Ask any question you want about Physics

a reply to: ImaFungi

No force is neccesary for gravity to work there is your problem you see gravity as a force pulling something towards it. Gravity is not a force!!!!!!

Gravity is the path of an object being changed relatuve to our observations. For example the international space station is in a perpetual fall. It is traveling a straight line however we see it as an orbit.The path of the orbiting space station around the earth is the projection of a geodesic of the curved 4-D spacetime geometry around our planet onto 3-D space. It all has to do with stress energy tensors we can use this to determine the path of an object. If a force were involved the calculations wouldn't work and would need to be adjusted. Then comes the problem of where this extra energy would come from.

originally posted by: Arbitrageur
but it still doesn't explain why mass bends space-time.

Ok, but I am not even asking that here, I know why mass bends space time;

I am asking, how, physically, causally, intimately interactionally, how 'bent space time' physically forces a brick to not remain besides your hand upon letting go of it from atop a tower.

(Or can dropping things from heights on earth be chalked up to the movement of Earth, more than the force of gravity? That is when you let go of the brick it is as if it is 'existing in a vacuum' an object not put in motion remaining not put in motion, but the earth moves toward it? Also, perhaps it could be the collection of air, moving through space as a body of earth, which when the brick is let go and suspended 'in near vacuum', the earth is moving, and the brick is no longer heartily attached the earths body, that is to say the air is not a sturdy tower that can hold the brick, so in some reference frame the air can be seen as an incline not a perfect wall in relation to the path traveled by earth and the incline of air is always slopped towards the ground, and this incline is always moving forward, and so the brick is shoveled to the ground.)

A great thread. A lengthy one also, I haven't read it all so if this topic is discussed, apologies.

I would like to get opinion of physicists on something that has for millennia been restricted to the realm of philosophy, but is slowly starting to be far more relevant to science (which is a very good thing IMO). That is the problem of human free will, or more aptly, do humans have free will? I realise it might be better in a philosophy forum, though I already know how that will usually go and find opinion of scientists can often be far more straightforward and relevant. In the end our cognitive faculties, underneath it all, have their basis in physics anyway.

The philosophical discussion often underlies just how unscientific philosophy can be (IMO) and ends up a war of semantics where definitions can change so readily between different people it makes me wonder how useful it is in this regard (and I'm usually an admirer of philosophy). The better arguments (Dennett for instance) seem to start out realising the normal notion of free will that most people hold doesn't exist, so they simply redefine the term and explain why something that isn't free will should be accepted in it's place to make us all feel better lol. Some of the ideas put forward by philosophy professors seem so lacking in the most basic logic to begin with they make me wonder more about the motives of those putting them forward, rather than the subject itself.

As far as more scientific opinions go, Krauss finds the idea of free will unlikely to be compatible with our current understanding of nature, yet stresses that a world where we either have/ don't have free will would be difficult to distinguish and either way we are stuck with "what is" so doesn't find it greatly important. While Dawkins simply refers such questions to philosophy.

The late Hitchens (not a scientist as much as promoter of science based secular views) gave a rather clever answer when asked does he think we have free will..."what choice do I have?" (or words to that effect).

Kaku gives his reasons why he thinks we have free will that seem so remarkably facile that he doesn't appear to have understood the question. The ideas put forward in support of free will from science pov usually hinge on indeterminacy with so much quantum explanation that it appears to veer towards Deepak Chopra type pseudo science (from a non physicist pov). The only (somewhat) scientific attempts to give a quantum explanation for consciousness (and a possible free will by extension) seems to be from Penrose, yet they haven't received a great reception (I remember one scientist calling it a "pixie dust" explanation). As far as I'm aware, there is still a divide between quantum/ classical physics regarding neural processes anyway, to the extent that no one has shown where quantum effects are directly relevant (though they may well be eventually) yet many seem to resort to rather vague explanation of this subject this way, re free will. Which looks a bit like protecting a belief, rather than an honest appraisal of things.

I think (hope) that between neuroscience and physics/ chemistry that one day a genuine understanding will be gained of how this all works. Overall there does seem to be less inherent bias in attitudes towards this subject from scientists (though not always, of course). At this stage neuroscience and (from what I can gather) the other relevant sciences seem to make the notion of "free will" look less likely (though not impossible), without resorting to "ghost in the machine" or "mind body duality" explanations.

I also realise that it isn't something that many will have considered in depth and as such might have no firm opinions regarding this subject and how their own branch of science fits with it (or not). Thought I would ask anyway.

The perspective of this physicist appears to be one of the better explanations of the current state of things IMO and more succinct and to the point than all of the philosophy I have read combined (and that's quite a bit).

backreaction.blogspot.com.au...

a reply to: ImaFungi

Everything in the universe searches for its lowest energy point. In curved space around earth that would be the earyhs surface. This has to do with potential energy. This is similar to wooden cars on a race track. The track is inclined this is potential energy we use energy to place our car on the track. We are placing it higher in curved space. Meaning it takes longer for it to move through curved space.

Lay dude is here)) Question to Arbitrageur and who ever might
be interested and can evaluate.

This is about concept of gravity works as how I see it so far. I am totally, for some unexplained reason, find Einstein GR
interpretation of gravity very intuitive. It allows to speculate about the very mechanism of ''attraction'' between the two and how objects fall toward the center.

Seems to me like the cause of all is altered geometry of gravity area.

Say, we draw xyz axes combination some where where space-time geometrically flat, where markings on my axes are equally distanced on all three.Now we move that xyz set inside gravity well of massive body like Earth with axes Z pointing toward the gravity center. If we measure distance between markings on all three now, we should find that distance between markings on axes Z are getting spaced further apart exponentially compared to x and y markings.

Now lets take a rubber ball the size of the Moon and superimpose it on xyz axis set inside Earth's gravity well.
What am I seeing now is an egg shaped rubber ball that was perfectly round some where in deep interstellar space with its narrow end pointing toward Earth.

I find it normal if I assume space-time is altered near Earth and my axes Z markings being further apart still allocate same
space volume albeit with different shape and the rubber ball has to occupy all of that volume (to occupy all of given 3D geometrical space).

Now briefly lets step aside from GR and space-time metrics and get to nuclear bonding inside my rubber ball(strong,weak,
electromagnetic forces). Since the ball as combination of atoms has its own center.

From the ball perspective its own center moves toward narrow end of the 'egg' (axes Z) to compensate stability via
restoring bindings while its shape has been shifted (stretched toward Earth). It is trying to assume round shape, the one the rubber ball had in interstellar flat space.The marking distance on axes Z is increasing exponentially (gradient) in essence never allowing the ball to take its original round shape from strong atom forces point. The center of rubber ball would move the outer thicker end of the 'egg' in effort to assume original round shape.

In essence my rubber ball moved toward Earth just now. Since it is inside of a gradient type of metrics its end pointing toward Earth enters run away shape shifting state.

To the out side observer the ball is falling.



Thank you. Just don't bring 'frame' stuff in your answer please.



cheers

a reply to: greenreflections

I think you got it just to clarify one thing though distortion occurs we don't see it because the distortion is in 4TH DIMENTION. we only see the distortion through time but never in real time.

originally posted by: Cogito, Ergo Sum
A great thread. A lengthy one also, I haven't read it all so if this topic is discussed, apologies.

I would like to get opinion of physicists on something that has for millennia been restricted to the realm of philosophy, but is slowly starting to be far more relevant to science (which is a very good thing IMO). That is the problem of human free will, or more aptly, do humans have free will?

Physics is about what is observable. All evidence shows that humans act as if they have free will, and there is no evidence of mechanisms to believe otherwise. Even intrinsic chaos of theoretically deterministic systems (like brains if imagined classically, which is not the reality) is enough to make them sufficiently unpredictable so future behavior is sufficiently unconstrained by physics, and dominated by internal cognitive reasoning programs---i.e. human thought. Human brains have enough stored state which is externally invisible---so one must assume that humans have free will.

originally posted by: ImaFungi

When the brick is let go, SOMETHING PHYSICAL/REAL, MUST BE, FORCING, the brick in the direction it travels.

Why do you say that.

People before Newton would say that something PHYSICAL/REAL, MUST BE, FORCING planets and stars to rotate around the Earth.

originally posted by: mbkennel

originally posted by: ImaFungi

When the brick is let go, SOMETHING PHYSICAL/REAL, MUST BE, FORCING, the brick in the direction it travels.

Why do you say that.

People before Newton would say that something PHYSICAL/REAL, MUST BE, FORCING planets and stars to rotate around the Earth.

Well, I retract my statement, though it is still true, if it is true that Earth 'moves towards the brick'.

The brick cannot move from where it is let go to the ground for NO REASON.

There must be a causal reason.

Either it is the movements of the Earth, which cause the brick to go toward the ground (which I am now thinking there might be more credence towards);

Or, the movements of a different material (ultimately related to earth and its movement) forces the brick toward the ground.

You do not have a comprehensive theory, if you think that there is no physical reason as to why the brick travels to the ground. If you just think its a magical code, that there is no physics relations, between bodies and forces and touching. I am not saying your simple view is not helpful for whatever you are and do, I am just saying I am only attempting to comprehend beyond your surface view.

A brick is let go from atop a tower over the edge;

Why does the brick not stay where it is?

Is it because the Earth is moving? And when let go the brick is as if it is in vacuum, no longer connected to the body of earth? And so the body of Earth continues to move through space, as the brick stays still, and the body of earth always crashes into the brick? That doesnt make sense, because if you labelled the front traveling direction of earth with an arrow, and directly the back tail of earth too, according to that theory, if you let go of a brick, there would be no reason it would not be left behind. So perhaps that theory can be salvaged, when considering the earths rotation. Attempt to follow up on the points I have made, because they are not all the ones I have made in relation to this, and I can continue to build on this musing, if you are kind enough to play along, maybe you will learn something.

Contrary to Einstein, gravity is not a result of space time geometry.
Just lift a bucket of water and tell me if bent space is causing you to feel the weight of the bucket
a reply to: greenreflections

originally posted by: mbkennel

originally posted by: Cogito, Ergo Sum
A great thread. A lengthy one also, I haven't read it all so if this topic is discussed, apologies.

I would like to get opinion of physicists on something that has for millennia been restricted to the realm of philosophy, but is slowly starting to be far more relevant to science (which is a very good thing IMO). That is the problem of human free will, or more aptly, do humans have free will?

Physics is about what is observable. All evidence shows that humans act as if they have free will, and there is no evidence of mechanisms to believe otherwise. Even intrinsic chaos of theoretically deterministic systems (like brains if imagined classically, which is not the reality) is enough to make them sufficiently unpredictable so future behavior is sufficiently unconstrained by physics, and dominated by internal cognitive reasoning programs---i.e. human thought. Human brains have enough stored state which is externally invisible---so one must assume that humans have free will.

Thanks for the reply.

I'm having trouble finding much in that that is actually correct, or where it is correct, relevant to the problem. The logic also seems misplaced. You might as well credit the mind with some magical properties that allow for free will.

Though in the end I would be happy enough if people considered it genuinely. The great advances that physics has brought us are obvious, if more resources were turned to understanding the mind (not only physics, but at least get the philosophers out of it, they have done nothing other than complicate the issue for thousands of years), an understanding of how it works has the possibility to ease more suffering than any other discovery. Not saying humans definitely don't have free will (I find it doubtful though), only the a priori assumption of things like "free will" seem to be a stumbling block to understanding.

originally posted by: Cogito, Ergo Sum

originally posted by: mbkennel

originally posted by: Cogito, Ergo Sum
A great thread. A lengthy one also, I haven't read it all so if this topic is discussed, apologies.

I would like to get opinion of physicists on something that has for millennia been restricted to the realm of philosophy, but is slowly starting to be far more relevant to science (which is a very good thing IMO). That is the problem of human free will, or more aptly, do humans have free will?

Physics is about what is observable. All evidence shows that humans act as if they have free will, and there is no evidence of mechanisms to believe otherwise. Even intrinsic chaos of theoretically deterministic systems (like brains if imagined classically, which is not the reality) is enough to make them sufficiently unpredictable so future behavior is sufficiently unconstrained by physics, and dominated by internal cognitive reasoning programs---i.e. human thought. Human brains have enough stored state which is externally invisible---so one must assume that humans have free will.

Thanks for the reply.

I'm having trouble finding much in that that is actually correct, or where it is correct, relevant to the problem. The logic also seems misplaced. You might as well credit the mind with some magical properties that allow for free will.

Though in the end I would be happy enough if people considered it genuinely. The great advances that physics has brought us are obvious, if more resources were turned to understanding the mind (not only physics, but at least get the philosophers out of it, they have done nothing other than complicate the issue for thousands of years), an understanding of how it works has the possibility to ease more suffering than any other discovery. Not saying humans definitely don't have free will (I find it doubtful though), only the a priori assumption of things like "free will" seem to be a stumbling block to understanding.

I lean towards we do however that doesn't have to be the case. If everything in our universe already happened then no we dont. Until we truly understand the nature of time I don't think we can answer the question. The multiverse would give us free will in that every possibility occurs. And we simply choose between these paths. The other possibility is the beginning and the end are fixed everything in between is total chaos.

originally posted by: Cogito, Ergo Sum
Not saying humans definitely don't have free will (I find it doubtful though), only the a priori assumption of things like "free will" seem to be a stumbling block to understanding.

People who are strict determinists (absolutely no such thing as free will) believe 'no free will' to mean; An individual cannot choose between multiple possible choices. That there are no such thing as multiple possible choices. That there is no such thing as any choice. There is only exactly what is determined at all times forever.

You seem to be hinting at a different definition of free will, maybe;

That a person cannot perhaps 'invent' anything purely original, thought, decision, etc.? Is that what you mean by free will? That a person can do something without cause? The terms get tricky, everyone arguing on these concepts must agree on clear defined terms. And state clearly exactly what they are saying and thinking.

The argument also does go on to say, if a person does 'do something that was not caused by their outer environment or inner body mechanisms', then how can it be known or claimed that such a thing was not 'random', and how does random outbursts relate to 'a will, and it being free'? I do not believe in some eternally impossible absolute free will; like "if your will is free, why can you not break the laws of physics with it", but I believe it is possible to make choices between multiple actually possible choices. The will is free to choose between real potentials. Not absolutely. But greater than 0.

originally posted by: Nochzwei
Contrary to Einstein, gravity is not a result of space time geometry.
Just lift a bucket of water and tell me if bent space is causing you to feel the weight of the bucket
a reply to: greenreflections

the weight of the bucket comes from two factors. Bucket is stretched from the bottom (along axes Z pointing toward Earth) and inner forces (QM forces) that will maintain bucket's shape. The stretch is not proportional, bucket is being pseudo pulled from the bottom along Z axes and inner forces that hold bucket in one piece will drag top part of the bucket to preserve its original, balanced shape.

I have probably two ways to verify my point.

Two dimensional object which has zero thickness positioned horizontal to gravity source will experience no gravity because it has Z=0. Only X and Y position.

Another silly one..

if we create a hologram in interstellar space and calibrate it to be precise square, for example, and then shoot same hologram from out side of gravity well to inside gravity well, we should see our holographic square become rectangular, elongated toward the center of gravity. That would show how volume of space-time is distorted compare to flat space-time.

)

a reply to: ImaFungi

A brick is let go from atop a tower over the edge;
Why does the brick not stay where it is?

How do you know it isn't standing still in space and the ground below is actually moving toward it?

originally posted by: Cogito, Ergo Sum

originally posted by: mbkennel

originally posted by: Cogito, Ergo Sum
A great thread. A lengthy one also, I haven't read it all so if this topic is discussed, apologies.

I would like to get opinion of physicists on something that has for millennia been restricted to the realm of philosophy, but is slowly starting to be far more relevant to science (which is a very good thing IMO). That is the problem of human free will, or more aptly, do humans have free will?

Physics is about what is observable. All evidence shows that humans act as if they have free will, and there is no evidence of mechanisms to believe otherwise. Even intrinsic chaos of theoretically deterministic systems (like brains if imagined classically, which is not the reality) is enough to make them sufficiently unpredictable so future behavior is sufficiently unconstrained by physics, and dominated by internal cognitive reasoning programs---i.e. human thought. Human brains have enough stored state which is externally invisible---so one must assume that humans have free will.

Thanks for the reply.

I'm having trouble finding much in that that is actually correct, or where it is correct, relevant to the problem.

OK, what do you disagree with?

The logic also seems misplaced. You might as well credit the mind with some magical properties that allow for free will.

Is there an empirical experimental diagnostic which could distinguish a mind with free will from one without?

I call "free will" to be, from what appears from the outside, sufficient unpredictability of action as seen by observers (other people don't know what a human will do) combined with that person's internal state and knowledge of reasons and choices for the action.

Anyway, I find this question to be fairly sterile unless it deals with empirical observables and guides practical human behavior.

Though in the end I would be happy enough if people considered it genuinely. The great advances that physics has brought us are obvious, if more resources were turned to understanding the mind (not only physics, but at least get the philosophers out of it, they have done nothing other than complicate the issue for thousands of years), an understanding of how it works has the possibility to ease more suffering than any other discovery. Not saying humans definitely don't have free will (I find it doubtful though), only the a priori assumption of things like "free will" seem to be a stumbling block to understanding.

Now I don't understand what you mean. There is extensive study devoted to cognitive and computational neuroscience, and they're trying to at least understand brains, and maybe a little bit of 'mind' there, in that pieces of computation and behavior done by animal brains seem to be replicable, roughly, by connectionist computational machines.

originally posted by: ImaFungi

originally posted by: Cogito, Ergo Sum
Not saying humans definitely don't have free will (I find it doubtful though), only the a priori assumption of things like "free will" seem to be a stumbling block to understanding.

People who are strict determinists (absolutely no such thing as free will) believe 'no free will' to mean; An individual cannot choose between multiple possible choices. That there are no such thing as multiple possible choices. That there is no such thing as any choice. There is only exactly what is determined at all times forever.

Physics of quantum mechanics and chaos means that this 'what is determined at all times forever' business is not useful in our real world, if any random fluctuation from a cosmic background photon may profoundly change the future.

You seem to be hinting at a different definition of free will, maybe;

That a person cannot perhaps 'invent' anything purely original, thought, decision, etc.? Is that what you mean by free will? That a person can do something without cause? The terms get tricky, everyone arguing on these concepts must agree on clear defined terms. And state clearly exactly what they are saying and thinking.

People have the internal experience of feeling like they are making choices. People have the external experience of watching others appear to act as if they are making choices. Physics does not support deep determinism in thermodynamically large systems.

From a useful point of view, I don't know if people have "real" free will whatever that is, but in the practical, moral and ethical world of biological homo sapiens, we should assume that people do.

I don't know if there "really is" an electromagnetic field either, for some definition of "really" and "is", but it sure as heck looks like it.

a reply to: mbkennel

Hey MB sent you an IM with something I'm very excited about. Seeing if you can take a look at it and get back to me.

It's a separate IM than the one titled "De Sitter Precession v. Lense-Thirring Precession and the Geodetic Effect" that's also sitting in you In Box that I'd also love to have your help with understanding. Any physicist actually. But if you could please check out the IM I just sent you a minute ago.

originally posted by: mbkennel
Physics of quantum mechanics and chaos means that this 'what is determined at all times forever' business is not useful in our real world, if any random fluctuation from a cosmic background photon may profoundly change the future.

Im glad you prefaced that statement with 'physics of quantum mechanics', meaning 'that which humans have written', or else you and others may have been wrong and confused in thinking that you were talking about the truth of reality.

Yes, not useful in our real world, yes, you are speaking about maps and tools, I am speaking about truth, precisely.

It is true, that everything is strictly determined absolutely besides that which can be said to have will greater than 0.

It is true that to the vantage point of a human mapping reality, that when things occur or interact with a human that was not in their map, that they can state that this event in accordance with the story of their map was not determined to occur in relation to their mapping of knowledge events, why they had everything they had written, and then something else happened, of course it is appropriate to call that something else which was not knoweldged to occur (something rare since humans have very nearly perfect knowledge of all matter and energy) random.



The statement you should focus on attempting to prove false, as it appears to be opposing what you have stated is this;

All, besides will, is absolutely determined, as objective reality.

(you will be urged to say things like 'mewhhh random beta decay, cosmic particle, supernova, ... but no... all events occur because they absolutely must, because they have no choice, because there is only that which exists, and the rules that are not even questioned to be broken because the rules are only extensions of the fact that something exists exactly as it does continuously at all times, reality is exactly to scale and exactly in real time, it is it, it is what is.

The reasons of reality are termed physics, chemistry, biology (etc.), the will is one of the most complex mechanisms (body in general) we are aware of and its primary function is inventing reasons. The reason ice melts is due purely to choiceless material and energy and their relational movements. The reason a person moves this way or that, is due to the, yes along with information from outside of themselves, invented reasons within themselves.