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Is gravity a by-product instead of a force of nature itself?

  1. May 12, 2014 #1
    Hi there!

    As you might find out from the question I have regarding the subject of gravity, I didn't have formal education into specialized science subjects. Just a bit of high-school knowledge may apply. I do have a general interest in Physics and it gets me thinking every time. Normally I will find an answer myself but this time the problem I asked myself is a bit to hard to handle and hope you guys can help me with it and please correct me where I go wrong with my assertions. :smile:

    As far as I know with my level of understanding: Higher volumetric mass density of a substance, means that it exerts more force in space-time. The force in question we call gravity. But isn't it possible that it's actually a by-product of electromagnetism? A planet for example, has a more or less net. electric charge of zero, but what if electromagnetism is the one having an effect on space-time at the particle level, which in turn affects objects like stars and planets?

    Gravity by property looks like a magnet with one pole (I must be careful here but: some sort of monopole?): It only attracts mass (that would mean inversely proportional, one would assume an exotic form of matter with negative mass to exist (dark matter?)). But assumptions aside, if Gravity interacts with mass only, why does it bend space-time by itself in such a way it can bend a massless photon for example into a black hole with no chance to escape?

    So I miss the connection between gravity and space-time.
    I can see a connection with electromagnetism because it can exert a force on the particle scale. Particles that make out the volumetric mass density of an substance which affect space-time.
    Whereas gravity works on the 'macro-cosmos' so to speak but fails on the micro-cosmos, Electromagnetism seems to work on both.

    Where did I go wrong in my own thought experiment? The errors are probably all over the place but I feel like I'm missing a couple of connections that I can't seem to figure out. :confused:
  2. jcsd
  3. May 12, 2014 #2


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    Staff: Mentor

    Many of your questions can be answered by looking into special and general relativity. These theories explain how spacetime works and where gravity comes from. Put simply, General Relativity is our most accurate gravitational theory and it models gravity as being the result of dynamic geometry. That is, mass and energy both alter the geometric properties of spacetime in certain ways that have the end result of making gravity appear to be a "force". Gravitational theories based on the EM force have been looked into over the years but none have ever been able to explain gravity as well as General Relativity.
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