[AntonioLao]

The mannequin (womannequin?) in the original movie ‘Time Machine’ circa 1960 stays motionless while the world of ladies’ fashion flashes by before the time traveler’s eyesight. Likewise, the time machine itself never changes its spatial coordinates while it travels through time. The temporal sequence of these two objects appears as two vertical parallel lines in a spacetime coordinate system where the vertical axis represents time and the horizontal axis represents space. Both mannequin and time traveler are said to be marching thru time separated by an invariant distance. This scenario conceptually agrees with special relativity and Newton’s 1st law of motion. However, within the framework of general relativity, the parallel lines exist if and only if the mass of both vanishes. Now, according to the standard model of particle physics only 3 candidates are able to satisfy this condition: photon, gluon, and graviton. If the photon is the messenger going back and forth between mannequin and time traveler and if the time traveler is made entirely of gluon then the march of graviton is equivalent to the march of the mannequin. By symmetry, if gluon and graviton switch role and position then the march of gluon is equivalent to the march of the mannequin. Again by symmetry, if the photon switches role and position with the others then the march of photon is equivalent to the march of the penguin, oops, sorry, slip of the pen, I meant mannequin.

Keep in mind that if the weak bosons (W+, W-, Z0) replace them then the mannequin marches nowhere, neither in time nor in space.

Hey! What about the neutrinos? Say, hmm, let me think? They should be able to keep the mannequin or even penguin marching forever or maybe not? What do you think?