Gravity/Space-time QuestionPosted By Neil Barnett |
Think of space time as having a 'pressure' like water. Space time looks at matter as an infestation and it pushes on it. Two objects in space time would thin out the area between them more so than the area around outside them, thus the objects would be pushed together.
Try this thought experiment. Think of a single bit of mass in and entire universe by itself. The space time around the mass is thinner closer to the mass and denser further away.
I don't like using the following idea because gravity is a property of space not matter. It is how space reacts to matter. None the less, think of matter as sucking in space time, like a vacuum cleaner sucking in air in a room. The air will be thinner closer to the vacuum cleaner. If you have two vacuum cleaners, the air between them will be thinner than the outside air around both objects.
It's actually the same thing in reality only reversed so to speak. It is not gravity from Earth that pulls you down, it is the pressure of space time on the Earths presence that crams you into the Earths surface.
If you want a real twist, try thinking about absolute spin. If something is spinning, then it is spinning relative to some other object(s). What if there was only one object in a universe? Lets put two rockets on it opposite from each other and fire them off to spin up the object. The object will feel the force and react accordingly with rotational acceleration. Then turn the rockets off. Is the object spinning? Spinning relative to what? There is nothing else for it to be spinning in relation to. This is where the fabric of space time comes in. The object will be spinning relative to the 'stationary' space time that was there prior to the rockets firing. It's kind of like an object in water. Spin the object in water and the water will begin to rotate with it.
Try this thought experiment. Think of a single bit of mass in and entire universe by itself. The space time around the mass is thinner closer to the mass and denser further away.
I don't like using the following idea because gravity is a property of space not matter. It is how space reacts to matter. None the less, think of matter as sucking in space time, like a vacuum cleaner sucking in air in a room. The air will be thinner closer to the vacuum cleaner. If you have two vacuum cleaners, the air between them will be thinner than the outside air around both objects.
It's actually the same thing in reality only reversed so to speak. It is not gravity from Earth that pulls you down, it is the pressure of space time on the Earths presence that crams you into the Earths surface.
If you want a real twist, try thinking about absolute spin. If something is spinning, then it is spinning relative to some other object(s). What if there was only one object in a universe? Lets put two rockets on it opposite from each other and fire them off to spin up the object. The object will feel the force and react accordingly with rotational acceleration. Then turn the rockets off. Is the object spinning? Spinning relative to what? There is nothing else for it to be spinning in relation to. This is where the fabric of space time comes in. The object will be spinning relative to the 'stationary' space time that was there prior to the rockets firing. It's kind of like an object in water. Spin the object in water and the water will begin to rotate with it.