The travel velocity of these two wave types is not the same (P-waves are faster than S-waves). Thus, if there is an earthquake somewhere, the first waves that arrive are P-waves. In essence, the gap in P-wave and S-wave arrival gives a first estimate of the distance to the earthquake.
With the mysterious U.S. Senator Eddie Morra (Bradley Cooper) providing him with a second drug to counteract NZT's deadly side effects, Brian uses his enhanced abilities to help FBI agent Rebecca Harris (Jennifer Carpenter).
The big, burly, baritone-voiced actor was infallible as Perry Mason, the defense attorney who championed the wrongly accused, and he was unstoppable as Robert T. Ironside, the wheelchair-bound homicide cop who went head-to-head with various and sundry killers, crooks, and psychos.