"In space, no one can hear you scream" was the tagline of the 1979 box office film success Alien. And it's true. Sound waves propagate mechanically as a vibration and therefore need a medium – solid, liquid or gas – to travel through. Although interplanetary (and interstellar) space is not completely empty, gas molecules and dust grains are so sparsely distributed that they do not form a continuous medium that would enable sound waves to be transmitted directly.
The daughter of former Vice President Al Gore is expected to appear in Boston Municipal Court today stemming from charges last month when she and two dozen other activists trespassed to protest a natural gas pipeline that its engineer says will provide reliable energy to the region.
While several of the 23 protesters struck deals to reduce the charges, Karenna Gore and five others have plead not guilty to charges of trespassing, resisting arrest and disturbing the peace.
