Time field

The Time Field was a field of time energy that spilled from cracks in the fabric of time and space. The cracks were caused by the TARDIS exploding on 26 June 2010, after coming under the control of an unknown entity who was somehow connected to The Silence and whose voice was heard repeating the words "Silence will fall".

Cracks
The cracks were described by the Eleventh Doctor as "two parts of space and time that should never have touched, pressed together". They were present in the very fabric of spacetime - a crack that appeared to be part of a wall would still be there if the wall were removed. (DW: The Eleventh Hour)

According to Rosanna Calvierri, the cracks ranged in size from tiny to "as big as the sky", and some connected to other worlds, while others led only to "silence, and the end of all things". (DW: The Vampires of Venice)

Some cracks acted like wormholes and could be opened to allow a passage between the places on either side. Rosanna Calvierri and her family travelled through a crack of this kind, (DW: The Vampires of Venice) as did Prisoner Zero. (DW: The Eleventh Hour) A sonic screwdriver could widen a crack, and if a crack was open wide enough, the forces would invert; and the crack would snap itself shut. (DW: The Eleventh Hour)

Other cracks released pure time energy able to wipe individuals from time itself and remove events from history. Time travellers such as the Doctor would still remember them, at least so long as the removed event or person did not relate to the time traveller's direct past. (DW: Flesh and Stone, Cold Blood)

Also, when the time energy erased people and events, the consequences would still remain: the Byzantium remained crashed when the Weeping Angels who had caused it were erased; and Amelia Pond still existed when her parents were erased from history. (DW: Flesh and Stone, The Big Bang) This time energy was visible as a glow of bright white light, which sometimes extended tendrils from the crack toward nearby people and objects to consume them.

The Doctor guessed that the time energy from these kind of cracks had erased events such as the CyberKing walking over London in the Victorian era, and the 2009 Dalek invasion of Earth; the latter being one of Earth's most publicly visible invasions. This explained why Amy Pond did not remember those events. Smaller, inconsequential things were erased as well, including, possibly, the ducks from a duck pond in Leadworth.



Regardless of the size and what was on the other side, all cracks appeared to be of the same shape and orientation. The Doctor stated that the only way to close such a crack was for it to consume a complicated space-time event, such as himself or a large group of Weeping Angels; all of them together were equivalent to him. River Song volunteered to let herself be consumed, but the Doctor sneered at the idea and said that she wasn't even as complicated as one Angel. (DW: Flesh and Stone)

Origin
The cracks in time originated in the destruction of the Doctor's TARDIS when it came under the control of an unknown, disembodied force which made it materialise outside Amy Pond's house on 26 June 2010. River Song tried to prevent the explosion, but completely lost control of the TARDIS. It exploded, cracking points in time and space, some of which the Eleventh Doctor had been to. This resulted in the destruction of the universe, but the TARDIS preserved Earth by putting itself in a time loop at the moment of its death. The heat from the perpetual explosion heated the alternate Earth in place of the sun. (DW: The Pandorica Opens, The Big Bang)

Closing
Having determined that the Pandorica - designed as the perfect prison - still contained some atoms of the original universe that existed prior to the TARDIS exploding, the Doctor flew it into the heart of the TARDIS explosion. Using the remaining atoms of the original universe inside the Pandorica and the restoration field, he repaired the damage caused by the cracks. The universe and the timeline were reset, all of the cracks closed and never existed, and the versions of Amy and Rory relevant to the old timeline were erased. To fully close the cracks, the Doctor let himself be absorbed by one and erased from existence.

Using the ability given to her by the crack in her room, Amy's remembrance of her parents and Rory undid their erasure in the rebooted universe. The Doctor, however, remained erased until Amy remembered him and their adventures and brought him and the TARDIS back. Despite everything being repaired, the Doctor remained clueless as to what was responsible for the destruction of the TARDIS in the first place. (DW: The Big Bang)

Notable cracks
Around Easter of 1996, a crack in Amy Pond's bedroom wall connected it to an Atraxi prison. This crack also erased Amy's parents from existence, and Prisoner Zero was able to escape through it to Earth from the Atraxi prison. The Eleventh Doctor closed this crack by widening it with his sonic screwdriver. (DW: The Eleventh Hour, The Big Bang) Cracks also appeared on the side of Starship UK in the 33rd century (DW: The Beast Below) and in the Cabinet War Room in 1941. (DW: Victory of the Daleks)

Another crack opened to a vast size aboard the spaceship Byzantium in the 51st century. It erased Crispin, Marco, Pedro, Phillip and many Weeping Angels from existence, then closed. The Weeping Angels had feared it and attempted to escape, only to be dropped into it after they had absorbed all of the Byzantium's energy, disabling the ship's artificial gravity. The Angels, combined, were a sufficiently complex space-time event to seal the crack for a while. (DW: Flesh and Stone) According to Rosanna Calvierri, she and the other Saturnynians fled Saturnyne because of the "silence" they saw through some of the cracks. They fled through one of the cracks to "an ocean like ours" on Earth, after which the crack closed behind them. When the Doctor saved Venice, the shape of the cracks appeared in the sky (though this may have just been a coincidence). Just before the Doctor left, silence abruptly fell over Venice. (DW: The Vampires of Venice)

There was a crack in the Silurian base beneath the Earth in 2020. The Doctor, Amy and Rory found it while leaving the base. Examining it, the Doctor reached inside the crack for "shrapnel" from the original explosion, and retrieved a burnt piece of the TARDIS. Before leaving, Rory was shot by the Restac, and came in contact with the light from the crack. Despite Amy's protests, the Doctor left Rory behind. The crack erased Rory from existence. The Doctor still remembered him and mentioned him later (DW: Vincent and the Doctor) and the engagement ring which he had bought Amy still existed in the TARDIS. Amy lost all recollection of Rory due to the crack directly affecting her past. (DW: Cold Blood)

There was a crack in Craig Owens' flat in 2010 in the kitchen wall, next to the fridge. Shortly after the Doctor left the flat, the Time Field energy began to emit from the crack and it began to expand. (DW: The Lodger)

Another crack appeared in the TARDIS whilst it was parked next to Amy's house on 26 June 2010. The TARDIS monitor read the time and place, and the glass cracked into the shape of the cracks. This was followed by a sinister voice rasping "Silence will fall". (DW: The Pandorica Opens)

Chronological appearances

 * 1929 - A crack appeared on one of the walls in the temple of Artemis. (NSA: The Hounds of Artemis)
 * 1941 - A crack appeared on the wall of Winston Churchill's Cabinet War Room. (DW: Victory of the Daleks)
 * 1996 - A crack appeared on young Amy Pond's bedroom wall, connecting it to an Atraxi prison. This was when the Doctor first noticed them. (DW: The Eleventh Hour)
 * 1996 - A crack appeared on Amy Pond's bedroom wall as the Doctor's timeline rewound. It was in the same place as the original crack (suggesting it may have been the same crack having reopened). To fully close the cracks in time, the Doctor stepped into this one, erasing himself. The crack then closed. (DW: The Big Bang)
 * 2010 - A crack appeared on a screen in the TARDIS before the Doctor turned it off. (DW: The Eleventh Hour)
 * 2010 - A crack appeared by the side of the fridge at the house of Craig Owens. (DW: The Lodger)
 * 2010 - A crack appeared on a screen in the TARDIS, followed by an unknown voice repeatedly saying "Silence will fall" soon after River Song left the TARDIS. (DW: The Pandorica Opens)
 * 2010 - A crack appeared on the circular TARDIS screen as the Doctor's timeline rewound. (DW: The Big Bang)
 * 2010 - A crack appeared on Aickman Road as the Doctor's timeline rewound. (DW: The Big Bang)
 * 2020 - A crack appeared in the rock wall of a Silurian base. After Rory Williams was shot, it consumed him and he was erased from time. The consequence of this was that Amy Pond forgot about him, with only the Doctor remembering him. (DW: Cold Blood)
 * 3295 - A crack appeared on the side of the Starship UK. (DW: The Beast Below)
 * 41st century - Some time in the 41st century, a crack appeared on a tank that held a Dalek Mutant. (GN: The Only Good Dalek)
 * 51st century - Some time in the 51st century, a crack appeared in the secondary flight deck of the Byzantium and consumed the Weeping Angels. (DW: Flesh and Stone)

Behind the scenes

 * The time crack was inspired by a crack Steven Moffat saw in his son's bedroom. It resembled a smiling mouth.
 * In 2010, NASA found what appears to be a crack shaped similar to the one in Doctor Who in the middle of the Milky Way.
 * According to Russell T Davies, the Doctor's closing of the cracks also closed the Cardiff Rift.
 * In DW: The Vampires of Venice, when the Doctor saves Venice, there is a sliver of sunlight on one of the clouds in the sky, which is a very similar shape to the cracks in time. This has led some fans to believe that it really was a crack, while others believe that the shape of the sliver of light was just a coincidence. The latter is supported by the fact that the sliver of light moves with the clouds, and slightly changes shape and orientation as it moves, like an ordinary sliver of light.