Video Friday – The Present Can Influence the Past?

In forecasting, the common assumption is that the present influences the future, but the opposite does not occur.

Oh to be sure, one develops expectations and, yes, predictions which may influence present actions. But these are not realized, but projected. What actually occurs tomorrow, however, is not usually considered to directly influence what transpires today, particularly chance events. Thus, if Roger flips a coin tomorrow and it comes up heads, that is not supposed to have any material effect on physical processes occurring today.

But this turns out to happen at the level of quantum reality – in other words, at a more fundamental level of physical reality, as the quantum eraser experiment proves.

OK, it is a good idea to begin with the classic double slit experiment, as a lead-in. Here are two videos, one with a comic strip professor, and the second with Professor Brian Greene of Columbia University and several of his collegues.


So you immediately get into what I would call metaphysics – issues of whether consciousness can impinge on what is being observed, thus changing it.

Again, Professor Brian Greene on the double slit experiment, another narrative.

 OK, so then there is the “quantum eraser.”

 I’m still thinking about this. It’s profound, experimental metaphysics. Time is not what we think it is, just as space is not what it seems.

Quantum entanglement, incidentally, is what Einstein called “spooky action at a distance.”

One thought on “Video Friday – The Present Can Influence the Past?”

  1. See Alain Aspect, the great French researcher and an experiment in Science magazine – Experimental Realization of Wheeler’s Delayed-Choice Gedanken Experiment, Vincent Jacques, E Wu, Frédéric Grosshans, François Treussart, Philippe Grangier, Alain Aspect, and Jean-François Roch,
    Science 16 February 2007: 966-968. Aspect again concludes there seem to be grounds for thinking the future could influence the past. More recent work, however, conducted at the University of Bristol in the UK may support more conventional interpretations.

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