> So you assumed the road is linear ? What kind of a perception is that > (((: have you heard the word "helical" ? If the road is not linear, but involves curves then even more energy will b= e required to replace the energy scrubbed off by turning. Even if that wasn't the case, the helix would still need to be as high as t= he linear road previously mentioned. --=20 Scanned by iCritical. --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .