Sunday, April 19, 2015

Geometry and Physical Space

Today's 'Sunday reflection' from physicist Carl Rovelli (via John Brockman's "This Idea Must Die")... in which I get to learn the word, "pullulating"!:
"We will continue to use geometry as a useful branch of mathematics, but it's time to abandon the longstanding idea of geometry as the description of physical space. The idea that geometry is the description of physical space is ingrained in us and might seem hard to get rid of, but getting rid of it is unavoidable and just a matter of time. Might as well get rid of it soon....
"Einstein discovered that the Newtonian space described by geometry is in fact a field, like the electromagnetic field, and fields are nicely continuous and smooth only if measured at large scales. In reality, they're quantum entities that are discrete and fluctuating. Therefore, the physical space in which we're immersed is in reality a quantum-dynamical entity that has very little in common with what we call 'geometry.' It's a pullulating process of finite interacting quanta. We can still use expressions like 'quantum geometry' to describe it, but the reality is that a quantum geometry is not much of a geometry anymore."

[…If you have a favorite math-related passage that might make a nice Sunday morning reflection here let me know ( If I use one submitted by a reader, I'll cite the contributor.]

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