Using four vectors, show that it is impossible to have an inertial reference frame in which a photon is motionless.

grav forces affect all objects magnetic forces affect magnetic objects and electric currents

the journeys of marquette, joliet and la salle a) new france expand.

all three of these explorers explored the midwest and the area around the great lakes, which they subsequently claimed for france.

this was a big portion of territory and expanded new france which before then only consisted of quebec province in northeastern canada