User:Lubal/Inertialess

An inertialess drive is a fictional form of space travel that involves eliminating the effects of inertia or reducing them to arbitrarily small values to allow for extremely high rates of acceleration and, in some versions, faster-than-light travel.

Science fiction
Spacecraft whose propulsion systems minimized or ignored the effects of inertia were commonplace in early space opera works, such as Edward E. "Doc" Smith's The Skylark of Space and Edmond Hamilton's "Crashing Suns", both published in 1928. However, these stories did not make it clear whether this approach to physics was intended as part of the setting or merely an oversight by the author.

In 1934, Smith approached the topic more directly in his novel Triplanetary, describing an faster-than-light "inertialess drive" which he claimed had a realistic basis described in Samuel Lawrence Bigelow's 1912 Theoretical and Physical Chemistry. Smith's theory, that inertialess mass would not be bound by the speed of light, offered a seemingly plausible way to tell adventures that could span the galaxy. Lester Dent, writing as Kenneth Robeson for the Doc Savage story "The Secret in the Sky", employed a similar fictional engine the following year. Later authors who wrote about similar fictional technology include Robert A. Heinlein, Larry Niven, Alastair Reynolds Wil McCarthy, and the Warhammer 40,000 science fantasy and wargaming setting.

Arthur C. Clarke proposed a different type of inertialess drive, which did not violate the speed of light, in his 1997 novel 3001: The Final Odyssey. Clarke provided scientific justifications for the science-fiction concepts in his novel. To explain his inertialess drive, he cited an academic journal article which argued that electromagnetic effects are responsible for the origin of inertia and, therefore, a suitably powerful energy source could be used to shield that interaction and reduce or eliminate inertia.

Scientific appraisal
Generally, the authors of these fictional drives do not offer detailed explanations of how inertia might be eliminated or why doing so would allow faster-than-light travel. The scientific consensus is that faster-than-light travel and gravitational shielding are impossible, and the model of inertia supporting Clarke's theorized drive is not widely accepted. If such a drive were nevertheless somehow possible, passengers would be weightless during the entire voyage. Additionally, navigation using such a drive would be impractical; an inertialess spacecraft would be easily deflected from its desired path by even the momentum of colliding photons.

Outside of mainstream science, ufologists have proposed inertialess drives as an explanation for the purported movements of unidentified flying objects, and proponents of free energy suppression conspiracy theories have argued that propulsion systems like the one Clarke described do, or will, exist.