Monday, August 7, 2017

How plate tectonics tries to kill us - boring story

Any boring story about physics is sure to put the kids to sleep.  When I tried to teach the kids how to fix computers, they said "Unlike you, Dad, we were born with electricity.'  To paraphrase, they also implied 'Unlike you, Dad, physics has no impact on our lives whatsoever.'  I feel that this is the entire world, at least those that do fb.  My son flies around the world in his VR room.  

At least I got the kids next door to pick up shiny rocks.  That's a good step.  But on to the love-hate relationship life has with plate tectonics.  Without pt we would be as dead as Mars, but pt keeps trying to kill us.  We have the large pt cycles of 150 million years.  So for 150 myrs it is too hot for mammals and only dinosaurs roam, and the next 150 myrs is too cold, and only large mammals live on land.  In the ocean, nobody cares about pt because the ratio of water to land has remained exactly the same.  That's amazing!  (No, it's not, say the kids).

The plates move around like the foam on boiling porridge.  They have this great habit of fully separating and then clumping together into a big lump.  Non-physics types would think that this has nothing to do with anything, but they are wrong.  Perhaps they are right, in their own way, since homanids have been around for the last 8 million years, nothing in the pt cycle.  

On a local scale, pt tries to kill people with earthquakes and volcanoes, but these also give life.  Everybody and their dog want to settle on the slopes of an active volcano because the soil is so rich.  Giant faults may be the only source of water.  But the large cycle has always tried to kill life.

When the plates clump together, amazing things happen (kids should almost be asleep now).  All that buried ocean crust gets baked.  Huge amounts of water and co2 come out.  Since water vapour is the only effect insulating agent, the earth  gets warm.  Plants love this.  They grow in great gobs, and give us coal.  Dinosaurs try to eat the mammals.  Volcanoes everywhere try to kill us.

-to be continued.

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