Tuesday, April 9, 2024

Absolute reference frame

Some philosophers think that notwithstanding Special Relativity, there is a True Absolute Reference Frame. Suppose this is so. This reference frame, surely, is not our reference frame. We are on a spinning planet rotating around a sun orbiting the center of our galaxy. It seems pretty likely that if there is an absolute reference frame, then we are moving with respect to it at least at the speed of the flow of the Local Group of galaxies due to the mass of the Laniakea Supercluster of galaxies, i.e., at around 600 km/s.

Given this, our measurements of distance and time are actually going to be a little bit objectively off the true values, which are the ones that we would measure if we were in the absolute reference frame. The things we actually measure here in our solar system will be objectively off due to time dilation and space contraction by about two parts per million, if my calculations are right. That means that our best possible clocks will be objectively about a minute(!) off per year, and our best meter sticks will be about two microns off. Not that we would notice these things, since the absolute reference frame is not observable, so we can’t compare our measurements to it.

As a result, we have a choice between two counterintuitive claims. Either we say that duration and distance are relative, or we have to say that our best machining and time measuring is necessarily off, and we don’t know by how much, since we don’t know what the True Absolute Reference Frame is.

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