is the gravity theory stil a theory or a law?

Question

and why it is either one

Answer 1

theory

Answer 2

Theory. General well-established theories were once called "laws", so the older ones like gravity still retain the title out of tradition. It's just semantics. Theories never graduate into laws or "facts" after being "proved", since facts are a catagorically different sort of proposition altogether and no theory can ever be absolutely proved. It's the Creationists' favorite red herring.

Answer 3

First lets clarify the scientific meaning of theory:

It is a statement which based on reliably and accurate evidence, observation, and inferences that logically appears to be true.

For example, a cube's faces are labelled 1-6 and placed on the table. The five visible sides are 2,4,5,1,6. In theory, based on observation (the five numbers), evidence (the number missing) and inferences (what is missing?), the number on the bottom is 3.

The same goes for gravity. The theory is well support, we can observe it at work (dropping a ball), there is considerable evidence for its existence(orbits of planets). Therefore it is inferred that in theory it exists.

There is a mathematical law for gravity as stated above, but remember that when an idea in science is accepted as a theory, it is not a guess or hunch, but a well back up, inteferred arguement for its existence - the greatest acknowledgement for any scientist.

Answer 4

Humans cannot change the properties of physics. Gravity is what it is. We have a very good idea of how to describe its effects, using mathematics. Our theory is that the gravitational force between two objects is:

F = G*m1*m2/r^2

And so far, all evidence points to this being correct. You can call it a law or a theory or total BS. The label does not change what gravity is and how it behaves.

The general consensus is that the equation is so accurate that it is considered a law. Calling it a theory does not change gravity or make it behave any differently, however.

Answer 5

gravity makes the world go around. Without is the world would not be in space the way it is. Talk to any astronaut and they will tell you that there is no gravity in space but there is on earth. It is a LAW of NATURE. Bounce a ball and see if it goes up or down. Is it a theory or is it true. Does a tree stand erect or does it fall? that is gravity. Do we stand straight or do we fall when we get out of bed, etc. etc. etc.

Answer 6

Gravity is a theory

Answer 7

Both.

The Law of Universal Gravitation is still used in numerous ways although it is only a postulate that has never been countered by observation.

There are broader theories regarding gravity and its nature (e.g. gravitons and gravity waves) that are being tested.

Answer 8

It is currently a working theory. It has described the universe as we experience it to any degree we are capable of testing. However its mechanism is still not understood so it remains theory for now

Answer 9

General Relativity has a perfect record versus observation in all venues at all scales, Harvard Tower experiment to GPS to binary pulsars to Einstein rings,

http://arxiv.org/abs/astro-ph/0609417
PSR J0737-3039A/B. Deeply relativistic neutron star binary

http://relativity.livingreviews.org/Articles/lrr-2001-4/index.html
http://arXiv.org/abs/gr-qc/0311039
http://www.physics.adelaide.edu.au/~dkoks/Faq/Relativity/SR/experiments.html
Experimental constraints on General Relativity

http://tycho.usno.navy.mil/ptti/ptti2002/paper20.pdf
Nature 425 374 (2003)
http://www.eftaylor.com/pub/projecta.pdf
http://www.public.asu.edu/~rjjacob/Lecture16.pdf
http://relativity.livingreviews.org/Articles/lrr-2003-1/index.html
Relativity in the GPS system

http://relativity.livingreviews.org/open?pubNo=lrr-2003-1&page=node5.html
Relativistic effects on orbital clocks

However, General Relativity requires that Plancks constant be zero, so it is wrong. Isn't that fun?

Answer 10

A law. The last time someone asked me about that was nearly twenty years ago when I was a college kid. Later on, they told me I was going for four or six hours, not "twenty minutes," so just be satisfied with the answer above.