The Myth of Gravity

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Dears,

All we know in fact about "gravity" is that it is an attractive force that works in our class of dimensions.

Einstein's idea of "space deformation" as explanation for gravity has been the most fake theory of all physics history...

Corpses are attracted, like they had a memory of an united state, nothing else is known...

Cheers,

Why would one think that the idea of physically real spacetime is "fake?"

Tom

"Why would one think that the idea of physically real spacetime is fake?"

Dear Tom,

Energy and time are two face of the same coin: both means motion an fragmentation.

The void/nothing can't move, so something apparently material do exists to be in motion (even though I think it is also virtual and dubious).

Space means simply some "distance" that separates parts of a fragmented system (in opposition to an unified on - even though imaginary).

Let's imagine a unified mass being exploded by inner repulsive forces: space and time starts! "Universe of things" also, for one unified corpse is all but a a "universe" (universe means fragmentation and plurality).

So, neither space nor time are "fakes", but clear realities.

Cheers

All that tells me, Wilton, is that you don't know the principles of general relativity. Spacetime, in which neither space nor time are independent, is the "clear" physical reality in Einstein's theory.

Tom

TH RAY,

We can measure space with a ruler. We can measure time with a clock. These are "physical entities", the product of our direct physical interaction within our reality. Spacetime, on the other hand, is a (META=not or beyond) metaphysical entity created to stitched up measures within our reality and what (little) we know about the underlying reality or metaphysical universe. Spacetime is not physical. It is a product of physics and as such, it contains both physical and metaphysical components by requirement.

People do not understand where one ends and the other begins and believe that spacetime is true physics (not) or true metaphysics (not). Spacetime is a hybrid tool we invented in order to keep doing physics where physics means nothing. In order to understand what we are doing , we must respect the boundaries of each, physics and metaphysics.

If we can just understand that the universe is not the experience we have of it, but rather what we can deduce from that experience of it while removing our own transform we effect as observers, then, we have a chance to get it. Do you?

Marcel,

The continuum of spacetime is explicitly physical in general relativity: " ... by 'physically real' we mean 'independent in its properties, having a physical effect but not itself influenced by physical conditions.'" (Einstein, 1956, The Meaning of Relativity)

General relativity is a physical theory, not a metaphysical proposition.

Tom

Tom,

Could you please explain the meaning of what is between the quote marks?

Thanks,

Marcel,

That covers a lot of physics, Marcel. I'll try to summarize as best I can. The quote is directly from Einstein, in his introduction to general relativity--following the explanation of special relativity. Special relativity is the "special case" of uniform motion; general relativity is the generalized case of accelerated motion.

To understand accelerated motion, we have to go back to Newton's theory of gravity. Newton had found that acceleration in a gravity field accounted for both the attraction of bodies toward the center of the Earth, and for celestial orbits.

In Newton, however, space is an absolutely smooth background and time is also absolute (i.e., clocks run at the same rate everywhere in the universe).

Einstein, with a deep background in classical mechanics, saw what Ernst Mach had done. By disregarding the role of space altogether, Mach had proposed that the motion of any body in the universe depends on the motion of every other body in the universe. That is, if one could determine the initial state (position and momentum) of all bodies at one moment, one could in principle predict future states in all other moments. In Mach, then, time is "physically real"--there is a non-arbitrary zero point of motion and space is just a convenient fiction. Of course, Mach's idea also depended on Newton's assumption of absolute time.

Einstein recognized that other than in a closed, isolated system, what he called "Mach's Principle" would be impossible to show experimentally valid. Like every good physicist (especially of the classical variety) Einstein was driven by the need to demonstrate correspondence between theory and physical result. And like almost every theorist of his era, he was troubled by Newton's theory that required "action at a distance"--the instantaneous influence of one body on another .

With Mach, since space doesn't matter, invisible gears crank the universe and all action is local. This property--locality--is how Einstein arrived at the idea that if Mach's Principle holds, there is no nonlocal influence on the motion of bodies. So there must be some physical boundary that prevents action at a distance. Since special relativity had already incorporated the absolute speed of light, Einstein reasoned that not only did the speed of light limit uniform motion, but that it limits local action as well--because accelerated motion (i.e., motion in a curved path rather than a straight line) would be bounded by the curve. If you think of this in terms of geometry, and you know that a straight line is a special case of a curve, you see that while the line extends from minus infinity to plus infinity, the curve limits the path of the straight line so that the distance-time relation to the common coordinates of three dimensional space adjusts the coordinates so that a body in time is continuous with its position in space. The metric signature of general relativity is +++-, which means that the straight line (the three plus signs) is truncated by the minus sign, and this is a physical boundary. The derivation is x^2 + y^2 + z^2 - (dt)^2. The xyz coordinates describe a body's position in space; dt is the distance-time term. At nonrelativistic distances and speeds, it doesn't mean much, but is significant otherwise. (All of this is experimentally validated.)

So. If all physical influences are local, there can't be a universal clock, because the measurement of local processes viewed by one observer at a relativistic distance (or speed) from another's locality differs from the measurement that the other makes. Every observer carries her own clock, in other words, which reads differently from one observer's state in relation to the other.

Not only is time physically real, as in Mach's mechanics--space is also physically real in general relativity. However, neither space nor time can be _independently_ real, because of the observer dependence. Time is treated as an extra dimension, a coordinate point continuous with space. In mathematics, this is called Minkowski space, or space-time. In explaining how this continuum acts on the apparent position and momentum of bodies, Einstein reminded us of what "physically real" means, in order to distinguish the true physics from the apparent: " ... independent in its physical properties, having a physical effect but not itself influenced by physical conditions." Time is not physically real. Space is not physically real. Spacetime is physically real.

Tom

Tom,

Thank you for taking the time to lay down your explanation. I learned much from your discourse. Here are a few comments.

- an action at a distance does not require to be instantaneous.

- "at non relativistic distances and speeds.." (Verlinde says the same on p2) There is no such thing! Relativity is always true in principle, even in the case where it is not measurable by the observer. If it is universal, the observer and its capacity of observation is not to be taken as a limit to Relativity. If I throw a ball in the air, the time within this ball, believe it, is relatively slower than mine, without any other proof than the fact that the equation shows no boundary. This case is where in fact it actually means the most, for understanding.

- It is strange, but consider that measuring a speed of zero is relative to the observer while the maximum of the scale is c, and this is relative .... to the universe! One end of the scale is relative to us (0) and the other end is absolute ( c) . Maybe we should use c as speed coordinate axis!

- The clock is universal because it runs everywhere ... it just doesn't run everywhere at the same rate...The passage of time is a universal process with a local value of its rate, just as in a gravitational field.

- "Time is not physically real". Time is by nature a dynamic process. We measure on a clock its first integral in a physical way. But this measurement and integration cannot exist without its first derivative i.e. the rate of passage of time. You see, time integrated as measurement on a clock is physical*. The underlying process, the rate of passage of time, is metaphysical. If we could "see" the rate of passage of time we would be technically as blind as a goldfish in a glass of milk. But we detect very short first derivative of the passage of time as photons, or gradient of it, as gravity. This is what I mean by "physical".

- But, my absolute partition of physics and metaphysics does not allow your explanation (last few sentences) of the content of the quote marks.

* The first function (and most basic one) of a clock is to show/detect the presence of the passage of time. It runs, then time is passing. The second function of a clock is to partition the local spontaneity of time into equal units used for measurement. The local rate of passage of time is an indication of the local rate of spontaneous processes, the clock being our standard spontaneous partitioned process used for measuring it.

Marcel,

Tom,

A quick tour on metaphysics 101. To help you understand where I am coming from..

Anything we call an experience (person or instrument) is a binary relationship between subject and observer. This experience (and all our knowledge) has meaning and exists only in this ephemeral relationship. Everything we know is about this experience, not about the universe itself. From this we understand that the universe as it is by itself is entirely metaphysical. Our job is to decode our experiences in order deduce what the subject matter really is by itself, starting by removing the transforms we effect on the data; integrations leading to the concepts of space and duration.

S___w the Copenhagen school! They said nothing worth our attention lied beyond the window.(underlying reality). In fact, everything that really exists is there.

With this tool you may dissect relativity into its physical and metaphysical components. You will understand that relativity is a bridge between our physical reality (what we can measure) and what little we know about the metaphysical universe. The theory itself is not wrong (it is physically proven!); only the metaphysics we deduced from it is wrong, mostly because we don't know or acknowledge the difference between the two; physics and metaphysics.

Marcel,

________________

Tom,

No solipsism here. Only a profound an honest pragmatism. We already know we create our whole reality from sensory experience. We make up colors, sounds, and space and our own version of time... There is no objective observer because we are part of the experience...

As for making something out of it, well. Look at all we could DO without understanding what we were doing. How much more could we DO if we actually understood what it is all about???

Marcel,

Marcel,

When I say "we" know something, I mean that I can point to an object or concept that we objectively agree is real, even if only metaphysically real. E.g., the counting numbers -- the real positive integers -- though we may "experience" them in different ways, are real in an objective sense.

What do you mean when you say "we" know anything, if objective reality doesn't exist, and again, how does one specifically and operationally distinguish this philosophy from solipsism?

Tom

** I cannot re-write my whole essay to answer your questions re physics vs metaphysics vs truth systems etc. ; you have to read it. But I can give you a sequence of arguments illustrating my position.

1- Something exists out there that supports the existence of a universe 14 billion years old. That is a substance (or process).

2- A substance requires the rule of non-contradiction because the substance either exists or it doesn't. From this rule, other rules of logic follow; addition, substitution, etc,

3- A universe that evolved for 14 billion years under logic must be operational under logic. For this, there can be only one substance in the universe. Logical operations can only operates on a single substance (single nature). (like no situation where apples add with oranges..)

4- All spontaneous operations can only have one type of cause because there is no logical reason to choose precedence between two types of causes.

5- A universe created from the logical rule of non-contradiction allows only the passage of time to exist. Why? A contradiction is two contrary states at the same time. A neat trick but, only time can in effect avoid the contradiction between its own existence and non existence by time insulation or, "not at the same time". Time evolves continually in an explosive process to avoid the contradiction. Such a universe is created from nothing, is locally something, but as a whole is still nothing.

6- The existence of the substance is more probable where the passage of time is slower because it is where in effect it stays longer. This influence of time on itself explains gravity as a field made of a gradient in the rate of passage of time and supports an action at a distance. A differential in the rate of passage of time is the one and only logical "Cause" for spontaneous processes. (What Verlinde calls "entropic force" I call "spontaneity")

Now, where are the concepts or energy, mass, real, objective, experience etc.in this? They are not here because this is the underlying reality, a material metaphysics, the ontology of the universe, where the observer is not present. All numbers driving our usual equations are absent. They were created for our need to know. The universe only needs substance and cause to exist and happen.

My metaphysics, or ontology of the universe, is based on an impossibility; the impossibility for something to exist by itself AND not follow the rule of non-contradiction. This makes this metaphysics a bona fide truth system, where truths derived from it are as true in it (this metaphysics) as general relativity is, as derived from the impossibility to distinguish inertia from gravity (equivalence principle). You have to explain to me how this is a solipsism, at least in your definition of it.

Marcel,

Okay, Marcel, I see your philosophy is based on Aristotle's metaphysics.

That's fine; however, why would one be compelled to accept metaphysical philosophy over scientific objectivity, when your question is "How much more could we DO if we actually understood what it is all about???"

What does one do with a belief system? It isn't about doing. Take for example your belief that time is continuous. That classical notion requires a metric of reversible trajectory in contradiction to your "explosive evolution" which is a one-way process. Compare this philosophy based on belief to Newton's scientific pledge to "make no hypoothesis." Inevitably, one who bases one's conclusions on logic alone will end in contradiction, because so much (most, actually) of what we objectively know of Nature is counterintuitive.

The anlogies you make between physics and metaphysics are not true. We certainly do know the difference between gravity and inertia, e.g. -- the equivalence principle refers to the equivalence between gravitational force and acceleration, and follows from Newtonian mechanics. Newton had shown that the acceleration of an apple toward the center of the Earth and the acceleration of the moon around the curvature of the Earth are due to the same physics -- Einstein extended this result to the vacuum, away from the influence of a gravity field, where an observer without external reference cannot distinguish between acceleration in one direction and gravity in the opposite direction. The significance is classical symmetry -- reversibility -- which gets right back to the time continuum.

Jacobson's and Verlinde's entropic model identifies gravity with information entropy. Because the mathematical model of information entropy (due to Shannon) is identical to thermodynamic entropy, one finds that if the world is made entirely of quantum information (and how's that for a metaphysical premise?) then information entropy holds it together. This goes right against the grain of classical gravity and its reversible continuous field.

Now that you've given me your operational meaning for metaphysics and I see that it is Aristotelian rather than solipsistic, I understand. However, I based my question on your claim, if I understood correctly, that there is no objective universe (which would imply solipsism). There is an objective component to your philosophy, however -- Aristotle's rules of logic and pure deduction.

As I implied, science does not shy from metaphysical realism -- I think the Jacobson/Verlinde model is an excellent example. Can we do more with a purely metaphysical POV than with science? I doubt it, though I wouldn't dare sell short the metaphysical contribution to scientific motives.

Tom

Repulsion and attraction have to be balanced in order for gravity and electromagnetism to be united/balanced, as DiMeglio says. This provides, and must be understood as providing, distance in space.

Okay, Marcel, I see your philosophy is based on Aristotle's metaphysics.

M= If you say so. I was more thinking along the lines of Plato's cave allegory...

That's fine; however, why would one be compelled to accept metaphysical philosophy over scientific objectivity, when your question is "How much more could we DO if we actually understood what it is all about???"

M= That's my whole point. Metaphysics, or more specifically ontology, can be an objective source of knowledge if it is structured like individual segments of science, as truth systems. A sequence logically deduced without a choice and starting from an impossibility is objective. Simply, the subject matter is different.

What does one do with a belief system? It isn't about doing. Take for example your belief that time is continuous. That classical notion requires a metric of reversible trajectory in contradiction to your "explosive evolution" which is a one-way process. Compare this philosophy based on belief to Newton's scientific pledge to "make no hypothesis." Inevitably, one who bases one's conclusions on logic alone will end in contradiction, because so much (most, actually) of what we objectively know of Nature is counterintuitive.

M= The reversible trajectory does not imply reversible time! While you watch the pendulum going back and forth, the time on your watch is not going backward!

The analogies you make between physics and metaphysics are not true. We certainly do know the difference between gravity and inertia, e.g. -- the equivalence principle refers to the equivalence between gravitational force and acceleration, and follows from Newtonian mechanics. Newton had shown that the acceleration of an apple toward the center of the Earth and the acceleration of the moon around the curvature of the Earth are due to the same physics -- Einstein extended this result to the vacuum, away from the influence of a gravity field, where an observer without external reference cannot distinguish between acceleration in one direction and gravity in the opposite direction. The significance is classical symmetry -- reversibility -- which gets right back to the time continuum.

M= Time is not reversible. While you do all sorts of experiments and observations, the rest of the world keeps going on; The grass grows, you get older, earth keeps flying around the Sun.. Why would anyone think that in his small experiment things are going dany ifferently than in the rest of the world or even the universe?

Jacobson's and Verlinde's entropic model identifies gravity with information entropy. Because the mathematical model of information entropy (due to Shannon) is identical to thermodynamic entropy, one finds that if the world is made entirely of quantum information (and how's that for a metaphysical premise?) then information entropy holds it together. This goes right against the grain of classical gravity and its reversible continuous field.

M= entropic model information identical -if- .. ; all this is not exactly rock solid. "is made entirely of quantum information (and how's that for a metaphysical premise?)" Do you think that metaphysics is any kind of weird flight of fancy? It is not.

Now that you've given me your operational meaning for metaphysics and I see that it is Aristotelian rather than solipsistic, I understand. However, I based my question on your claim, if I understood correctly, that there is no objective universe (which would imply solipsism). There is an objective component to your philosophy, however -- Aristotle's rules of logic and pure deduction.

M= The problem is in the words you use and your constant attempt at trying to match this approach to a category that you know about i.e. Solopsism. The universe was existing and evolving by itself long before we showed up to observe it. It does exist, but not in the form we transform it into by our experience. The real trick is to strip off our knowledge from the transform we effect by experience and effectively remove the observer from the equation.

As I implied, science does not shy from metaphysical realism -- I think the Jacobson/Verlinde model is an excellent example. Can we do more with a purely metaphysical POV than with science? I doubt it, though I wouldn't dare sell short the metaphysical contribution to scientific motives.

M= We would get right to the point much faster.. Understanding, I mean. Doing, will come in time.

Marcel,

Marcel, your laws of logic are directly from Aristotle: Identity, Noncontradiction, Excluded Middle.

Before science became distinct from philosophy (and especially physics, which until relatively recent times was known as "natural philosophy") we did do science according to Aristotelian logic. Why don't we still? Because we found that deep nature does not necessarily obey physical intuition. Take the one instance of Aristotelian science that Galileo overthrew. Until Galileo's experiments, one would not question that objects of different mass fall at different rates -- it's logical. The Galilean model gave Newton the basis to show that the acceleration of the moon falling around the curvature of the Earth is the same force that accounts for an apple falling toward Earth's center, which could never have been deduced by Aristotelian physics. Newton's model gave Einstein the basis to show the equvalence between gravity and acceleration, i.e., between gravitational mass and inertial mass. And as a result of this equivalence, because an observer away from the influence of a gravity field cannot distinguish between a force pushing up and a force pulling down, we find one demonstration of time reversibility (symmetry) in classical physics. This is not controversial, and not something you could deduce from your logic.

That time is apparently not reversible is even deeper and even further removed from your logic, because it involves quantum physics which outright contradicts your metaphysical rules.

Scientists in general don't deny the role of metaphysics in reaching for that which is beyond grasp. When you say, however, that understanding gets us to the point faster -- well, it didn't get you to the point of understanding time reversibility in classical physics, did it? I am reminded of von Neumann's reply to a young physicist who said he did not understand von Neumann's recommendation to use a certain mathematic method: "One does not understand (a math technique)! One gets used to it!"

Contemplating "existence" is, I agree, an important part of being human and an excellent way to condition one's imagination to break free of traditional ways of thinking. When we get to exploring how nature really behaves, though, most of what we know is counterintuitive, often to an extreme.

Tom

Tom,

Marcel, your laws of logic are directly from Aristotle: Identity, Noncontradiction, Excluded Middle.

M= For that part, yes, the rule of non-contradiction was for Aristotle of the highest order.

Before science became distinct from philosophy (and especially physics, which until relatively recent times was known as "natural philosophy") we did do science according to Aristotelian logic. Why don't we still? Because we found that deep nature does not necessarily obey physical intuition. Take the one instance of Aristotelian science that Galileo overthrew. Until Galileo's experiments, one would not question that objects of different mass fall at different rates -- it's logical. The Galilean model gave Newton the basis to show that the acceleration of the moon falling around the curvature of the Earth is the same force that accounts for an apple falling toward Earth's center, which could never have been deduced by Aristotelian physics. Newton's model gave Einstein the basis to show the equivalence between gravity and acceleration, i.e., between gravitational mass and inertial mass. And as a result of this equivalence, because an observer away from the influence of a gravity field cannot distinguish between a force pushing up and a force pulling down, we find one demonstration of time reversibility (symmetry) in classical physics. This is not controversial, and not something you could deduce from your logic.

M= logical operations are not possible with physical intuition or physical reality because they appear to us as multiple natures that are not additive or operational in any way under logic. We therefore compute elements of our experience; mass, color, space etc.

That time is apparently not reversible is even deeper and even further removed from your logic, because it involves quantum physics which outright contradicts your metaphysical rules.

M= my ontology presents logical understanding for both QM and relativity behaviors, not for their measurement. The metric is for our own need to know. It is interesting to consider how in QM the probability of finding (say) a particle in one place in effect represents the relative time of residence of that particle in that place with respect to all other place it may be found in. Within the set of all places where the particle may be found, the places where time runs the slowest is where the probability of finding it is the highest; this distribution of the rate of passage of time is what the wave function describes.

Scientists in general don't deny the role of metaphysics in reaching for that which is beyond grasp. When you say, however, that understanding gets us to the point faster -- well, it didn't get you to the point of understanding time reversibility in classical physics, did it? I am reminded of von Neumann's reply to a young physicist who said he did not understand von Neumann's recommendation to use a certain mathematic method: "One does not understand (a math technique)! One gets used to it!"

M= Physics is our experience; ontology is about what's out there. Where we do not agree is in the metaphysical conclusions of physics.

Contemplating "existence" is, I agree, an important part of being human and an excellent way to condition one's imagination to break free of traditional ways of thinking. When we get to exploring how nature really behaves, though, most of what we know is counterintuitive, often to an extreme.

Tom, it is a new field and I can only use words that are already used and carry meanings that do not entirely apply. The "existence" I speak of offers no chance for contemplation. "Existence" is the logical operation of substitution where one complex (derivative) form of time replaces locally the base time because time in one place cannot be both derivative and not derivative (rule of non-contradiction).

It is entirely possible that you never get to understand this. My own inhability to find the right combination of old words and the overwhelming simplicity of this logic may conflict with some very of your very complex (and complete) philosophical and scientific baggage. Kids would understand this and it may well be part of 6th grade curriculum one day... ??

Marcel,

Superman, are you saying that a type of inertial resistance/inertial binding energy/GRAVITY -- that would either increase or decreased with distance -- with generally balanced attraction and repulsion -- would thereby fix or determine position/distance in space within the framework/context of what is described herein?