What makes you tick, whom you know, where you go, even where you might end up. The information you share in your profile is a mere snippet of what Facebook and its partners really know about you. Kevin Roose, a technology columnist for The Times, explains.

Military forces often boast about the awe of airstrikes and missile launches, but what’s it like to experience their deadly shock on the ground?

Mr. Ryan said Wednesday that he would not seek re-election, ending a brief stint atop the House and signaling the peril that the Republican majority faces in the midterm elections.