Backscatter machines use X-rays, while millimeter wave machines use radio waves.

CNN: TSA removing 'virtual strip search' body scanners

In the U.S., the TSA uses both types of scanners: 250 X-ray scanners and 264 millimeter wave scanners.

FORBES: Europe Bans Airport Body Scanners For "Health and Safety" Concerns

Instead of X-ray scanners, European airports will use millimeter-wave scanners that utilize low-energy radio waves.

FORBES: Europe Bans Airport Body Scanners For "Health and Safety" Concerns

In addition to the backscatter machines, the TSA has also deployed about 260 millimeter-wave machines which use radio waves and do not emit X-rays.

CNN: SHARE THIS

Since this term is totally without meaning, she can then claim that the latest forest fire, the latest hurricane, the latest drought, flood, snow, cold snap, heat wave, or tornado were cause by man, and that scientist X said so.

FORBES: Truthmarket Challenge Demonstrates Everything That Is Wrong With the Global Warming Debate

The series -- about a group of space explorers given various superpowers after being hit by cosmic rays -- began a new era for Marvel Comics, signaling the start of their wave of Silver Age characters, including Spider-Man, the X-Men, the Hulk, Iron Man and many more.

CNN: 2011 is bringing a death to the 'Fantastic Four' family

If an aggressor launches a nuclear device of whatever size and detonates it above the atmosphere and in the line of site of its target country, the x-rays and gamma rays emitted by the blast will cause an electromagnetic pulse, or wave a million times stronger than the strongest radio wave.

CENTERFORSECURITYPOLICY: An urgent memo to the next government