In a message dated 11/20/1999 9:38:42 AM Eastern Standard Time, [log in to unmask] writes: << 1. Was the gravity constant G (F=Gm1.m2) the same in tnose days 2. Was the atmospheric oxygen concetration the same as today? >> I would think that these were just about the same then as now, and if there were any small deifferences they would be nowhhere near 50%