(adsbygoogle = window.adsbygoogle || []).push({}); The "is" of identity

It is one thing to say that "Gravity is caused by the curvature of spacetime" and it is a stronger statement to say "Gravity is the curvature of spacetime".

Before you run, cringing in semantic horror, how about a more interesting example:

[tex]G_{\mu\nu} =8\pi G T_{\mu\nu} [/tex]

This equation can be interpereted in two ways. Either "the curvature at a point of spacetime is equal to the energy-momentum density at the point" or in a stronger sense, "Energy density is the curvature of spacetime". Wheeler said: "Mass tells spacetime how do curve, spacetime tells mass how to move" but I am asking, if Einstien's equals is the "is" of identity i.e. the definition of energy.

Suppose charge is nothing more than the divergence of the electric field? In other words, take the = in Gauss' law to be the is of identity, rather than a computationally convenient "is equal to".

Before you say this is crap, I would like you to think about the meaning of "Unified Field Theory". In order to except field as the only entity (no particles at all) how would our physical ideas have to change? Look at the lorentz force law, and think of q as "del dot E". How would we define v and dp/dt ? (a rhetorical question perhaps, but what would kinematical concepts be in a field only universe?"

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# The is of identity

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