Gravity is measurement of the distortion of space, caused by mass. It is an emergent property. The more massive something is, the more its gravity will distort the space around it.
So, a small piece of rock that you can hold in your hand, will cause a gravitational ripple in the space surrounding it. This is similar to how the Earth causes a gravitational ripple in the space around it, and it keeps us grounded to the ground. But, the Earth causes a much bigger gravitational ripple, than a small rock.
And we as humans, are grounded to the Earth, as if we are at the bottom of this massive and invisible whirlpool. We cannot see it, but this whirlpool is rotating all around us, and we cannot get out. It is easy for us to move around horizontally, but it is very difficult for us to move vertically. Unless we can move horizontally so fast, that we can reach escape velocity, and then, we orbit the Earth.
That said. What is gravity? Why does mass cause a ripple in the space around it?
I wonder if gravity is just some type of neutral electro-magnetic force. Kind of like the magnetic field lines that you see with the North pole and South pole. But instead of being magnetically charged, it is neutrally charged, and it affects everything around it equally.
Or, instead of being magnetically charged like the North or South pole, it is gravitationally-charged, and the direction points in only one way, into the center of your massive object. And unless you are moving faster than that massive object's escape velocity, then you will always be stuck in that object's gravitational ripple.
If we can truly understand what is gravity, then I wonder if we can create a counter gravity. Like, in your spaceship, if you can create a negative mass above you, then it would cause your spaceship to act buoyant in the planet's atmosphere. And you can use thrusters to move around vertically, as easy as you can move around horizontally.
Or, maybe you can create a temporary blackhole above your spaceship, and instead of your spaceship falling into the gravitational ripple caused by the Earth, then it becomes attracted to the gravitational ripple caused by your blackhole. And this causes your spaceship to rise, and defy the Earth's gravity.
Anyways. I'm not a gravitational physicist. Maybe I should take this idea, and write a novel. There has been much worse Sci-Fi ideas created, like Time Travel, or the ridiculous many-worlds-interpretation theory of quantum mechanics.
From a physics perspective, the many-world, as ridiculous as it sounds, is a more sound theory (believed to be correct by some top physicists) than negative gravity.
The explanation of why gravity is only positive is a complex one, but physicists believe it's almost axiomatic.
This doesn't mean that you can't have repulsive type of effects, similar to one of the contributions that's believed to make the universe expand more quickly than with the simple 4 fources (often called fifth force, maybe related to dark energy, and to the rate of the universe expansion acceleration).
PS.
There are a number of Sci-Fi stories that use this idea, including a famous one from Asimov, in which if I recall correctly the normal gravitational force was working negatively when traveling in FTL speed. Obviously that seemed fishy but the book was cool (Nemesis).
> The explanation of why gravity is only positive is a complex one, but physicists believe it's almost axiomatic
Isn't that a consequence of relativity, the speed of light being constant by definition? I'm not sure that makes any sense, though, what is the physical unit of gravity N? Jf you mean classical mechanics, than there has to be a negative counterforce by the three axioms of newtonian mechanics and it's just a question of frame of reference.
The trouble with this is that an electric field causes exactly the same observed effects on an oppositely charged particle.
Why would an electric field cause this by one mechanism, and gravity by another, when the observed effect is identical?
> then I wonder if we can create a counter gravity
You can not create counter gravity any more than you can create counter electric field. What you can do is move two charges apart.
To do that with gravity you would have to find a way to make double the gravity in one place, and negative gravity in the other, and then separate them.
(Creating counter/negative gravity directly would violate conservation of energy.)
So, a small piece of rock that you can hold in your hand, will cause a gravitational ripple in the space surrounding it. This is similar to how the Earth causes a gravitational ripple in the space around it, and it keeps us grounded to the ground. But, the Earth causes a much bigger gravitational ripple, than a small rock.
And we as humans, are grounded to the Earth, as if we are at the bottom of this massive and invisible whirlpool. We cannot see it, but this whirlpool is rotating all around us, and we cannot get out. It is easy for us to move around horizontally, but it is very difficult for us to move vertically. Unless we can move horizontally so fast, that we can reach escape velocity, and then, we orbit the Earth.
That said. What is gravity? Why does mass cause a ripple in the space around it?
I wonder if gravity is just some type of neutral electro-magnetic force. Kind of like the magnetic field lines that you see with the North pole and South pole. But instead of being magnetically charged, it is neutrally charged, and it affects everything around it equally.
Or, instead of being magnetically charged like the North or South pole, it is gravitationally-charged, and the direction points in only one way, into the center of your massive object. And unless you are moving faster than that massive object's escape velocity, then you will always be stuck in that object's gravitational ripple.
If we can truly understand what is gravity, then I wonder if we can create a counter gravity. Like, in your spaceship, if you can create a negative mass above you, then it would cause your spaceship to act buoyant in the planet's atmosphere. And you can use thrusters to move around vertically, as easy as you can move around horizontally.
Or, maybe you can create a temporary blackhole above your spaceship, and instead of your spaceship falling into the gravitational ripple caused by the Earth, then it becomes attracted to the gravitational ripple caused by your blackhole. And this causes your spaceship to rise, and defy the Earth's gravity.
Anyways. I'm not a gravitational physicist. Maybe I should take this idea, and write a novel. There has been much worse Sci-Fi ideas created, like Time Travel, or the ridiculous many-worlds-interpretation theory of quantum mechanics.