah I guess I took that for granted. Great exercise to demonstrate in action. Subbed. Looking forward to some vids once they are up.

    • @seven5677
      @seven5677 3 년 전 +15

      Wow I have never thought of that. That is really interesting.

    • @lastditcheffort7123
      @lastditcheffort7123 3 년 전 +1

      @terry riley Hilarious, but the directions were super clear unless you already had brain damage from shaking you head too much previously

    • @bennet615
      @bennet615 3 년 전 +6

      WOW , THIS IS AMAZING !
      I WANNA LEARN MORE ABOUT THIS

    • @Wykydtronx4055x
      @Wykydtronx4055x 3 년 전 +3

      So what does it mean if you see no blur on both tries. Not a sniper but do like archery.

  • @rueisabelle8765
    @rueisabelle8765 3 년 전 +424

    7:58 "You are not an inertial observer."
    Me, watching this while skydiving: You sure about that?

    • @pedtrog6443
      @pedtrog6443 3 년 전 +15

      Ummm... no. maybe initially as you leave the plane, but you soon reach terminal velocity because of air resistance and cease accelerating in relation to the Earth.

    • @thecrazyeagle9674
      @thecrazyeagle9674 3 년 전 +16

      @@pedtrog6443 It was a joke.

    • @wave8092
      @wave8092 2 년 전 +12

      @@pedtrog6443 you're out of line, but you aren't wrong

    • @kevinchang8090
      @kevinchang8090 2 년 전 +2

      @@wave8092 is that a geodesic pun?

    • @wave8092
      @wave8092 2 년 전

      @@kevinchang8090 Sort of yea

  • @onlyvoid
    @onlyvoid 5 개월 전 +1

    Speaking about gravity is a simplification of a more complex explanation. It is much more convenient to speak about "gravitational pull" than to go with more lengthy explanation and get the same result.

    • @ronald3836
      @ronald3836 2 개월 전

      Especially since we know that the lengthy explanation is not the final word on the subject (and fails to give a real physical explanation of space-time bending anyway, it's just a mathematical model).

  • @noodletribunal9793
    @noodletribunal9793 7 개월 전

    i didnt start to understand it till 9:32 in when you said the observers in the building were being pushed up. this was really fun to watch

  • @shamsunislam5009
    @shamsunislam5009 2 년 전 +1033

    my physics teacher: Draw an arrow showing the direction of gravity.
    me: [draws nothing]
    my physics teacher: What video did you see this time?

    • @YorinSenpai
      @YorinSenpai 2 년 전 +56

      also your teacher : *tries to teach you something that maybe can't exist or maybe we never will be able to understand completely*

    • @KenLinx
      @KenLinx 2 년 전 +18

      cringe

    • @MagikarpMan
      @MagikarpMan 2 년 전 +47

      @@YorinSenpai well it doesn't really matter. Especially with how low level the physics u get taught in school is. 99% of the time u get the watered down version cus that's all that's needed

    • @frankkrumnow7194
      @frankkrumnow7194 2 년 전 +30

      Usually school starts with teaching you the things that have already been proven wrong like the bor atom model. Just because humans are still able to understand that - in contrast to quantum physics.

    • @GlatHjerne
      @GlatHjerne 2 년 전 +29

      @@frankkrumnow7194 And it's really all that's needed unless you pursue something more scientifically minded. If you take chemistry you will learn that everything you thought you knew was actually a simplification multiple times. 😂
      The thing is that often the simple models and theories describe what is happening just fine for almost everything we need it to.

  • @Noriek_tok
    @Noriek_tok 2 년 전 +273

    “In curved space-time, you have to accelerate to stand still”
    Mind. Blown.

    • @marzi_kat
      @marzi_kat 2 년 전 +1

      It's makes obvious why you can't even stand still inside of black hole - space is so bent it would require FTL acceleration

    • @chaitanyabatra6952
      @chaitanyabatra6952 2 년 전

      @@marzi_kat i dont think ftl acceleration means what you wanted to convey)

    • @manasdas8793
      @manasdas8793 2 년 전 +3

      cant wrap my head around it yet

    • @Telleelle
      @Telleelle 2 년 전

      Yeah, why would it be curved. Time is added all the time, so spacetime is everexpanding, perhaps we need to accelerate to stand still. Far fetched I know.

    • @saphired02
      @saphired02 2 년 전

      @@manasdas8793 if you don't accelerate it will seem like everything around you is moving and you are "falling" toward earth. But if you let earth push you along it will seem like your just standing still not moving up or down.

  • @CharvakUA
    @CharvakUA 8 개월 전

    Love the content and quality of videos

  • @loganskiwyse7823
    @loganskiwyse7823 2 개월 전

    Just found this video. Thanks, this might be the best explanation for why there is no finding of a graviton I have ever seen.

  • @Verrisin
    @Verrisin 3 년 전 +345

    " acceleration is a deviation from a geodesic "
    - core point

    • @Dylan-ni1tc
      @Dylan-ni1tc 3 년 전 +2

      not all acceleration tho

    • @Verrisin
      @Verrisin 3 년 전

      @@Dylan-ni1tc I guess when 2 things push on one another, there is more acceleration than just "deviation from a geodesic" ? ... I'm not sure, maybe the math would turn out it's equal, but ... probably not? I'm definitely not qualified to answer that...
      (at first I thought I thought it would always be that, but now I think that you are probably right....)

    • @circuitboardsushi
      @circuitboardsushi 3 년 전 +6

      @@Dylan-ni1tc all acceleration as observed from an inertial frame. Bodies in freefall only accelerate with respect to non-inertial frames.

    • @user-lk2wi8od9x
      @user-lk2wi8od9x 3 년 전

      Can someone tell me what that means

    • @Verrisin
      @Verrisin 3 년 전 +2

      @@user-lk2wi8od9x ... I think it's the point of the video? - Best way to be told what it means is to watch the video. :D

  • @mbrsart
    @mbrsart 3 년 전 +128

    "Come on, Doc, I can't be accelerating if my spatial coordinates don't change."
    "You're not thinking fourth-dimensionally, Marty!"

  • @averagehooligan620
    @averagehooligan620 10 개월 전

    The animations and video editing were really great

  • @JasonMcMullen
    @JasonMcMullen 9 개월 전 +8

    Some issues with the use of language in this video. 5:31 It is stated that "gravity does not exist" which is simplified too much. It may not exist in the way we think it does, and it may depend upon or be conditioned by an observer, but to say it does "not exist" is to misunderstand what is meant when we talk about existence. Things can exist in an illusory way, in fact the more we learn about the universe the more we learn about the illusory nature of the universe. Also a 'force' is simply something that has an effect and therefore even if the 'effect' we experience is caused by something like acceleration through space-time it is still a 'force' we experience

    • @ronald3836
      @ronald3836 2 개월 전 +2

      Indeed gravity very much does exist. It is just the theory of general relativity that describes gravity not as a force but as the effect of the curvature of spacetime.
      For all we can tell, that curvature is at least as illusory as gravity as a force. And I would argue it is far more illusory and just a mathematical description.
      If one day someone comes up with a fundamental explanation of what spacetime really is and how mass curves it, then I may reconsider my view.

  • @Zitro_685
    @Zitro_685 2 년 전 +889

    Props for the camera man who went through space to film this video

  • @francisvellara7132
    @francisvellara7132 3 년 전 +301

    Veritasium: You can accelerate even if your spatial co-ordinates do not change.
    Me: Say what now?

    • @Virtueman1
      @Virtueman1 3 년 전 +35

      Yeah was hoping for better clarification since this contradicts the common concept of "acceleration".

    • @DerDean_HD
      @DerDean_HD 3 년 전 +6

      Say sike right now

    • @thulyblu5486
      @thulyblu5486 3 년 전 +20

      I have heard this argument before and the claim was that you are accelerating *in time* since space-time includes, you know... time... and time moves forward, we don't know how to stop accelerating through time.

    • @Henrix1998
      @Henrix1998 3 년 전 +12

      Good thing to know I'm exercising even in my bed

    • @thulyblu5486
      @thulyblu5486 3 년 전 +7

      This would mean that time would pass at different "speeds" depending on how close you are to a big pile of mass... and that's actually how it is. The bigger the mass, the slower the time. In black hole singularities time should literally stop. And no, I don't fully grasp that, it's just what I remember from watching so many pop science stuff about relativity.

  • @pramitd7761
    @pramitd7761 2 개월 전

    The way you explain it is divine!

  • @leonardaubry4236
    @leonardaubry4236 2 개월 전

    Hi Veritasium, great work, i've just discovered your channel and it's a pleasure to watch your videos and learning by feeling and picturing things. I have a question though, about what you are saying at time 15:40. You say that if GR view is more valid, we should see radiations emitted from the stationnary particles but bot from the free falling ones. That's the part i don't get. Since a charged particle emits radiations when accelerating with respect to an observer, a free falling particle will be accelerating with respect to the observers on earth, and therefore radiates in our referential, with no possibility to distinguish if either Newton or Einstein theory is more valid at that level. That's what i understand about the situation. I hope you'll get the time to answer and explain me what i miss, or anyone else reading me and having better understanding than me.

  • @hydranmenace
    @hydranmenace 2 년 전 +285

    No officer. I wasn't accelerating unnecessarily. I was trying to stay still at the light.

  • @ButzPunk
    @ButzPunk 3 년 전 +363

    Rocket Man Derek just floating around with a single molecule of ethanol.

    • @sahilchouhan6459
      @sahilchouhan6459 3 년 전 +7

      @Ben Rowe He was flying HIGH

    • @nicholasbrown3197
      @nicholasbrown3197 3 년 전 +13

      Gotta drink responsibly

    • @raffaeledivora9517
      @raffaeledivora9517 3 년 전 +1

      That's way too little

    • @ishworshrestha3559
      @ishworshrestha3559 3 년 전

      Kk

    • @partypoet2012
      @partypoet2012 3 년 전

      @@nicholasbrown3197 I wonder if you guys get paid extra, to come up with names that will attract a flat earther to this video and what's really funny is in the beginning he even tells you the truth, gravity is not a force and then a miracle in your mind happens because you think of it as a force.. this way, they can present you with two different types of reality and flip flop between the two so that whatever you can think of will match whatever you can see, you just can't do it with one reality.. you need three or four because you will notice , Things Are Falling in his video he forgets to take into the account the Earth is spinning at Mach 1 beneath him and for some reason nothing seems to deviate but that's okay Einstein was brought in to create a whole new reality in case 4 or 5 just didn't do it for you ..you got Einstein to add a couple more.. the only question is do you live in four or five different realities at the same time or just one?? in short if you stop making videos that sounds like it's a flat Earth video.. flat earthers won't wind up telling you, you have a belief based on pseudoscience ..you think it's real but it's not
      if you live the dream, remember it all works perfectly.. right up to the time you wake up and that's the problem once you wake up you can't go back to sleep.... Black Swan

  • @RespecterAlexander
    @RespecterAlexander 개월 전 +1

    What a great Veritasium video!

  • @neelbagayatkar7794
    @neelbagayatkar7794 3 년 전 +697

    Imagine having a physics class where you learn gravitation fields and forces then go on to watch this video right after...

    • @syn2896
      @syn2896 3 년 전 +21

      My physics teacher is making our class example this and how dose this work lmao.

    • @StRanGerManY
      @StRanGerManY 3 년 전 +52

      "everything you learned was a lie"

    • @dagmbisrat3740
      @dagmbisrat3740 3 년 전 +12

      This exactly what happened to me rn 😭 idk if I should confront my teacher😭

    • @Fadee
      @Fadee 3 년 전 +11

      I'm currently in a physics class, hope this doesn't mess me up

    • @TheSassi14
      @TheSassi14 3 년 전 +53

      @@dagmbisrat3740 Classic physics is still being used successfully and not wrong, it is just a different explaination for what we see. Maybe send this to your teacher. If they are nice, they will apreciate that you take your education further.

  • @cameronthomas3398
    @cameronthomas3398 2 년 전 +221

    I’ve never understood the concept of bending space time around masses until this video. And now it makes sense how light gets trapped in black holes despite having essentially no mass

    • @georgesmith8988
      @georgesmith8988 2 년 전 +15

      my understanding of this is, mass shapes space, and matter (mass) follows the shape of space, and we give this following of space the name gravity. That’s how understand it?

    • @jwjustjw8946
      @jwjustjw8946 2 년 전 +15

      *correction
      Light doesn't have essentially no mass, it has precisely no mass. Photons are massless particles.

    • @cameronthomas3398
      @cameronthomas3398 2 년 전 +2

      @@jwjustjw8946 Yes. Thank you!

    • @captainmaim
      @captainmaim 2 년 전 +1

      I'm confused. How does a laser exert force on an object if the light beam has no mass?

    • @Malpheron
      @Malpheron 2 년 전 +6

      @@captainmaim Light does have a mass, it does not have a rest mass. E = mc^2; m = E/c^2.

  • @joepmannak4631
    @joepmannak4631 19 일 전

    Im just flabergasted. Every question i ask myself during this video gets ansert within a few minetes. Thats how you can regognise a great video!

  • @rontaylor3403
    @rontaylor3403 8 개월 전

    even the visual example of planets on a trampoline type test bed that is supposed to represent the curvature of space time are both supported by a material that is consistent in its elasticity
    so if a helium filled balloon were resting on the test bed even if its size were the same size of either of the example planets the curvature of space would have to curve the same exact amount as either of the two test planets on the test bed however there would be a massive difference in the density between the helium filled balloon and the 2 example planets.

  • @kanishkasikriwal1803
    @kanishkasikriwal1803 3 년 전 +630

    The only thing that remains stationary is my understanding

    • @prasunbagdi6112
      @prasunbagdi6112 3 년 전 +1

      Copied

    • @xiaoxiao-kg5np
      @xiaoxiao-kg5np 3 년 전

      Don't feel bad, this theory of Einstein seems hard to grasp, simply because its utter NONSENSE! the ramblings of an insane mind are hard for rational people to understand. This Video of Veritasuim is so full of garbage that its amazing how so many people are sucked in by the slick presentation, while they ignore their personal sensibilities. SpaceTime is a nonsense fantasy idea. And Gravity is really a Force associated to the Earth and other Planets. Imaginary math based fantasies like SpaceTime cant be curved by real Matter. And certainly cant push real matter about. But Gravity can and does. Use your own brain.

    • @zofar9565
      @zofar9565 3 년 전 +44

      @@xiaoxiao-kg5np Unfunny troll

    • @xiaoxiao-kg5np
      @xiaoxiao-kg5np 3 년 전 +3

      @@zofar9565 Who is? If you have something to say, just say it. You think I'm a troll? Then try explaining where my statement is wrong. Just calling people names, is NOT smart.
      Explian my errors or shutup!

    • @zofar9565
      @zofar9565 3 년 전 +33

      @@xiaoxiao-kg5np Still a unfunny troll 😭😭

  • @rockstarpunkthegamer2631

    Love the fact all of a sudden there are 2 Veritasium’s, when there is only one.

  • @Cymock1
    @Cymock1 13 일 전

    Thanks you!
    This cake recipe will make my son happy for sure!

  • @flamep2145
    @flamep2145 3 년 전 +670

    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.

  • @mrawesomelemons
    @mrawesomelemons 3 년 전 +492

    Whenever my mom says I am being lazy and not doing anything I will tell her that I am accelerating.

    • @user-tb8zt7wg4p
      @user-tb8zt7wg4p 3 년 전 +14

      Not just accelerating you are also moving with a constant speed because the earth is rotating

    • @jerrymclean5263
      @jerrymclean5263 3 년 전 +1

      😅😅😅😅😂😂🤣

    • @-aaron-9971
      @-aaron-9971 3 년 전 +9

      tell her that you are busy coverting oxygen into carbon dioxide

    • @liamnilssonIFS
      @liamnilssonIFS 3 년 전 +1

      good one

    • @0_-
      @0_- 3 년 전

      @@user-tb8zt7wg4p There's leap seconds because earth doesn't rotate constantly, but it doesn't matter. I just wanted to tell you about leap seconds

  • @danny91pr
    @danny91pr 7 개월 전

    The budget for this video most have sky rocketed

  • @dyerex7
    @dyerex7 3 개월 전

    Time moves more slowly when relative density is higher.
    The pulling down sensation you feel is your particles literally being dragged by slower time.
    Like when your tires hit the gravel on the side of the road and your car lurches towards the shoulder.

  • @hunternotthewriter
    @hunternotthewriter 3 년 전 +386

    jokes on you, i watched this in a crashing airplane so yes. i am a inertial observer

  • @anweshdas6510
    @anweshdas6510 3 년 전 +485

    I'm an apple 🍎 ... I was just chilling the other day and suddenly my tree detached and started moving up and before I knew it a freakin scientist just came straight at me from the bottom and rammed me with his gigantic head.... Like what is wrong with that dude... Thanks to him now no one will eat me

    • @kletops46
      @kletops46 3 년 전 +7

      Absolutely LOL brilliant...!

    • @JassCodes
      @JassCodes 3 년 전 +8

      He is now eating our brains !

    • @astitvasrivastava1159
      @astitvasrivastava1159 3 년 전 +1

      P.S. The apple actually didn't fall on Newton's head.

    • @ahraj777
      @ahraj777 3 년 전

      Every smart aleck is rehashing the old, but another Einstein is illusive.

    • @LinkinPark4Ever1996
      @LinkinPark4Ever1996 2 년 전

      actually, that scientist ate that apple afterwards

  • @KrampusVsChristmas
    @KrampusVsChristmas 9 개월 전 +1

    Even in space as an “inertial observer,” the universe is always expanding, gravity stills exists(even if minute), and there can never be a fixed position anywhere in space. Difference of subjective interpretation vs objectivity.

  • @artimess3268
    @artimess3268 7 개월 전

    Props to Cameraman keeping up with Derek with Derek in space and Earth at the same time..

  • @adamsteele44
    @adamsteele44 2 년 전 +117

    "In curved space-time, you need to accelerate just to stand still". Mind. Blown.

    • @Bretaxy
      @Bretaxy 2 년 전 +1

      Curved space time, what does that even mean?

    • @failyourwaytothetop
      @failyourwaytothetop 2 년 전

      @@Bretaxy GEODESIC

    • @mathewsteven
      @mathewsteven 2 년 전 +9

      @@Bretaxy I assume it means the space time that's curved due to mass, such as space time around the sun or the earth

    • @j_taylor
      @j_taylor 2 년 전 +1

      The "curve" is a way to represent acceleration outside your frame of reference.
      To remain stationary relative to something else, the acceleration within your frame of reference must balance that outside.

    • @shannons.1233
      @shannons.1233 2 년 전

      Yep this is when my head exploded

  • @observantmagic4156
    @observantmagic4156 2 년 전 +858

    So newton wasn’t observing the apple, the apple was observing him

    • @thedaranesianconfederation7221
      @thedaranesianconfederation7221 2 년 전 +34

      General relativity:
      Hello there

    • @moxamir
      @moxamir 2 년 전 +90

      That poor apple was just an inertial observer, and Newton accelerated up and headbutted it.

    • @matigekunstintelligentie
      @matigekunstintelligentie 2 년 전 +19

      Newton used Linux

    • @egtaha
      @egtaha 2 년 전 +15

      There was never an apple to begin with. Newton had a brilliant mind but he had to dumb things down for others to understand hence the apple. In reality, who knows what was going through his mind.

    • @tmadvillain4028
      @tmadvillain4028 2 년 전 +5

      @@matigekunstintelligentie 😂😂😂What do u feed your brain!!🤨😂

  • @TheLoveajay
    @TheLoveajay 7 개월 전

    Beautifully explained

  • @eomoran
    @eomoran 7 개월 전

    Regarding the answer at the end, much like acceleration of mass is deviation from a geodesic, is there not an equivalent for the deviation of a charge in a magnetic field?

  • @finleysmurflton4851
    @finleysmurflton4851 3 년 전 +283

    “...and I will prove it to you by blasting off into space.”
    *Reaches for giant bong*

  • @Marc-db8cy
    @Marc-db8cy 3 년 전 +61

    That's my first thought too when I see someone falling from a building....."Oh look, someone inertly observing my acceleration through spacetime."

  • @samhelmer1978
    @samhelmer1978 7 개월 전

    This blew my mind @Veritasium ! and is the clearest explanation of (the consequences of) general relativity i have ever seen...(This video should be part of every middle school curriculum on the planet 🧑‍🚀🚀🌎)

  • @yf1177
    @yf1177 3 개월 전

    I've seen other excellent videos on this topic. This one is the best.

  • @ylstorage7085
    @ylstorage7085 3 년 전 +375

    "a falling man appreciates the gravity of the situation"

    • @cl4655
      @cl4655 3 년 전 +20

      but he doesnt experience it

    • @kaushikgupta9490
      @kaushikgupta9490 3 년 전 +2

      @@cl4655 underrated comment

    • @metalcake2288
      @metalcake2288 3 년 전

      Confucius plays

    • @lemmingscanfly5
      @lemmingscanfly5 3 년 전 +2

      I’m sure he’d be feeling quite the opposite of appreciation.

    • @wudubora
      @wudubora 3 년 전 +4

      It's not the fall the kills you, it's the sudden stop, will really it's the sudden acceleration.

  • @samsonoke1765
    @samsonoke1765 2 개월 전

    Law of relativity, I am understanding it for the first time as a non-scientist person that I am. Your explanation is brilliant!! Thank you

  • @BookOnThrough
    @BookOnThrough 일 전

    3:09
    And all the science, I do understand.
    It's more than just my job five days a week.

  • @austinalves7626
    @austinalves7626 3 년 전 +512

    *"You are not an inertial observer"*
    Astronauts watching this: Am I a joke to you?

    • @MartinHindenes
      @MartinHindenes 3 년 전 +7

      Is the Earth an inertial observer? What separates me from the Earth except time and definitions of physical object boundaries?

    • @weirddemocracy3432
      @weirddemocracy3432 3 년 전 +1

      You are in a Game called MAYA

    • @apacheattackhelicopter8778
      @apacheattackhelicopter8778 3 년 전 +1

      @@MartinHindenes from what I remember from school.. No, Earth is not an inertial observer since its accelerating.

    • @kylebybee5909
      @kylebybee5909 3 년 전 +8

      @@apacheattackhelicopter8778 No! The Earth is not accelerating. The Earth is not accelerating towards the sun, it's just following a straight line through a curved space time that is curved by the sun's mass.

    • @asadasifsyed4046
      @asadasifsyed4046 3 년 전 +2

      Whoo naruto fan😃😃

  • @andrewmaperson
    @andrewmaperson 3 년 전 +138

    "Einstein tells us one thing: focus on the experience of the observer"
    He really was a genius
    Now, all marketing is based on this

    • @kimi7614
      @kimi7614 3 년 전

      If you really want to know how cravity work I highly recommend this video krplus.net/bidio/mc6QdJSHqoTSdHY
      It's not marketing

    • @hoodyk7342
      @hoodyk7342 3 년 전 +4

      But also he was a plagiarist and a fraud apparently

    • @Communist-Doge
      @Communist-Doge 3 년 전 +8

      @@hoodyk7342 No, he was not. Don't believe everything you read on the Internet.

    • @Jack-do5tq
      @Jack-do5tq 3 년 전 +9

      We are 3 comments in and this is the most random reply’s ever
      -a random k pop link and two people arguing that Einstein was a fraud

    • @ManMan-ko7ll
      @ManMan-ko7ll 3 년 전 +1

      @@hoodyk7342 He was kind of a fraud, but most of his “theories” were correct, just because he possibly stole other scientists ideas doesn’t mean he was incorrect.

  • @zLumi
    @zLumi 8 개월 전 +1

    You should do a video on the Lagrange points!

  • @WyFoster
    @WyFoster 6 개월 전 +1

    I watch this video every couple months and think of it often. Definitely more than the Roman Empire.

  • @BIGDUEL
    @BIGDUEL 3 년 전 +602

    “Are you in an inertial frame of reference? No!”
    *The people on the ISS watching this video:*

  • @spacejunky4380
    @spacejunky4380 2 년 전 +629

    Trying to explain this to a friend is a crazy challenge. I've tried. I think it's more confusing, this is such a great explanation

    • @walteroreilly8963
      @walteroreilly8963 2 년 전 +7

      Thats because the video treats us a rigid body or singular particles. We have th ability to have distinguish different parts of our bodies in discrete frames. We feel our stomachs get queasy because the food inside and the fluid in our ears are behaving in different ways relative to their confinements. As the observer approached the planet he would indeed feel the difference if the curvature was great enough. He would not act in perfect synchronicity to the ship, just very very close to synchronicity.

    • @lukky6648
      @lukky6648 2 년 전 +1

      @@walteroreilly8963 that actually makes a lot of sense , just confused about how gliding would work if this theory was true

    • @AverageAlien
      @AverageAlien 2 년 전 +2

      Basically, space is distorted and your movement through time is what causes you to fall to earths core

    • @AverageAlien
      @AverageAlien 2 년 전 +7

      @@lukky6648 it's not "if". This theory IS true, general relativity accurately explains gravity at these levels. This isn't some guess. This is reality

    • @AverageAlien
      @AverageAlien 2 년 전 +1

      @@lukky6648 gliding works because of lift. Lift works against curvature of spacetime into the earth. Lift provides an upwards force due to air newtons 3rd law

  • @lakerowen2345
    @lakerowen2345 9 개월 전

    5:43 that's a good visual explanation

  • @curtiscole3735
    @curtiscole3735 8 개월 전 +1

    We need a video on how the earth doesn’t expand along with everything else. Another thing I’d like to say is that, let’s say matter does bend spacetime. Wouldn’t we not be able to tell that that was the case since particles would just move as they normally would but instead through bent space. Like they would move the same way but instead just bent but everything else would be bent too so how could they even tell gravity was going on?

  • @urmomgay
    @urmomgay 2 년 전 +848

    "Do you feel weightless?"
    Me, looking in a mirror:
    ...no

    • @segnos
      @segnos 2 년 전 +5

      lol

    • @kurushimee
      @kurushimee 2 년 전 +17

      Underweight me:
      ...yes

    • @frankdimeglio8216
      @frankdimeglio8216 2 년 전 +2

      THE CLEAR, TOP DOWN, ULTIMATE, AND BALANCED MATHEMATICAL PROOF OF THE FACT THAT ELECTROMAGNETISM/ENERGY IS GRAVITY IS GIVEN BY THE FACT THAT E=MC2 IS F=MA:
      Consider the man who IS standing on what is THE EARTH/ground. Touch AND feeling BLEND, AS ELECTROMAGNETISM/energy is gravity; AS gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE; AS E=MC2 IS F=ma. The Earth constitutes the FULL DISTANCE in/of SPACE in BALANCED and UNIVERSAL relation to what is the MIDDLE DISTANCE in/of SPACE, AS E=MC2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY !!! (The sky is BLUE, AND THE EARTH is ALSO BLUE. The stars AND PLANETS are POINTS in the night sky.) Time DILATION ultimately proves ON BALANCE that E=MC2 IS F=ma, AS ELECTROMAGNETISM/energy is gravity. INDEED, TIME is NECESSARILY possible/potential AND actual IN BALANCE; AS ELECTROMAGNETISM/energy is gravity; AS E=MC2 IS F=ma. Gravity IS ELECTROMAGNETISM/energy. E=MC2 IS F=ma. This NECESSARILY represents, INVOLVES, AND DESCRIBES what is possible/potential AND actual IN BALANCE, AS ELECTROMAGNETISM/energy is gravity.
      By Frank DiMeglio

    • @frankdimeglio8216
      @frankdimeglio8216 2 년 전 +3

      WHY AND HOW THE CLEAR, TOP DOWN, AND BALANCED MATHEMATICAL PROOF OF THE FACT THAT ELECTROMAGNETISM/ENERGY IS GRAVITY IS GIVEN BY THE FACT THAT E=MC2 IS F=MA:
      Energy has/involves GRAVITY, AND ENERGY has/involves inertia/INERTIAL RESISTANCE. "Mass"/ENERGY involves BALANCED inertia/INERTIAL RESISTANCE consistent WITH/as what is BALANCED electromagnetic/gravitational force/ENERGY, AS ELECTROMAGNETISM/energy is gravity; AS E=MC2 IS F=ma. GRAVITATIONAL force/ENERGY IS proportional to (or BALANCED with/as) inertia/INERTIAL RESISTANCE, AS E=MC2 IS F=ma; AS ELECTROMAGNETISM/energy is gravity. Consider the man who IS standing on what is THE EARTH/ground. Touch AND feeling BLEND, AS ELECTROMAGNETISM/energy is gravity; AS gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE; AS E=MC2 IS F=ma !!! SO, objects fall at the SAME RATE (neglecting air resistance, of course); AS ELECTROMAGNETISM/energy is gravity; AS E=MC2 IS F=ma. Moreover, the rotation of WHAT IS THE MOON matches it's revolution. The Earth constitutes the FULL DISTANCE in/of SPACE in BALANCED and UNIVERSAL relation to what is the MIDDLE DISTANCE in/of SPACE; AS E=MC2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY !!!! (The sky is BLUE, AND THE EARTH is ALSO BLUE. The stars AND PLANETS are POINTS in the night sky !!!) Accordingly, time DILATION ultimately proves ON BALANCE that E=MC2 IS F=ma; AS ELECTROMAGNETISM/energy is gravity !!! INDEED, TIME is NECESSARILY possible/potential AND actual IN BALANCE; AS ELECTROMAGNETISM/energy is gravity; AS E=MC2 IS F=ma. Gravity IS ELECTROMAGNETISM/energy. E=MC2 IS F=ma. This NECESSARILY represents, INVOLVES, AND DESCRIBES what is possible/potential AND actual IN BALANCE, AS ELECTROMAGNETISM/energy is gravity. Very importantly, outer "space" involves full inertia; AND it is fully invisible AND black. Think. It ALL CLEARLY makes perfect sense. BALANCE AND completeness go hand in hand. Great !!! SO, a given PLANET (INCLUDING WHAT IS THE EARTH) sweeps out EQUAL AREAS in equal times consistent WITH/AS E=MC2, F=ma, AND what is PERPETUAL MOTION; AS E=MC2 IS F=ma; AS ELECTROMAGNETISM/energy is gravity. Gravity IS ELECTROMAGNETISM/energy. The stars AND PLANETS are POINTS in the night sky. A PHOTON may be placed at the center of WHAT IS THE SUN (as A POINT, of course), AS the reduction of SPACE is offset by (or BALANCED with) the speed of light (c); AS E=MC2 IS F=ma; AS ELECTROMAGNETISM/energy is gravity. TIME dilation ULTIMATELY proves ON BALANCE that E=MC2 IS F=ma, AS ELECTROMAGNETISM/energy is gravity. Great !!!! Gravity AND ELECTROMAGNETISM/energy are linked AND BALANCED opposites, AS E=MC2 IS F=ma; AS ELECTROMAGNETISM/energy is gravity !!!! It all CLEARLY makes perfect sense. MAGNIFICENT !!!!
      By Frank DiMeglio

    • @joshuagaldys2049
      @joshuagaldys2049 2 년 전 +1

      @@frankdimeglio8216 can you send me a video that has that in it

  • @Niightblade
    @Niightblade 3 년 전 +117

    @EVERYONE: He's NOT saying gravity doesn't exist... he's saying it's not, technically, a force. EDIT: Ok he does actually say it doesn't exist a few times. *shrug* More importantly: Don't mess with the wiring in your house unless you know what you're doing and you're not breaking any laws/regulations.

    • @Random84530
      @Random84530 3 년 전 +5

      5:31 Gravity is just like that force, it doesn't actually exist.
      Hahahaha.

    • @ronrothrock7116
      @ronrothrock7116 3 년 전 +1

      No, he IS saying gravity doesn't exist. What you think/see/feel as gravity is an illusion. IT DOES NOT EXIST.

    • @elangavinindrav.a.h3725
      @elangavinindrav.a.h3725 3 년 전 +1

      @Brian Hensley acceleration.

    • @exitiumexitium3756
      @exitiumexitium3756 3 년 전 +4

      @Brian Hensley It’s not that gravity doesn’t exist, it just isn’t like other forces per se. More specifically it would be more similar to a fictitious force. What he’s trying to say is essentially that gravity’s effects are definitely there, but that it’s not a force, but a curvature in space time.

    • @NicsITV
      @NicsITV 3 년 전 +3

      @Brian Hensley The sides of the mug?

  • @user-sk5bc7jt1i
    @user-sk5bc7jt1i 20 일 전 +1

    7:57 Little does he know i'm falling of a building while watching this

  • @onyeagusisteven5080
    @onyeagusisteven5080 2 개월 전 +1

    Best presentation ever

  • @itsjatinrao
    @itsjatinrao 2 년 전 +579

    Just imagine a German man giving all these Mind blowing ideas 100years ago.

    • @kristofnagy7813
      @kristofnagy7813 2 년 전 +114

      And nowdays some people beleive the earth is flat

    • @ahamay2012
      @ahamay2012 2 년 전 +36

      Now they prevent climate change by missing school days...

    • @baronvonbeandip
      @baronvonbeandip 2 년 전 +9

      ngl, they do put out alot of useless hot air in school. maybe it's not so bad.

    • @akagetobimaru1994
      @akagetobimaru1994 2 년 전 +8

      People don't have time n money to think anymore nowadays....
      Everyone was so busy nowadays

    • @Gettindirty187
      @Gettindirty187 2 년 전 +6

      And Nicola Tesla said all Einstein’s ideas were crap!

  • @HuyNguyen-ws2sh
    @HuyNguyen-ws2sh 3 년 전 +788

    "There is no gravity"
    Flat-earthers: "write that down, write that down"

    • @8c4e
      @8c4e 3 년 전 +11

      Flat-earthers: 'I should go research this' Heliocentrists: 'You see how stupid flat tards are?'. Makes you wonder who really honors 'science', doesn't it?

    • @bridgetonlongfellow2971
      @bridgetonlongfellow2971 3 년 전 +3

      dumb half-baked comment. Perfect for flat-earthers though.

    • @relaxxxrrr
      @relaxxxrrr 3 년 전 +14

      Why you gotta be so dishonest, "There is no gravity".... just curvatures in space-time that cause.... GRAVITY!!!!!

    • @grywacz
      @grywacz 3 년 전 +2

      What do you mean by "down"?

    • @deadlyEuphoria420
      @deadlyEuphoria420 3 년 전

      dude i was thinking the same thing lol

  • @madhupriya9579
    @madhupriya9579 3 개월 전

    Finally got to know why I get so tired while lying on bed all day. I am working(accelerating) so hard to stay still!!

  • @dtb7872
    @dtb7872 4 개월 전

    please expand on gravity not being a field and therefore no field carriers but why the theory of the graviton exists and how this all parties with the quantum gravity theories especially when it comes to gravity around and inside black holes!

  • @abenezerfetsum3632
    @abenezerfetsum3632 3 년 전 +187

    After watching this video I couldn't stop shaking my head due to the fact that I just realized Einstein was way ahead of his time like imagine if he was here today. Legend says that I am still shaking my head from amazement.

    • @vidhoard
      @vidhoard 3 년 전 +4

      Bruh same here - like that guy was incredibly smart to be thinking that way so long ago

    • @iamgt2392
      @iamgt2392 3 년 전 +1

      I am too thinking...like his iq must have been equal to the 'one way speed of light'

    • @chocolate_squiggle
      @chocolate_squiggle 3 년 전 +7

      I think it was a different way of living back then. From documentaries and audiobooks I've consumed over the last decade, one thing that kept surprising me was how young so many scientists of past eras were, AND, that they often made great contributions in multiple fields. There was no TV after school, evenings & weekends. It was a harder time for many and perhaps these chaps were more aware/grateful for their privileged education. I guess what I'm saying is people had less distractions with more motivation & time to move through the subjects. I think they were far better educated than us at equivalent ages - at least those who managed to get an education.

    • @abenezerfetsum3632
      @abenezerfetsum3632 3 년 전

      @@chocolate_squiggle 💯💯💯

    • @watcher314159
      @watcher314159 3 년 전

      @@chocolate_squiggle More like the problems they were solving were much easier than the ones we're left to tackle today. Even with our superior education, we still need more of it to make progress because almost all the low-hanging fruit is gone.
      Now, this isn't to say our education system is perfect; it's anything but, to the point that allowing students to skip lectures and do literally anything else with their time raises GPAs by over 15% (twice that for students of colour). But we also know that IQ is, near as we can tell, purely a measure of socioeconomic factors like nutrition and education rather than anything genetic (yes, IQ is highly heritable, but lots of non-genetic things are inherited), and it keeps going up; people at a given age do still keep getting measurably smarter every year and every generation as long as they are given access to the shoulders of giants. Despite all our many problems and issues, we're still getting smarter faster than the problems we're faced with are growing more difficult. We could definitely be doing much, much better, but it's reassuring to know we at least aren't doing bad.

  • @donallen7830
    @donallen7830 7 개월 전

    Your experimental test segment made me start to think about Maxwell and the electrons in a copper wire.

  • @mattross83
    @mattross83 10 개월 전

    Brilliant explanation for a brilliant theory.

  • @bullsquid42
    @bullsquid42 3 년 전 +486

    7:50 Ha! Joke's on you, because I'm watching this while falling from a

  • @Razza2250
    @Razza2250 3 년 전 +121

    "what should i have floating around in this carton rocket?" "how about that ethanol molecule, it looks kind of like a cute puppy"

    • @kamikater14
      @kamikater14 3 년 전

      Ever heard of Snatoms?

    • @Razza2250
      @Razza2250 3 년 전

      @@kamikater14 if you mean the molecular model kits, i use them with my classes

  • @getgaijoobed6219
    @getgaijoobed6219 4 개월 전 +2

    Thanks for the video, I will be showing it to my boss tomorrow to convince him we don’t actually need to take gravity into account in our next engineering project 😅

  • @liviomatheus6316
    @liviomatheus6316 7 개월 전

    Finally someone appeared to say that the bent sheet analogy for curved space-time is misleading!

  • @luciazifcakova7348
    @luciazifcakova7348 2 개월 전

    while watching this great video, it got me thinking. If time space is curved than it means that the light will never travel the same path as the time will change but also the position of the earth in the univrs, so if the light is deflected using the mirror, thus the speed of light will be different in each direction.

  • @ZenZooZoo
    @ZenZooZoo 3 년 전 +168

    “Gravity is an illusion”
    Heavy facts, dude.

    • @nealthediscordguy2524
      @nealthediscordguy2524 3 년 전

      Good one

    • @LordDragox412
      @LordDragox412 3 년 전 +3

      Damn, does that mean that illusionists can *actually* fly?

    • @AxxLAfriku
      @AxxLAfriku 3 년 전

      I am the ALPHA MALE of this comment section and I command RESPECT. Right now I am ordering you to NOT view any of my videos. Instead just look at my thumbnails and be JEALOUS. Bye bye ca.

    • @jettaeschroff6924
      @jettaeschroff6924 3 년 전 +1

      @@AxxLAfriku whaat?

    • @kaizokujimbei143
      @kaizokujimbei143 3 년 전 +2

      @@LordDragox412 Flight is the utilization of aerodynamics. Levitation is the utilization of an inertial frame of reference. And suicide is the utilization of the Earth's acceleration towards your face. xD

  • @deejayf69
    @deejayf69 2 년 전 +805

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

    • @deltablaze77
      @deltablaze77 2 년 전 +46

      I was just thinking this, with the right level of fundamentally misunderstanding this video I could see it feeding into the FE crazy ideas of the world just accelerating upwards at 9.8m/s squared.

    • @KibyNykraft
      @KibyNykraft 2 년 전 +6

      Nonlocality and "general" relativity is about the level of flat earthers, denying all science and energy conservation laws. How will one prove that space is a magical gelly of extra time or instant energy transfer?
      Gravity is an acceleration yes, because a force is the outcome (the field of) of particle charge due to spin states and vibratory conditions.
      Relativity is the opposite of anything general.. It is by being relativity, "special"(localities measured)

    • @baronvonbeandip
      @baronvonbeandip 2 년 전 +8

      @@deltablaze77 Isn't that what they believe, tho? Doesn't the pizza just fly through space propelled by dark energy or whatever flavor-of-the-month untestable excuse they can come up with?

    • @festassorteio2488
      @festassorteio2488 2 년 전 +2

      @@baronvonbeandip we also have dark enery on relativility but yeah their logic make way less sense

    • @foxtrotalphagolfgolfoskart3224
      @foxtrotalphagolfgolfoskart3224 2 년 전 +4

      This video made more sense in a flat earth way than any flat earth video?¿?🤷🏽‍♂️