e=mc^2 implieth negative time

This is because c is a measure of distance divided by time, so that:

With time reckoned a positive, and measured in units i, its square is negative; so that e[nergy] is negative while m[ass] is positive, which is not physically possible.

But with time reckoned a negative, and measured in units -i, its square is also negative; so that e[nergy] is negative while m[ass] is negative, which is physically very much possible.

This is because any reckoning in negative time must perforce take mass to be negative anyway.

Now, once mass and time are both taken to be negative, then gravitation can be cogently explained:

Gravitons (assumed to be positive in mass) sweeping outward bombard matter having negative-mass, inducing a cancellation-process (implosion) drawing the matter toward the source of the gravitons.

To get a like result (viz., a cancellation) from positive time, gravitons should have to be assumed to be themselves negative in mass. If negative in mass, however, they should be associated with negative energy; and this is not believed to be the case.

magnetic attraction can be explained in a somewhat different way:

In negative time, unlike magnetic poles mutually repel -- but this could a result of the reaction-process being an explosion (instead of an implosion). [Feynman assumed an implosion here, as he was reckoning in positive time.]

But if implosions were involved, the magnetic field would be self-cancelling (and so could not transfer magnetism, magnetize other objects); which is not the case. True implosion is like gravitation, unable to transfer qualities.

An explosion is an event productive, creative -- so the mutual repulsion by unlike magnetic pole can be regarded similar to sexual procreation.

On the other hand, mutual attraction by like magnetic poles is implosive, sterile -- and so can be regarded as similar to homosexuality unable to procreate.

differing attractions

In (negative-time) magnetism, repulsion is by far more abundant than is attraction; just as among living beings, heterosexuality is by far more common than homosuxuality.

In electrostatics, however, attraction is as common as repulsion; so a likeness to there to bisexual animals (worms, mollusks) might be considered.

Real photons are dominated by their magnetic component, which (by self-inductance) generateth its wave-form.

Virtual photons, on the other hand, are electrostatic, lacking [inhaerent] wave-form.

It is its magnetic component, set [like a jibbered sail] perpendicularly to its electostatic one, which enableth the real photon, by "tacking into the wind" to make headway in the opposite direction [in time, supposedly, but perhaps simply in space].

[Virtual photons were assumed by Feynman to be able to retract mass at an infinite velocity; but we replace this "infinite velocity" with ordinary velocity backwards in time.]

The "transactional interpretation" is easily applied to the antics of virtual-photons.