Football and sum of infinite series?

So the sum of this infinite series, 1/2+1/4+1/8+1/16+1/32+...+(1/2)^n equals 1 right? If this is the case, would a football team score a touchdown eventually if the defense keep committing half-a-distance-to-the-goal-line penalties? Theoretically, the team should be able to, right? I would like to know what the rules are in football. (NFL, college)