If a storm has knocked out physical phone lines, no landline attempts will be successful.

FORBES: 5 Lessons From Hurricane Sandy For Emergency Preparedness

Women supporting supply missions have been drawn into battle in Iraq and Afghanistan, where there are no physical front lines.

CNN: Former troops say time has come for women in combat units

Where engineering in the 1880s organized itself around lines suggested by the physical sciences, the new technologists are organizing in new ways, along lines suggested by the cognitive, aesthetic and social sciences and arts: computer science, psychology, social psychology, user-experience and design.

FORBES: Entrepreneurs are the New Labor: Part II

It blurs the lines between the physical and virtual world.

CNN: In touch with the digital age

The beauty of fiber optic communications systems is that they are very hard to penetrate - unless, that is, you own the infrastructure and, therefore, have physical control of its cable lines.

CENTERFORSECURITYPOLICY: Strategic fire-sale

As software eats the world, every sort of engineering (and indeed, every sort of profession organized along lines suggested by the physical sciences, including fields like medicine) is becoming effectively a branch of computer science.

FORBES: Entrepreneurs are the New Labor: Part II

The instructors draw a lot of those Johnny Miller lines on your swing, which beginners may have trouble interpreting or translating into actual physical changes.

WSJ: Online Golf Instruction: What Works | Golf Journal by John Paul Newport