Black holes

mechsmith,

Gravity is not caused by the motions and forces between particles.

on a side note it's not just mass that has gravity -- all forms of energy have gravity.

Stuh,

I am happy to know that gravity is not a result some sort of interactions between masses and space-time.

If you could tell us what gravity is in much the same way that we would explain inertia for instance. Or temperature, or energy, or wave length, mankind will be forever in your debt.

As far as I am aware the best explanation for gravity is that it is the result of the curvature of space by mass. However this has limitations also and even Einstein wasn't very happy with himself and the explanation.(Probably why he became a socialist :wink: ) Consequently I think it still fair game for speculation!

You see, inertia, practically speaking, is the tendency of a mass to stay put unless one applies energy (or causes) to move it differently from whatever motion it may have. Consequently all orbital motions are straight paths in curved space. Mass curves space---- HOW

Gravity, as a force, is a tendency for mass to continually increase its density. What makes it do this Some characteristic of matter (or interchangeble energy) is responsible I am sure. What characteristic I have never found an explanation that isn't a prime example of circular reasoning.

We need an explanation for, not a description of gravity. Got one

There is a laser lab somewhere in Louisiana USA trying to detect gravity waves. I've lost the link somewhere but you may want to try searching
LISA for the gravity lab. Shouldn't be hard to find if you need a bit more confusion on the subject. I'll look a bit harder after I post this. It's an interesting site.

My memory was better than I give it credit for.


Google LISA and LIGO For the gravity wave labs. Have a good trip.

Mechsmith,

Please lose the sarcasm because you act as though I am claiming to know what causes gravity, when I said no such thing. Nobody knows this and I am no wiser.

On the contrary, YOU are the one who seems to have ideas on what causes gravity. You suggested that gravity was "caused by the relative motions and forces between atomic or sub-atomic particles."

I don't know what other mysterious "forces" you think can be used to describe gravity, but this theory of yours just doesn't hold up.

I'm way outta my depth here but.....

I remember an explanation of gravity (as Einstein saw it) that because mass curves space-time (not just space) that an object at rest in one instant will still be at rest in the next instant, but now closer to the mass that is causing the distortion, assuming nothing pushes against it to prevent it (such as the ground). That makes more sense to me, as it seems that no force is acting on the mass while it is falling, i.e. it is not moving at all from it's own perspective.....while clearly there is a measurable force of the ground against the object trying to fall.

All that remains is to understand what spacetime is and how exactly mass "curves" it....oh well.....

Well, when you get right down to it, in the end, the ultimate answer is ....

.... now that's a Deep Thought.

Aw Stuh,

Please don't get bent outa shape. I was emphatically noting that no one KNOWS what causes gravity. So far anyhow.

However being a mechanist of sorts I sorta tend to suscribe to "causality" as a prime mover. Noting that there probably never was a prime mover, or first cause as such.

Consequently something causes gravity to act as a force. If I knew what it was or if any body else did they or I would have a very light teaching load at Princeton. (And a decent salary)

I can imagine that "something" at least as well as a snake handling preacher. And I further can further imagine that that force is somehow related to the motions of sub-atomic particles. And if that force turns out to be related to the other three --- Well if we can unify the three forces then it just may be possible to include the fourth. And furthermore if we can figure out what causes gravity it may just be possible to nullify it. Under precise mechanical conditions of course .

If LISA finds gravitational perturbrations, which I think she will, and if they travel at "c"( which I don't think they will)(they will travel faster) then my hypothesis that gravity (as a force) does not exist when all molecular, atomic, sub atomic, and quantum forces are canceled out, my hypothesis would have some basis. They could be canceled by inertia perhaps.

So, in conclusion Stuh, If you think I am full of male bovine excrement then may I suggest that you look up the observations of quasars and then tell us how they work. Personally I think they work much better if you cancel gravity for a very brief time.

I hope that I'll live long enough to see LISA come home. But I am afraid that her answers will also be ambiguous. Thats been true of most the women in my life

it's great that you follow modern news in science but extremely naive of you to attempt to explain gravity by collisions of newtonian particles. it's simply absurd and i can't take anything you have to say on the subject seriously after that.

Eorl,
Thats what I have been trying to get at. Basically --How does Gravity (or mass) curve spacetime

IMO there must be some connection, and the only one that I can come up with is relative motion on some scale. Whether the motion of an electron relative to the nucleus, the charge of an electron,( another way of saying the same thing) or the spin or color of a quark, something is causing mass to act on mass or spacetime.

We call this characteristic of mass (the ability to act at a distance) gravity. I dunno. Is it an inherent characteristic of mass--OR is it an inherent chatacteristic of motion.

Thats why I got into this thread. Apparently nobody knows ---------- YET

Stuh,

Crossed Posts.


Can you tell me briefly and succintly, why gravity is NOT caused by by the relative motions of particles (or masses for that matter)

If we know what doesn't cause it maybe we can figure out what does.

it seems that you are trying to liken the force of gravity to something like pressure, where it is the interactions of many particles that result in a higher order force. gravity is a fundamental force and we know this because of it's mathematical simplicity, the fact that it works across great distances, and small distances, and in the absence of other interfering particles. it also works on pure energy in all forms. it may be mediated by the graviton, which would be a particle, albeit a massless one, but this is not the kind of particle you seem to be referring to.

and once again i do not know how the force is actually mediated. although spacetime warping is a useful mathematical construct for solving the equations i do not believe it is an accurate representation. philosophical discussions about the nature of gravity are destined to futility, it has all been thought about very carefully by men smarter than us...the only way for mankind to learn more about the nature of gravity is to make more precise and clever measurements and then let the thinking tanks ponder the new evidence. it is not for you nor i.

I'm sorry Stuh, but that just sounded like something that may have been written in 1907....or 1807....or 1707..... about things like computers, or flight, or disease.....

Imagination is more important than knowledge.

Right now, I'd say that Physics is due for another revolution if someone were to think of a new model that would fit experiment as well as be able to predict new experimental results.

So what's up with string theory?

Any matter or energy exerts gravitational attraction on any other matter or energy, e.g. 2 atoms. It's simply an inherent property. However, you may be interested to read:

Gravitons

not sure if you read my post but yeah, you said the same thing. an atom is perhaps not the best for example because it consists of many many smaller particles and so the system is rather complex...to better understand the simplicity think about 2 photons. at this scale classical physics no longer applies and that is another reason why your idea doesn't work

Which idea of mine doesn't work?

Not your idea, I was referring to Ray's idea that gravity is not really a fundamental force.

Stuh,
I wasn't exactly trying to liken gravity to pressure. But I reason, perhaps erroneously, that a combination of mass, inertia, and the effects of gravity (a mechanical device ) which would result in some extreme pressures may be enough to nullify gravity momentarily. I was looking to see if anybody that could understand, and care, had bumped into any papers on the subject probably coming from some supercollider research.

I hope you noticed that the expansionist phase of "Big Bang" theories is made out of whole cloth also. It is an expansion OF space, not an expansion within space. It is required to make things square with observation. If you are bored try to describe an expandible space without space . Kind of like describing God

The inability to distinguish between hypothesis, theory, facts, and observations is unfortunetly not limited to the religious forums I tried to make myself clear. Aparently I failed to. My heartfelt apologies

I kind of agree with Eorl, philosophically any way

Brandon,

Thanks, That is a wonderful site. I have spent some time there. Hopefully it's noticeable, but aparently not .

Well I've experienced white women, Japanese, Chinese, Mexican...but never a black woman.

No idea what their holes are like in comparison.