Its Gravity or Air Pressure~~~
 

Well fellows we all know according to newtonian physics all things fall on earth due to gravity factor.Its always confusing for me that its gravity the only factor for stabling things on earth or kept us stand on earth.I think its Air pressure too(a major factor) that help us stand on earth.I hypothise Any where its air pressure that cause objects to experience their weights. Like in space where there is no air pressure but vacuum, materials experience no force of attraction or weightfulness.Similerly how does gas baloons move away from earth, so it seems air play more vital role than gravity for objects weight!I would also like to mention here that in University of California a Physics processor,Micheal Ritch, claims the same thing resonating in my mind.Prof. Micheal Ritch Performed some experiments too!But to perform such an experiment needs highly restrictive environment!since when u pull air out off any object it just blow or pinch....So i think maintability factor is air pressure not Force of gravity that even varies place to place.Here i discuss this issue to share my fellows precious views specially those who are critically good at physics or geophysics!

Best Regards,

only gravity no air pressure
 

i think first of all u should define weight,
weight is force by which a body is attracted to the earth
so in space since there is no attraction of earth so no weight there in space
and secondly ur example regarding baloons
baloons move up due to pressure gradient ,in baloon we fill higher pressure
outside is lower pressure so everything move from higher to lower thats why baloons move away frome arth
and one thing more that if ur weight depends upon air pressure then air pressure changes from one point to other on the surface of earth but weight(gravity)remain same
I dont say i m right,but its my thinking being a student of science
zaman from engineering university lahore

[QUOTE=zaman]i think first of all u should define weight,
weight is force by which a body is attracted to the earth
so in space since there is no attraction of earth so no weight there in space
and secondly ur example regarding baloons
baloons move up due to pressure gradient ,in baloon we fill higher pressure
outside is lower pressure so everything move from higher to lower thats why baloons move away frome arth
and one thing more that if ur weight depends upon air pressure then air pressure changes from one point to other on the surface of earth but weight(gravity)remain same
I dont say i m right,but its my thinking being a student of science
zaman from engineering university lahore[/QUOTE]
Well bro nice to hear from u! honorable Zaman ur definiton of weight is quite bookish!but its true since we all read it in our books!But friend we know W=mg...where m=mass and g=gravity!And remember the gravity gradient is not just related to earth only!U know tht moon has gravity but its not 9.8 but very less!
In ur second example u said baloon goes upward due to air pressure that pulls it up....thts what i am confused that Air pressure effects more than Gravity!And other point is Air has pressure on all earth its intensity vary!U know at high altitudes ur weight decreses...its in accordance with relativity theory...so i m not saying ur weight decreases but relative weight decreses.So point again comes air pressure influences more:con ...Nwayz thanx a lot Zaman for ur view sharing!:blush:

okey but
 

i know that gravity on moon is less than gravityforce on earth
reason is simple that attraction between moon and earth is less
and second thing at altitude weight decreases becz distance from centre of earth increases and gravity force is inversly proportional to distance (u may verify from its formula)so gravity decreases and as a result weight decreases.
and engineering is application of knowledge of science u know it!so in many many applications we have read this concept and u know this concept on which newton presented his laws are backbone of science
let see in future may be it prove but still not possible
u can send ur theory to any professor of physics about his comments
Best of luck
Allah hafiz

Its gravity at most and air pressure to an extent.

[B]consider this for our sensation of weight[/B]

The weight force that we actually sense is not the downward force of gravity, but the normal (upward) force exerted by the surface we stand on, which opposes gravity and prevents us falling to the center of the Earth. This normal force, called the apparent weight, is the one that is measured by a spring scale.

For a body supported in a stationary position, the normal force exactly balances the earth's gravitational force, and so apparent weight has the same magnitude as actual weight. (Technically, things are slightly more complicated. For example, due to the earth's rotation objects are subject to a small centrifugal force, varying with latitude, which partially offsets gravity. The normal force therefore balances a force slightly less than the true force of gravity.)

If there is no contact with any surface to provide such an opposing force then there is no sensation of weight (no apparent weight). This happens in free-fall, as experienced by sky-divers and astronauts in orbit who feel "weightless" even though their bodies are still subject to the force of gravity. The experience of having no apparent weight is also known as microgravity.

A degree of reduction of apparent weight occurs, for example, in elevators. In an elevator, a spring scale will register a decrease in a person's (apparent) weight as the elevator starts to accelerate downwards. This is because the opposing force of the elevator's floor decreases as it accelerates away underneath one's feet.

[B]Baloons go up since the gases contained inside them (eg. Helium) are lighter then the surrounding gases (i.e. our atmospheric gases). As the place for lighter gases is at a higher altitude in our atmosphere, they tend to move there and their pressure applied on the poor baloon's walls lift it as well:)[/B]

[B]For hot air baloons (baloons that carry people), a burner injects flame in them to raise their temperature. According to Charle's law, the volume of gases is directly proporsional to the temperature at a constant pressure. An increase in the volume of air in the baloon gives it a lift.[/B]

[B]We stand balance on earth since our atmosphere exerts equal pressure on us from all sides, thus neutralizing its effect.[/B]

Rectify me on anything that u find wrong, since this my own hypothesis lol.

Salaam,

Well, can anyone tell me that which is the real thing that holds the air molecules around the earth?

The point is valid that things experience the centrifugal force under the motion of earth around its axis. But that force is overcomed by the gravitational forces between the earths center and the body on its surface. Acoording to the law of gravitation, this force of gravity is inversely proportional to the square of the distance b/w the centres of the two bodies. So, up above the earths surface, the magnitude of the g force is decreased and there it is possible that air may play a comparatively greater role in keeping the body directed towards the ground.So, if the distance is small, the force experienced by the two bodies is greater.So, at the earths surface, this force exerted by air can simply be neglected. This is the main reason thats why we have satellites in the earths orbit. when we reach a distance above the earth surface, where the effect of the gravitational pull is balanced by the centrifugal force experienced by the satellite due to its circular motion around the earth. The satellite is balanced in its orbit and keeps in this orbit since any external force is aplied from
any other direction.

To the point that why moon being far away than the earth satellites keeps it motion around the earth. Well, the answer is realted to the first part of the law, that states: The force of gravitation is directly proportional to the mass of the object. Since mass of the object is the amount of matter in any body, and we know that the mass of moon is much greater than that of a satellite. This helps moon to keep in orbit around the earth by even a greater distance.

One other example to prove that air doesnot play in keeping the things on the ground is by looking at a fused bulb. The broken element of tungsten always fall off in to the direction towards earths center. Same phenomenon can be observed in various devices where we create a vaccum like a CRT of television etc.

Its not a new thing for me to hear that i m wrong, but the only thing that will be is that "where and how". So, if u have anything new for me, then please tell me. Perhaps can correct someone else mistaken as me.

Take care,

Allah Hafiz

@ Zaman......Thanx Zaman for ur valuable comments!they are very fine but not negate my hypothesis..nwayz a good news is i have a call from PAEC,hope there i got ample chance to discuss this issue with physics brains!Though i m I.T person!But anlysis is part of our life so i m interested in this matter.I also have some doubts in concepts of Black holes in space.since their credibility is not yet proven.I will discuss it later.But for the time thanx for sharing ur considerable views!