early universe
esiegel | March 6, 2013"The atoms come into my brain, dance a dance, and then go out - there are always new atoms, but always doing the same dance, remembering what the dance was yesterday." -Richard Feynman
Here you are, a human being, a grand Universe of atoms that have organized themselves into simple monomers, assembled together into giant macromolecules, which in turn comprise the organelles that make up your cells. And here you are, a collection of around 75 trillion specialized cells, organized in such a way as to make up you.
Image credit: J. Roche at Ohio University.
But at your core, you are still just…
esiegel | February 7, 2008The Universe isn't a static place. Although the laws of nature (physics, chemistry, biology, etc.) don't appear to change over time, everything in the Universe appears to evolve, and changes over time. One of the simplest ways that this happens is through Hubble expansion.
General relativity tells us how the Universe expands, and more specifically, it tells us that the expansion rate (which we call the Hubble constant, H0) is related to the total energy density of the Universe. More matter density: faster expansion. Greater density of photons (i.e., light): faster expansion. More of any and…