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The gravity of things

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posted on Jul, 17 2022 @ 12:26 AM
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a reply to: ErosA433




The Standard model of particle physics has a few places in which you could 'easily' insert a new particle, or lets say, that there are postulated candidates that would actually be quite welcomed.


Oh, sure! But the problem is that most of such few places are already at the reach of current colliders' energy range, yet none of those particles have been detected. A nice example are supersymmetric partners: they should have been detected by now, but they have not (that's the problem with SUSY). Additionally, inserting new particles causes all kind of violations (lepton number violation is the obvious one). On the other hand, postulating new particles when the standard model has not even been able to account for neutrino masses means perhaps it's time to start from scratch reformulating a new model (the unexplained mass spectrum problem was always a caveat for the standard model). And yes, the Higgs mechanism explains how particles get mass, but it doe not explain at all why they get exactly the mass values you measure.

But even accepting dark matter consists of a yet unknown particle, the energy density of dark matter accounts for roughly one fourth of the critical energy density, so DM is not an answer to the problem by itself: you still need to justify the origin of the remaining energy density deficit, which clearly points to GR rather than QM.

Finally, the mere supersymmetrization of the SM faces an immediate problem, as I'm sure you know. The most general Lagrangian you could formulate already contains terms that violate baryon and lepton numbers producing a too fast proton decay, something which is clearly a catastrophic result. Given all this, I still prefer to exhaust the exploration of changes in GR rather than tweaking and re-tweaking , and tuning and finetuning the standard model.



posted on Jul, 17 2022 @ 05:26 AM
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Great post Terpene. keep up the good work.

If we blindly belive scientists we Dont find the truth and move on.
we would still belive the earth is flat!
Flat earth was the science of old.
a Grate deal of what we belive now
will be stupid in 500 years.



posted on Jul, 17 2022 @ 06:32 AM
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a reply to: Arbitrageur


The earth radius is 6378 km at the equator and if peak gravity occurs at about 3400 km from Earths' center, that's not close to the surface at all, it's just over half the distance to the surface.


Ok, thanks for the specification.
I hope I'm at least right about this

it has to do with the total of mass as the core makes up most of earth mass.


Lets take a planet where the mass of its denser core equals the mass of its less dens surrounding, would the mass of the less denser surrounding add to the total gravity and emanate from its surface or would we see the same discrepancies moving to the center? Where would gravity be highest?



posted on Jul, 17 2022 @ 10:12 AM
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originally posted by: Terpene
Ok, thanks for the specification.
I hope I'm at least right about this
"it has to do with the total of mass as the core makes up most of earth mass."

As far as I know that is very wrong. I say "as far as I know" because estimates of the mass of the core versus the mass of the mantle can vary a bit, but most estimates I've seen seem to be not too far from the following values for the purposes of this discussion:

Geochemistry

The solid Earth is made up of three fundamental layers, the core, mantle and crust, which are the products of planetary differentiation. The core, which is about half and Earth radius wide or only about 1/8 of an Earth volume, makes up about 1/3 of the Earth's mass

So if the core makes up 1/3 of the Earth's mass, that means most of the Earths' mass (~2/3) is NOT in the core.


Lets take a planet where the mass of its denser core equals the mass of its less dens surrounding, would the mass of the less denser surrounding add to the total gravity and emanate from its surface or would we see the same discrepancies moving to the center? Where would gravity be highest?
Hopefully this question seems irrelevant since the assumption upon which it was based was completely wrong. Think in terms of density. Recall this comment I made in a post I made earlier in the thread:

www.abovetopsecret.com...

originally posted by: Arbitrageur
Getting back to your question on density, the Newton formula is all amout mass and again is a pretty good approximation.
But it's based on the center of mass, so the density may affect things like surface gravity of a planet. A denser planet will have higher gravity on the surface than a less dense planet even if the planets have equal mass. This is simply because the surface is closer to the center of the denser planet.
So I gave you an example of two planets with equal mass but different surface gravity because they have different density.

We expect there is higher gravity near Earth's core because the core has higher density, not because the core has higher mass.



posted on Jul, 17 2022 @ 01:29 PM
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a reply to: Arbitrageur

a reply to: Arbitrageur

That seems to at least hint at an unaddressed answer of mine.

if i had x mass, would that mass bend the fabric to the same depth no matter its density. Or does it bend the fabric more when its denser or is it only the curvature that is diffrent with diffrent density?

Sounds like density is affecting gravity, more than mass does.
Does this apply to atoms too?
Osmium being the densest material does it has the highest gravity of all materials known, and where between mass and density is the threshold. Like from what density on would you expect mass to determine gravity of other less denser mass?
Does matter even compress without gravity? Isn't denser matter settling towards the center because of gravity? What made it go there in the first place?



posted on Jul, 17 2022 @ 09:16 PM
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originally posted by: Terpene
a reply to: Arbitrageur

a reply to: Arbitrageur

That seems to at least hint at an unaddressed answer of mine.

if i had x mass, would that mass bend the fabric to the same depth no matter its density. Or does it bend the fabric more when its denser or is it only the curvature that is diffrent with diffrent density?

Sounds like density is affecting gravity, more than mass does.
I wouldn't say that. Remember the example of the two planets with the same mass but different densities and different surface gravities?

If you had identical moons around those planets they might be in identical orbits. The moons can't tell the difference in the density if they are far enough away, like our moon is from Earth. So in that example of the moon orbits, planet density doesn't matter at all, it's only mass.


Does this apply to atoms too? Osmium being the densest material does it has the highest gravity of all materials known, and where between mass and density is the threshold. Like from what density on would you expect mass to determine gravity of other less denser mass?
I don't really understand the question. In the example of the planets with orbiting moons above, the density matters for surface gravity of the planets, but it doesn't matter for moon orbits. One threshold in that case would be to get beyond the radius of the less dense planet, so at that distance and greater the acceleration due to gravity would be the same for both the more dense and less dense planets.

As I already explained for atoms:
www.abovetopsecret.com...

In Newton's approximation gravity occurs between masses. In Einstein's model it's between masses and energy as I already explained in this thread, with a minutephysics video explaining this. So since individual atoms have mass and energy, gravity occurs even between atoms. But we don't usually talk about this much because the gravity is maybe a trillion trillion trillion times weaker than other forces, like the electromagnetic interaction, and is even weaker still from other forces, the strong and weak nuclear forces.

When we talk about gravity at Earth's surface, it's between every atom in your body being attracted to every atom in the Earth. If you go below Earth's surface toward the higher density inner core, the varying densities of the Earths' interior complicate things. It's still every atom in your body attracted to every atom in Earth, but inside the Earth you have different atoms pulling on you in different directions (or warping spacetime in different directions if you prefer), so how Earth's mass is distributed internally (which is not homogeneous) will affect the gravitational acceleration inside the Earth.

But at the atomic level there are much stronger forces creating density, like the strong nuclear force, which allows all those Osmium protons and neutrons to get compacted so closely


Does matter even compress without gravity?
It depends on how you define "compress" I suppose, but sure gravity is a dominant form of compression which occurs in stars allowing fusion to take plase inside the star. One reason fusion power on earth is so hard to do economically is because it takes so much energy to compress and heat up the fusion reaction to conditions like the interior of a star. But there are much stronger forces than gravity like the strong nuclear force, which allows the protons and neutrons in Osmium and other heavy elements to get packed closely together, making dense nuclei.


Isn't denser matter settling towards the center because of gravity? What made it go there in the first place?
In the case of a star forming it's gravity which causes the disk of gas to collapse and form a star and probably all the planetisemals which will eventually form a planetary system. Again every atom gets attracted to every other atom and they all tend to get pulled together. But there are counteracting factors like the rotation of disk where "centrifugal force" prevents the total collapse and allows the planets to form.

edit on 2022717 by Arbitrageur because: clarification



posted on Jul, 17 2022 @ 10:19 PM
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originally posted by: Direne

Oh, sure! But the problem is that most of such few places are already at the reach of current colliders' energy range, yet none of those particles have been detected. A nice example are supersymmetric partners: they should have been detected by now, but they have not (that's the problem with SUSY).

Yes and no - see most of the reasons why SUSY is disfavoured is political, it is exactly because if it still exists, it would most certainly be well outside the reach of current colliders energy range by roughly an order of magnitude or so. THATs the whole problem, it actually doesn't mean we can cross it off as a possibility.




Additionally, inserting new particles causes all kind of violations (lepton number violation is the obvious one).

Not really - see adding a sterile neutrino doesn't violate lepton number in its interactions. The other possibility is that neutrinos are Majorana which would actually mean that fundamentally neutrinos may violate lepton number at will without any problems since they are their own antiparticles.



On the other hand, postulating new particles when the standard model has not even been able to account for neutrino masses means perhaps it's time to start from scratch reformulating a new model (the unexplained mass spectrum problem was always a caveat for the standard model). And yes, the Higgs mechanism explains how particles get mass, but it doe not explain at all why they get exactly the mass values you measure.

Deriving the mass from first principles has always been a problem, inferring them, mmmm only a BIT of a problem. Which is actually where the heavy right handed sterile comes in. The see saw mechanism would give an extremely well founded and motivated origin of the mass ranges that the neutrinos have and probably the hierarchy too.




But even accepting dark matter consists of a yet unknown particle, the energy density of dark matter accounts for roughly one fourth of the critical energy density, so DM is not an answer to the problem by itself: you still need to justify the origin of the remaining energy density deficit, which clearly points to GR rather than QM.

If we are talking about what we observe in gravitational models, dark matter solves that problem. The real enigma is dark energy which is what i think you are talking about in this. but correct me if I misinterpret you. So in short... dark matter fixes or solves the issues with orbits of galaxies in clusters and stars within galaxies etc... however it doesn't fix the observed acceleration in expansion of the universe.



Finally, the mere supersymmetrization of the SM faces an immediate problem, as I'm sure you know. The most general Lagrangian you could formulate already contains terms that violate baryon and lepton numbers producing a too fast proton decay, something which is clearly a catastrophic result. Given all this, I still prefer to exhaust the exploration of changes in GR rather than tweaking and re-tweaking , and tuning and finetuning the standard model.

Yeah this is where naturalness and fine tuning comes in, which is the real part where theorists kinda go "well this is getting a bit to messy and complex sooooooo the model is disfavoured." Personally I don't see why the universe has to be simple, despite the general principle that it is often the simplest solution that is the right one. If i was to bet... id say SUSY doesn't exist... but yeah we shall see.



posted on Jul, 18 2022 @ 12:23 AM
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a reply to: ErosA433

Eros, I see you do favor the sterile neutrino option. Admittedly, it is the one proposal with requires minimum shifting of the current worldview, if and only if one feels a bit detached from whatever GR has to say about the very fabric of spacetime.

So yes, we could agree most of the dark matter must be non-baryonic in nature and, in addition to that, the dark matter particle should be stable and electrical and color neutral. Neutrinos were the preferred SM candidates, albeit the estimated relic density falls far short of what's required, therefore one was "forced" to introduce some changes to the nature of the SM neutrinos, and thus the new flavor was born: your sterile neutrinos. If we rule out SUSY (MSUSY) we then rule out the best candidate it has to offer: the neutralino (and so we can dispose of those pesky binos, winos, and Higgisinos).

And now that the table is free from all those beasts we could focus on designing a proper sterile neutrino. A singlet-fermion purely SMish is not asking for much, but then we run into the old problem of agreeing on what its mass should be, and how its mixing with known particles would be, which is certainly a new Vietnam...

I am a relativist, so I'm just waiting for your sterile neutrino. If it turns out to be a KeV sterile neutrino (and mildly non-relativistic), then I will certainly throw at it all the constraints imposed by the large-scale structure of my manifold. It indeed is my only condition: we need to explain not just how the Universe came to be the way we observe, but also why does it have the distribution and large-scale structure we observe.

WIMPs, axions, and sterile neutrinos are the contenders, but only because what you call a minimum change to SM is based solely on introducing new particles. Why not keeping SM as is, and introducing... an extra dimension? That is the Kaluza–Klein Dark Matter proposal, which I find more to my liking. There you can have a SUSY-like plethora of particles (the KK tower) and then you can find that the first KK partner of the hypercharge gauge boson is as good a candidate for a bosonic DM as a sterile neutrino (without having to cool down your otherwise too hot sterile neutrino).

So yes, I agree with you in the criticism of SUSY, but I still prefer a GR-like solution: adding an extra dimension instead of adding a new particle (mind: I do believe there is new physics beyond Higgs as, in the SM, the Higgs boson mass is
unstable owing to large radiative corrections; therefore, the discovery of the Higgs boson with a finite mass clearly indicates that physics beyond the SM must exist to stabilize the mass and I find room for sterile neutrinos in that scenario).

On the political criteria to rule out SUSY I think it is fair to also accept that, SUSY or not, new physics requires more and more powerful colliders, and more and more efficient algorithms to deal with the vanishing short-lived tracks in the detectors. This holds for all those future billion-euro scale facilities like DUNE and Hyper-Kamiokande, too.

NB:

Yes, the paragraph you mentioned in your reply was meant to read dark energy instead of dark matter. Sorry, my bad.



posted on Jul, 18 2022 @ 12:43 AM
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looks ok. still watching.




posted on Jul, 18 2022 @ 02:46 AM
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a reply to: Arbitrageur


So in that example of the moon orbits, planet density doesn't matter at all, it's only mass.

Why I was assuming that gravity would keep growing until there is no more mass between me and the center. So why is all the mass from the core onward not adding to total gravity when mass is the defining factor?


in the case of a star forming it's gravity which causes the disk of gas to collapse and form a star and probably all the planetisemals which will eventually form a planetary system. Again every atom gets attracted to every other atom and they all tend to get pulled together. But there are counteracting factors like the rotation of disk where "centrifugal force" prevents the total collapse and allows the planets to form.

ok, so I have a mass of not dense gas what is causing the gravity that attracts all the atoms to one singular point causing it to collapse under gravity, when every atom atract every atom and there is no significantly denser material?



posted on Jul, 18 2022 @ 03:26 AM
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originally posted by: Terpene
a reply to: Arbitrageur


So in that example of the moon orbits, planet density doesn't matter at all, it's only mass.

Why I was assuming that gravity would keep growing until there is no more mass between me and the center. So why is all the mass from the core onward not adding to total gravity when mass is the defining factor?
The mass from the core onward is adding to total gravity! The gravitational acceleration at the "surface" of the core is not the "total" gravity.

Let's say there was just earth's core, which has about 1/3 of the gravity we have now. The moon would feel only 1/3 the gravity if the mass was only 1/3 as large.

The reason gravitational aceleration is higher at the "surface" of the core is because you're closer to Earth's center, and the density of the core is a lot higher. Remember the example of two stars with the same mass but different densities? The gravitational acceleration on the surface of the denser planet is only higher because of being closer to the center. The "total mass" and thus the total gravity of each planet is the same.


ok, so I have a mass of not dense gas what is causing the gravity that attracts all the atoms to one singular point causing it to collapse under gravity, when every atom atract every atom and there is no significantly denser material?
Here's a description of what leads to star formation, a collapse of molecular clouds.

How Do Stars Form?

Molecular clouds in the interstellar medium are large. In fact, a single molecular cloud can be hundreds of thousands of times heavier than the Sun. Their volumes also vary: a molecular cloud can be the same size as, or many times bigger than, our entire solar system. These enormous molecular clouds undergo turbulent motion. This means that the gas and dust within the clouds do not stay in the same place as time passes. These substances move around in all directions, like children running around in a school yard. This turbulent motion of the gas and dust distributes the atoms and molecules unevenly, so that some regions of the molecular cloud will have more matter in them than other regions Figure 1A. If the gas and dust pile up to a very high level in a certain region, that region starts to collapse due to the pull from its own gravity. The region is smaller than the molecular cloud and lives inside the molecular cloud. The region is “only” a few hundred Astronomical Units (AUs), which is a few hundred times the distance from the Earth to the Sun.
It's more complicated than that, but that should give you some idea.

Center of mass need not have any mass at all. Here are examples of everyday objects which have a "center of mass" with no mass at all. All the atoms in these objects are attracted to a center of mass where nothing is there. If you made a gas cloud in distant space in these shapes, the atoms in the gas cloud would tend to collapse to the center of mass.


CG=Center of Gravity aka center of mass for the purpose of this discussion. Note there is nothing there in these objects, it's a massless point in space.


originally posted by: sarahvital
looks ok. still watching.

I'm not crazy about her description of the International Space Station at 7 minutes, when she says "It has no engines anymore, the engines are turned off."

It does have engines on the Zvezda service module, and they are usually turned off, but they do turn them on once in a while to boost the decaying orbit (or they can attach a spacecraft to the Zvezda service module and use the spacecraft engines). It wouldn't be that hard or confusing to say that, so I don't know why she didn't. Maybe she didn't want to get into why they have to turn on the engine once in a while.


That video demonstrates the effect of the re-boost engine and explains why the reboost is needed once in a while. She also says "once it's out there, it's not coming back down", which again is not true, because it's always coming down slowly due to the small drag, which as explained in the ISS video is why they have to use the boosters once in a while.

This type of thing is par for the course for just about every science documentary...they almost all tell us incorrect things for the sake of simplicity, when the reality is more complicated than what's being explained and the scientists usually know the more complicated and more accurate explanation.

When she explains gravity to level 2, the teen, most of the time it seems like she's talking about relativity, then special relativity, which is not really about gravity. It's general relativity that is about gravity but it's probably too complicated to explain to that student. She does explain some of Einstein's intuition leading to general relativity to the level 3 college student.

edit on 2022718 by Arbitrageur because: clarification



posted on Jul, 18 2022 @ 04:37 AM
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yes the explanation is pretty much geared to who she is talking to.



posted on Jul, 18 2022 @ 05:18 AM
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a reply to: sarahvital

your low shots, are dully noted



posted on Jul, 18 2022 @ 08:12 AM
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The mass from the core onward is adding to total gravity! The gravitational acceleration at the "surface" of the core is not the "total" gravity.



if i had x mass, would that mass bend the fabric to the same depth no matter its density. Or does it bend the fabric more when its denser or is it only the curvature that is diffrent with diffrent density?


Like the denser the deeper the perturbation, or is the depth the same, but only the steepness is diffrent?



posted on Jul, 18 2022 @ 09:16 AM
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originally posted by: Terpene
Like the denser the deeper the perturbation, or is the depth the same, but only the steepness is diffrent?
I'm not sure this language is adequately descriptive because you're ignoring the math. At some point you should stop ignoring the math and start incorporating it into your thinking to clear this up. You say nothing about the radius here, or distance between the objects, and maybe that's part of your confusion. The radius or distance between the objects is a huge part of Newton's gravity equation and you won't have a clear description without it.

If you want to express it in words I've already said it three times with the planet examples. The density only matters when you're closer to the center of mass of the two planets with the same mass but different densities and different surface gravities, because the densities don't affect the moon orbits at a distance.

What the less dense planet does is block you from getting to any steeper part of the inverse square curve because the surface is further from the center. On the more dense planet you get closer to the center, so there you can get to a steeper curve, but just between the radius of the denser planet and the radius of the less dense planet. Above the radius of the less dense planet, the curves or "steepness" is identical for two planets of identical mass.

So in that example, within certain ranges of radius the "steepness" is identical and with other ranges of radius the steepness is not the same. You can't ignore radius and unambiguously talk about "steepness". So when you ask if steepness is different with the two planets of the same mass but different density, the ambiguous answer is both yes and no, because the question is ambiguous as it ignores radius, one of the most important factors in Newton's equation. There aren't many factors in Newtons' equation so it's not a factor you should be ignoring:

Newton's law of universal gravitation



edit on 2022718 by Arbitrageur because: clarification



posted on Jul, 18 2022 @ 10:10 AM
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a reply to: Arbitrageur

I mean, if mass is the same and the only changing factor to said mass is density. It would seem to me, that the denser the mass, the smaller it's radius?

like obvious
but maybe not?



posted on Jul, 18 2022 @ 10:30 AM
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a reply to: Terpene
If you're talking about just the gravitational acceleration at the surface of a planet, yes.
But in general, if you have two planets with the same mass and different density, and want to calculate the orbits of some moons around those planets, at the same radius to the moons (specifically center of the planet to center of the moon) the radius you plug into Newton's equation is identical. So you don't have a smaller radius to the more dense planet in the case of a moon orbit.



posted on Jul, 18 2022 @ 02:05 PM
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a reply to: Arbitrageur

Man what satisfaction to get an ALMOST unambiguous yes from you


I was mainly scratching my head about the stuff happening to ME on the surface of the planet going up or down due to gravity.

Like just before i was looking for an answer of how long the transition takes for astronauts from sitting in their chairs to being weightless, turns out they aren't really weightless, gravity is just 10% weaker at the ISS than at surface. Is there a limit, other than energy capacity, as to what hight you could achieve zero g orbits? Could i have a zero g orbit on the ground with enough speed? Is the centripetal force always equal gravity?

I hope I'm starting to understand a little better, I'll just postulate some things i think to have glanced so far, feel free to expand or not if I'm way off.
on an atomar scale the weak force of gravity is not really observable in its interaction and mostly irrelevant?
its just happenstance that a gravity center is created in non dense mass?
the perturbation in the uniform mass creating a denser cluster with a singular gravity point is due to strong forces?
Every thing from that point on is just things falling down the gravity well?
The gravity wells inverse square geometry defines gravitational acceleration?

It's baffling that something has little influence close up but its effects reach so far, especially considering that the inverse square implies that the force is strongest from where it emits.

I fail to imagine the dynamics once you enter the steep part of that inverse square graph and im not sure about the correlation to the physical location on earth.

Earth gravity is highest at the core surface, so is the peak/start of that inverse square graf at the surface of the core or at the center?

If the calculation is done from center to center, shouldn't that inverse square start at center as highest?

It kind of feels like gravity is just an effect of the perturbation in time space and not really a force doing anything.


edit on 18-7-2022 by Terpene because: (no reason given)



posted on Jul, 18 2022 @ 03:04 PM
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originally posted by: Terpene
Man what satisfaction to get an ALMOST unambiguous yes from you
Right, but the way the universe works can be complicated so we should only try to simplify it as much as it's accurate enough to meet our needs. This means sometimes the simplest interpretations don't explain everything. Newton's math explained most things for centuries, and is still good enough for explaining many things. But, it doesn't work everywhere so there's even room for making a choice of which gravity math you need to use for your application (Newton's or Einstein's).


Like just before i was looking for an answer of how long the transition takes for astronauts from sitting in their chairs to being weightless, turns out they aren't really weightless gravity is just 10% weaker at the ISS than at surface. Is the centripetal force always equal gravity?
In geosynchronous orbit I think so, but those are stable orbits. Orbits don't have to be stable, they can spiral in or out if the momentum of the orbiting body and gravity aren't in balance.


I hope I'm starting to understand a little better, I'll just postulate some things i think to have glanced so far, feel free to expand or not if I'm way off.
on an atomar scale the weak force of gravity is not really observable in its interaction and mostly irrelevant?
Yes, the gravity is still there but it's usually dwarfed by other forces at that scale, electromagnetic or nuclear.


its just happenstance that a gravity center is created in non dense mass?
I suspect it's more or less determinstic but identifying all the variables is often difficult so it may seem like happenstance.


the perturbation in the uniform mass creating a denser cluster with a singular gravity point is due to strong forces?
Confusing terminology to refer to "strong forces" since the strong nuclear force is what holds neutrons and protons together in an atomic nucleus, and such atomic nucleii are extremely dense. Gravitational interaction is considered to be an exceptionally weak force, it's about 1000000000000000000000000000000000000 times weaker than the electromagnetic interaction and about 1000000000000000000000000000000000000 times weaker than the strong nuclear force. If an interstellar medium is hot and ionized, electromagnetic forces can play a role.


The gravity wells inverse square geometry defines gravitational acceleration?
Well, it doesn't do that for the interior of the Earth does it? And you seem to be interested in things like that. It does above the surface of the Earth.


It's baffling that something has little influence close up but its effects reach so far, especially considering that the inverse square implies that the force is strongest from where it emits.
It may sould baffling at first but it's really not. Gravity may be an extremely weak force on an atomic scale, but a body like the Earth has so many atoms that the forces of all those atoms adds up.

It's like if you had a few pennies you wouldn't consider yourself rich. But if you had enough pennies, you would be rich, where the pennies are like the small amounts of gravity that atoms have.


Earth gravity is highest at the core surface, so is the peak/start of that inverse square graf at the surface of the core or at the center?
Simple Inverse square of the entire Earth's gravity begins at the surface of the Earth and on upward. But actually in a more complex fashion, the inverse square applies within the earth too, between every atom in your body attracted to every atom in the Earth, it's just that when you add up all those inverse square relationsips it gets rather complicated. In fact even adding a third body is more complicated than a two body problem.


If the calculation is done from center to center, shouldn't that inverse square start at center as highest?
Center to center is a simplified calculation we can do to approximate attraction between bodies like the earth and the moon. But the real more complex way gravity works is every atom on Earth attracts every atom in the moon, it just turns out the simple equation from Newton gives a good approximation of that. Newton's approximation is no longer a good approximation when you start burrowing into the earth.


It kind of feels like gravity is just a effect of the perturbation in time space and not really a force doing anything.
Perhaps gravity isn't a force at all, in fact that's one possible interpretation of Einstein's math. If your car makes a sharp right turn, you feel "forced" to the outside of the curve to the left by "centrifugal force", but centrifugal force is a "fictitious force", meaning it's actually your momentum pusing you toward the left side of the car, and momentum is not a real "force". Likewise, gravity may also be a "fictitious force", but it doesn't feel fictitious at all when you land hard after falling down the stairs. It's a matter of how we define different reference frames and real forces versus fictitious forces.

However we still teach that gravity is one of the four fundamental forces to beginning students, and we don't get into teaching about Einstein's math and gravity being a fictitious force until the students take more advanced courses.


edit on 2022718 by Arbitrageur because: clarification



posted on Jul, 18 2022 @ 05:13 PM
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a reply to: Arbitrageur

Thank you so much, for taking the time. I definetly had a knot mixing Newton with Einstein. Also I feel sorry for not having taken a long hard look at the graf you posted in the beginning, couple of my questions would have become obsolete.

I will have to take some time and read into Einstein further. Maybe I will have more questions then.



It's like if you had a few pennies you wouldn't consider yourself rich. But if you had enough pennies, you would be rich, where the pennies are like the small amounts of gravity that atoms have.

More like, the paper money, which is half of everything, surrounding my other half of pennies, is only there to stop deflation. You wouldn't know the accuracy of that comparison yet

But on a more serios note, how are they creating a force that has a calculable center ? They are all separate bodies with their own gravity center. Why would they all be in my pocket, what makes them go there in the first place?



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