Saturday, April 6, 2013

Reflections on Einstein's Space

I am finally reading “How the Universe Got its Spots” by astrophysicist and writer Janna Levin.  Written as a series of diary entries, Levin mingles her reflections on the nature of space and time with personal stories.

At times, Levin’s personal and theoretical reflections merge in poignant ways.  Describing a series of moves that left her feeling untethered, Levin writes, “We keep moving.  Moving, moving, moving.”  Maybe Levin is simply conveying a feeling of unease that accompanies frequent relocations, but it’s hard not to imagine she is also describing a greater reality: Einstein’s rejection of any fixed frame of reference.  In Einstein’s model, no one is tethered; nothing is fixed.

As I reflect on Levin’s description of Einstein’s theory of gravity, two concepts seem to be at the heart of his description of reality: continuity and contact.  Before Einstein’s theories, Newton’s mathematical model was the best explanation of the effects of gravity. In Newton’s model, two masses fall towards one another, attracted to each other across empty space.  By contrast, Einstein imagines space as a geometrical structure that is bent, curved, and re-shaped by mass and energy.  Space is contiguous, like a bed sheet, or water in a swimming pool.  In Newton’s model, space is nothing.  In Einstein’s model, space is something, and, in fact, objects are always in contact with space.  Continuity.  Contact.  Einstein’s model of the nature of reality evokes a more intimate relationship between matter and space than Newton’s model.

Now I am wondering how to work with the conception of space as a continuous medium that connects everything in the universe....