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preitiey
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why is gravitational force always attractive in nature?
Sorry, can you clarify: are you asking about gravity according to general relativity or about Newtonian gravity?preitiey said:Agree with you both! But gravitational force doesn't depends on mass only. so how can we determine its nature on the basis of mass only? and if we consider relativity, how one can relate it with the force's nature? pls someone elaborate.
Newtonian gravity doesn't elaborate on this.preitiey said:I was too asking about Newtonian gravity. ...I am searching for a satisfactory elaborated answer
OK sir, because mass is positive, we have this gravitational force attractive.DaleSpam said:OK, in Newtonian gravity the gravitational force is always attractive because mass is always positive. I don't understand what else you are looking for.
The Coulomb force can be either attractive or repulsive. It can go either way because charge can be positive or negative. Mass is not like charge, it cannot be either positive or negative, it is always positive and thus Newtonian gravity is always attractive.
In principle, the fact that mass is always positive would also be consistent with gravitational force always being repulsive. Experiment shows that gravity is not repulsive, however.preitiey said:OK sir, because mass is positive, we have this gravitational force attractive.
You are going to have to come up with a better reference than "someone said" or a better description of what they said. Or both.Someone explained this concept on the basis of cosmic rays, can that be any how?
Yes. This is a good point. The positive and negative charges is what allows the Coulomb force to be sometimes attractive and sometimes repulsive. A positive-only mass could in principle be associated with an always repulsive force. But that is counter to observation.jbriggs444 said:In principle, the fact that mass is always positive would also be consistent with gravitational force always being repulsive. Experiment shows that gravity is not repulsive, however.
I think that you are referring to le Sage's push gravity theory. That has been discredited for something like 200 years now. It is still occasionally mentioned on the internet, but it has already been examined and discarded scientifically.preitiey said:Someone explained this concept on the basis of cosmic rays, can that be any how?
Is that the one where you have many, many particles hitting the earth, and they sort of push it around the sun? Like, the particles hit the Earth from the side away from the sun, because the sun blocks particles moving the other way and this results in the gravitational force. If yes, Richard Feynman debunks that one in one of his " The Character of Physical Law" Lectures. Probably the one on Gravitation, in case someone wants a good explanation of why it's wrong.DaleSpam said:I think that you are referring to le Sage's push gravity theory. That has been discredited for something like 200 years now. It is still occasionally mentioned on the internet, but it has already been examined and discarded scientifically.
UncertaintyAjay said:Is that the one where you have many, many particles hitting the earth, and they sort of push it around the sun? Like, the particles hit the Earth from the side away from the sun, because the sun blocks particles moving the other way and this results in the gravitational force.
That has been discredited for something like 200 years now. It is still occasionally mentioned on the internet, but it has already been examined and discarded scientifically.
Reference https://www.physicsforums.com/threads/why-is-gravitational-force-always-attractive-in-nature.845944/
The reason why gravitational force is always attractive in nature is because of the fundamental law of gravity, which states that all objects with mass are attracted to each other. This attraction is caused by the curvature of space-time created by the presence of mass, known as the gravitational field.
No, there are no exceptions to the attractive nature of gravitational force. All objects with mass, regardless of their size or composition, will always be attracted to each other due to the presence of a gravitational field.
The strength of gravitational force between two objects is inversely proportional to the square of the distance between them. This means that the farther apart two objects are, the weaker the gravitational force between them will be.
The moon orbits around the Earth because of the balance between its forward motion and the gravitational force of the Earth. This is known as centripetal force and it keeps the moon in a stable orbit, preventing it from colliding with the Earth.
According to the current understanding of gravity, no, gravitational force cannot be repulsive. However, some theories such as the cosmological constant suggest that there could be a repulsive force at very large scales in the universe. This is still a topic of ongoing research and debate among scientists.