Originally posted by adam warlockThanks for your posts. Much appreciated. Must read Feynman ... some time ...
But on the second part of your post. Can you please post some links that say that? I'm not into cosmology/gravitation/relativity but I know (or at least I thought I knew) that gravity is transmitted at the speed of light. If I'm not mistaken I think I've seen an article recentely were some guys claimed that they had measured gravity waves and they went at c just like everybody was expecting.
Speed of gravity:
http://metaresearch.org/cosmology/speed_of_gravity.asp
Originally posted by Bosse de NageAs Palynka says, gravity is empirical knowledge based on measurement. I'm just wondering why it's always described as 'something'?
Steady on old boy. Let me put my glasses on straight ...
Come again?
I'm out of my depth with the physics of it but would be interested to
know if it is possible that gravity could be described as the absence of
other forces?
Originally posted by Thequ1ckAlthough equally out of my depth, I'll just slip in that I thought gravity could perhaps best be described as a means to describe relationships between bodies, rather than a Dingumsick.
As Palynka says, gravity is empirical knowledge based on measurement. I'm just wondering why it's always described as 'something'?
I'm out of my depth with the physics of it but would be interested to
know if it is possible that gravity could be described as the absence of
other forces?
Originally posted by Bosse de NageI believe that the most popular theories to date have fundamental particles which by jumping between other fundamental particles create the known fundamental forces (gravity, electromagnetic, strong and weak nuclear).
All right. Gravity is empirical knowledge derived from experience, but cannot be known as a thing-in-itself. Gotcha.
That kind of destroys my line of enquiry. Unless gravity is a formal characteristic of the empirical world? I know it's meant to be space, time and the Categories, but gravity seems to be implicated in time, so ...
If this is the case then gravity is caused by a particle called the graviton.
See: http://en.wikipedia.org/wiki/Graviton
It is important remember as has been noted previously in this thread, that we have the same issues with all the fundamental forces - ie we don't really know how they work yet. However we can calculate and predict them all with remarkable accuracy.
We could of course say the same about fundamental particles. Are they waves, are they things, are they strings? Or are they probabilities? If Schrödinger's cat is neither dead nor alive does it really exist?
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Originally posted by Bosse de NageWell it makes sense to me to equate gravity to pressure. Not as a description of a force but a potential. Can potential really be described
Although equally out of my depth, I'll just slip in that I thought gravity could perhaps best be described as a means to describe relationships between bodies, rather than a Dingumsick.
as a particle?
It seem to me like looking for the difference between 1 and 2!
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Originally posted by Bosse de NageAll right. Gravity is empirical knowledge derived from experience, but cannot be known as a thing-in-itself. Gotcha.
All right. Gravity is empirical knowledge derived from experience, but cannot be known as a thing-in-itself. Gotcha.
That kind of destroys my line of enquiry. Unless gravity is a formal characteristic of the empirical world? I know it's meant to be space, time and the Categories, but gravity seems to be implicated in time, so ...
That's not exactly what I'm saying...
Unless gravity is a formal characteristic of the empirical world?
But this pretty close. The 'turtles all the way down' story is deceptive. A turtle might always be need to have another underneath it but the story is silent on why do we need turtles in the first place!
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Originally posted by Thequ1ckA vacuum does not arise from the absence of something. A vacuum is the absence of something by definition. If Gravity was too, then they would be equivalent and there would be no need to use two different words.
Coult it instead be stead that gravity, like vacuum, arises not from
something but from the absence of something?
Originally posted by twhiteheadI don't understand, how can you have a vacuum without having 'something'?
A vacuum does not arise from the absence of something. A vacuum is the absence of something by definition. If Gravity was too, then they would be equivalent and there would be no need to use two different words.
Isn't vacuum the 'nothing' between matter?
Why can't gravity be the 'nothing' between mass?
Originally posted by Thequ1ckExcept that a vaccuum doesn't 'do' anything. The vaccuum does not suck; instead, the non-vaccuum blows.
I don't understand, how can you have a vacuum without having 'something'?
Isn't vacuum the 'nothing' between matter?
Why can't gravity be the 'nothing' between mass?
Likewise, gravity would be the pulling of matter rather than the pushing of the vaccuum.
--- Penguin.
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Originally posted by PenguinSo in this analogy, gravity would not be a pulling force but instead
Except that a vaccuum doesn't 'do' anything. The vaccuum does not suck; instead, the non-vaccuum blows.
Likewise, gravity would be the pulling of matter rather than the pushing of the vaccuum.
--- Penguin.
the absence of a pushing force.
Let us assume that the pushing force was the absence of mass,
(I'm really going to go off on one here) but could that pushing
force was what we now call 'dark matter'?
The opening post is a bit of an ambigous question. Science is not about understanding what causes certain reactions, but rather how they are naturally caused. We study correlations between events and deduct formulas from our findings. That doesn't mean we understand the reason behind it, if there is such a thing.
*What makes an apple fall?
Gravity
*What causes a gravitational field between earth and an apple?
Mass
*Why do objects with mass create gravitational fields?
The objects with mass create geodesic lines in time-space
*Why do they create these lines?
We don't know...
*Is it the gravitons, then why do objects with mass emit gravitons? And why do gravitons create attraction between the objects that send them out?
See, in general the more we learn the more questions pop up. It's a battle we can't win.
Originally posted by Bosse de NageI don't understand the question. What do you mean by the "origin" of gravity? Do you mean when did it begin? Do you want to know more about the mechanism of how gravity works?
I've read that the origin of gravity has yet to be discovered, but I'm not so sure. Does anybody know where gravity comes from?
GRAVITATION, n. The tendency of all bodies to approach one another with a strength proportion to the quantity of matter they contain -- the quantity of matter they contain being ascertained by the strength of their tenden ...[text shortened]... of of B, makes B the proof of A. Ambrose Bierce (1842-1914), 'The Devil's Dictionary', 1911