Monoliths are fictional advanced machines built by an unseen extraterrestrial species that appear in Arthur C. Clarke's Space Odyssey series of novels and films.

During the series, three monoliths are discovered in the solar system by humans and it is revealed that thousands if not more were created throughout the solar system, although none are seen. The subsequent response of the characters to their discovery drives the plot of the series. It also influences the fictional history of the series, particularly by encouraging humankind to progress with technological development and space travel.

The first monolith appears in the beginning of the story, set in prehistoric times. It is discovered by a group of hominids, and somehow triggers a considerable shift in evolution, starting with the ability to use tools.

Nomenclature

The first monolith to be discovered in the modern age was unearthed on the moon near Tycho Crater due to it emitting a powerful magnetic field which was detected and investigated. It was called Tycho Magnetic Anomaly 1 (TMA-1) before the monolith was discovered. The name stuck even after it was discovered to be an obvious alien artifact. Subsequent to this, a second, larger monolith was soon discovered orbiting Jupiter and called TMA-2. A few centuries in the future, a third monolith was discovered buried on Earth in rocks that were clearly millions of years old and surrounded by primitive human artifacts. This was retroactively named TMA-0 (as opposed to TMA-3) in reference to the fact it was obviously the first monolith discovered by human ancestors in prehistoric times.

The term "Tycho magnetic anomaly" is something of a misnomer when referring to TMA-0 and TMA-2, as neither was found on the moon (let alone in Tycho) and neither emitted a significant magnetic field. This critique was mentioned in the novel 2010: Odyssey Two. In the same novel, the Russian Crew of the spacecraft Cosmonaut Alexei Leonov affectionately and somewhat respectfully refer to TMA-2 as "Zagadka" (Russian for Enigma or Riddle).

Origins

The extraterrestrial species that built the monoliths is never described in much detail but some knowledge of their existence is granted to Dave Bowman after he is transported by the stargate to the "cosmic zoo", as detailed in the novel versions of 2001: A Space Odyssey and 2010: Odyssey Two. The existence of this species is only hypothesized by the rest of humanity but is obvious because the monolith is immediately identified as an artifact of non-human origin.

The extraterrestrial species that built the monoliths achieved intergalactic travel millions or perhaps billions of years before the present. In the novels, Clarke refers to them as the "Firstborn" - not to be confused with the identically-named race in Arthur C. Clarke's and Stephen Baxter's Time Odyssey Series - as they were quite possibly the first sentient race to achieve widespread interstellar travel. They explored the galaxy with the intent of acquiring knowledge, especially of other intelligent life.

While they discovered that life was very common, they observed that intelligent life was often stunted in its development or died out prematurely and so they set about promoting it. The "Firstborn" were in many ways physically different from humanity, though taken another way they were fundamentally the same, in that they were creatures made of "flesh and blood", and thus like humans they were mortal. However, the evolutionary development projects they began would by their very nature require time spans to complete that were far greater than the lifetimes of their mortal creators. Therefore, the aliens created increasingly complex automated machines to oversee and carry out their projects over long time periods. When they encountered a living world that was favourable for the evolution of intelligence, they left behind monoliths as remote observers that were also capable of taking a variety of actions according to the wishes of their creators. The monoliths are possibly the last remaining (and ultimate) technology they ever devised. One such planet, encountered when it was still quite young, was the Earth, as well as (later) Jupiter and Europa (the ancient ecosystem that existed on Mars was already dying when they encountered it, so they ignored that planet). The aliens left behind three monoliths to observe and enact a very intricate plan to promote the human race to pursue technology and space travel.

Eventually, the Firstborn discovered how to ingrain their consciousnesses into computers, and became a race of Thinking Machines. Ultimately, they surpassed even this achievement, and became able to convert their physical forms into a non-corporeal form - omniscient, immortal and capable of traveling at great speed, the Lords of the Galaxy. The Firstborn had abandoned physical form, but their creations, the monoliths, remained, and continued to carry out their original tasks.

Appearance and capabilities

All the monoliths are black, extremely flat, non-reflective cuboids whose dimensions are in the precise ratio 1:4:9 (the squares of the first three integers). These dimensions are the main source of debate regarding the monoliths' simple external design. It is suggested in the novel that this number series does not stop at three dimensions.Clarke A (1968). 2001: A Space Odyssey, Signet. "How obvious—how necessary—was that mathematical ratio of its sides, the quadratic sequence 1:4:9! And how naive to have imagined that the series ended at this point, in only three dimensions!"
The monoliths are observed in several different sizes - TMA-0 and TMA-1 are both exactly 11 feet long and TMA-2 is two kilometres long on the longest axis, while the monolith that appears on Europa is considerably larger. They may be able to assume any size, for in 2010: Odyssey Two, the starchild, David Bowman, cryptically notes that the monolith is actually one size - as large as necessary.

They appear to be extremely long lived and reliable machines, essentially an incredibly advanced form of multifunction robot, being able to survive for millions of years buried in the ground or resisting meteorite impacts and radiation in space, with no apparent damage. The two monoliths recovered and examined by humans reveal themselves to be virtually indestructible and impenetrable, resisting all attempts to analyze their composition or internal structure right up to the end of the series. It is suggested by Dr. Heywood Floyd that they possess some sort of force field, an impression he gets from touching it and much later accepted as most probable because the monoliths resist destructive testing beyond the theoretical limits of material strength. However, they are not completely indestructible - TMA-4 suffers damage from a blast caused by a giant meteorite of solid diamond impacting Europa in 2061: Odyssey Three. In the final book, 3001: The Final Odyssey, all three monoliths known to mankind are destroyed simply by giving them a computer virus.

While it is unclear what the composition of the monoliths is, they clearly have mass, about the only observation that can be made. In 2010, the Leonov mission measured the mass of TMA-2 and reported a density slightly higher than air (presumably at a standard temperature and pressure). The masses of TMA-0 and TMA-1 are never revealed, though it can be assumed that the densities are the same.

Among the more dramatic functions of the monoliths are the ability to teleport and self replicate.

In 2001, TMA-2 opens a stargate which permits Bowman to travel across the galaxy at faster-than-light speeds and with tremendous accelerations. In 2010 and again in 3001, TMA-2 is observed to teleport itself (disappear and reappear elsewhere).
TMA-2 is observed to self-replicate by a form of symmetrical binary fission and grow exponentially to thousands or millions of units in just a matter of days. In 2010, the many units act to increase the density of the planet Jupiter until stellar ignition is achieved, converting it into a miniature star. In 3001, millions of copies of TMA-2 are observed to assemble themselves into two megastructure disks that attempt to block the sun from Earth and its human colonies in the Jovian system in an attempt to cause the extinction of humanity.

The monoliths are clearly described in the novels as being controlled by some sort of computer. In 2061, the non-corporeal entities of Bowman, HAL, and the newly-created entity of Heywood Floyd, are essentially downloaded and stored as programs in the 'matrix' of TMA-2, currently observing and shielding the Europans from human interference.
TMA-1 and TMA-2 are observed to produce powerful, directional radio transmissions. TMA-2 is observed, in the 2100s, to direct a radio transmission toward a star system about 450 light years distant. Only TMA-1 demonstrates the ability to generate a strong magnetic field around itself, for which the three artifacts are named.

Tycho Magnetic Anomaly-1

Tycho Magnetic Anomaly-1 (also known as TMA-1) refers to the apparent magnetic irregularity found at the Tycho crater on the Moon's surface by American astronauts. The anomaly is caused by a monolith buried 40 feet under the lunar surface; when exposed, it was found to be a black cuboid whose sides measured in the precise ratio 1:4:9 (1²:2²:3²). In the book it is indicated that this ratio extends past the three spatial dimensions we are familiar with.

Not long after the monolith is exposed to sunlight after excavation, it emits an extremely powerful burst of radio-frequency energy outward through the Solar System, and the magnetic anomaly surrounding it simultaneously disappears.

Tycho Magnetic Anomaly-2

An identical (except in size) object was found later, orbiting Jupiter (on a moon of Saturn in the book, although this was changed to Jupiter in the sequel book, 2010: Odyssey Two). This object was dubbed "TMA-2", a term that the book calls "doubly inappropriate": it had no magnetic field and was millions of miles from Tycho (TMA-2 was often referred to as "big brother" due to David Bowman's comments on its immense size). In 3001: The Final Odyssey, HAL and Bowman destroy TMA-2 with a computer virus after it is learned that its superiors are sending an order to kill humanity.

Tycho Magnetic Anomaly-0

By the year 3001, the first Monolith to be encountered by mankind's prehistoric evolutionary predecessors was found in Africa buried in ancient rock, and was retroactively dubbed "TMA-0".

Namesake

In the late 1980s, Apple Inc. bought a Cray supercomputer to model experimental processor designs. After the machine was installed and set up, a company-wide contest was held to choose a name for the machine: the winning suggestion was TMA-1.

Seattle Monolith

On New Year's Day 2001, a replica of the Monolith made out of welded steel appeared on a hill in Seattle's Magnuson Park, apparently having been placed there during the night before. It disappeared overnight three days later, and was presumed to be a reference to the monolith in 2001: A Space Odyssey.

In popular culture

Tributes to Monoliths have appeared in several video games. In SimEarth and Spore, Monoliths are used to encourage the evolution of species. In Duke Nukem 3D, the level "Dark Side" is set on the moon and a Monolith is used as a teleporter. In E.V.O. the Monolith is also used as a teleporter to progress from one chapter to the next.
They Might Be Giants reference Monoliths, as well as 2001: A Space Odyssey, in their song "The Statue Got Me High" from Apollo 18.

The metal band Rosetta references the Tycho Magnetic Anomaly-1 (TMA-1), in their song "TMA-1" from the split album Project Mercury with Balboa.