Re: the absurd implied density of moons kills gravity
meemoe_uk wrote: Yeah, I've read a bit on the selene mission. There a crucial thing missing from the articles though. Quantification. It's a given that gravity varies slightly over a relief map with different density rocks. So nothing new there. But did the results match the conventional model of the moon?
I honestly don't know what specifically entails the conventional model of the Moon. I assume it's the same as any other planet, a crust, mantle, and core--standard boilerplate boredom
meemoe_uk wrote: Space science is so use to its theory being falsified by new measurements that they sometimes don't bother to tell anyone when it happens. Using radio sonar to detect the rocks just down to a km or 2 might already be enough to cause results to diverge from a conventional model if gravity theory is wrong.
But its only scratching the surface. We need to get 50km deep inside a moon or planet. Then we'll see some new stuff.
Sure I'd like to see the Moon cut in two so we can look inside. I say it's hollow It's still amazing to realize that what planets are composed of, how they are structured, is actually unknown. Yet we live on one.
marengo
Re: the absurd implied density of moons kills gravity
CharlesChandler wrote: Oh, OK. Newtonian mechanics was simple. But gravity-based astronomy was found to be so full of anomalies that a whole new model was required, so the simplification was GR? And then things got way simpler when you realized that if your theory predicts something, you don't really have to worry about whether or not the effects can be measured? Yep, having to get theories to match measurements would just make things complicated, and Occam's Razor can take care of that for you!
What are you talking about? Of course you must measure the predictions of a theory. Newton did not predict the effect of gravity on light (actually gravity is light as I have stated) so a new or modified theory was required. That had to happen, did it not?
CharlesChandler wrote: Let me ask you a question. Given that answers cost $1, and correct answers cost $2, which is better?
I have given you the answer to gravity. Yet not one single comment from you.
marengo
Re: the absurd implied density of moons kills gravity
meemoe_uk wrote: It seriously concerns me that you are prepared to contradict yourself.
I never contradict myself.
meemoe_uk wrote: I notice you forgot to write down the evidence based solution to creation and gravity. Until you do, I'll be searching for new ideas. As far as I know we haven't yet found the hard evidence for either, so I have to hypothesize new physics. The biggest gap in our understanding of everything is the interior of stars planets moons, so by deduction that's where the answers should be. That's my judgement. If you think you have better please say.
If you could be more precise as to what your problem is then I might suggest a solution for you.
marengo
Re: the absurd implied density of moons kills gravity
viscount aero wrote: You're still stuck on "point source" which I explained is a fallacious phrase and idea. A point cannot exert any influence of gravity as it is massless and dimensionless. Objects are not attracted to dimensionless points. It is further false when considering that there is no gravity at the alleged core, absolute center, of any planet.
And you are still stuck on the meaning of words. You cannot seem to separate the theoretical from physical reality. Theoretical ideas are useful concepts to aid understanding. In your case they just confuse you.
Gravity 'appears' to emanate from a point source. You will no doubt try dissecting the word 'appears' for the next ten posts.
marengo
Re: the absurd implied density of moons kills gravity
meemoe_uk wrote: Conventionally though gravity force is F = V1 d 1 V2 d2 / r2 where V and d are Volume and density
You are merely complicating Newton's law for the sake of trying to be right.
marengo
Re: the absurd implied density of moons kills gravity
viscount aero wrote: appears throughout that traditional mathematical equation. But moreover, I'm refuting marengo's insistence of continuing to describe the force of gravity as originating from a de facto "point source." Such a notion is more than likely untrue as the source of the gravitation is not reduced to single point of existence because it geometrically cannot be. It cannot theoretically nor physically.
I never said that gravity emanated from a point source. I said it EFFECTIVELY emanates from a point source. Can I have an apology please?
marengo
Re: the absurd implied density of moons kills gravity
viscount aero wrote: Ok. But SELENE has evidence of a relationship between an increase in gravitation over areas of greater density on the Moon. That is the whole reason why I posted the article as it is the most recent Lunar mission to my knowledge. Therefore there is a correlation. Density, as you can see, appears throughout that traditional mathematical equation. But moreover, I'm refuting marengo's insistence of continuing to describe the force of gravity as originating from a de facto "point source." Such a notion is more than likely untrue as the source of the gravitation is not reduced to single point of existence because it geometrically cannot be. It cannot theoretically nor physically.
Naturally, if a planet is not homogeneous in density then gravity will not effectively emanate from a single point source. That is obvious. But what on Earth is the further significance of it. Your discussion is just like the fanatics who spent their lives arguing as to how many angels you could get on the head of a pin.
CharlesChandler
Re: the absurd implied density of moons kills gravity
marengo wrote:
CharlesChandler wrote: Oh, OK. Newtonian mechanics was simple. But gravity-based astronomy was found to be so full of anomalies that a whole new model was required, so the simplification was GR? And then things got way simpler when you realized that if your theory predicts something, you don't really have to worry about whether or not the effects can be measured? Yep, having to get theories to match measurements would just make things complicated, and Occam's Razor can take care of that for you!
What are you talking about? Of course you must measure the predictions of a theory.
Here was the exchange:
marengo wrote: I predict the effects of gravity from calculations based upon the properties of my Aether model. Observations such as Eddingtons and gravitational redshift merely confirm my predictions.
CharlesChandler wrote: And what did Eddington observe? A couple of arc-seconds of deflection? Did he have the instrumentation to make such an accurate measurement?
marengo wrote: You are also forgetting that my theory predicts these effects.
So your theory predicts gravitational lensing, and I question whether or not it has actually been measured, and you respond that your theory predicts these effects. Then I call attention to the fact that you're putting all of your weight on theory, and none on measurements, and you say that the predictions of a theory must be measured. And of course, you're convinced that Eddington's measurements confirm your theory. But wait... you never established that Eddington's instrumentation was accurate enough to rule out the mirage effect to within a couple of arc seconds. How are you going to do that? By telling me that it doesn't matter — your theory predicts such effects?
marengo wrote: Newton did not predict the effect of gravity on light (actually gravity is light as I have stated) so a new or modified theory was required. That had to happen, did it not?
You're assuming the conclusion. Einstein's theory predicted gravitational lensing. Newton's did not. Therefore Newton is wrong? But wait... did anybody measure gravitational lensing before concluding that Einstein was right, and were the measurements independently confirmed before being accepted? Ummm... we still don't have the instrumentation necessary to estimate the mirage effect to within a couple of arc-seconds, which means that we still don't have confirmation of gravitational lensing. This means that you're solving a non-problem.
marengo wrote: I have given you the answer to gravity. Yet not one single comment from you.
No, I have made several, but you didn't hear any of them.
marengo wrote: You cannot seem to separate the theoretical from physical reality.
@viscount aero: I'd take that one as a compliment if I were you! He appears to have theory and physical reality fully divorced, and he's on the wrong board to be talking trash like that. You can do that on CosmoQuest, or JREF, but not here. We don't all agree here, but at least we understand that theory cannot be separated from physical reality.
marengo wrote: I never said that gravity emanated from a point source. I said it EFFECTIVELY emanates from a point source.
It would be just a tad more accurate to say that gravity can be calculated as if it emanated from a point, and assuming that you're completely outside of the sphere. The gravitational sources are the particles with mass, and if they're distributed, the gravitational sources are distributed. But the calcs can be simplified.
marengo wrote: Naturally, if a planet is not homogeneous in density then gravity will not effectively emanate from a single point source. That is obvious.
If you're outside the sphere, gravity can be calculated as if it was all coming from a single point, but if the density varies, the point might not be at the geometric center of the sphere. Try to be as precise as possible in your wording, and you'll have to ask for fewer apologies because people find fault with your sloppy statements, and with the way you use constructs as if they were physical entities, while disregarding true physical entities.
viscount aero
Re: the absurd implied density of moons kills gravity
marengo wrote:
viscount aero wrote: You're still stuck on "point source" which I explained is a fallacious phrase and idea. A point cannot exert any influence of gravity as it is massless and dimensionless. Objects are not attracted to dimensionless points. It is further false when considering that there is no gravity at the alleged core, absolute center, of any planet.
And you are still stuck on the meaning of words.
Yes because that is the source of all expression here. Without effective communication in texting we have nothing. One thing has been proven in multiple offenses: You are the master of sleight of hand with language and you are being held to the fire by me. Your convenient bending of meanings allows you to move goal posts and spin whatever rubbish you find necessary.
marengo wrote: You cannot seem to separate the theoretical from physical reality.
LOL! You're talking about yourself!
marengo wrote: Theoretical ideas are useful concepts to aid understanding.
Yeah I know that.
marengo wrote: In your case they just confuse you.
No. That is 180º from the truth. I totally understand metaphor, symbolism, analogy, conceptual thinking, etc...
marengo wrote: Gravity 'appears' to emanate from a point source. You will no doubt try dissecting the word 'appears' for the next ten posts.
Ok but even if you can calculate gravity as if the source were a single point we both know that is not at all a mirror of reality. The center of the Earth and all planets theoretically have no gravity whatsoever. How can something be attracted to the center of nothingness?
This illustrates that mathematical calculations are not outright demonstrative of physical reality. Some are, many are not. Math is highly useful. For the record, I have never advocated abandoning mathematics in general. Math is a gift to mankind. However a distinction must be drawn between concept and reality. How close to an actuality is a given concept?
Despite its applied usefulness in the sciences and technology, mathematics cannot actually act as a stand-in for reality particularly when attempting to apply it to cosmology, ie, gravitation. I have stated my position on mathematics in that context dozens of times throughout this site. In general, cosmology demonstrates a perpetual "Clashing of the Maths." In other words, math doesn't work consistently in cosmology from subject matter to subject matter, nor does it find itself expressing true reality, the "point source" being a great example. In many cases cosmological math is only describing a fantasy world based on pure creative imagination and assumption. The Universe turns math on its head (which attests to the eternal mystery posed by the Cosmos--it cannot be harnessed or figured out ultimately).
Therefore it is misleading to denote that gravity emanates from a "point source." It does not and it cannot for the reasons I have stated previously. When you state "point source" for gravity you are not talking about physical reality. That is why I object to your assertions in that direction.
marengo
Re: the absurd implied density of moons kills gravity
CharlesChandler wrote: So your theory predicts gravitational lensing, and I question whether or not it has actually been measured, and you respond that your theory predicts these effects. Then I call attention to the fact that you're putting all of your weight on theory, and none on measurements, and you say that the predictions of a theory must be measured. And of course, you're convinced that Eddington's measurements confirm your theory. But wait... you never established that Eddington's instrumentation was accurate enough to rule out the mirage effect to within a couple of arc seconds. How are you going to do that? By telling me that it doesn't matter — your theory predicts such effects?
You constantly refuse to discuss gravitational redshift which has been accurately measured and is just another effect of the gravitational slowing of light by a massive body as is gravitational light bending.
CharlesChandler wrote: You're assuming the conclusion. Einstein's theory predicted gravitational lensing. Newton's did not. Therefore Newton is wrong? But wait... did anybody measure gravitational lensing before concluding that Einstein was right, and were the measurements independently confirmed before being accepted? Ummm... we still don't have the instrumentation necessary to estimate the mirage effect to within a couple of arc-seconds, which means that we still don't have confirmation of gravitational lensing. This means that you're solving a non-problem.
See my comments above.
CharlesChandler wrote: @viscount aero: I'd take that one as a compliment if I were you! He appears to have theory and physical reality fully divorced, and he's on the wrong board to be talking trash like that. You can do that on CosmoQuest, or JREF, but not here. We don't all agree here, but at least we understand that theory cannot be separated from physical reality.
Your comments above are uncalled for and seriously diminish you. The physical reality is that gravitational redshift is observed and requires a theory to explain it
marengo
Re: the absurd implied density of moons kills gravity
viscount aero wrote: Ok but even if you can calculate gravity as if the source were a single point we both know that is not at all a mirror of reality. The center of the Earth and all planets theoretically have no gravity whatsoever. How can something be attracted to the center of nothingness?
You prefer arguing to doing physics. As anyone so far got to the centre of a planet? NO. You spend your time dealing with fantasy rather than reality.
viscount aero wrote: This illustrates that mathematical calculations are not outright demonstrative of physical reality. Some are, many are not. Math is highly useful. For the record, I have never advocated abandoning mathematics in general. Math is a gift to mankind. However a distinction must be drawn between concept and reality. How close to an actuality is a given concept?
Then why dont you sometimes use logic and maths.
viscount aero
Re: the absurd implied density of moons kills gravity
marengo wrote:
viscount aero wrote: Ok but even if you can calculate gravity as if the source were a single point we both know that is not at all a mirror of reality. The center of the Earth and all planets theoretically have no gravity whatsoever. How can something be attracted to the center of nothingness?
You prefer arguing to doing physics. As anyone so far got to the centre of a planet? NO. You spend your time dealing with fantasy rather than reality.
No. I am doing physics. The physical concepts are the same whether I speak it or have it expressed as an equation. I'm not a mathematician and never will be nor claim to be. I will never express myself with math using equations. But my reasoning can follow a logic that can be mathematically expressed.
Conversely, your verbal reasoning is often a nonsense and is not logically sound verbally or scientifically.
marengo wrote:
viscount aero wrote: This illustrates that mathematical calculations are not outright demonstrative of physical reality. Some are, many are not. Math is highly useful. For the record, I have never advocated abandoning mathematics in general. Math is a gift to mankind. However a distinction must be drawn between concept and reality. How close to an actuality is a given concept?
Then why dont you sometimes use logic and maths.
Ok, g at any radius r, less than rEarth, will be linearly proportional to the distance from the center. At the center the gravity will be zero. In other words, the net gravitational force on a "point mass" inside a spherical shell of mass is zero. This is the same thing I have been saying all along. Go look it up: "Gravity Force Inside a Spherical Shell". They will provide all manner of equations and operations but the logic is the same. The conclusion is the same. I'm not designing a space craft or device to traverse the center of the Earth or anywhere so I don't need to perform a mathematical feat of engineering for such purpose. We're talking about the fallacy of a point mass. There is no such thing. "Point" and "mass" are mutually contradictory words.
marengo
Re: the absurd implied density of moons kills gravity
viscount aero wrote: Ok, g at any radius r, less than rEarth, will be linearly proportional to the distance from the center. At the center the gravity will be zero. In other words, the net gravitational force on a "point mass" inside a spherical shell of mass is zero. This is the same thing I have been saying all along. Go look it up: "Gravity Force Inside a Spherical Shell". They will provide all manner of equations and operations but the logic is the same. The conclusion is the same. I'm not designing a space craft or device to traverse the center of the Earth or anywhere so I don't need to perform a mathematical feat of engineering for such purpose. We're talking about the fallacy of a point mass. There is no such thing. "Point" and "mass" are mutually contradictory words.
I am well aware of zero acceleration inside a spherical shell. Just tell me where you can find one. Try dealing with reality instead of some theoretical construction which does not exist. It seems to me that you always take the most awkward standpoint that you possibly can in order just to be argumentative.
I am also totally aware that there is no such thing as a point mass. You are pretending that I think so in order o be argumentative. I said EFFECTIVELY. You do not understand theoretical concepts. They are used all the time in physics. The inertial reference frame is another one. Spacetime is another.
I will now repeat a statement of physics. Gravitational potential is the speed of light. What do you make of that?
viscount aero
Re: the absurd implied density of moons kills gravity
marengo wrote:
viscount aero wrote: Ok, g at any radius r, less than rEarth, will be linearly proportional to the distance from the center. At the center the gravity will be zero. In other words, the net gravitational force on a "point mass" inside a spherical shell of mass is zero. This is the same thing I have been saying all along. Go look it up: "Gravity Force Inside a Spherical Shell". They will provide all manner of equations and operations but the logic is the same. The conclusion is the same. I'm not designing a space craft or device to traverse the center of the Earth or anywhere so I don't need to perform a mathematical feat of engineering for such purpose. We're talking about the fallacy of a point mass. There is no such thing. "Point" and "mass" are mutually contradictory words.
marengo wrote: I am well aware of zero acceleration inside a spherical shell. Just tell me where you can find one. Try dealing with reality instead of some theoretical construction which does not exist.
That is one of the bases for gravitational theory today. I am only acting as a messenger here. I did not invent the idea. Most of the standard model is fashioned upon theoretical constructions. Einstein's STR and GR are theoretical constructions. But about a point mass: It is ironic in that, theoretically, gravity calculated for falling bodies assumes a zero g moment at the center of the body, with diminishing gravity occurring up to the point. So what is the falling body attracted to? It cannot be the "point" at the center. That has been my whole point for past few posts: A body is attracted to regions of ever diminishing gravity up to zero g. How is this possible? This more a question for general preponderance. You personally don't need to answer or address it. You've been a catalyst for further exploration however.
excerpt from: http://hyperphysics.phy-astr.gsu.edu/hb ... hell2.html "The net gravitational force on a point mass inside a spherical shell of mass is identically zero! Physically, this is a very important result because any spherically symmetric mass distribution outside the position of the test mass m can be build up as a series of such shells. This proves that the force from any spherically symmetric mass distribution on a mass inside its radius is zero. If a given mass m is inside a spherically symmetric distribution of mass, that part of the mass outside its radius does not contribute to the net force on it."
and here: http://hyperphysics.phy-astr.gsu.edu/hb ... le.html#c1 Journey through the center of the Earth excerpt: "For a spherically symmetric mass, the net gravity force on an object from that mass would be only that due to the mass inside its radius, and that would act as if it were a point mass located at the center. When this is analyzed in detail, you find that the gravity at any radius r less than REarth will be linearly proportional to the distance from the center."
That is all theoretical concept. It's not that difficult to understand. Most people who lurk and post on this site are curious and more than likely understand theories of cosmology. They may not agree with some of them but they are generally understood. Discussions such as this, too, help readers to picture in their minds what possible abstraction is being discussed.
marengo wrote: It seems to me that you always take the most awkward standpoint that you possibly can in order just to be argumentative. I am also totally aware that there is no such thing as a point mass. You are pretending that I think so in order o be argumentative. I said EFFECTIVELY. You do not understand theoretical concepts.
I just posted the theoretical concept for a point mass, and links with math, and I understand the general idea very clearly. Theory and models are applied in the absence of fact and act as fact in most cases, ie, local effects of gravitation. Newton's universal law for gravitation F = Gm1m2/r2 generally works up to a point (as it is not actually universal). So it is highly useful. Almost anyone could understand it who can read.
marengo wrote: They are used all the time in physics. The inertial reference frame is another one. Spacetime is another.
Yes I know. We agree.
marengo wrote: I will now repeat a statement of physics. Gravitational potential is the speed of light.What do you make of that?
I don't think anyone knows what you mean by that. You've been saying that for months now. When asked to explain it you don't. Maybe you don't understand it either!
marengo
Re: the absurd implied density of moons kills gravity
viscount aero wrote: marengo wrote: I will now repeat a statement of physics. Gravitational potential is the speed of light. What do you make of that?
I don't think anyone knows what you mean by that. You've been saying that for months now. When asked to explain it you don't. Maybe you don't understand it either!
The gravitational potential is the speed of light' is a statement. If you disagree then you must say why you disagree. If you believe the grav.potential to be something different then please tell me what you think it is. But please do not remain dumbstruck.
It's still amazing to realize that what planets are composed of, how they are structured, is actually unknown. Yet we live on one.
He appears to have theory and physical reality fully divorced, and he's on the wrong board to be talking trash like that. You can do that on CosmoQuest, or JREF, but not here.
We don't all agree here, but at least we understand that theory cannot be separated from physical reality.
marengo wrote:It would be just a tad more accurate to say that gravity can be calculated as if it emanated from a point, and assuming that you're completely outside of the sphere. The gravitational sources are the particles with mass, and if they're distributed, the gravitational sources are distributed. But the calcs can be simplified.
