Spill Cam

The hypnotic video of mud, gas and oil billowing from the seafloor has become an Internet sensation as Americans watch to see whether BP’s effort to plug the gusher in the Gulf of Mexico succeeds.

BP warned Friday that it could be Sunday or later before the outcome of the cliffhanger becomes clear. And scientists cautioned that few conclusions can be drawn with any certainty from watching the spillcam coverage of the “top kill.” But some said the video seemed to suggest BP was gaining ground.