The Accidental Time Machine

by Joe Haldeman

The protagonist, Matthew Fuller, is a research assistant for physics professor Jonathan Marsh at the Massachusetts Institute of Technology, in 2057, when he builds a calibrator to supply one photon per unit of time. When he presses the reset button, the box unexpectedly disappears for one second. When he presses the button a second time, he finds it disappears for about 10 seconds. The third time, it disappears for a bit less than three minutes. Fuller deduces it is traveling forward in time at intervals approximately 11.8 times the previous interval and he further deduces how to bring other objects, such as himself, along. On the seventh press of the button, Fuller and the box are taken 39 days into the future and unexpectedly land on a busy road. He is arrested on suspicion of murder but is bailed out of jail by an anonymous person he comes to believe is himself from the future. He continues forward, 465 days, then 15 years, when he is greeted by Professor Marsh who tracked Fuller and calculated the theoretical physics behind time travel.

Unsatisfied, Matt travels to 2252 where he learns that the Second Coming of Jesus has occurred and resulted in the One Year War. Society is now governed by a theocracy led by Jesus and shuns technology. Jesus had anticipated Fuller's appearance at the Massachusetts Institute of Theosophy, where he is appointed to be professor with a female student named Martha assigned to be his assistant. As Fuller tries to scientifically rationalize Jesus's seeming omnipotence, Jesus orders Fuller to destroy the time machine but he instead flees, along with Martha, and lands in the year 4346 outside of California. There they find a society where all of humanity is wealthy and satisfied to a point of apathy. It is here that they encounter an artificial intelligence, named La, that controls Los Angeles. La is curious about her own mortality, and having learned about Matt's time machine from historical records, wishes to join him on a journey to the end of time (heat death of the universe) to discover if she can die.

Matt and Martha begin to receive messages in their dreams from beings that appear to Matt as future versions of himself and to Martha as Jesus. He/they warn Matt and Martha of La's willingness to sacrifice their lives in pursuit of her goal, and advises them to stall for time to allow them to catch up. Matt and Martha, accompanied by La in a spacecraft, begin to travel further into the future, discovering evermore unfamiliar species of life, including androgynous evolutions of humanity and a race of intelligent bears. Time travelers are not always welcome - some future societies having been devastated by diseases brought from the past by such travelers for which future humans had no immunity, and therefore regard them as a dangerous threat.

After a confrontation where they narrowly avoid being killed by La, they meet the people who have been sending them subliminal messages. These beings tell Matt and Martha that the future becomes ever more alien and unpleasant, and offer to send the two back in time, while allowing La to continue jumping forward in time. The beings can specify either the exact time or the exact location to which Matt and Martha will be sent, but not both (this limitation is similar to the uncertainty principle). Concerned about the couple possibly materializing in the middle of the ocean or inside of a mountain, they opt to be specific about location and send them to MIT.

When they arrive, they find that it is the late 19th century, and the main MIT campus in Cambridge has not yet been built. Having no other option, they live in this society, where Matt studies and teaches physics, aided significantly by his advanced knowledge both of physics and historical events. However, he takes care not to change history – for example, he does not anticipate Albert Einstein in "discovering" the theory of relativity, as he could have easily done; rather, he takes care to appear a talented but not outstanding professor. Matt and Martha have several children, and the end of the book reveals that Professor Marsh (Matt's MIT professor in the mid-21st century) is actually Matt's descendant.

Timeline and list of societies

* February 2, 2058: Matt's first time jump - 39 days. Appears in the middle of the street, still in [[Boston, Massachusetts]].

* May 15, 2059: 465 days later. Appears on a busy highway.

* 2074: 15 years later. Matt appears on a field in a stadium named the "Matthew Fuller Sports Centre". The society is similar to 2057 but with advances in science and technology and new cultural trends, like facial scarring.

* 2252: 177 years later. Matt appears near the New Hampshire border in a theocratic society ruled by a being who claims to be Jesus. The inhabitants shun technology and the study of history before the One Year War which they believe was fought between believers and non-believers of Jesus following his Second Coming. They refer to the year as 71.

* 4346: 2094 years later. Matt and Martha arrive near California in a society governed by an artificial intelligence named La. There appears to be no poverty or illness and the inhabitants live by the rules of bartering focused on material wealth.

* 24,709 years later. Martha, La, and Matt land in the Pacific Ocean off the coast of Indonesia and travel to Australia and America. They are greeted by a hologram which does not allow them contact with society due to its experience with disease transmitted by other time-travelers. They otherwise encounter bioengineered dinosaurs and bear-like people.

* 320,000 years later. There appears to be no life on Earth and they travel to the moon. They only encounter large, hostile mechanical creatures.

* 3.5 million years later. They meet six other time-travelers who send Martha and Matt to the past and La to the future.

* 1898. Martha and Matt arrive back in Boston.