Tuesday, December 10, 2013

Part II - Philosophy


Take another look at yesterday's diagram (from my Biography of a Planet). It's hard to imagine another half-page of notebook paper that could tell you more about the universe that's worth knowing. So blow it up to poster size and put it on the classroom wall. This is what makes stars burn. This is why the universe is not dark and dead. This is the source of your corn flakes. This is the force that through the green fuse drives the flower.

And you ask: How do we know what's going on at the center of the Sun, 93 million miles away and half-a-million miles down inside that roiling sphere?

1) If not this, then we don't know what.

2) We know this works. This is what happens when a hydrogen bomb explodes. Physicists are working hard to create a controlled version on Earth.

3) The numbers all work out.

4)

5) And the kicker. Back to the diagram. See those two neutrinos I didn't mention before. What happens to them? They have no charge. Hardly any mass. They rarely interact with more ordinary matter. In their staggering (but calculable) numbers they fly up and out of the Sun in every direction, barely impeded by a half-million miles of hydrogen and helium. Eight minutes after their creation, a hurricane of neutrinos intercepts the Earth -- and flies right through. Tillions per second penetrate your body. Nothing stops them. Well, almost nothing. Colossal neutrino detectors deep underground snag a few. A calculable few. A direct "look" at the very heart of the Sun.

And so we know. A collective of human brains has figured it out. Meat against mystery. Neurons versus neutrinos. Synapses versus sunshine. Men and women of every faith, politics and ethnicity have pooled their intelligence to understand whence the grain of sand and the flower in the crannied wall.