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In GR gravity is neither pull or push, it's just a geometry. If you fall you don't feel pushed but rather 'drawn' towards the floor, so in that manner you can use a 'pull', and we do. To describe a free fall as something pushing is not what you experience, it's rather a absence of 'force'. And a magnet can pull, you just need to hold it above a nail to see it lift, getting 'pulled' towards the magnet. The 'force' stopping your geodesic (free fall) on Earth is the floor, applying a 'push' equal to the 'pull' one might define gravity as, from that perspective. And gravity always comes together with mass, which is why one can define it as a pull, as that is how we experience it, observing stuff around us. 'Mass attracts mass' as the saying goes. As for if 'pull' doesn't exist? We define it as existing, how would you explain a car towing a another car from a perspective of 'pushing' it? The forces we define all come from what we see, relative a 'inertial point of view' (being 'still'), as our Earth.Here you lose me "If you swap pull with push, and swap mass with a hole, so negative mass instead of mass you get physics reversed, but maths that works the same. Then the Cosmological Constant is reversed, and the Universe expands instead of contracts."How do you get a 'hole'? And what would 'negative mass' be? It's not that you're assuming wrong as I, behind the words, can see that you're trying to apply a 'symmetry' to your description, but reading it I'm not sure what it means.
How do you get a 'hole'? And what would 'negative mass' be? It's not that you're assuming wrong as I, behind the words, can see that you're trying to apply a 'symmetry' to your description, but reading it I'm not sure what it means.
Ok, but 'drawn towards', and 'attracted' also don't exist in nature.
Quote from: Pincho on 27/02/2013 12:52:04Ok, but 'drawn towards', and 'attracted' also don't exist in nature.But those do exist in nature. Forces can act between two objects to pull them together. Forces can also act to push them apart. Classically, gravity is an attractive force, meaning it acts between two masses to pull them towards each other. An electrostatic force can also be a "pull" force, as you've no doubt experienced with static cling. There are more in-depth models in quantum mechanics and relativity, but they all reduce, in our everyday lives, to the simple idea of an attractive force. In particular, in quantum mechanics, all forces (except for gravity) can be expressed as exchanges of virtual particles. Virtual particles are somewhat funny beasts, such that if two particles are exchanging them, this exchange can actually pull the particles together. This is, as far as I know, the deepest explanation we currently have of attractive forces.
The physics is simply that objects released from rest tend to configure themselves at the minimum potential energy due to whatever fields of force exist around them. This means they move in directions to minimize this energy. This can be in any direction, really, and "push" and "pull" are simply words you're using to describe them moving towards or away from each other. And again, check out descriptions of virtual particles and how they account for "pulling." There's lots of physics there: http://math.ucr.edu/home/baez/physics/Quantum/virtual_particles.htmlIt's not simple, though, so you'll probably have to put in some significant effort to understand it.
Why do you insist on using the word push instead of just saying force has a direction? You're bogging yourself down in a particular choice of term and losing sight of the physics here. You can always say a force is a "push" along the direction of the force if you want, but that's not standard language and you'll end up confusing people.
Pincho, if you want to understand forces, I suggest starting smaller than the big bang and trying to understand how forces work in physics. You keep saying how Newton or physics defines forces, but you're getting it completely wrong. Physics says a force has a direction. That's backed up extremely well by observations. All this push, pull (and now blow) force is your own terminology--not that of physics.
,My physics are all visible to the human eye, but science uses virtual particles to do the same thing.
Quote from: Pincho on 27/02/2013 23:23:16,My physics are all visible to the human eye, but science uses virtual particles to do the same thing.If your goal here is to promote your own theory, then please keep discussion of it in the New Theories forum.