The Holtzman Effect or Holtzmann Effect was a scientific theory relating to the repellant force of subatomic particles, and is part of a branch of scientific discoveries in the area of physics to bear the root name Holtzman.

Thousands of years later, Duncan Idaho realized that the mysterious entities known as Daniel and Marty had found another way to use Holtzman's ancient theories.

The effects of this theory were felt on humanity for tens of thousands of years, and proved to be the catalyst for rapid technological developments in several areas. These include:

• Shield: The Effect allowed the creation of a shielding that repelled most methods of fast moving projectiles, but allowed slower moving objects, such as hand-held knives, to pass through. This changed the nature of warfare - conventional projectile weapons became mostly useless and laser weapons became incredibly dangerous, forcing humanity to return to the use of hand-weapons.
• Suspensors: The Effect's repellent effect allowed physical objects equipped with a Holtzman field generator to defy gravity.
• Glowglobe: Another practical use of the Holtzman Effect was the invention of the glowglobe, which produced light self-powered usually by organic batteries, and float allowed by a small Holtzman field suspensor generator.
• Space travel: Probably the most profound effect of the Holtzman Effect was its ability to fold space and time, and thus allow for instantaneous travel from one side of the universe to the other.