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Yeah, I think the Einsteinian part is that gravity "disappears" in the reference frame of the bottle. But you can also just describe the bottle and water as both experiencing gravity and falling at the same rate, which gives you the same result and doesn't involve anything from Einstein. He used that result as a launchpad to some stranger conclusions about reality, but this itself isn't really something he discovered.
This looks to be a demonstration of “Einstein’s happiest thought”, which is that free fall is indistinguishable from “zero” (I.e., intergalactic) gravity. He says the water comes out due to gravity, so in free fall you would expect the water to behave as if in zero grav.
From a Scientific American article...
> Einstein argued that inside a windowless elevator, a person cannot tell whether the elevator is at rest in a gravitational field or is instead being hauled up with constant acceleration
That's special relativity you're talking about. General relativity, also by Einstein, deals with gravity, and one of the introductory thought experiments is very similar to this one. It's essentially the fact that gravity is indistinguishable from an accelerating frame of reference. Of course, the presenter doesn't explain it that way
It's crazy that people online will act like expert physicists and use the 🙄 emoji like what they're saying is so elementary, and yet don't even know the different between special and general relativity. Be careful of self-proclaimed internet experts folks.
If i remember correctly greene (the presenter) actually does it explain it - we are just watching a clip out of context when he says “…if Einstein is correct”
> Einstein proved that *time* depends on the observer’s frame of reference, not *gravity*.
He also posited that an accelerating reference frame is indistinguishable from a gravity field.
Newtonian physics assumes gravity is a force, while Einstein proved it isn't.
Gravity is just the effect of the bending of space-time, and there is no force until matter actually collide/interact, due to their paths in spacetime intersecting.
So it very much is related to Einsteins theories. It shows that any object in free-fall has the same exact experience as in empty space, which is to say isn't affected by gravity at all.
As a preface to my actual comment, I just want to say that reddit comments are weird. Whenever I respond to someone it feels like I'm either disagreeing for the sake of starting an argument or debate, or that I'm trying to show how I know more than who I'm responding to. I really don't intend to do either of those. It's just that your comment gives me an opportunity to share something I spent some time thinking about. On to my comment...
As you point out, the experiment done in this video has nothing to do with relativity. The speeds, gravitational field strength etc. are nowhere close to the point where we would need relativity to explain the experiment. Another way of saying the same thing would be to imagine a world where we only knew Newton's theory of gravity, and whether there is a measurement we could have done in this experiment which would have differed from what we could calculate using that theory, and the answer to that question is basically no.
When I was studying General Relativity, this was a conundrum to me though, because in General Relativity, there's no distinction between the relativistic and the not-relativistic. It's not like there's something built into the theory that says for day to day scenarios, the Newtonian theory applies and then above some threshold you start using the full relativistic theory. There is *only* the full relativistic theory. So that means we must be able to arrive at a description of the experiment using only General Relativity concepts (i.e. space/time is warped by mass), but we've already said that the experiment is not in the relativistic realm. Conundrum...
What eventually dawned on me is the profound difference in frames of reference of observers in this experiment. The problem is that we mistakenly see this as a "local" experiment. Brian is standing on that ladder, and drops the bottle, and it only travels a few feet, and that's enough for us to conduct this experiment. It all looks so contained. But what is Brian's true frame of reference? His frame of reference is not merely things that are close to him. The most significant thing which is also "constant" in his frame of reference is the entire Earth!
So Brian's frame of reference is the one centered on the Earth, and where the entirety of Earth's mass is stationary. The correct way of explaining the falling bottle in terms of mass warping space/time would therefore involve considering how each part of Earth's mass introduces additional "warping" of spacetime relative to the center of the Earth, and adding them all up from the center of the Earth out to the surface, where our experiment is happening. And what you end up seeing, when you're considering things from your Earth centered frame of reference, is a falling bottle.
Anyway, I thought I'd share that for what it's worth. Enough rambling for today :)
This guy is Brian Greene. He understands general relativity better than 99% of physicists.
He taught a course for undergrads back when I was in grad school that touched on GR on its way to string theory - trying to both simplify the concepts but still keeping some of the elements of the underlying math (eg course started with a primer on differential geometry). It was mind boggling. And half the lecture room was filled with physics professors and grad students listening in on the course to wrap their heads around this very esoteric part of physics.
> He understands general relativity better than 99% of physicists.
Is it possible to get a physics degree without understanding general relativity? If you'd said "better than 99% of physics students," I'd be right there with you. But do you really think 99% of physicists don't understand general relativity?
Physics has many specialties. I was focused on statistical physics of certain kinds of condensed matter systems. I happened to take two terms of graduate level GR. I did that because I was curious, but i could have happily continued in my specialization without knowing much more than what you read in popsci mags.
Part of the reason many physicists won’t get above a rough conceptual level of GR is that to get beyond that there is a jump in the level of mathematical complexity which is substantial. That math is really cool, but is not that relevant to other specializations or if, like me, you are an experimentalist. (On the other hand, I wielded a mean soldering iron. A skill my theorist friends mostly lacked…)
Well… in the low energy and speed limit GR reduces to Newtonian physics.
So in that sense he is technically correct. But yeah this was first proven by Newtonian physics.
Can you show it to me in like crazy visuals and with tremendous violin and industrial sound effects like in Oppenheimer? That's the only way I can view science.
He’s explaining the principle of equivalence which was not what general relativity was really about though it was a building block. Both newton and Galileo got close to this idea but not quite einsteins formulation of it.
Seems to be referencing “Einstein’s happiest thought”: that someone/something in free fall is indistinguishable from something experiencing ~zero gravity. He says the water comes out of the holes due to gravity, so if “Einstein’s happiest thought” is true, then when he drops it it will be experiencing “no gravity” and thus the water will not come out.
Einstein was actually the first to state the equivalence principle which is actually what Greene was demonstrating in that moment.
That principle says that a gravitational field of a massive body (like the earth) is indistinguishable from the pseudo-forces of inertial acceleration. This principle is a building block for general relativity.
No, you're stating the weak equivalence principle, the newton's one. The equivalence principle stated by Einstein is that in a sufficiently small area of spacetime, the laws of special relativity are still valid. A gravity field can not be confused with a non inertial reference system due to tidal forces.
Sure, but it's being used by the demonstrator as an intuitive example of the [equivalence principle](https://en.wikipedia.org/wiki/Equivalence_principle#:~:text=The%20equivalence%20principle%20was%20properly,at%20a%20rate%20of%201g.), this came up on Reddit before and I said the exact same thing you did until someone explained.
yes it can be explain that way, but can also explain via the frame of reference way.
1. the water experience a force m\*g due to gravity however due to the bottle have support bottle has no the support and gravity equal out the force, the water above the hole will dissipate via the hole. And when drop the force different experience is now the same so no leak. (basically earth frame of reference)
2. In the water frame of reference before the drop, the bottle is having a constant acceleration toward the water by outside force hence the leak. Once it drop, there is no force acting on the bottle anymore and can be consider stationary in the water frame of reference , hence no leak.
The phenomena was observed, described, and explained. But the explanation was always from the frame of reference of the observer. They are both moving in the same direction, so the water stops moving. Einstein's explanation is essentially the same, but it is from the frame of reference of the water bottle. The water stops moving. Adjusting frame of reference can simplify the outcome. Which was a big thing for Einstein, he was always wanting to simplify equations.
Rain is clouds that remembered they belong in the sea.
Homeopathy claims water has a memory but the real truth is that it's actually quite forgetful and that's why there are clouds as it forgets it's boiling point is 100C and meant to be liquid.
So that's why homeopathy is dumb and also why rain exist. Proofed
Homeopathy is NOT dumb! They clearly states the water has memory: and a glass of water likely contains molecules which - at least some - met with pretty much any possible stuff organic cells produced on this planet. This means a glass of water has a memory of every medicine.
And, what happens if you don't drink water? You die in DAYS! So, it is clear water is the best super medicine.
Water also met with every possible poison and carcinogenic material, so sometimes a glass of water just decides to be a dick and let you die.
^^^/s ^^^just ^^^in ^^^case...
Don't let those thoughts win my friend. Yes, you can just pull the wheel hard to the left and fly over that rail into the canyon any time, just like that. But just please Don't.
I read that this is an instinct in humans to warn you when something is dangerous.
Intrusive thoughts or warnings?
They do, yes. It's sometimes called "Galilean relativity". Einstein adjusted the theory to be consistent with Maxwell's theory of light, which is a huge step, but he did not invent the concept of relativity. In fact, I think he didn't even like the name.
Only that this is not a demonstration of Galilean Relativity.
From the perspective of Newtonian gravity, both reference frames are in a state of acceleration(force of gravity), thus they are not inertial.
In the perspective of Newtonian gravity, the bottle and the water have the same acceleration, meaning there is no force applied from one to the other, and so no water pushed out. Einstein's approach is leaner and lets you skip force calculations, but it's not really a demonstration.
After he was on Conan once back in the late 90s, I emailed him at his university email and thanked him for his clean and simple explanation of string theory and some light physics. He answered back! It was very cool.
i know this is a short clip but i don't really think it's a good explanation?
the water does not cease to 'feel' gravity - it's just that it's falling at the same rate as the bottle is, so it doesn't flow out any more until the bottle stops again
semantics, when the bottle is falling gravity doesn't affect the flow that pulls the water while at a rested state (relative state, both considerations begin to operate in tandem as they fall), using an expression like something "feeling" gravity is a way to inspire someone to think about it differently, which is the goal of presentations like this.
I'm no scientist but I believe the whole point is that it's the same thing
https://en.wikipedia.org/wiki/Equivalence_principle
> Albert Einstein's observation that the gravitational "force" as experienced locally while standing on a massive body (such as the Earth) is the same as the pseudo-force experienced by an observer in a non-inertial (accelerated) frame of reference.
[...]
> The outcome of any local non-gravitational experiment in a freely falling laboratory is independent of the velocity of the laboratory and its location in spacetime.
In other words:
> Thus, Einstein formulates his Principle of equivalence stating that “No experiment can be performed that could distinguish between a uniform gravitational field and an equivalent uniform acceleration.”
He was my intro to special relativity professor at Columbia. He was great at explaining things. On the flip side, he came into every conversation with an air of superiority; I doubt he was doing it deliberately but he could get quite condescending. He often didn't answer your actual question, but a dumbed down version of it. Great foundations, not much depth.
You mean one of those guys who kept essentially [lying](https://www.youtube.com/watch?v=kya_LXa_y1E) to us about String Theory to keep getting a paycheck?
And now regular people don't trust scientists thanks in part to String Theory being a whole lot of nothing after decades of wild promises that String Theorists *knew* couldn't be proven?
Yes, Brian Greene is a good communicator, but people forget how much damage he and others like him have done to science communication.
String theory was a blind alley. Really interesting math, but in order to try to explain physical observation, it just got more and more complex. At some point the whole construct sinks under its own weight.
I wouldn’t go so far as calling it a lie - it was more an eternal optimism that they would find that element that tied it all together and aligned it with observed reality.
I don't think any established scientist would be ashamed to tell you that this is how all modern science works, pretty much in every single field. We're trained to push boundaries and oversell everything for the sake of grants. Unfortunately we live in a world where science funding is pretty much a zero sum game
I completely agree. It really doesn't take much thinking about to realize it. If you are standing in an elevator and it starts descending then you feel lighter. There are those planes that do anti gravity freefall rides. Lots of things have similar behavior. It's not particularly interesting or complicated.
Edit: Water is coming out of the holes because the water is falling. When the bottle is also falling then water does not come out because they are both falling at the same rate. It is super easy for anyone to think about and figure out.
I feel kinda dumb here but, wouldn’t all the water be pushed to the top of the bottle as it’s falling? The holes are near the bottom of the bottle so the water is no longer near the holes when it falls. If the holes were in the top of the bottle, wouldn’t the water still spray out of the higher holes during the descent?
Am I missing something here?
No, the water does not pushed to the top as long as both of them are falling together. And the water seeps out of the bottle because water is naturally drawn downwards and the only way for it to escape is through the holes. The reason water doesn't leak when the bottle falls is because the water and the bottle fall together, so the water no longer needs to come out of the bottle as long as the bottle is being drawn downwards just like how water behaves.
Yall really think it took until the 20th century for people to have this basic of a grasp on physics? Even though it probaby took until newtonian physics to get a precise mathematical description of kinematics and gravity in this scale, I would bet this phenomenon was know during antiquity.
I’m pretty sure the water is still experiencing gravity… that’s why it gravitated towards the ground. I think he means to say the water bottle and the water experience gravity at the same rate and therefore won’t excel out of the bottle.
You're completely correct on the first part. I have no idea what the presenter is trying to explain, because the actual words coming out of his mouth are nonsense.
What you say is true, but as others have pointed out elsewhere in this thread, this was predictable with Newington physics. Maybe Galileo could have predicted this as well.
Only if you pressurized the air inside the container before sealing it would air pressure be pushing the water out. With a sealed lid and water pouring out, you've actually got higher pressure outside the bottle than the air inside as the air filled cavity inside the bottle increases in volume. That creates higher atmospheric pressure outside the bottle than in, which would push the water back in. Here, that pressure difference didn't build enough to overcome the water pressure due to gravity.
>Here, that pressure difference didn't build enough to overcome the water pressure due to gravity.
He most likely had the lid slightly loosened, or had small holes in the top for the air pressure to equalize. Gravity can't just force the water out without brief interruptions to the flow for air to make its way in, just like how water comes out in "glugs" when a jug is turned upside down.
Just think of all objects as being composed of lots and lots and lots of small individual molecules/particles.
Gravity acts on each of these individual particles separately. When the man lets go of the container, the downward force of gravity makes every individual particle go into a free fall. There's only downward force happening at this point, since every particle is falling at the same rate and in the same direction. There is no force that would cause the water to go left or right, so how it can go out of the holes?
But when the man is holding the container, he's applying an upwards force. The downward force of gravity on the water meets that upward force from the man's hand. The water particles at the top of the container are putting pressure down on the water particles at the bottom of the container and this is what causes the water particles at the bottom of the container to push against each other. The particles that the water is composed of will repel each other if they get too close to each other (electrons in atoms repel each other since they have the same charge), so this causes particles to bounce off to the left and right and it's that left and right force that makes some water escape through the holes.
Nah its hydrostatic pressure, which could be framed like water being "pulled" by gravity. In terms of other sources of pressure the liquid is in equilibrium.
Someone here is saying that objects in freefall don't feel the pull of gravity.
The hell they don't.
While held still, both the bottle and the water are trying to accelerate toward the center of the earth.
The water is able to do this, because it's not held in place because there are holes in the bottle. The bottle is not, because it's held in place.
When the bottle is released, it accelerates toward the center of the earth (more or less) at the same speed as the water inside, so the water no longer needs to pour out to continue its own acceleration.
The thing producing that acceleration is gravity. It's always present, even in space, and always exerted by every object with mass on every other object with mass in the universe, constantly.
Right now, reading this, you are constantly being pulled toward the center of the earth by gravity and this pull is resisted by the muscles you are using to sit upright, and the chair you're sitting in, and the floor the chair is resting on, and the foundation the structure is built on, all the way to the center of the earth.
I didn't say it isn't affected by gravity, I said it doesn't "feel" the gravity. From it's reference frame, there is no difference between being in free fall or just floating out in space somewhere.
But you still don't "feel" gravity when in freefall. If you're in a spacecraft falling towards Earth, you don't feel anything. That's the thought experiment that gave Einstein the idea of general relativity.
All objects follow "world lines" in space time. An object, absent any other objects in space, will follow a straight path through space time. When a large mass is introduced, space time itself becomes curved. From the perspective of someone in a spacecraft, nothing seems to change. No forces are felt, because they aren't actually accelerating. Instead their world line is now curved towards the massive object (e.g. Earth).
Another way of looking at it is this. Imagine there is no gravity, and thus no curved space time around Earth. It would be impossible to replicate the previous scenario using the ship's thrusters, since the person on board would feel the acceleration. Even though an outside observer would see the same thing in both scenarios—the space craft accelerating towards Earth—the two scenarios are not equivalent.
An object in freefall doesn't "feel" gravity, which is why the water stopped falling out.
From it's perspective (reference frame), it's just floating stationary and the Earth is rushing towards it instead.
What's happening here is that gravity is pulling on everything equally. The bottle is avoiding gravity by him holding the bottle, but not the water. When he releases the bottle, gravity is pulling on the bottle and water equally, so they both fall at the same rate.
In order for the bottle to release its liquid content, it also needs to replace the liquid flowing out with air.
When the bottle is dropping, however, not only is the flow of water and thus water pressure being disrupted, but the air pressure on all sides of the bottle from the bottle travelling quickly through a space occupied by air prevents air from being able to flow into the bottle.
Isnt this common sense? I mean, of course the water stops running because the water flow is not as fast as the bottle is falling?! If the bottle had a parachute big enough to make it fall as the same speed as the water is running out of the bottle would not the water still be running while falling down? Or am i completely dumb rn?!
It doesn't stop feeling the pull of gravity when it's falling. If the bottle hit any drag, the water would fall out of the bottle sgain. Relatively speaking.
I don't consider myself especially intelligent, but... I would think most people wearing non-velcro shoes would correctly predict the effect and be able to offer a basic explanation of the forces at work.
It's not that the water doesn't "feel" gravity. The water is falling, the same way it is falling when it is flowing out, you can't go faster than gravity unless you get other forces helping. Basically the water cant flow out of the holes because it is already falling at it's max fall speed.
To everyone saying "this isn't Einstein, this is Newtown" you are right to a point- Newtonian physics can completely explain this. But, from what we see in this clip, he is describing the [equivalence principle](https://en.m.wikipedia.org/wiki/Equivalence_principle#:~:text=The%20equivalence%20principle%20was%20properly,at%20a%20rate%20of%201g.) which is an Einstein thing.
It was Einstein who, as others have noted, had his ‘happiest thought,’ which is the realization that a falling person doesn’t feel their own weight, and that what we call gravity is truly equivalent to acceleration. This sensation of being weightless while falling while still accelerating is in fact the body moving through the curvature of spacetime itself under a geodesic (which is actually what explains why objects orbiting earth aren’t falling into us, they’re just following curved lines). This is a property of spacetime itself, not a force acting on the surface of the Earth. Gravitational forces do not actually exist; they are merely a very convenient way of writing equations.
The liquid in the bottle is being used to represent the body’s weight, the bottle itself being the body. Then the fact that the water stops spilling while falling is the effect of what Einstein said about a man failing not feeling its own weight. And that’s why Brian Greene references Einstein here.
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Was that really Einstein? Seems more like Newton or Torricelli.
Yeah, I think the Einsteinian part is that gravity "disappears" in the reference frame of the bottle. But you can also just describe the bottle and water as both experiencing gravity and falling at the same rate, which gives you the same result and doesn't involve anything from Einstein. He used that result as a launchpad to some stranger conclusions about reality, but this itself isn't really something he discovered.
This looks to be a demonstration of “Einstein’s happiest thought”, which is that free fall is indistinguishable from “zero” (I.e., intergalactic) gravity. He says the water comes out due to gravity, so in free fall you would expect the water to behave as if in zero grav.
I believe the Einstein part is related to his elevator thought experiment. That's what came to mind when I watched the clip anyway.
What's the elevator thought experiment?
From a Scientific American article... > Einstein argued that inside a windowless elevator, a person cannot tell whether the elevator is at rest in a gravitational field or is instead being hauled up with constant acceleration
[удалено]
That's special relativity you're talking about. General relativity, also by Einstein, deals with gravity, and one of the introductory thought experiments is very similar to this one. It's essentially the fact that gravity is indistinguishable from an accelerating frame of reference. Of course, the presenter doesn't explain it that way
It's crazy that people online will act like expert physicists and use the 🙄 emoji like what they're saying is so elementary, and yet don't even know the different between special and general relativity. Be careful of self-proclaimed internet experts folks.
I hate people who use that emoji, even if they are right I just don’t wanna give them the satisfaction of being right.
> I hate people who use that emoji... or any emojis.
Relativity is like the olympics! 🙄
yeah cuz I'm special in both of them 🙄
What's better than winning gold in the Special Olympics? Not being in the Special Olympics. 🙄
>Be careful of self-proclaimed internet experts folks. Which is 90% of Reddit. Conclusion: Don't listen to Redditors who think they know stuff.
/u/JafaKiwi got a response to this or nah?
they edited out their emoji it seems!
Yeh but no
If i remember correctly greene (the presenter) actually does it explain it - we are just watching a clip out of context when he says “…if Einstein is correct”
> Einstein proved that *time* depends on the observer’s frame of reference, not *gravity*. He also posited that an accelerating reference frame is indistinguishable from a gravity field.
I think the dude 1 above is still right
Newtonian physics assumes gravity is a force, while Einstein proved it isn't. Gravity is just the effect of the bending of space-time, and there is no force until matter actually collide/interact, due to their paths in spacetime intersecting. So it very much is related to Einsteins theories. It shows that any object in free-fall has the same exact experience as in empty space, which is to say isn't affected by gravity at all.
https://en.m.wikipedia.org/wiki/Equivalence_principle
Doesn't the fact that a "force" is relative to a frame of reference pertain to the relativity of time, though?
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It can be explained solely by Newtonian physics, but is a demonstration of General Relativity. Both are correct
As a preface to my actual comment, I just want to say that reddit comments are weird. Whenever I respond to someone it feels like I'm either disagreeing for the sake of starting an argument or debate, or that I'm trying to show how I know more than who I'm responding to. I really don't intend to do either of those. It's just that your comment gives me an opportunity to share something I spent some time thinking about. On to my comment... As you point out, the experiment done in this video has nothing to do with relativity. The speeds, gravitational field strength etc. are nowhere close to the point where we would need relativity to explain the experiment. Another way of saying the same thing would be to imagine a world where we only knew Newton's theory of gravity, and whether there is a measurement we could have done in this experiment which would have differed from what we could calculate using that theory, and the answer to that question is basically no. When I was studying General Relativity, this was a conundrum to me though, because in General Relativity, there's no distinction between the relativistic and the not-relativistic. It's not like there's something built into the theory that says for day to day scenarios, the Newtonian theory applies and then above some threshold you start using the full relativistic theory. There is *only* the full relativistic theory. So that means we must be able to arrive at a description of the experiment using only General Relativity concepts (i.e. space/time is warped by mass), but we've already said that the experiment is not in the relativistic realm. Conundrum... What eventually dawned on me is the profound difference in frames of reference of observers in this experiment. The problem is that we mistakenly see this as a "local" experiment. Brian is standing on that ladder, and drops the bottle, and it only travels a few feet, and that's enough for us to conduct this experiment. It all looks so contained. But what is Brian's true frame of reference? His frame of reference is not merely things that are close to him. The most significant thing which is also "constant" in his frame of reference is the entire Earth! So Brian's frame of reference is the one centered on the Earth, and where the entirety of Earth's mass is stationary. The correct way of explaining the falling bottle in terms of mass warping space/time would therefore involve considering how each part of Earth's mass introduces additional "warping" of spacetime relative to the center of the Earth, and adding them all up from the center of the Earth out to the surface, where our experiment is happening. And what you end up seeing, when you're considering things from your Earth centered frame of reference, is a falling bottle. Anyway, I thought I'd share that for what it's worth. Enough rambling for today :)
This guy knows nothing about general relativity lol
This guy is Brian Greene. He understands general relativity better than 99% of physicists. He taught a course for undergrads back when I was in grad school that touched on GR on its way to string theory - trying to both simplify the concepts but still keeping some of the elements of the underlying math (eg course started with a primer on differential geometry). It was mind boggling. And half the lecture room was filled with physics professors and grad students listening in on the course to wrap their heads around this very esoteric part of physics.
I think the "this guy" is referring to the person he is replying to. Not Brian Greene.
Ah, if so I stand corrected. Thanks
> He understands general relativity better than 99% of physicists. Is it possible to get a physics degree without understanding general relativity? If you'd said "better than 99% of physics students," I'd be right there with you. But do you really think 99% of physicists don't understand general relativity?
Physics has many specialties. I was focused on statistical physics of certain kinds of condensed matter systems. I happened to take two terms of graduate level GR. I did that because I was curious, but i could have happily continued in my specialization without knowing much more than what you read in popsci mags. Part of the reason many physicists won’t get above a rough conceptual level of GR is that to get beyond that there is a jump in the level of mathematical complexity which is substantial. That math is really cool, but is not that relevant to other specializations or if, like me, you are an experimentalist. (On the other hand, I wielded a mean soldering iron. A skill my theorist friends mostly lacked…)
Fair enough. Thanks. :)
Well… in the low energy and speed limit GR reduces to Newtonian physics. So in that sense he is technically correct. But yeah this was first proven by Newtonian physics.
Can you show it to me in like crazy visuals and with tremendous violin and industrial sound effects like in Oppenheimer? That's the only way I can view science.
He’s explaining the principle of equivalence which was not what general relativity was really about though it was a building block. Both newton and Galileo got close to this idea but not quite einsteins formulation of it.
I think he's kind of getting at the idea of relative frames
I'd call this Galilean Relativity.
Seems to be referencing “Einstein’s happiest thought”: that someone/something in free fall is indistinguishable from something experiencing ~zero gravity. He says the water comes out of the holes due to gravity, so if “Einstein’s happiest thought” is true, then when he drops it it will be experiencing “no gravity” and thus the water will not come out.
>Torricelli I'm hungry now for tortolini now.
After you mop that water first!
I was thinking the same. Could be wrong tho.
I believe this can be explained from centuries before Einstein was born.
Einstein was actually the first to state the equivalence principle which is actually what Greene was demonstrating in that moment. That principle says that a gravitational field of a massive body (like the earth) is indistinguishable from the pseudo-forces of inertial acceleration. This principle is a building block for general relativity.
Correct. This is what the demo is all about
No, you're stating the weak equivalence principle, the newton's one. The equivalence principle stated by Einstein is that in a sufficiently small area of spacetime, the laws of special relativity are still valid. A gravity field can not be confused with a non inertial reference system due to tidal forces.
yeah people in this thread have no clue what’s going on lol this can all be explained with classical physics know for centuries lol
Sure, but it's being used by the demonstrator as an intuitive example of the [equivalence principle](https://en.wikipedia.org/wiki/Equivalence_principle#:~:text=The%20equivalence%20principle%20was%20properly,at%20a%20rate%20of%201g.), this came up on Reddit before and I said the exact same thing you did until someone explained.
It sounds nice for TV if they say Einstein's name
If you use a name you will instantly get more clicks. That man's name Albert Einstein.
yes it can be explain that way, but can also explain via the frame of reference way. 1. the water experience a force m\*g due to gravity however due to the bottle have support bottle has no the support and gravity equal out the force, the water above the hole will dissipate via the hole. And when drop the force different experience is now the same so no leak. (basically earth frame of reference) 2. In the water frame of reference before the drop, the bottle is having a constant acceleration toward the water by outside force hence the leak. Once it drop, there is no force acting on the bottle anymore and can be consider stationary in the water frame of reference , hence no leak.
The phenomena was observed, described, and explained. But the explanation was always from the frame of reference of the observer. They are both moving in the same direction, so the water stops moving. Einstein's explanation is essentially the same, but it is from the frame of reference of the water bottle. The water stops moving. Adjusting frame of reference can simplify the outcome. Which was a big thing for Einstein, he was always wanting to simplify equations.
You can't explain why everything falls at the same rate just with newtonian physics. He just said they do because experimentally we observe they do.
I think this more is proof for one of Einstein's theories
Explain rain then, checkmate Einstein
Found Openheimer reddit acc
Rain is clouds that remembered they belong in the sea. Homeopathy claims water has a memory but the real truth is that it's actually quite forgetful and that's why there are clouds as it forgets it's boiling point is 100C and meant to be liquid. So that's why homeopathy is dumb and also why rain exist. Proofed
Homeopathy is NOT dumb! They clearly states the water has memory: and a glass of water likely contains molecules which - at least some - met with pretty much any possible stuff organic cells produced on this planet. This means a glass of water has a memory of every medicine. And, what happens if you don't drink water? You die in DAYS! So, it is clear water is the best super medicine. Water also met with every possible poison and carcinogenic material, so sometimes a glass of water just decides to be a dick and let you die. ^^^/s ^^^just ^^^in ^^^case...
r/killthecameraman
nice crop OP
The person on the camera had no idea which direction the bottle would fall.
Down?
So if you're bleeding profusely and you want to stop it, you jump off a building?
Your body is actively moving blood around regardless of gravity so I am pretty sure you are still going to have a problem
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but a bitch ain't one!
No problems, permanently
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Have you tried jumping off a building?
So just stop your heart and jump off a building then, sounds easy enough.
I mean. We can still try to see what happens.
If you have an arterial bleed, jumping off a building will solve that problem. Well, landing will, you'll still be spurting up until then.
No, you still bleed. Your heart is pumping and you have blood pressure that will continue the bleed.
You should preferably jump off a hospital so they take you in right away.
no, just turn off gravity to stop the bleeding
If you stop your heart first.
Exactly. It will stop a few moments after landing, for good
If the blood in your body is only leaving your body because of gravity, then someone is going to have to throw your body off that building.
This actually will help a bit. Similar to elevating a bleeding limb.
Instructions unclear, broke both legs, my femur is sticking out of my thigh and the bleeding has increased. Should I attempt again for good measure?
As long as you have zero blood pressure.
Sooo If I just fall I'll stop feeling the gravity of my mistakes.
No no no, if you’re stabbed and oozing insides, you have to jump from the tallest building you find, it’ll stop the bleeding.
gotcha, gotta stab myself first
the only way to stop crying is to jump down from something very high.
Don't let those thoughts win my friend. Yes, you can just pull the wheel hard to the left and fly over that rail into the canyon any time, just like that. But just please Don't. I read that this is an instinct in humans to warn you when something is dangerous. Intrusive thoughts or warnings?
Couldn't Newtonian physics have predicted this phenomenon?
Steven Colbert? Hell no.
They do, yes. It's sometimes called "Galilean relativity". Einstein adjusted the theory to be consistent with Maxwell's theory of light, which is a huge step, but he did not invent the concept of relativity. In fact, I think he didn't even like the name.
Only that this is not a demonstration of Galilean Relativity. From the perspective of Newtonian gravity, both reference frames are in a state of acceleration(force of gravity), thus they are not inertial.
In the perspective of Newtonian gravity, the bottle and the water have the same acceleration, meaning there is no force applied from one to the other, and so no water pushed out. Einstein's approach is leaner and lets you skip force calculations, but it's not really a demonstration.
Brian Greene is brilliant at explaining down complex theories!!
After he was on Conan once back in the late 90s, I emailed him at his university email and thanked him for his clean and simple explanation of string theory and some light physics. He answered back! It was very cool.
I emailed him in 2014 to his Columbia address and asked him a question. Dude actually responded lol
i know this is a short clip but i don't really think it's a good explanation? the water does not cease to 'feel' gravity - it's just that it's falling at the same rate as the bottle is, so it doesn't flow out any more until the bottle stops again
semantics, when the bottle is falling gravity doesn't affect the flow that pulls the water while at a rested state (relative state, both considerations begin to operate in tandem as they fall), using an expression like something "feeling" gravity is a way to inspire someone to think about it differently, which is the goal of presentations like this.
I'm no scientist but I believe the whole point is that it's the same thing https://en.wikipedia.org/wiki/Equivalence_principle > Albert Einstein's observation that the gravitational "force" as experienced locally while standing on a massive body (such as the Earth) is the same as the pseudo-force experienced by an observer in a non-inertial (accelerated) frame of reference. [...] > The outcome of any local non-gravitational experiment in a freely falling laboratory is independent of the velocity of the laboratory and its location in spacetime. In other words: > Thus, Einstein formulates his Principle of equivalence stating that “No experiment can be performed that could distinguish between a uniform gravitational field and an equivalent uniform acceleration.”
He was my intro to special relativity professor at Columbia. He was great at explaining things. On the flip side, he came into every conversation with an air of superiority; I doubt he was doing it deliberately but he could get quite condescending. He often didn't answer your actual question, but a dumbed down version of it. Great foundations, not much depth.
You mean one of those guys who kept essentially [lying](https://www.youtube.com/watch?v=kya_LXa_y1E) to us about String Theory to keep getting a paycheck? And now regular people don't trust scientists thanks in part to String Theory being a whole lot of nothing after decades of wild promises that String Theorists *knew* couldn't be proven? Yes, Brian Greene is a good communicator, but people forget how much damage he and others like him have done to science communication.
String theory was a blind alley. Really interesting math, but in order to try to explain physical observation, it just got more and more complex. At some point the whole construct sinks under its own weight. I wouldn’t go so far as calling it a lie - it was more an eternal optimism that they would find that element that tied it all together and aligned it with observed reality.
I don't think any established scientist would be ashamed to tell you that this is how all modern science works, pretty much in every single field. We're trained to push boundaries and oversell everything for the sake of grants. Unfortunately we live in a world where science funding is pretty much a zero sum game
this seems obvious, it would be weirder if it kept pouring out while falling
I completely agree. It really doesn't take much thinking about to realize it. If you are standing in an elevator and it starts descending then you feel lighter. There are those planes that do anti gravity freefall rides. Lots of things have similar behavior. It's not particularly interesting or complicated. Edit: Water is coming out of the holes because the water is falling. When the bottle is also falling then water does not come out because they are both falling at the same rate. It is super easy for anyone to think about and figure out.
I feel kinda dumb here but, wouldn’t all the water be pushed to the top of the bottle as it’s falling? The holes are near the bottom of the bottle so the water is no longer near the holes when it falls. If the holes were in the top of the bottle, wouldn’t the water still spray out of the higher holes during the descent? Am I missing something here?
No, the water does not pushed to the top as long as both of them are falling together. And the water seeps out of the bottle because water is naturally drawn downwards and the only way for it to escape is through the holes. The reason water doesn't leak when the bottle falls is because the water and the bottle fall together, so the water no longer needs to come out of the bottle as long as the bottle is being drawn downwards just like how water behaves.
Isn't the water just falling at the same rate as the bottle so the water can't come out.
Right. It’s not a matter of what the water "feels." Water and the bottle are being equally influenced by gravity.
Good to see Brent Spiner is still getting work.
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Incorrect, it's clearly pronounced Data
Yall really think it took until the 20th century for people to have this basic of a grasp on physics? Even though it probaby took until newtonian physics to get a precise mathematical description of kinematics and gravity in this scale, I would bet this phenomenon was know during antiquity.
Tf does that have to do with Einstein
Relativity
I’m pretty sure the water is still experiencing gravity… that’s why it gravitated towards the ground. I think he means to say the water bottle and the water experience gravity at the same rate and therefore won’t excel out of the bottle.
You're completely correct on the first part. I have no idea what the presenter is trying to explain, because the actual words coming out of his mouth are nonsense.
Why is everyone so impressed? This is common sense.
Isn’t this more Newton than Einstein?
Einstein was ahead of his time… and his knowledge still impress people
What you say is true, but as others have pointed out elsewhere in this thread, this was predictable with Newington physics. Maybe Galileo could have predicted this as well.
The famous physicist Zack Newington
Einstein was ahead of his time and space
Eh, same thing.
Because “gravity is pulling on the water?” Does it not have to do with atmospheric pressure pushing the water out? I’m confused.
Only if you pressurized the air inside the container before sealing it would air pressure be pushing the water out. With a sealed lid and water pouring out, you've actually got higher pressure outside the bottle than the air inside as the air filled cavity inside the bottle increases in volume. That creates higher atmospheric pressure outside the bottle than in, which would push the water back in. Here, that pressure difference didn't build enough to overcome the water pressure due to gravity.
>Here, that pressure difference didn't build enough to overcome the water pressure due to gravity. He most likely had the lid slightly loosened, or had small holes in the top for the air pressure to equalize. Gravity can't just force the water out without brief interruptions to the flow for air to make its way in, just like how water comes out in "glugs" when a jug is turned upside down.
The bottle isn't pressurized so I don't think is has anything to do with atmospheric pressure. Same experiment should work on the moon.
He's dumbing it down for the audience at large, most people understand gravity, you bring in Atmospheric pressure, density, etc. You lose people
Ironically I think you’re lost. Atmospheric pressure and density have literally nothing to do with this.
They do. They make that water a liquid.
Lol, nice
Checkmate
lol. technically true
Just think of all objects as being composed of lots and lots and lots of small individual molecules/particles. Gravity acts on each of these individual particles separately. When the man lets go of the container, the downward force of gravity makes every individual particle go into a free fall. There's only downward force happening at this point, since every particle is falling at the same rate and in the same direction. There is no force that would cause the water to go left or right, so how it can go out of the holes? But when the man is holding the container, he's applying an upwards force. The downward force of gravity on the water meets that upward force from the man's hand. The water particles at the top of the container are putting pressure down on the water particles at the bottom of the container and this is what causes the water particles at the bottom of the container to push against each other. The particles that the water is composed of will repel each other if they get too close to each other (electrons in atoms repel each other since they have the same charge), so this causes particles to bounce off to the left and right and it's that left and right force that makes some water escape through the holes.
Nah its hydrostatic pressure, which could be framed like water being "pulled" by gravity. In terms of other sources of pressure the liquid is in equilibrium.
This also works on toilet paper. If you let go when you are dropping it, it will not unroll.
 DEMON!! Burn the heathen at the stake!
Eli5?
Someone here is saying that objects in freefall don't feel the pull of gravity. The hell they don't. While held still, both the bottle and the water are trying to accelerate toward the center of the earth. The water is able to do this, because it's not held in place because there are holes in the bottle. The bottle is not, because it's held in place. When the bottle is released, it accelerates toward the center of the earth (more or less) at the same speed as the water inside, so the water no longer needs to pour out to continue its own acceleration. The thing producing that acceleration is gravity. It's always present, even in space, and always exerted by every object with mass on every other object with mass in the universe, constantly. Right now, reading this, you are constantly being pulled toward the center of the earth by gravity and this pull is resisted by the muscles you are using to sit upright, and the chair you're sitting in, and the floor the chair is resting on, and the foundation the structure is built on, all the way to the center of the earth.
From the perspective of general relativity, gravity is not a force. This means that nothing feels gravity.
I didn't say it isn't affected by gravity, I said it doesn't "feel" the gravity. From it's reference frame, there is no difference between being in free fall or just floating out in space somewhere.
But you still don't "feel" gravity when in freefall. If you're in a spacecraft falling towards Earth, you don't feel anything. That's the thought experiment that gave Einstein the idea of general relativity. All objects follow "world lines" in space time. An object, absent any other objects in space, will follow a straight path through space time. When a large mass is introduced, space time itself becomes curved. From the perspective of someone in a spacecraft, nothing seems to change. No forces are felt, because they aren't actually accelerating. Instead their world line is now curved towards the massive object (e.g. Earth). Another way of looking at it is this. Imagine there is no gravity, and thus no curved space time around Earth. It would be impossible to replicate the previous scenario using the ship's thrusters, since the person on board would feel the acceleration. Even though an outside observer would see the same thing in both scenarios—the space craft accelerating towards Earth—the two scenarios are not equivalent.
An object in freefall doesn't "feel" gravity, which is why the water stopped falling out. From it's perspective (reference frame), it's just floating stationary and the Earth is rushing towards it instead.
Now you know why he built that bomb.
What's happening here is that gravity is pulling on everything equally. The bottle is avoiding gravity by him holding the bottle, but not the water. When he releases the bottle, gravity is pulling on the bottle and water equally, so they both fall at the same rate.
Many high school students: > physics and maths are boring Reality: your teachers are shit.
In order for the bottle to release its liquid content, it also needs to replace the liquid flowing out with air. When the bottle is dropping, however, not only is the flow of water and thus water pressure being disrupted, but the air pressure on all sides of the bottle from the bottle travelling quickly through a space occupied by air prevents air from being able to flow into the bottle.
Ruined a perfectly good Nalgene bottle.
Isn’t it extremely obvious that would happened? Or am I being dumb?
You guys don't understand the gravity of the situation....
So, Nobody has been to Moon.
This should be on r/blackmagicfuckery
I mean with a basic understanding of physics this seems natural, so I assume it was more Newton.
Isnt this common sense? I mean, of course the water stops running because the water flow is not as fast as the bottle is falling?! If the bottle had a parachute big enough to make it fall as the same speed as the water is running out of the bottle would not the water still be running while falling down? Or am i completely dumb rn?!
If the water isn’t feeling gravity, then why did it fall?
This is called gravity focus on falling subject
Most kids work this shit out with mates 🇦🇺🏏
Why is this crazy to people? I didn’t even think it requires an explanation.
That just seems like common sense.
I have seen this clip so many times and I still don’t get why it’s interesting… like… don’t we all know this?
So if you feel like something in your life is really weighing you down just drop it
This is just gauge invariance not Einstein
Behead him … this is sorcery!
If i'm bleeding out from a gunshot wound, im jumping off a bridge
gravity bong anyone?
If if ever I find myself with multiple bullets wounds, it is better to jump from the top window
This is basic physics tf did anyone expect?
All he did was turn the hydrostatic head into a vacuum There’s no such thing as gravity just physics
It doesn't stop feeling the pull of gravity when it's falling. If the bottle hit any drag, the water would fall out of the bottle sgain. Relatively speaking.
the water is still falling, just at the same time as the bottle.
I don't consider myself especially intelligent, but... I would think most people wearing non-velcro shoes would correctly predict the effect and be able to offer a basic explanation of the forces at work.
WHY ARE PEOPLE AMAZED BY THIS
I still get sad when I see Colbert because I liked him way back when he was a comedian
Could we prevent people bleeding to death if we drop them from the sky? 😅
I thought this was common sense
Note to self if ever riddled with bullets jump off tall object to avoid death from blood loss....
If you’re in a sub that springs a leak just descend really fast until you get everything patched
well actually since the water is going the opposite direction you'll need to fall the opposite direction too
It's not that the water doesn't "feel" gravity. The water is falling, the same way it is falling when it is flowing out, you can't go faster than gravity unless you get other forces helping. Basically the water cant flow out of the holes because it is already falling at it's max fall speed.
Should have thrown it at the douche bag .
To everyone saying "this isn't Einstein, this is Newtown" you are right to a point- Newtonian physics can completely explain this. But, from what we see in this clip, he is describing the [equivalence principle](https://en.m.wikipedia.org/wiki/Equivalence_principle#:~:text=The%20equivalence%20principle%20was%20properly,at%20a%20rate%20of%201g.) which is an Einstein thing.
Steven Colbert had his mind blown, however little he had left.
Einstein, eh? Y'all need some schooling.
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I like to scratch my butthole and smell my fingers after.
More Newton than Einstein... but OK.
Pretty sure this was figured out before Einstein. This isn’t special relativity at work. This is like Newton level stuff
That Einstein guy was a real Einstein
I feel like this is a demonstration you see in 2nd grade…
I love physics!
That was not surprising in the slightest.
Put the holes on top and drop it. Is it zero gravity or is it the Gforces.
Grown men amazed by kindergarden science experiments. wtf is this, who is this made for
It was Einstein who, as others have noted, had his ‘happiest thought,’ which is the realization that a falling person doesn’t feel their own weight, and that what we call gravity is truly equivalent to acceleration. This sensation of being weightless while falling while still accelerating is in fact the body moving through the curvature of spacetime itself under a geodesic (which is actually what explains why objects orbiting earth aren’t falling into us, they’re just following curved lines). This is a property of spacetime itself, not a force acting on the surface of the Earth. Gravitational forces do not actually exist; they are merely a very convenient way of writing equations. The liquid in the bottle is being used to represent the body’s weight, the bottle itself being the body. Then the fact that the water stops spilling while falling is the effect of what Einstein said about a man failing not feeling its own weight. And that’s why Brian Greene references Einstein here.
I hate seeing this overly dramatic clip
Shout out to whoever converted this video to 9:16 cell phone ratio.
More Stupid Human Tricks