Geophysics made easy 020417

Recently discovered (if you knew about MinuteEarth, why didn't you tell me?) series of short videos on rivers:

• Meandering
• Delta v estuary

Another power-of-water update: last view of the Azure Arch minutes before collapse 08/03/17: stormy weather.
Géophysique c'est une aventure
Geophysicists have the biggest hammers

And geophysics segues naturally into rocks:

• Making a granite counter-top.
• Where the rock might come from
• previously Splitters
• And mother of god: the journey down hill

And from rocks to materials science:

• This last week, a 100m elevated section of I-85N out of Atlanta, GA collapsed to the ground >!kaDUNNNNG!< as a fire broiled underneath. Juan "Oroville" Browne quickly found probable cause in rolls and rolls of PVC pipe stored for a decade under the highway (it's dry and 10-lanes capacious). Concrete and steel  doesn't burn easily, let's look for an accelerant, said Juan. The Atlanta police soon found probable perps in 3 black homeless men. (It's dry and not far from town) The event is a clarion-call, as if one were needed, drawing attention to the high dependence of the USA (and the Western World) on aging infrastructure that is getting near it's sell-by date. 130,000 similar bridges at risk. 250,000 cars a day used to use that section of the Interstate system.  That's a lot of inconvenience. Maybe 
• IF 
• The Man sorted the homelessness 
• THEN 
• this collective inconvenience wouldn't happen. 
• 9/11 deniers / conspiracy theorists might re-reflect on whether fire can destroy ferro-concrete.