The intercourse between the Mediterranean and the North or between the Atlantic and Central Europe was never purely economic or political; it also meant the exchange of knowledge and ideas and the influence of social institutions and artistic and literary forms.
Why do the President and Vice-President constantly change the subject when asked to explain why things are going so badly in Iraq? The answer is simple. They have been consistently wrong about Iraq, and the results speak for themselves.
The fundamental point in fabricating a chain reacting machine is of course to see to it that each fission produces a certain number of neutrons and some of these neutrons will again produce fission.