The ongoing technological process of miniaturization attained its ultimate objective in the Nano Age. Nanotechnology had its first successes in the early 21st Century in medical applications. But subsequent improvements in imaging and manipulation techniques allowed for the creation of "nanomachines," with sizes measured in billionths of a meter. Working in concert, these amazing machines could theoretically build anything, atom-by-atom, including copies of themselves.

Programming the trillions of nanomachines needed to make a sizable object in a reasonable amount of time was a major hurdle to overcome. The solution involved developing a simple coding system — not unlike DNA — that provided the instructions on how to make any type of compound. Larger structures were then assembled from the compounds. Quantum computers — the smallest and most powerful computers yet devised — handled the astronomical amount of data involved.

Nanomachines were soon being used to build a wide variety of things. Biological structures were merged with mechanical structures, creating cyborgs and other hybrids. The designs for mechanized military units — already highly successful — received a host of internal refinements that made them even more effective. And researchers developed artificial viruses that could be used for everything from medical treatments to mind control. The only restriction was that objects first had to be described on an atomic level, which was usually a time-consuming process.

The other major development of the period was learning to synthesize "negative matter," an exotic substance with extraordinary physical properties. First hypothesized in the 20th Century, the formulation of the Theory of Everything in the 21st Century brought negative matter into clear focus. Applying the theory allowed humans to do something previously considered impossible: travel through time. Nanotechnology provided the means to magnify a phenomenon known as the Casimir effect to open a wormhole — a tunnel through the fabric of space-time. Once enough negative matter was synthesized to enlarge and stabilize the wormhole, objects were able to pass through. As soon as other technological barriers were overcome (for example, protecting the fragile human body from the extreme forces involved and controlling where the "far end" of the wormhole appeared) time travel became a reality.

In the Nano Age, humankind gradually gained mastery over matter and energy, time and space. Yet despite these achievements and the virtually limitless possibilities they presented, life on Earth continued much the way it had over the previous 500,000 years. Though a mere speck in the cosmos, Earth remained the cradle of human civilization.