Co-author of The Prisoner's Dilemma model

Jen and Sam take Alex back in time to help solve the question, who did discover North America? Mike Ackerman co-stars as Sam.

Wrote the short stories "Blood Trail" (2001), "Red Letter Day" (2010), and "Uncertainty" (2013)

15 year old AJ (John Patrick White) likes to learn so he uses his time machine to enter into a world of fantasy. This time, he and his friends travel to Mesopotamia.

Flesh is a recurring story in the weekly anthology comic 2000 AD created by writer Pat Mills.

Traveled in the film Terror From The Year 5000! (1958).

Thomas meets a messenger from the future who brings him six words. Written by Hans Hergot

As the Doctor (Matt Smith) prepares to face his darkest hour, key players conspire and a grim warning is given...

Traveled in the TV series Rooftop Prince (2012)

Stopping off in present-day Cardiff to recharge the TARDIS, The Doctor, Rose and Jack encounter an old foe in the midst of hatching a scheme that could destroy the entire planet. Featuring Annette Badland as Margaret Blaine.

After his landing on Jupiter moon Alpha64, the cosmonaut Yuri Lennon (Marc Hosemann) is confronted with an extraordinary paradox.

Jamie (Sam Heughan) trains his militia men for the upcoming Rising before joining the forces. Claire keeps to Jamie and gives him full disclosure on what little she knows about Scotland's fate in the Rising.

German children's television program show in which four children are appointed as "Wachter" (guardians) by their deceased aunt Hedda to prevent Zanrelot, the "Herrscher der Finsternis" - the lord of darkness (Udo Kier) from leaving the underworld and gaining control over Lubeck.

Traveled in the film Lara Croft: Tomb Raider (2001)

Traveled in the film Donnie Darko (2001) and the TV movie The Librarians 2: Return to King Solomon's Mines (2006), and the TV series The Librarians (2014 - )

In the 30th century, time travel becomes illegal after a time paradox crisis. The Time Protection Department (TPD) is established to watch for and stop time crimes. Narration by Yukitoshi Hori

Traveled in (and co-wrote, and co-directed) the film Nothing Left To Do But Cry (1984)

A member of The Doctor (Matt Smith)'s team has been abducted and he will call in every favor and maybe even go to war to get him/her back.

In a what-if tale, Ben (Tara Strong) wakes up back at the start of summer vacation (with full memories of the coming weeks) and finds himself not the one to whom the Omnitrix affixes itself.

Jamie trains his militia men for the upcoming Rising before joining the forces. Claire provides him full disclosure on what little she knows about Scotland's fate in the Rising. Featuring Graham McTavish as Dougal MacKenzie.

Furious about the outcome of her brother's trial, Becky breaks Noah (Jeffrey Walker) and Geneva out of the Discipline Centre and takes them to Dr. Pretorius who gives Noah a pair of PH-Ts.

Stopping off in present-day Cardiff to recharge the TARDIS, The Doctor, Rose and Jack encounter an old foe in the midst of hatching a scheme that could destroy the entire planet. Featuring Annette Badland as Margaret Blaine.

A neurotic inventor (Michael Nathanson) creates a time machine and gets lost traveling around yesterday.

Traveled in the TV series Doctor Who episodes "Doctor Who and the Silurians" (1970), "The Mutants" (1972), and "Voyage of the Damned" (2007), Ashes to Ashes episode "Alex's Big Day" (2008), and as the narrator of the TV series 1940's House (2001).

Traveled in the TV series Eureka episodes "I'll Be Seeing You" and "Founder's Day" (2010)

When a clock lands on Mater(Larry The Cable Guy)'s engine, he travels back in time to 1909 where he meets Stanley, an ambitious young car on his way to California.

The Doctor (William Hartnell), Steven and Dodo investigate why there are Savages in the Elders' city and uncover the true price of the Elders' perfect society.

It's Harry (Daniel Radcliffe)'s third year at Hogwarts; convicted murderer Sirius Black has escaped the Wizards' Prison and is coming after Harry.