Time loop A time loop , known technically as a " chronic hysteresis " ( TV : " Meglos " ) , was a loop in time in which the occupants experienced the same events in endless repetition . Science . An accurate time loop took little energy to perpetuate . An incomplete time loop ( where each repetition was not the same as the last or the loops were not the same length ) was unstable . Energy requirements increased with each iteration . ( PROSE : " The Pirate Loop " ) While there was no known technological method of escaping a time loop , the Fourth Doctor and Romana broke a time loop by deliberately recreating the events of the loop out of phase with the loop itself . ( TV : " Meglos " ) The Third Doctor was able to escape the time loop he created around Axos by boosting the signal . This might indicate that the person creating a time loop could still leave it . ( TV : " The Claws of Axos " ) As he later related , however , due to the Time Lord s tampering with his TARDIS and knowledge of time travel the loop he created was not an accurate time field / threshold ( AUDIO : " The Feast of Axos " ) so this may have allowed his exit . Characteristics . The Third Doctor attempted to explain the concept to the Brigadier and Jo Grant as a " loop in time , " the same events in space occurring over the same place in time . Time loops had the appearance of the infinity symbol , ( TV : " The Claws of Axos " ) a figure of eight looping through four dimension s . The threshold of a time loop , possibly called the " time barrier , " could be crossed into . Echoes of the past and future could be experienced , such as messages repeating themselves . This was evidence that various futures were possible ; a message from the future did not guarantee those events would happen as time was in flux . A time loop would eventually decay naturally over six billion years . ( AUDIO : " The Feast of Axos " ) Chaotic time loops could have the appearance of a spiral or spider web . ( AUDIO : " Spider ' s Shadow " ) Occurrences . Several planet s were placed into time loops by the Time Lord s , including the War Lord s ' planet , ( TV : " The War Games " , PROSE : " " ) the Vardan homeworld , ( TV : " The Invasion of Time " ) and Planet 5 . ( TV : " Image of the Fendahl " , PROSE : " The Taking of Planet 5 " ) Leela thought the time loop into which Planet 5 was placed was " very clever " , but the Fourth Doctor replied that it was " criminal " . ( TV : " Image of the Fendahl " ) Axos was placed into a time loop ( TV : " The Claws of Axos " ) but some part of it was freed by Chiyoko to ensure her own existence . ( COMIC : " The Child of Time " ) The rest of it was released by an expedition attempting to harness it as a power source , but the Sixth Doctor later restored the time loop , trapping Axos in the moment of its own destruction . ( AUDIO : " The Feast of Axos " ) While the completed Key to Time would have stopped time altogether , five pieces and a makeshift sixth made of chronodyne was enough to generate a temporary time loop . The Fourth Doctor put the Marshal of Atrios ' s Command Capsule in a time loop to stop him from destroying Zeos , but his incomplete control of the Key initially put the entire universe in a loop apart from the TARDIS console . ( TV : " The Armageddon Factor " ) Meglos used a time loop to trap the Fourth Doctor and Romana in the TARDIS and prevent them reaching Tigella , but the loop was incomplete , allowing them to break free of it after they realised what had happened by repeating the opening moments of the loop on their own . ( TV : " Meglos " ) Koel Paddox unintentionally trapped himself in a time loop when he attempted to duplicate the Arboretan s ' ability to live their lives over again , transferring his mind into his past self at the moment of birth but unable to change any actions committed by his past self . ( PROSE : " Festival of Death " ) Events on the planet Puxatornee were essentially caught in a time loop , as the Seventh Doctor and Melanie Bush were forced to create two different alternate timelines when they arrived on this world , with residents of each timeline unwittingly creating the other by attempting to avert or cause the assassination of President Bailey thirty years ago . ( AUDIO : " Flip - Flop " ) The Dalek s were trapped in a time loop inside the Time Vortex . ( AUDIO : " The Time of the Daleks " ) Jack Harkness was trapped in a two - week time loop with his fellow renegade Time Agent John Hart for five years . ( TV : " Kiss Kiss , Bang Bang " ) Lucie Miller materialised the TARDIS inside a time loop when she and the Eighth Doctor chased the rogue time - traveller Nick Zimmerman after he deliberately placed himself within one to prevent his wife Rachel from dying . ( AUDIO : " No More Lies " ) The Eighth Doctor and Charley Pollard got trapped inside a time loop and space loop in an Edwardian house . ( AUDIO : " The Chimes of Midnight " ) When the " Brilliant " was attacked by space pirate s , the engine was engaged and accidentally caused an incomplete time loop . Though things were brought back after destruction , it was inconsistent and mistakes were made . The Tenth Doctor finally fixed the time loop , causing less damage . ( PROSE : " The Pirate Loop " ) The Trickster placed Sarah Jane Smith , Peter Dalton , the Tenth Doctor , and Sarah ' s friends in a time loop in the hotel where Sarah and Peter ' s wedding was taking place , with Peter and Sarah trapped in one second and the Doctor and Sarah ' s friends in another . ( TV : " The Wedding of Sarah Jane Smith " ) A crashed time ship trying to find a pilot for itself created several time loops in the local area during its failed attempts to repair itself . ( TV : " The Lodger " ) The Doctor ' s TARDIS put River Song in a time loop to stop its explosion killing her - simultaneously putting itself in a time loop at the moment of its own destruction so that it could serve as a substitute sun for Earth - until she was rescued by the Eleventh Doctor . ( TV : " The Big Bang " ) In 2050 , due to the Oroborus consuming time , time distortions such as time loops occurred across London . ( TV : " Oroborus " ) The life cycle of the Cinder was a form of time loop ; the creature was defeated by the First Doctor and Vicki Pallister in 1814 . Its surviving form was accidentally taken back to the 12th century B . C . by Vicki . That form would eventually grow into the creature defeated in 1814 . ( AUDIO : " Frostfire " ) The Eighth Doctor set up a time loop inside Edward Fyne ' s body to temporarily slow down the progress of his tyger - fever . ( PROSE : " The Eye of the Tyger " ) The Fifth and the Eighth Doctor used their TARDISes to trap the Dalek Prime in a time loop . ( AUDIO : " The Four Doctors " ) The whole of the Divergent Universe was in a time - loop , throughout its whole existence , preventing time - travel inside the universe as it was impossible to focus on specific temporal coordinates as every moment had happened several times before ; Rassilon had been through this loop 85 times by the time the Eighth Doctor caught up to him , despite the Doctor entering the Divergent Universe less than an hour after Zagreus threw Rassilon into the universe . ( AUDIO : " The Next Life " )