[pct-l] Gravity

[wayneskraft at comcast.net (Wayne Kraft)]

OK, let's see if I can put this thought into words.  Gravity doesn't  
exactly operate to pull you down hill.  It operates to pull you  
toward the center of the earth.  A car rolls down a real hill because  
it's contact with the earth prevents it from falling straight down.   
If a we refer to a road that follows the curvature of the earth as  
"flat" then presumably a car stopped on this road would remain  
motionless even with the brake off.  However, if the road is REALLY  
flat in absolute terms (that is, it doesn't follow the earth's  
curvature, but is level in each direction from the center point)  
would not a car roll toward the center from either end of the level  
road?  It would seem like the car would be attracted to the point  
closest to the center of the earth.  Or would such a road appear to  
us to be curved or uphill in both directions?  Is there even a way to  
measure or conceptualize absolute level independent of earth's curve?

List physicists, please address this 	question ASAP.  There is a  
trail in Portland here called Leif Ericksen Drive (actually it is  
kind of an abandoned dirt road) that is about 11 miles long.   
Sometimes I run it out and back for 22 miles.  There's about three  
miles in the middle that I swear is uphill both directions.  It has  
caused me to seriously question my sanity. I need to have an answer  
to this before I head back out there.

Wayne Kraft