Well, It may not be a force, but it sure acts like one.Why Gravity is NOT a Force
There is only one EM force that's fundamental to the universe as we understand it. The electric and/or magnetic 'fields' we interact (accelerations) with are a consequence of spacetime projections of that force into our 3D world. Gravity is (in a sense) that acceleration.Well, It may not be a force, but it sure acts like one.
But then relativity also says that a magnetic field is simply the relativistic result of a moving electric field.
Imagine you were inside a closed box accelerating through empty space at 9.8 m/s/s . Your apple would fall exactly the same way, and would would infer The same incorrect conclusion.But consider the situation on earth (or any other planet), as Sir Issac Newton realised, an apple falling from a tree is falling under the force of gravity accelerating at 9.81m/s/s (in a vacuum). Many experiments can be conducted on earth to quantify this force – to claim it does not exist is nonsense.
Sure you can. Think about a superconductor magnet with zero resistance.Also I don't believe you can have a magnetic field without an electric field but vice versa is possible.
Your spaceship's engine causes the acceleration. And since there is no physical experiment that can distinguish between the acceleration caused by the engine thrust or the acceleration caused by standing at sea-level on Earth's surface, the two are physically equivalent.But if I am accelerating at 9.8 m/s/s through empty space there must be some force causing this acceleration (gravity?).
But you wouldn't say that the apple falls to the ship's floor because the engine is producing gravity, would you? The simpler explanation is that the once the apple is let go, there are no net forces acting on it and so it doesn't move. The ship's floor, however, has a force acting on it (the engine), causing it to rush up to meet the apple. Upon coming to rest on the floor, the apple now experiences the normal force of the ship's floor. If we put a scale under the apple, it would weight exactly as much as it does on Earth.In my spaceship, the apple will fall to the floor due to the accelerating force applied by the ship’s rocket engines – on earth the apple will fall in exactly the same way due to the force of gravity.
What does superconductivity or resistance have to do with it?Sure you can. Think about a superconductor magnet with zero resistance.
Yes, exactly. An object in free-fall experiences no net forces ("weightless") and hence has no proper acceleration. We can always choose a coordinate frame in which the object appears to accelerate, but then we must introduce a ficticious force (gravity) to explain the acceleration.So does it mean that when I am sitting steady (Zero Flat Space Time Acceleration), I am actually experiencing acceleration in time dimension of Curved Space time...?? Is that what he meant...??
Thank you for picking up my post to reply...!!Yes, exactly. An object in free-fall experiences no net forces ("weightless") and hence has no proper acceleration. We can always choose a coordinate frame in which the object appears to accelerate, but then we must introduce a ficticious force (gravity) to explain the acceleration.
When you drop an apple on Earth, the apple is in free-fall and has no acceleration; once it hits the ground, the ground stops the apple from continuing in free-fall and so it now has a net force (the ground's normal force) acting on it. Hence, the apple -- sitting there on the floor -- has proper acceleration.
by Jake Hertz
by Jake Hertz