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Physicist and philosopher Bruce Gordon asks, IS the moon there if no one looks?


That’s just not clear if we are talking about the world of quantum mechanics:

Bruce Gordon: Here’s another one that’s absolutely fascinating. It’s been dubbed the quantum Cheshire cat phenomenon. You may recall from the story of Alice in Wonderland that Alice observes this grinning Cheshire cat (pictured, 1865 edition) that then disappears, leaving only its grin. Alice remarks that she’s “Often seen a cat without a grin, but never a grin without a cat.”

In essence, that’s what’s going on here because certain experiments — in particular, one using a neutron interferometer — have separated the properties of neutrons from any sort of substrate. So micro physical properties don’t necessarily require a substrate. What did the experiment do? Well, it sent the position of neutrons along one path and their spins along a separate path.

So that’d be kind of like sending a top along one path, and the fact that it was spinning along a separate path. Or the redness of an object along one path and the location of that object along another path. Micro physical properties then can be separated from any idea of a substrate. They can be abstract properties moving through space.

So what do you get then? It would seem that under appropriate experimental conditions, quantum systems are decomposable into disembodied properties. A collection of Cheshire cat grins, if you will.

News, “IS the moon there if no one looks? Or is there no “there” there?” at Mind Matters News

Takehome: Elementary particles do not need to be in a particular place until they are observed and then that’s where they are. The spins of elementary particles can be separated from their positions, just as the grin was separated from the Cheshire Cat.

Here’s the first part of this podcast: In quantum physics, “reality” really is what we choose to observe Physicist Bruce Gordon argues that idealist philosophy is the best way to make sense of the puzzling world of quantum physics. The quantum eraser experiment shows that there is no reality independent of measurement at the microphysical level. It is created by the measurement itself.

Here are stories from Bruce Gordon’s previous podcast with host Michael Egnor, where he defends idealism as a way of making sense of nature:

Why idealism is actually a practical philosophy. Not what you heard? Philosopher of science — and pianist — Bruce Gordon says, think again. Is reality fundamentally more like a mind than a physical object? Many are sure of the answer without understanding the question.


A physicist and philosopher examines panpsychism. Idealism says everything is an idea in the mind of God. Panpsychism says everything participates in consciousness (thus is not just an idea). Bruce Gordon thinks that, for a thing to be conscious, there must be something that it “is like” to be that thing. Can panpsychism demonstrate that?


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