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Q: Gravity ( Answered 3 out of 5 stars,   22 Comments )
Question  
Subject: Gravity
Category: Science > Physics
Asked by: r23sakamoto-ga
List Price: $2.00
Posted: 24 Feb 2005 06:23 PST
Expires: 26 Mar 2005 06:23 PST
Question ID: 479978
Why does Gravity exist ? I don't want explanations on how to calculate
how it applies.
Answer  
Subject: Re: Gravity
Answered By: siliconsamurai-ga on 24 Feb 2005 07:18 PST
Rated:3 out of 5 stars
 
Hi, thank you for submitting your question to Answers.Google, I hope I
can provide the information you are seeking.

?Why? is actually a question of philosophy. I am going to assume that
you are really asking for some basic information about gravity and
will provide that information since there is no answer to ?why? beyond
some religious or philosophical speculation.

Unfortunately, the explanation of gravity from the standpoint of
science is almost as much a matter of debate as the philosophical
question is.

The easiest to understand explanation is that provided by Einstein,
that gravity is actually just the observed result of the shape of the
four-dimensional space time continuum.

Don?t worry, it is actually easy to understand conceptually, although
not mathematically.

The usual example given is to imagine (or build) a sheet of rubber or
other elastic substance in a frame. Place an object on the surface and
the sheet distorts. Roll a small ball across the surface and it will
not go in a straight line.

It turns out that if you express this in mathematical terms it almost
exactly describes how we observe gravity to ?work.?

The reasons for this theory are complex and based on the assumption
which says nothing can move faster than light.

There are other theories of gravity, some involve particles
(gravitons), still others involve quantum events and an attempt to
explain all forces in one grand unified theory which is currently
known as M, Manifold, or String Theory.

Explaining these unproven theories would take many pages and go far
beyond the price offered for this question but here are some useful
links you can pursue.

http://www.itp.ucsb.edu/online/colloq/damour1/

http://web.mit.edu/afs/athena.mit.edu/user/r/e/redingtn/www/netadv/gr.html

Here is an explanation of some aspects of Relativistic gravity
http://www.coolissues.com/gravitation/gmetric.htm

Here is a link to some information about M theory and supergravity.

http://en.wikipedia.org/wiki/M-theory

PBS, in particular, NOVA, has run a number of programs about these theories.

http://www.pbs.org/wgbh/nova/elegant/program.html

This page lets you view the programs in QuickTime or RealVideo.

(Disclaimer, I used to work for the PBS station which produces NOVA,
but I have no financial connection with them at this time.)

Thank you again for turning to Answers.Google for help. If you would
like one physicist?s philosophical answer as to ?why? there is
gravity, it is simple - without gravity there would be no universe or
solar system and we wouldn?t be here to ask the question.

Clarification of Answer by siliconsamurai-ga on 24 Feb 2005 07:58 PST
Did you miss the final paragraph of the answer?

"If you would like one physicist?s philosophical answer as to ?why? there is
gravity, it is simple - without gravity there would be no universe or
solar system and we wouldn?t be here to ask the question."

Other than that, the question of Why is there gravity has no more
meaning than Why is there light? Why is there energy?

I'll remind you that you placed this question in the Science>Physics
category which is what led me to guess that it wasn't a question about
religion.

If you post the same question under  Relationships and Society >
Religion  you might get a very different answer, we can only answer
the question asked based on our understanding and you asked a physics
question.
r23sakamoto-ga rated this answer:3 out of 5 stars
The answer is nicely written, gives some links, and is pretty cool to read.
On the other hand, it is rather answering to "how ?" or to "What
conscequences ?" than "Why ?", so I basically don't know anything more
about what I wanted to know.

But I expected even worse for $2, so not bad after all : I'll give 3
stars (I would have given 5 stars if any clue had been given about
"why?").

Comments  
Subject: Re: Gravity
From: lrulrick-ga on 24 Feb 2005 06:30 PST
 
I believe it exists in order to keep us from floating away.
Subject: Re: Gravity
From: barnacle_bill-ga on 24 Feb 2005 07:24 PST
 
why do we have fingernails?
Subject: Re: Gravity
From: siliconsamurai-ga on 24 Feb 2005 08:00 PST
 
When it comes to questions such as this,
Physics is about "what" 
Philosophy and Religion are about "why"
Subject: Re: Gravity
From: barnacle_bill-ga on 24 Feb 2005 08:10 PST
 
So 'Why' do we have fingernails?
Subject: Re: Gravity
From: siliconsamurai-ga on 24 Feb 2005 08:19 PST
 
fingernails

That is actually a very different kind of WHY question and has an
answer if you believe in science. I'll refer you to a guy by the name
of Charles Darwin for some good leads.

http://www.bartleby.com/11/
You want the section on Natual Selection.

or see gutenberg.org
Subject: Re: Gravity
From: thx1138-ga on 24 Feb 2005 08:20 PST
 
Q."So 'Why' do we have fingernails?"
A. What else would we pick our noses with?...............................(Sorry)

================================================================================

"Why do we have fingernails?"

"Our fingernails are similar to claws or hooves found in other
animals. More generally called ?digital appendages?, they are enlarged
keratinized structures (the same stuff that horns are made out of)
that protect the tips of the fingers and toes in most vertebrate
species, or aminals with backbones. Fingernails are broad, and
slightly curved, and mostly cover the top surface of our fingers.

In other species, this structure is slightly different - for example,
crocodiles have a thimble-shaped structure that covers the whole tip
of their digits, whereas hawks and owls have talons, highly recurved
claws specialized for prey capture, and horses and cows have hooves
that protect their feet.

So, the reason we have fingernails is simply that everyone in our
family tree has some sort of digital appendage that probably served to
protect fingertips in our distant ancestors, and each group has
evolved modifications that best fit their needs for a particular
environment. Fingernails in monkeys, apes and humans always cover only
one side of the fingertip and thus they protect but don?t limit the
motion or sensitivity of our fingertips."
http://www.ccmr.cornell.edu/education/ask/?quid=448
Subject: Re: Gravity
From: siliconsamurai-ga on 24 Feb 2005 08:25 PST
 
Perhaps barnacle should post that as a question for thx, accept what
has just been posted, and pay for such a detailed and accurate answer.

Just a suggestion.
Subject: Re: Gravity
From: r23sakamoto-ga on 24 Feb 2005 08:27 PST
 
I was unable to find a "philosophy" category (I'm not looking for any
answer given by religions), that's why I posted under the "Science"
category.

I am willing to post this question in a more suitable category then,
where should I post it ?
Subject: Re: Gravity
From: barnacle_bill-ga on 24 Feb 2005 08:36 PST
 
Will do... as always THX1138 first class answer!
Subject: Re: Gravity
From: mwpdallas-ga on 24 Feb 2005 08:37 PST
 
"Why does gravity exist?"  Gravity exists because heavy objects--dense
objects with mass--warp space time, which causes other
objects--lighter objects--to move towards them.  That movement is what
we call gravity, and it exists simply because some objects have
greater mass and density than others.
Subject: Re: Gravity
From: siliconsamurai-ga on 24 Feb 2005 08:41 PST
 
Hi, 

Religion is a a common place for a philisophical question, you can
also put it in miscelaneous and make it clear in your question that
you really DO want a philisophical answer rather than a scientific
one.


I realize you are new to answers and hope you continue to use the
service but you really shouldn't complain when you get a scientific
answer to a question posted in the science section, especially when
the answer clearly explains that the question as asked was a matter of
philosophy.

The more detailed your question is the more likely the researcher is
to find exactly the answer you REALLY wanted. There is no particular
limit on how long your question can be.

There is something called Philisophy of Science but that involves
questions of epistimology, the verifiability principle of meaning,
scientific method, and such.

Asking WHY about a fundamental characteristic of the universe is a
religious question.

Best wishes.
Subject: Re: Gravity
From: siliconsamurai-ga on 24 Feb 2005 08:43 PST
 
mwpdallas that isn't WHY, that is an explanation of WHAT which, in a
more accurate and detailed way, is what I gave as an answer.
Subject: Re: Gravity
From: barnacle_bill-ga on 24 Feb 2005 08:46 PST
 
enven if i do say so my self! lol
Subject: Re: Gravity
From: siliconsamurai-ga on 24 Feb 2005 08:49 PST
 
way to go barnacle, good show
Subject: Re: Gravity
From: r23sakamoto-ga on 24 Feb 2005 09:29 PST
 
I am indeed absolutely new to "Google Answers", that was my very first question !

I would never have guessed I should have posted my question in the
category "Relationships and Society>Religion" as I don't want any
answer in terms of "Relationships", nor "Society" nor "Religion"...

Though I'm absolutely clueless about the Category choices, I have
posted it there, and increased the price.

thanks anyway.

Note : I've read that I was NOT allowed to post questions about
"Google Answers", that's sad, as I would probably have paid a fair
price to have the answer to : how the "Category" system work ? ;)
Subject: Re: Gravity
From: well0placed0comma-ga on 26 Feb 2005 07:10 PST
 
Somebody spoke of super-massive objects earlier being the reason for gravity.
i think this is not the case.
Remember that Physicists argue that our Solar System (and all others)
were generated by the collapse of a nebula (in our case a stage two
nebula) that generated the sun and planetismals. This collapsion,
according to common thesis is due to the gravitational attraction of
the gas particles.
I don't see these as being super-massive, or even massive. Therefore,
this approximation has to be flawed.
If we look further still, the atomic model (note: it is still ONLY a
model. Electrons are unfortunately prone to the wave-particle duality
of the photon) has several forces acting within it that keeps the
particles (thought subatomic) in place. Physicists still argue (a bit)
over whether these forces are magnetic or gravitational.
If they are magnetic, which is common suggestion, then it gives
greater stregnth to the idea of a grand unification theory because of
the obvious repurcussions of this.
However, if they are gravitational it makes perfect sense for the
composit particles of these particles to be conditioned to gravity and
thus the question on the source of gravity will follow the Hisenburg
Hypothesis.

Also, something earlier in this question made me laugh, "I believe it
exists in order to keep us from floating away."
If gravity hadn't existed in the first place, our planet - and thus
ourseleves - would never have existed to 'float away'!
Subject: Re: Gravity
From: lrulrick-ga on 26 Feb 2005 11:44 PST
 
I now believe that well0placed0comma-ga lacks my sense of humor. In
all honesty if you look up the "why" there is not defined answer for
"why". There is the how it exists, the reasons why it is needed, even
the theory of it, but never a clear cut answer as to "why":

http://www-personal.umich.edu/~pberman/20grintro.html
The Special Theory of Relativity appeared in 1905. It took Einstein
another 10 years to work out his General Theory of Relativity, which
appeared in 1916. The General Theory is often referred to as one of
the most beautiful theories in physics. Einstein worked very hard on
this theory and made some mistakes. He had to learn mathematical
techniques which were not as yet commonly employed in physics. The
General Theory is a theory of gravity. It does not explain why gravity
exists, but it does give another way of looking at gravity."
 Even your scientific rambling cannot explain the "why" of gravity,
its like why is the grass green, you can tell me all the reasons of
"how the graa" displays the color green, but yet you can't tell me why
those things make it green. Why not purple? True I am not found of
purple, and am rather glad that grass is green... which is something
else you can not explain the "why" of. Science deals with the "how",
not "why".

Another why question for thought "why toenails?"
Subject: Re: Gravity
From: alex101-ga on 28 Feb 2005 17:55 PST
 
I saw your question in the Religion category where you asked the "why"
question but stated that you refused to accept religious explanations.
 Now what sense does that make ?  You are searching for answers with
blinders on.  You can see where you look ok but you may miss the truck
coming at you from the side.  If you are going to ask "why" questions
but refuse to accept answers from one particular perspective or
another, then you are intentionally closing your mind.  If you close
your mind, you voluntarily limit your potential for understanding.

Quantum physics may interest you.  I love it.  Science can describe. 
However, only philosophy and religion can hope to answer "why"
questions.  I will attempt to tip toe around your aversion to the
"religious" while I try to answer the why of gravity.

"Why" assumes intent, consciousness.  "How" would simply explain but
asking "why" reveals perhaps even just a feeling that there must be a
reason for gravity as well as other phenomena.  To answer "Why" there
must be a reason.  Reason, of course, involves reason-ing.  So, if you
are certain that there is no intelligent power greater than yourself,
or humankind, then your answer is obvious.  There is no "why."  It
would have to be a fluke, kind of a universe sized, purely by chance
occurrence.  No reason at all.

On the other hand, if you think it is illogical to think that
something could come from nothing, you concede that everything that is
created must contain aspects of that from which it came, you know that
infinity exists as surely as gravity and your Aunt Hattie (and the
implications of infinity are-well- infinite) and you believe that
humans could not have created what you see, then you will also accept
that "why" is a reasonable question.  It is reasonable because you can
reasonably conclude that what you see and what you know are entirely
compatible with, they even demand, the conclusions that there is
something greater than you, or me, and that we are not at the pinnacle
of existence.  The answer to your "why" is It's "because."

I hope you are not so invested in your beliefs that you are not
willing to consider explanations inconsistent with them.  Good luck.
Subject: Re: Gravity
From: mariocim68-ga on 05 Mar 2005 05:21 PST
 
The question "why" gravity exists demands an observer (an entity) to
"make" (or build) the question. It more likely that gravity exists
because the observer "desires" it. It's philosophical I know but the
"desire" is a kind of twist (or tension) "in" the consciousness
substance. The ultimate state of "matter" (that shows the property of
gravity) is unknown since it will ALWAYS require an observer (a Self)
to "watch it. Probably "matter" is "Science" in the way that it
describes the state-of-being-aware since all the distinctions between
the object (matter, or gravity if you want) and subject (the Self) are
mental constructs. There is no "why"separate from the observer. I hope
this can help.
mario
Subject: Re: Gravity
From: siliconsamurai-ga on 07 Mar 2005 07:16 PST
 
If anyone is interested, PBS is re-running The Elegant Universe in
most areas this week.

It can explain a lot of basic cosmology - check your schedules to see
if it is airing in your area.

Disclaimer - Although I used to work for the station which produces
Nova (WGBH), I am no longer affiliated with the station and am simply
pointing out that this is an interesting program.
Subject: Re: Gravity
From: asveron-ga on 25 Jan 2006 18:37 PST
 
gravity has to do with mass the more there is the more stronger it is.
it is not fully explained yet but similar to the magnetic theory we
havent figured that out also. basicly in my view things like to join
up (elements etc) so when there are alot of things perhaps it just
crams together?
Subject: Re: Gravity
From: siliconsamurai-ga on 26 Jan 2006 08:54 PST
 
asveron - sorry, unlike gravity EM theory is well understood, see Maxwell

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