What is gravity?

[klah]

Originally posted by: SuperCyrix

i'm not seeing the connection.....

What I meant was, someone had to have came along and set all this in motion.
Suppose when matter first appeared in this empty universe, it would just set there and do nothing.
Why should it move? I believe somebody must have came along, install this gravity system that binds all objects to each other and then gave the system a nudge to start it all.

So you attribute everything that we do not understand to "GOD"?

 

[tcsenter]

gravity = when we get old we sag...thank god i am only 25

You're not gettin any younger.

 

[kherman]

Originally posted by: klah

Originally posted by: SuperCyrix

i'm not seeing the connection.....

What I meant was, someone had to have came along and set all this in motion.
Suppose when matter first appeared in this empty universe, it would just set there and do nothing.
Why should it move? I believe somebody must have came along, install this gravity system that binds all objects to each other and then gave the system a nudge to start it all.

So you attribute everything that we do not understand to "GOD"?

Religion is the blinder of truth!

 

[Hayabusa Rider]

Gravity-
I can tell you what it does, but not what it is.
Matter has mass. Mass distorts space. That distortion is gravity. A "wrinkle" in spacetime. Here is a little thought experiment. Take a trampoline and roll a golfball across it. The ball travels in a straight line. Now put a bowling ball in the middle so that the surface is deformed. Now roll the golfball across again, but near the bowling ball. The little ball is deflected and no longer travels in a straight line. If you roll the ball slow enough or close enough it will spin around it and fall into the larger object. This is due to rolling resistance of the surface.

Now imagine that the larger ball is the Sun, and the smaller a comet passing by. The surface is spacetime. If the comet travels fast enough, then it escapes the solar system. if it is slow enough it falls into orbit. It does not fall into the sun unless it is aimed right at it, because space has no rolling resistance.

This is the Einstein's General relativity simplified. Now WHY does this happen? No one has the foggiest idea. Why is completely different than how.

The problem with even this is that gravity is one if the four fundamental forces of nature.

They are for completeness,
Gravity
Electromagnetism
the Weak Force ( which mediates radioactive decay)
and the Strong Force (which holds atomic nuclei together)

There are quantum theories that explain all the above (except for gravity). At an absurdly simple level, each force consists of a field and an associated mediating particle. In the case of electromagnetism. it is the electromagnetic field and the photon.

So for gravity we have a field and a postulated particle, the graviton.
Now for the problem (one of several actually) How do you reconcile General Relativity's explanation of gravity, and that of any Quantum Gravity theory (which really doesnt exist in any verifiable theory) In other words, how is a particle identical to the curvature of space? Again no idea.

Anyway, that is where physicists are.

Someone mentioned gravity causing the universe eventually to contract. This not automatically true. Say you are Superman and have a ball. You toss it in the air at say 100 MPH. The ball reaches a maximum height and then returns to earth. But suppose Superman has a special ball which is immune the heat generated by moving at extreme speeds through the atmosphere. Now he really gives it a good heave. He tosses it at 100,000 MPH. When does the ball return? Never. That is because the energy imparted to the ball exceeds the gravitational attraction of the earth. It reached the escape velocity of the earth (in fact by quite a lot). Likewise, if the amount of energy imparted to the universe exceeded the total attractive force of creation, then the universe expands forever. More recently, there has been shown good evidence that the expansion is self fueling and something amounting to antigravity exists. If true, then not only will the universe expand, but at an increasing, not decreasing rate.

 

[UNCjigga]

Question 2: What is fire? Is it a solid, a liquid, a plasma or a gas? I always thought that flames were the result of gasses in a fissile state, but I've never actually found the scientific definition of fire before.

 

[Nitemare]

9.8 meters per second square?

 

What is fire

A rapid, persistent chemical reaction that releases heat and light, especially the exothermic combination of a combustible substance with oxygen.

 

[josphII]

Originally posted by: SuperCyrix
Gravity is what keeps the conservation of energy law valid. It's really simple if you think about it.

The universe is still expanding but it won't be forever. You see, as matter continues to drift apart from each other in the expanding universe, the only real force acting upon these mass is gravity. It doesn't matter if two objects as small as a tennis ball are 10^100 meters apart, there still exist a force of attraction between them. Suppose there are only two little tennis balls in the universe 10^000 meters away from each other not moving. Though it will take a long long long time, after 10^100000 years the two tennis ball will collide because of the gravitational force between them.

So as the mass in space are expanding outwards at a certain velocity, gravity is very very slowly but surely slowing down this expansion until at a certain point the expansion stops and the universe starts to suck itself back into the one giant mass of whatever that leads to the big bang. Like a swinging pedulum that swings back and forth forever in a self contained system, The Big Bang hurls everything outwards while gravity eventually brings it back. The energy bounces back and forth between the heat generated from massive clutter of mass prior to the big bang to gravity which eventually brings it all back.

Using the theory from above,
Maybe all gravity is nothing more than a rubber band that binds all matter.

you are wrong

two particles can be traveling fast enough away from each other that the distance grows at a rate faster than the gravatational acceleration can bring them together. the gravatational acceleration falls off according to 1/r^2

 

[josphII]

Originally posted by: SuperCyrix

i'm not seeing the connection.....

What I meant was, someone had to have came along and set all this in motion.
Suppose when matter first appeared in this empty universe, it would just set there and do nothing.
Why should it move? I believe somebody must have came along, install this gravity system that binds all objects to each other and then gave the system a nudge to start it all.

so where does this 'someone' you spoke of come from? nowhere? he/she/it just exsists? same can be said of matter. the difference is we know matter exists, duh

 

[silverpig]

It also seems as though the expansion rate of the universe is increasing, suggesting a repulsive force of a vacuum. It's still in the works though.

Question 2: What is fire? Is it a solid, a liquid, a plasma or a gas? I always thought that flames were the result of gasses in a fissile state, but I've never actually found the scientific definition of fire before.

Fire isn't matter. It's just glowing air. When the air molecules heat up, they impart energy to outer electrons, which radiate energy. AFAIK, fire is just the blackbody radiation given off by the air molecules.

 

[Hayabusa Rider]

Fire-
Open or uncontained self perpetuating combustion?

Howz zat work?

 

[Kadarin]

I don't understand gravity either, so it must be because the Baby Jesus wanted it so.

 

They should have called it Grabbity because it grabs you and pulls you down

 

[Goosemaster]

Gravity is simply the "End-result" of individual atomic-magnetism.


Just as the positive and negative charges from the Protons and electrons, respectively, atract each other, so do the outlying electrons of atoms with the protons of other atoms.


Metals for example, are on the left of the periodic table of the elements, therefore they are lacking in valance electrons....albeit a little lonely, they still seek to fill their energy levels, so an "attraction" exists at the atomic level..


Now take a pretty piece of ass such as the earth, and this "attraction" grows exponentially because it is predominantly made of metals amoung other substances disregarding water.



So now you a whole PLANET of "horny" electrons, and that obviously creates an extreme amount of magnetisum, attracting any and everything that gets near it.



Obiously, our sun, other stars and supernovas are larger, so they obviously create larger forces, as they still contain substances such as nitrogen, which as many of all you know, does not naturally carry its maximum payload of 8 valance electrons

 

[ObiDon]

Originally posted by: Jellomancer
What is gravity?

You put your left foot in
you put your right foot in
BAM!

That's gravity.

 

[Hayabusa Rider]

Originally posted by: Goosemaster
Gravity is simply the "End-result" of individual atomic-magnetism. Just as the positive and negative charges from the Protons and electrons, respectively, atract each other, so do the outlying electrons of atoms with the protons of other atoms. Metals for example, are on the left of the periodic table of the elements, therefore they are lacking in valance electrons....albeit a little lonely, they still seek to fill their energy levels, so an "attraction" exists at the atomic level.. Now take a pretty piece of ass such as the earth, and this "attraction" grows exponentially because it is predominantly made of metals amoung other substances disregarding water. So now you a whole PLANET of "horny" electrons, and that obviously creates an extreme amount of magnetisum, attracting any and everything that gets near it. Obiously, our sun, other stars and supernovas are larger, so they obviously create larger forces, as they still contain substances such as nitrogen, which as many of all you know, does not naturally carry its maximum payload of 8 valance electrons

You are kidding, right? :Q

 

[silverpig]

Originally posted by: Hayabusarider

Originally posted by: Goosemaster
Gravity is simply the "End-result" of individual atomic-magnetism. Just as the positive and negative charges from the Protons and electrons, respectively, atract each other, so do the outlying electrons of atoms with the protons of other atoms. Metals for example, are on the left of the periodic table of the elements, therefore they are lacking in valance electrons....albeit a little lonely, they still seek to fill their energy levels, so an "attraction" exists at the atomic level.. Now take a pretty piece of ass such as the earth, and this "attraction" grows exponentially because it is predominantly made of metals amoung other substances disregarding water. So now you a whole PLANET of "horny" electrons, and that obviously creates an extreme amount of magnetisum, attracting any and everything that gets near it. Obiously, our sun, other stars and supernovas are larger, so they obviously create larger forces, as they still contain substances such as nitrogen, which as many of all you know, does not naturally carry its maximum payload of 8 valance electrons

You are kidding, right? :Q

I'll second that with a genuine WTF???

 

[Goosemaster]

whaaa....I was bored okay

 

[Dark4ng3l]

you are wrong

two particles can be traveling fast enough away from each other that the distance grows at a rate faster than the gravatational acceleration can bring them together. the gravatational acceleration falls off according to 1/r^2


Actualy there is no force propulsing the two particles appart, only the ataraction of them together, since the atraction never reaches 0 the two particles will slowly lose their speed and then start to slowly come back together, even if it takes infinity time it will eventualy happen.

 

[silverpig]

Originally posted by: Dark4ng3l
you are wrong

two particles can be traveling fast enough away from each other that the distance grows at a rate faster than the gravatational acceleration can bring them together. the gravatational acceleration falls off according to 1/r^2


Actualy there is no force propulsing the two particles appart, only the ataraction of them together, since the atraction never reaches 0 the two particles will slowly lose their speed and then start to slowly come back together, even if it takes infinity time it will eventualy happen.

Um, no. There is a certain amount of energy that will overcome a gravitational field. Give an object this amount of kinetic energy, and it'll keep going farther from the object forever. Let's say that you have two objects and an initial velocity such that Fg drops off as 1/r^2 (as it does) but so that their relative velocities drop off as 1/r. This is entirely possible, and as you can see, even as r -> infinity, 1/r is always positive. Add to that the suggestion that a vacuum seems to have some sort of repulsive force, and the expansion tendency of space, and you can see how two objects might not ever come together.

 

[Goosemaster]

so...



I look like a dumbass right about now....

:|