I have a couple of questions regarding the new detection of signals believed to be gravitational waves at LIGO 1. Two similar signals were detected at both facilities. Why does the Livingston signal appear to be weaker than the Hanford signal? 2. The signal in Livingston was reported to have been detected 7 milliseconds after the Hanford signal. How can this be possible if gravitational waves are supposed to travel at the speed of light? Is there just a margin of error involved, or does this imply that g. waves actually propagate at a different speed than predicted?