also would like to complement alan alda for doing his physics homework and einstein homework well enough to have a discussion with brian that bridges the gap between lay and expert.

A particle walked into a bar.... and it didn't

9:58 Brian: "... Jump out a window, and then gravity goes away." Alan Alda: "What? You jump out the window, gravity makes a quick entrance." hardest I've laughed all day.

It's always worth bearing in mind that usually, whenever we think that Einstein was wrong about something, it turns out he was right all along.

The world Needs more professors like Brian Green 😌👏👏👏👌👌👌

I love science, it is art, it is imagination, it is specific, intellectual, considered, controversial, creative, psycholically impacted by the researchers and possibly the assessors. It opens up many possibilities and chaos. What a stimulating endless field.

can we just acknowledge those 2 catches :)

love to see an actor not only good at acting, but has enough knowledge to talk about Einstein with a physicist

This is how science should be, the impossible comment followed by clear as a bell demonstration - terrific

Darn he explained things better than professor michio kaku....damn this explanation was worthwhile..15 minutes well spent

Einstein took the simple observation that light had a fixed speed ...and like pulling a thread on a sweater, unraveled all of these other equations and revelations. But Einstein viewed things as concrete and could never accept the uncertainty of quantum mechanics.

What a wonderful chat.

spooky = spukhaft Einstein called it "spukhafte Fernwirkung" = spooky remote/distance-effect"

i could never imagine an old man this cool,..

Every now and then i return to this beautiful conversation

11:28 is no one gonna appreciate Brian's catching damn

I like the reaction "What?!!? you jump out of window, gravity makes a quick entrance!".

Brian is so great at explaining concepts, it's great to listen to him

great video. I feel like I'm discovering Mr. Alda for the first time even though I've known who he is for about 40 years. what a cool guy to listen to

Two more intelligent and gracious people I have never seen having a public discussion.

A photon checks into a hotel when the bellhop asks, "Would you like help with your luggage?" The photon replies, "I don't have any. I always travel light."

Brian Greene, he is the best at explaining (Classic physic,Quantum theory,String theory,.....)Science in general.I think one day he will surprise us with something new, we all need to understand. ( Greene joined the physics faculty of Cornell University in 1990, and was appointed to a full professorship in 1995. The following year, he joined the staff of Columbia University as a full professor. At Columbia, Greene is co-director of the university's Institute for Strings, Cosmology, and Astroparticle Physics (ISCAP), and is leading a research program applying superstring theory to cosmological questions. He is also one of the FQXi large grant awardees, his project title being "Arrow of Time in the Quantum Universe". His co-investigators are David Albert and Maulik Parikh.)....

Enjoy listening to that great conversation. Love physics. Brian Greene and Alan Alda are both great communicators for science. Have been following Brian Greene from the 90s greatly enjoying his book The Elegant Universe as well as his other books, appearances on science panels which I watch often on KZfaq, CSPAN, PBS specials and whatever else. He is very good at conveying physics and making it clear and understandable. Love listening to him.

My new favorite explanation of General Relativity. Thanks, Dr. Greene.

Seriously? We have 41 people NOT LINKING this video? What has happened to this world?

Great simplified explanation and discussion :)

I hope to attend one of Brian greens world science festivals one day .Alan alda was or is a very underrated actor. I actually was working on a script at one time with him in mind in the leading role.

I like Brian Greene because he explains things in a simple manner. My favorite book of his is The Fabric of The Cosmos.

Here are two people I never thought I would see together. So heartwarming

BRIAN GREENE IS ONE OF THE BEST. NOT TOO MANY UNDERSTAND QUANTUM MECHANIC LIKE HIM. THANK YOU

Loved the analogy of the elvator speeding up in free space. But 8f thats the case , why does earth stops "rushing" towards you when you are above it in space ? By this theory , even if your are in outer space above the earth , the earth shoukd rush towards you ? Right ? Anyone ?

I love Alan Alda's science shows. He's funny and asks the questions people like myself, who are interested but don't know much, want to get answers for!

Einstein said "If you can't explain it simply, you don't understand it well enough", Only a few can explain Quantum physics as Brian did.

"Imagination is more important than knowledge" because imagination GETS YOU TO KNOWLEDGE.

The water does not leak for the container when it is dropped cause the water and container are dropping at the same constant rate

13:05 Einstein reduced gravity to motion. Now we just have to reduce electromagnetism to motion and we have a theory of everything. Walter Russell has done this already and it is worth investigating.

For those who ask: the video starts at 0:00 and ends at 15:14

The title should be, "Einstein's Happiest Thought: If a person falls freely, he cannot feel his own weight!" Turn to 9:00 for this thought, a demonstration of it using water, and some comments on the role it plays in Einstein's general theory of relativity. Turn to Kip S. Thorne's book Black Holes and Time Warps: Einstein's Outrageous Legacy chapter 2, for a good telling of the way this happiest thought came to Einstein in 1907 and how it bloomed into a theory of curved space-time eight years later.

I wish they would put the date on these videos.

I've had so-called quantum physicists explain different facets of that science and contradict themselves within three sentences. They were quite secure in their explanations. Do not, under any circumstance allow a quantum mechanic to repair your car.

Thank you Brian, Thank you Allen, that was beautiful, peace and love, Doug.

I feel privileged to be here listening to Brian Greene and laughing at his sarcasm like anyone else present there with him in the room... I feel privileged that I am among those curious people who understands such complex things

Frankly, I think Einstein was right. Once we have a grand unified theory, I think the seemingly randomness of quantum mechanics will be shown its not pure chance & probability & Einstein will be proven right. String theory or/and M theory might be the answer. Higher dimensions might explain entanglement.

Greene explains Einsteins equivalence of gravity field and accelerated frame of reference but should have taken it to next level explaining the affect of light traveling in that gravity field and how it provided the insight that gravity is the consequence of the variations of the geometry of space-time (where mass-energy tells us the geometry).

I loved this conversation and the older gentleman was just a delight haha

A particle walks into a bar ... through two different doors ... waving.

where is this complete talk?

amazing host and guest

11:35 I love how puzzled Alda looks at the wet floor, for a solid five seconds 😂

change places with heat and motion. Interesting relationships starts to be revealed.

Einstein, my number 1 teach who taught me about everything that exist through general relativity.

Could it be possible if unlike single particle acting as a wave can't be given a prediction but if multiple particles are taken together as one they could definitely be predicted with certainty. Or as the number of interacting particles increase the certainty increase?

You don't see round earth deniers or conspiracy theorist about the earth or universe on these type videos, it's too much information for them to comprehend.

Alan Alda is brilliant. Great comic timing, and he obviously knows his stuff about physics. Great way to make it interesting and comprehensible.

Love Brian Green and Alan Alda is such an intelligent interviewer. Nice video

That's a terrible description. It's not that gravity no longer exists. It's just that the bottle and the water are both experiencing gravity's force, so they would both fall at the same rate if it weren't for air resistance.

I love this stuff so much.... when I was younger I didn't have much interest but now I find this very intriguing

Relativity describes the relationship between the force and the observer . . . a great deal of this discussion is pretty confounded. Gravity is simply an expression of momentum, albeit on a planetary (or cosmic) scale, and indeed the two forces (gravity and momentum) behave in an almost identical manner. Greene seems to rush through the most pivotal portion of Einsteins discovery. When Einstein envisioned a man trapped inside of an elevator, one that was caught in free-fall down its shaft, the man inside that elevator observes an actual weightlessness as real as any scale could possibly register him in that moment (without the force of gravity acting upon his body at all.) That was actually the apex of his theory, not the man simply jumping out the window. We, observing outside of the falling elevator, know that the force of gravity is working equally upon the man as it is on the environment around him, making the negation of the force of gravity relative to his personal observation. It is the same for an object caught in orbit around a cosmic body: The "weightlessness" an object experiences in space is actually micro-gravity, not "anti-gravity". That micro-gravity is a point of free-fall that holds its own momentum equally in tandem with that of the Earth, skirting just around the very edge of the dent the Earth's mass affects onto space/time. That relativity is the same with the water bottle: Gravity did not go away inside the bottle when it was dropped, but the force of gravity was working equally on the water molecules inside it as it was on the bottle itself. Only the observation was that of "anti-gravity". It does not matter if the observable point - and in that case the water - contains no conscious sensory organs to observe the negated effects (such as proprioception or visual orientation;) There is still a physical point which can be observed. What seems to be missed in this discussion is the objective mass of an observer (or point of observation,) and the most vital ramification of a scale registering an equal amount of applied gravitational force when the elevator is lifted, adding momentum to the already existing force generated by the Earth itself. Quantum Mechanics never negated the empirical reality of General Relativity, and I cannot understand why Einstein couldn't see that - as Greene suggests here. I've only studied Einstein's work, not his personal life. What he actually nailed exactly was the reality of the physical universe, of gross matter, which we also know he described as being composed of energetic constituents (of course though E=MC^2.) It is those energetic constituents that defy observation, which is why pure energy particles must be considered in terms of a wave and their location deduced with uncertainty. But quantum phenomenon, such as entanglement, may very well adhere to a certain type of relativity that simply defies our current understanding of existence, being unobservable (except perhaps in their effects.) And I would bet every dime that I have, or ever will have, against there being found a "graviton" or any quantum particle to equate the force of gravity.

Maybe someone can answer a question about the video experiment. Situation 1: Brain holds the bottle. Water is accelerated out at 9.81m / s. Situation 2: Brain drops the bottle. And water comes to a standstill. Water come to 0m / s Situation 3: Brain throws the bottle in the air? Now my question: Then water should come out faster for a short period of time? 9.81M + speed up?

Normal calculation: 2+2=4 Quantum computers: Perhaps...

alda reminds me of a cross between ralph nader and carl sagen.. 'thats a compliment of major proportions'..

gravity and motion have the same effect on angular momentum play with that and you will win

I wished this guy was my professor in college ❤️

0:24 sounded like Wii tennis when you get too close to the fence

Generally, I like Brian Greene, he knows his stuff but his commentary is a bit confused. Einstein's problem was indeed with non-locality, (*not* with determinism, or entanglement), entanglement just implies some correlation, not causation, and Einstein rejected non-local hidden variable theories, like David Bohm's. His position was that determinism and hidden variables would follow as a consequence of the principle or locality. Of course, we now know Einstein was wrong, not because of any experimental confirmation of entanglement (much less spooky-action-at-a-distance) but because of Bell's inequality theorem. I think it would be more accurate to say Einstein hated the Copenhagen interpretation, rather than quantum mechanics, as-a-whole. Unfortunately, those two are used interchangeably.

These guys are good. I already knew all that science, but I did not know it could be presented that well.

The demonstration was excellent.

Alan Alda has one of the beutiful voices in cinematic history i know of. He is truly inn the likes of Swaggersoul

The man in free fall is 100 percent experiencing gravity. It's the force rocketing him toward the ground . Just because the scale is also rocketing toward the ground, and he is no longer experiencing gravity RELATIVE to the scale, does not mean he's not experiencing gravity at all. Think Brian could have done a much better job of explaining how this served as a gateway into general relativity for Einstein. Hell, I'm not sure he ever even used the word relativity after initially bringing it up.

I'm looking for Alan Alda stuff because I love him as an actor, not a scientist. You guys are way too smart for me, I feel belittled xD

General Relativity: G(F/m)(H/m) = 7.426157905 x 10^-28 m/Kg. Special Relativity: (F/m)(H/m)c^2 = 1.

Who else misses Scientific American Frontiers with Alan Alda? Such a fantastic show.

I love listening to Brian Greene, he explains things in such a clear way, even a layman (like me) can understand quantum physics at a high level.

That look 14:00 😂😂😂

Nice, this video finally made me understand how gravity really isn't a force of attraction but, as Einstein proposed it, a warping of space time which creates an accelerating field.

6:46 -- "spukhafte Fernwirkung" . . . in which "spukhafte" may mean something more like "ghostly" (in the sense of not material . . .)

Gravity is clearly an emergent force as per #Verlinde . It's becoming more and more clear that what Einstein said, that Quantum Mechanics is "incomplete," is undoubtedly correct. .

Alan Alda!

I have a question, I think quantum entanglement is a phenomenon in which if two Entangled electrons are separated then the any action caused on one should reflect on other that's what experiments conclude so my question is can it be an effect of probability means if we measure the property of an electron at one end so we are only measuring the probability of that property and every electron in existing universe has the same property if Ur getting my point then uh might have a question then each and every electron should show similar Entangled behaviour but wait it's the matter of what uh want to see I means we saw two electrons Entangled because we are searching for same properties. Apologies if I'm wrong but please correct me

Science and religion work similarly - both try to give an idea that explains everything (before creation + creation + the end). Science uses logic & equations, while religion uses faith & philosophy to come to their respective theories/conclusions. Unfortunately, the universe is so vast and random that none can completely understand/explain even a tiny percentage of it.

Brilliant watch

I don't think Einstein was wrong about the quantum mechanics. I think what Einstein was trying to figure out was a theory that is able to describe the motion of subatomic particles when they were not interfered by human observation. Once observed, the particles are already interfered by human being's observation. Quantum mechanics best describes the subatomic world only because it can explain the result of experiments, which are all human intervention. In my humble opinion, quantum mechanics works but still a superficial theory. A deep, fundamental theory should be just one theory that explains all.

We will probably have to wait hundreds of years before knowing if Einstein's belief was correct or not. Interesting to realize that he will never know, and that people who probably haven't been born yet (and who have yet to hear about Einstein at all) will know

Dear Brian, with due respect -Gravity goes away - when Water stopped spewing from holes..NO.. gravity was still very much there without any change..When bottle was still...gravity pulled water..when bottle was dropped gravity pulled the bottle and water both at same force (resulting same speed)..as a result water followed the bottle ..still going down . If gravity would have gone away than water should have been coming out top of the bottle.. Gravity was always doing it's job ..very honestly !! I always admire you dear Brian -you being a excellent Guru for me and will always be.

Brian talks like he's about to sneeze.

Brian Greene is awesome!

Very good explanations about gravity.

The guest of owner is from the TV series called the blacklist

I truly agree with Brian green, you have to find deep pattern in the nature to understand how universe works in broader spectrum, & exactly that is what I did.

Alda's voice doe

Gravity doesn't go away, it simply pulls both water and the bottle. Before, only water was being pulled.

Long story short; gravity doesn't mean diddly squat until more than one object is in play. In other words, you don't die falling out a window, you die hitting the ground.

That water bottle tipping over at the beginning bothered me for the rest of the video

Starting to wonder what if the uncertainty in quantum physics is somehow tied to our consciousness. What if our thought/choice itself is the hidden variable upon which all these mysterious phenomenon are taking place?

13:20 what is that sound??

Dear Publisher, Please make following corrections: at 14:30, acceleration does not bring "Gravity" into "existence", Gravity was still there, acceleration makes it perceptible, i.e. it brings "Gravitation" into our perception.

Imagine if Einstein embraced Quantum Mechanics i wonder if he would have been able to unify the forces then.

In quantum mechanics the physical system is described through a wave function whose evolution over time is determined by the Schrodinger equation. The wave function represents infinite different possible results for the physical quantities related to the system, but when we take a measurement, only one of these infinite possibilities becomes real; after the measurement, we must therefore modify the wave function “by hand” to eliminate all other possible results, and this modification is called the “collapse” of the wave function. The fundamental problem with quantum mechanics is that interactions among particles are already included in the Schrodinger equation and such equation does not predict any collapse. The collapse of the wave function is a violation of the Schrodinger equation, i.e. a violation of the most fundamental laws of physics and therefore the cause of the collapse cannot be determined by the same laws of physics, in particular, it cannot be determined by the interactions already included in the Schrodinger equation. The Schrodinger equation is what allows us to make quantitative predictions about the outcomes of future measurements; everytime we make a measurement, we receive new information about the system, and we need to "update" our wave function, i.e. to collapse it, otherwise the Schrodinger equation would provides wrong predictions relative to successive measurements. After one century of debates, the problem of measurement in quantum mechanics is still open and still represents the crucial problem for all interpretations of quantum mechanics. In fact, on the one hand it represents a violation of the Schrodinger equation, that is, a violation of the fundamental laws of physics. On the other hand, it is necessary for the laws of quantum physics to make sense, and to be applied in the interpretation and prediction of the phenomena we observe. This is the inescapable contradiction against which, all attempts to reconcile quantum physics with realism, break. Quantum mechanics is incompatible with realism (that's why Einstein never accepted quantum mechanics); all alleged attempts to reconcile quantum mechanics with realism are flawed. Quantum mechanics implies that physical reality (the universe) consists of the collection of all observed phenomena and such phenomena do not exist independently of consciousness. In fact, the properties of a physical system are determined only after the collapse of the wave function; when the properties of the system are not yet determined, the system is not real, but only an idea, a hypothesis. Only when collapse occurs do properties become real because they take on a definite value. It makes no sense to assume that the system exists but its properties are indeterminate, because properties are an intrinsic aspect of the system itself. The collapse represents the transition from a hypothetical system to an actual system. The collapse of the wave function represents a non-physical event, since it violates the fundamental laws of physics, and can be associated with the only non-physical event we know of, consciousness. Therefore, the only consistent rational explanation of the collapse is that it occurs because consciousness is involved in the process. However, the fact that properties are created when a conscious mind observes the system in no way implies that it is the observer or his mind that creates those properties and causes the collapse; I regard this hypothesis as totally unreasonable (by the way, the universe is supposed to have existed even before the existence of humans). The point is that there must be a correlation between the collapse of the wave function (=violation of the physical laws) and the interaction with a non-physical agent (the human mind); however, correlation does not mean causation because the concomitance of two events does not imply a causal link. The consciousness that causes the collapse of the wave function must be an eternal consciousness, that is, a conscious God. This is the idealistic perspective, which implies that physical reality exists as a concept in the mind of God who directly creates the phenomena we observe, according to the matematical models through which He conceived the universe (the laws of physics); the collapse of the wave function is a representation of the moment when God creates the observed phenomenon. This is essentially the view of the Irish philosopher George Berkeley, and in this view God is not only the Creator, but also the Sustainer of the universe. Idealism provides the only logically consistent interpretation of quantum mechanics, but most physicists do not accept idealism because it contradicts their personal beliefs, so they prefer an objectively wrong interpretation that gives them the illusion that quantum mechanics is compatible with realism.

Great interview

everything is flowing electro magnetic pressure, sometimes through unperceivable scales