What is gravity?

[xelasnave]

Originally Posted by sjastro

Alex,

Your repetitious tirades against GR and the role of maths, frankly is becoming quite tiring, and only serves to illustrate you have no understanding of either subject.

I have explained to you on numerous occasions how GR works from a non technical viewpoint. Whether you accept it or not is up to you, but please don't regurgitate the same questions and statements that have been dealt with in the past.

Steven

Hi Steven happy Monday.

Your observation that I have no understanding Steven is entirely valid:lol, although I dont like to think of my posts as tirades I have no problem if you like to see them that way.

I do not understand how gravity works and it seems that is the case for most folk.

Now whenever the question is raised "how does gravity work?" GR is offerred as an answer...so if it is the answer it must be able to provide understanding and unfortunately for me I still do not get it.

No doubt I am the only person on the planet who does not understand and so I feel left out and it is this left out feeling that has me asking the same old questions.. as I asked can the premise be stated succinctly ..if it can someone will do so perhaps they will ..perhaps they can not...
I say this if it is reasonable and follows a flow of logic the premise can be stated relatively simply one would think.

My thoughts are that before getting too involved in the validity of the proof one should consider what it is that the math sets out to establish... in GR's case it seems we need to be satisfied with a notion that leaves a major part of the idea unestablished and unclear....well not for the rest of the world just me I guess....

AND you know Steven I do not hold respect for math if it seeks to become the dog and not remain the tail of an idea... I know it is your profession and as such perhaps you over estimate its role and that is reasonable for you... but math is what it is and as far as GR is concerned I object to the manner math is offerred as the machine that drives the Universe when clearly that is not the case... now that is my opinion..this does not mean it is correct but it is an opinion I have ...now folk here have commented upon the fact that some physics has become a mere math exercise..this makes me feel uncomfortable as I feel the focus moves from what is happening out there to how interesting the complexities and derivations playing with the math lets us enjoy without going outside..as it were.

I see in your request to stop asking the wrong questions as futil as I wont stop asking until everything sits well with me..now I dont care who complains about that, and as much as I dont like to offend you or anyone for that matter simply say this...regurgitating the undigested questions will continue ... and until I can get a technical explaination on the mecahnics of gravity I will not enure a tummy ache for the sake of opting to be a non pain in the arse... but to labour under the belief GR has given us an absolute understanding of gravity is silly..the implication is that the science of GR will last forever and I personally doubt it... there will be things in it that wont be viewed as reasonable a century from now I suspect ..as with many parts of science etc..things progress but gravity will not if we are to content ourselves that GR has answered everything.. I say that would be foolish but no doubt most will not entertain my point let alone consider I may well be on track and more needs to be done on the mechanics of gravity.
If you feel that the statement "gravity is a weak force because it leaks into other dimenions or universes as I have read in accepteable science forums than I feel one is closer to black magic than science..and I remind you it is math tha takes us to these dark regions of imagination but really standing out in the sunlight can anyone really believe the explaination as to why gravity is a weak force based on such dribble...sorry that sounds like a tirade I guess but its just my opinion and you can call it drivel as you are entitled to do..I have no problems there...

ANYWAYS this is general chat ..it is supposed to be fun as some have already admitted.. and that is the way to see it... that is the way I see it... and it is no surprise you find it tiresome..for you know the answers, you have enjoyed receiving education that enables you to look at folk like me and think I could never have a clue..maybe..but does it matter really...

I dont want to make you feel bad reading my stuff and suggest it is not me that makes you feel bad but how you feel about me and my tiresome questions that makes you feel bad...

But look on the bright side.. in the area we discuss you are very knowledgable and presumably you can provide the complex answers...In fact I would call you."an authority on the subject" ..not all of us are or can be ...and I commend you patience with me I sincerley appreciate it.

BUT take this on board..do you think someone could post a question such as started this thread and me not regurgitate questions that have been asked many times before.

ANYWAYS I will look up GR today..there must be some place who offers a simple introduction to the subject which in effect outlines the simple statement..premise..I seek.

Thank you for all you have done for me in the past but never let me get under your skin I count for little and its not worth having even a blink of discontent on this when you are doing real work etc.

Have a great day... When I find the premise I will post it to see what you and others think.
alex

[xelasnave]

From We...........
In physics, spacetime (or space–time) is any mathematical model that combines space and time into a single continuum. Spacetime is usually interpreted with space being three-dimensional and time playing the role of a fourth dimension that is of a different sort than the spatial dimensions.
alex

[xelasnave]

from WIKY.....
General relativity or the general theory of relativity is the geometric theory of gravitation published by Albert Einstein in 1916. It is the current description of gravitation in modern physics.
alex

[xelasnave]

There is more..........

and (GR) describes gravity as a geometric property of space and time, or spacetime. In particular, the curvature of spacetime is directly related to the four-momentum (mass-energy and linear momentum) of whatever matter and radiation are present. The relation is specified by the Einstein field equations, a system of partial differential equations.

[TrevorW]

Maybe one should attack it from the opposite direction, instead of trying to establish what it is, eliminate what it is not, then once you have removed all the other variables you'll have your answer

[marki]

Hmmm


Mark

[xelasnave]

Originally Posted by marki

Hmmm


Mark

???

There is no arguement all is good.

alex

[xelasnave]

Originally Posted by TrevorW

Maybe one should attack it from the opposite direction, instead of trying to establish what it is, eliminate what it is not, then once you have removed all the other variables you'll have your answer

I agree and it is on that basis one should consider what one will find in nothing ..the answer is of course everything is in nothing...

Anyways All I hope from this sort of thing is..more folk will ask questions simply to understand what is before us now and if a youngster to realise that science is very exciting and there are more questions to answer than have ever been answered and as such the choice of a career in science will be the most rewarding given the discoveries waiting to have your name on them...

I say a lot tounge in cheek but the reality of what I try to pass on is this...education and enquirey are the key to happiness and sucess... but never be happy that what is before you is as far as the subject can go...

alex

[AlexN]

anyone with a firm enough grasp of mathematics can create an equation to explain anything, even make it look very elegant, this does not make the explanation correct or valid. It simply offers a mathematic model that suits the question. You can use mathematics to predict an outcome, or to explain any outcome you have already observed, that in my opinion is not enough. Yes, the math may be well thought through, yes i might understand what the math is trying to say. But i do not accept that as the final answer to a question.

[renormalised (Carl)]

Originally Posted by avandonk

We will always wonder what reality is. We will never know for certain!

Even that statement is open to conjecture!

bert

Maybe the Buddhists got it right in the first place. This reality is an illusion. We've just been kidding ourselves. Nothing actually exists except within our own consciousness...we create the reality we experience and use whatever energy is present to create it. So, in order to experience the truth of existence, we need to understand our minds, consciousness and what they actually are.

How's that for throwing a spanner in the works

[TrevorW]

Yeah they debunked magic and maybe we all need a little magic in our lives

[xelasnave]

With little respect to most in the banking game I say this... one can adjust figures on projected investment returns to say one will see a profit or a loss by minor adjustments to the inputs..a subdivision that shows a profit on paper can show a loss by variations in sales price,time to sell, interest rate etc... I have done this many times .. and observe that even a novice like me can make the numbers obey my commands..

however the spread sheet does not dictate to the market .

The price is dictated by the market not what one chooses to put in the spread sheet... and as infalable as the spread sheet becomes it is not the main game...it records and projects..nothing more... How do you actually subdivide a 5 acre block can not be answered by the spread sheet strangly.
Its like some of the forrest schemes..folk see the math and have no idea the scheme will never work...but it will work the sums say so... yes sure... but they are your sums and do what you wish them to do...

alex

[xelasnave]

Originally Posted by renormalised

Maybe the Buddhists got it right in the first place. This reality is an illusion. We've just been kidding ourselves. Nothing actually exists except within our own consciousness...we create the reality we experience and use whatever energy is present to create it. So, in order to experience the truth of existence, we need to understand our minds, consciousness and what they actually are.

How's that for throwing a spanner in the works

I doubt if any two humans see what is before them the same as the other would... we tend to think..I think this way therefore thats how everyone thionks (or should think) and this is not the way of it... reality is personal and adjustable ... reality is often ones definition of ones self and beliefs rather than a broad overview.

There is a God..there is not...two people two realities..does either need to be correct??? That man is a good man or a bad man..who decides these things...
alex

[sjastro]

Alex,

Throwing up a few superficial definitions of GR which at the very best are slightly better than chapter headings doesn't convey what GR is.

A good example of a little knowledge being a dangerous thing....

Your comments on maths is totally incomprehensible. Every major theory in physics uses a mathematical framework and foundation.

For example:

GR uses Riemannian geometry.
Elementary Quantum Mechanics uses Hilbert spaces.
Quantum Field Theory uses Lie algebras.

Take the maths out and the physics is non existent.
(Although QM can sputter along as a physics only subject).

You may be interested in knowing that even though GR and QM are usually associated as Physics subjects, they are in fact branches of Applied Maths. It highlights that it is the maths that drives the physics not the other way.

Steven

[KenGee (Kenith Gee)]

Look just think of gravity as the thing you feel when you not doing anything else....or
It;s the thing that makes straight lines look curved ha,ha
did that help.

[xelasnave]

Steven said "Throwing up a few superficial definitions of GR which at the very best are slightly better than chapter headings doesn't convey what GR is."
Yes I agree but I felt the attempt worthwhile to focus on GR..
AND we certainly agree that the math is the focal point..that was my point.
AND as you point out and I referred to above it is the math that is the subject not the physics..now you see that as a good thing and given your work could you think other wise... no worries there but I simply say it should not be this way...and that does not mean my view is valid..it is a view...
Sorry I could not convey the point I was trying to make as to the math such that you could not comprehend it but thanks for reading it... I do respect the science of math but I know in the wrong hands it can be manipulated to a degree to suit the outcome one is seeking.
AS a professional you will see that in the same bad light as would I.... and again I dont question the math and all I have said was to point to my belief that math is the tail wagging the dog..and you have agreed that is the way it is...
I did find out some stuff today that took me further with my understanding of GR so it has been well worth the time...
AND my point in posting the "headings" (as it were) was in an attempt to draw attention to the references to math and geometry and I suppose that within those definitions an apparent absence of detail as to how space may be bent etc... I did find something however mentioning "particle" interaction so I went away happy.

Thanks for taking the time and hope you have a great day.
alex

[xelasnave]

Originally Posted by KenGee

Look just think of gravity as the thing you feel when you not doing anything else....or
It;s the thing that makes straight lines look curved ha,ha
did that help.

Yes but if you are "there" the lines seem straight to you even though they are "bent"...
As to the flute etc I am unfortunately so inoccent of the ways of the world all you say is lost on me...
besides being a guitar player I feel drawn to the string theory "hypothisis" ...

Funny thing...a couple of weeks back there was a big day at the Drake Pub..it was around Phil Emmanuel (guitar player to God) but there was a band after..guess what their name was..."PUSH" ...had a great time danced with Phils lady whilst he played for a while and then sat back to be entertained by "PUSH" so I felt to a degree the Universe in falling into place and it will be no time at all until push gravity is elevated to its destined position of respect...

So its back to the bush any moment now.. I left yesterday because the "others" were possibly killing each other and I did not want to become the key witness... I will sneak in tonight get my stuff and head for Sydney, the boat and a bit rate of 30 kb per sec. So life can not get much better.
alex

[Peter Ward]

Originally Posted by sjastro

..... It highlights that it is the maths that drives the physics not the other way.

Steven

Steve...that's a little dangerous. Vis: the old tale, a Physicist is looking to get some dry-cleaning done, and sees a sign "dry-cleaning" in a shop front.

Goes inside, and is greeted by the store owner who and as it turns is a mathematician.
"I need this shirt dry-cleaned" says the Physicist.
"Sorry..I can't help you" replies the owner.
"Why not??"
"We just make signs!"

In short, without the physics, the math can be a little meaningless.

[sjastro]

Originally Posted by xelasnave

AND as you point out and I referred to above it is the math that is the subject not the physics..now you see that as a good thing and given your work could you think other wise... no worries there but I simply say it should not be this way...and that does not mean my view is valid..it is a view...

Alex. It has nothing to do with what I see as being a good thing.
You can't write a book without words. The physics mentioned in this thread is simply an expression of the mathematics. The mathematics are the words so to speak. I cannot make it any clearer than that.

Sorry I could not convey the point I was trying to make as to the math such that you could not comprehend it but thanks for reading it... I do respect the science of math but I know in the wrong hands it can be manipulated to a degree to suit the outcome one is seeking.

That's a conspiracy theory Alex. Science papers are peer reviewed which minimizes the chances of such nefarious activities.
I've mentioned the concept of renormalization earlier in the thread as an example to indicate that the science community will react to any perceived tampering with mathematics.

Regards

Steven

[g__day (Matthew)]

To your initial post - you have stated our current model correctly, and their (scale) limitations.

I could believe that gravity as we perceive it is more a property of complex geometry than a seperate, distinct force. So that is simply an abstraction that what we percieve as gravity is an indirect occurence of our reality that appears most commonly as a force.

A reason why relativity and quantum mechanics doesn't work well - is that relativity is scale invariant - it makes big assumptions on scale that don't well stand our test at either an atomic scale (or below) or glactic super cluster sizes and above.

Scale relativity is a newer model (under development) that posits that the universe isn't quantised into Planck units, that rather at very small scales spacetime is fractal (e.g. 2.68 not 3 dimensional). Quantum positions and irregularities can be modelled as movement along fractal paths in spacetime (vs movement through an exact grid).

Personally I think the science of this generation will build breakthroughs based on discoveries about the geometry of spacetime, as well as those substances and forces within it. Geometrical construction of the spacetime field may add to our understanding of the universe (and of course pose more complex, fundamental questions to resolve)!