Miracle Machine

The Miracle Machine is a fictitious device in the DC Comics universe. The machine first appeared in "Adventure Comics" #367, April 1968.
It was created by the Controllers no later than 1982, and given as a gift to the Legion of Super-Heroes in the late 30th century for their work in defeating a renegade Controller. It has the power to convert thoughts into reality.
Brainiac 5 has stated that the Machine's technology was reverse-engineered from that of the Guardians' Green Lantern tech (i.e. willpower in manipulable form), though this detail is only accurate in post-"52" continuity. The dying New God Darkseid mockingly describes the Miracle Machine as a cargo cult Mother Box, highlighting the similarities between the two items in the DC Universe, able to provide seemingly limitless alteration of the most basic physics law at will.
The Miracle Machine had been featured in stories only four times in the pre-Crisis era DC Universe, and just twice in the post-Crisis era DC Universe, most recently at end of Final Crisis.
Appearances.
In "Adventure Comics" #367 (April 1968), Brainiac 5 first discovered its function and used it to repel an invasion of Earth by the Dark Circle and to create a new headquarters for the Legion. One of the Controllers briefly appeared and cautioned against its further use, saying a stray thought could cause catastrophe. The Legion sealed it inside an Inertron block, vowing only to use it for the direst of emergencies, or at a future date when mankind can use it wisely.
In "Superboy" #201 (March—April 1974), the hero later known as Wildfire used the Miracle Machine to defeat a would-be assassin and robber.
In "Superboy" #213 (December 1975), a thief vows to steal the machine, brazenly informing the Legion that he would do so prior to the attempt. Such was his skill that the Legion prove unable to capture him. Facing the possibility of the Machine being stolen, they instead use it to capture the thief.
In "DC Limited Collector's Edition #55" (1978), the Time Trapper has altered history such that the Earth and other planets have been warring factions for 1000 years. The Legion confronts the Time Trapper at the end of time, who attempts use the Miracle Machine to kill the Legion. The team combines their willpower against the Machine to defeat him and to restore the proper history. This was the same issue that featured the marriage of Lightning Lad and Saturn Girl.
In "Superboy and the Legion of Super-Heroes" #250-251 (April–May 1979), it was used by an insane Brainiac 5 in a scheme to destroy the universe. As he can't imagine so grandiose a death, he uses the Machine to create a being which could, Omega. In order to stop his creation, he has Matter-Eater Lad consume the Machine, which drives M-E Lad insane for a number of years.
In "DC Comics Presents" #50 (October 1982), the first fictional chronological appearance of the Miracle Machine, Superman inadvertently used it to create a duplicate of himself as Clark Kent. This story established that the Miracle Machine was created sometime before the then "present" 1982 in another universe.
In "Legion of Super-Heroes (v4)" #49 (early November 1993), after Matter-Eater Lad was cured, it is speculated that he still contains residue from the Machine. This might explain why he is always coming out of situations without much trouble from that point on, including his later career as a Senator. This leads Prince Evillo to kidnap him to try and force him to use this power to create a monstrosity based on the most fearsome thing Matter-Eater Lad could imagine. This he does, after a fashion, though not quite what Evillo had hoped for — his "monstrosity" was based on a really bad date he once had.
In the Elseworlds story "Castles in the Air" ("Legionnaires Annual" #1, 1994), a subplot involves a group of Legionnaires on a quest for the Miracle Machine, only to discover it was destroyed by Mordru. (The story is a pastiche of the story of King Arthur, with the Miracle Machine serving the role of the Holy Grail).
In "Final Crisis" #6 (January 2009), Brainiac 5 unlocks the Miracle Machine and allows Superman to memorize its construction, stating that Superman is the only being he would trust to look at it, the Legion being unable to use the original machine as it had been turned off. This enables Superman to construct a duplicate using 21st century materials in "Final Crisis" #7 (February 2009), recruiting multiple scientists to work on various components of the machine which he will then assemble himself to avoid giving anyone else the full picture. With the machine complete, Superman energizes it with the solar energy in his own cells, using it to restructure reality and remake the Universe without Darkseid, thus averting the end of creation as Darkseid's spirit attempted to drag reality down with his own death.
The machine also appears in the novelization of the 'Final Crisis' storyline, written by Greg Cox.