The Core of the Earth

Into The Heart of Our World

A Journey to the Center of the Earth: A Remarkable Voyage of Scientific Discovery

David Whitehouse. Multco Hillsdale . 551.11 w593i 2016

Also ...

• Journey to the Centre of the Earth / A Remarkable Voyage of Scientific Discovery into The Heart of Our World
• Journey to the Centrer of the Earth / A Scientific Exploration into the Heart of Our Planet

http://davidwhitehouse dot com/journey-centre-earth (sorry, my wiki software doesn't like the string wh---house.com

• p8 tunnel to center of the Earth, free fall in 21 minutes
  • er, no, unless you drop from the poles. The Earth rotates, and you start out moving east with a velocity of cos(latitude)*465 m/s with a specific angular momentum of approximately 3e9 m2/s. That angular momentum corresponds to a perigee radius of around 260 kilometers deep inside the "reduced gravity" core of the Earth.

Much of the book is about using sound waves from earthquakes and bomb tests to evaluate seismic propagation through the core, Interesting, but the take-home lesson is that there is a lot of noise and not much accumulated signal, so far.

I skimmed much of this; I wasn't engaged.