Here's a reply to my post about the future of aviation and fossil fuels from my friend Robert Green.  If you're  a physics geek . . . hold on!

"About 320 years ago, after the breakthrough work of Isaac Newton’s 1687 Principia Mathmatica (and its revolutionary quantification of gravity) he and fellow English scientist Robert Hooke theorized the construction of gravity tunnels through the earth’s crust to achieve rapid travel from point to point on the globe.  The calculations show a trip time of 42 minutes from any point to any other point via a straight line to take advantage of the Earth’s tendency to make us “fall” to the center then using conservation of momentum to catapult us back to the surface on the other side (minus, of course, any frictional losses).

That’s right, New York to Hawaii in 42 minutes.  New York to Shanghai in 42 minutes.  Los Angeles to Milwaukee in 42 minutes.  You get the idea.

It seems to me this idea could work just like a submerged subway infrastructure (think BART in the Bay Area) using magnetic levitation (MagLev) concepts to constrain the vehicle inside the tunnel and deliver energy to overcome frictional losses during the catapulting out phase of the trip.  Surface rail could then take you from the main tunnel ports to your ultimate destination.

I admit that I am a physics geek who masquerades as a Mechanical Engineer and CAD consultant but I think this idea has merit.  What we need are your Civil Engineering buddies and their Geology brethren to start computing the stresses and infrastructure requirements for such a series of global tunnels.

It may sound far fetched now, but did anybody fathom routine air travel a century ago?"

Robert has a great BLOG.