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Cosmic Treadmill, as it appears in Flash #196. Art by Paul Winslade
|First appearance||The Flash #125 (December 1961)|
|Created by||John Broome|
|In story information|
|Type||Time travel device|
|Element of stories featuring||Flash|
The treadmill was first seen in The Flash #125 written by John Broome. It was initially developed as a means of allowing Barry Allen to travel through time precisely to battle aliens who had taken over the Earth in 2287 by projecting a hive into the past that stopped technology, so Kid Flash traveled to the past to stop it, while the Flash battled the aliens in the Future. Kid Flash succeeded, enabling the aliens to be defeated. The Flash had already travelled through time to return a future criminal to his own time using superspeed vibrations in his second story, and passing through a 'roadblock' in the mists of time called the Time barrier.
The treadmill appeared in a handful of stories, notably allowing Barry Allen to travel to the 25th century and meet Professor Zoom (Eobard Thawne).
The treadmill appeared during the Crisis as well, in issue 11. Jay Garrick (the Earth-Two Flash), Wally West (Earth-One's Kid Flash), Kal-L (the Earth-Two Superman) and Kal-El (the Earth-One Superman) attempted to travel to Earth-Two to allow Kal-L to return home. Instead of finding Earth-Two, there was simply a void, a consequence of the multiverse collapsing into a single universe. Upon returning from the void, the treadmill exploded.
The treadmill has appeared several times since the Crisis, during Wally West's time as the Flash.
The first significant appearance of the treadmill was in Flash #79, when it was revealed that a man previously thought to be Barry Allen was in fact Professor Zoom, who had traveled back in time from the 25th century using the treadmill and lost his memory. This was Professor Zoom's first trip through time, Wally subsequently tricking him into using the treadmill again to return home. The battle also released Wally's previous block on his speed, Wally having previously placed a mental block on his powers because he was afraid of replacing Barry by surpassing him.
In Impulse #21, several time-lost Legionnaires attempt to use the Treadmill to make it back to their own time. The unwanted assistance of the hero Impulse seemingly destroys the Treadmill and the time-lost heroes leave, dejected. It is soon revealed that Impulse had accidentally sent the treadmill itself a few minutes into the future.
Impulse later travels into the future, several years before the Legion is formed. He uses it to retreat from hostile forces. He is worried about it malfunctioning again but is reassured that the Flash of the 23rd century had made improvements. As such, Impulse is able to return to the appropriate time period.
Hunter Zolomon attempted to use the treadmill in Flash #196 in order to travel back through time and prevent the events that had left him a paraplegic. The attempt proved disastrous as the treadmill exploded, destroying itself and the Flash Museum while also shifting Zolomon slightly out of time. Zolomon subsequently became Zoom, the third Reverse-Flash, the treadmill's explosion having essentially 'derailed' him from the timeline and granted him the ability to control the rate at which he perceives time.
The treadmill last appeared— rebuilt by Zoom and unwillingly powered by Jay Garrick— during the Rogue War storyarc featured in Flash #220–225. Zoom (Zolomon) used it in order to bring Professor Zoom (Thawne) back from the future. Wally was assisted by Barry Allen, who took Professor Zoom back to his rightful place in the timeline. The treadmill was seemingly destroyed during the fight between Zoom and Wally.
In a possible future where members of the current incarnation of the Teen Titans mature into a corrupt and tyrannical Justice League, the Cosmic Treadmill is absent from the Flash Museum; it is instead kept in a more secure location inside the Batcave, presumably to ensure that their "enemies"—in truth, a group of right-minded Titans—cannot alter the past and change their timeline.
The cosmic treadmill allows any being with super-speed to precisely travel time, and pre-Crisis it allowed travel between the multiple Earths. The treadmill works by generating vibrations that will shift the user into a specific time. The vibrations require a high amount of speed to generate, and attempts to use the treadmill without it have proved dangerous. Initially, the vibrations had to be kept up internally, or one would fade back into the time from whence they came. This was fixed by John Fox in Flash #112.
Since the treadmill needs a speedster in order to function, in many stories a working one can be found inside the Flash Museum. Since few people have the speed to have it work, it is usually seen as an exhibit, though at times it has been stored in the archives. It is shown that over time the Treadmill can become unstable and unreliable, and cause extreme stress to the mind of the user.
In other media
- In the Justice League episode "Eclipsed", Wally uses the term in a different way, referring to a ramp created by Green Lantern's ring to run through space towards the sun, in order to plant a device to stop the sun from going out from Eclipso.
- Though only seen briefly, the cosmic treadmill did make an appearance in Wally's apartment in Central City during the Justice League Unlimited episode "Flash and Substance."
- The device is featured in Batman: The Brave and the Bold episode "Requiem for a Scarlet Speedster!", where it is used by Batman, and the two Flashes: Jay Garrick and Wally West, to rescue Barry Allen in the 25th century from Professor Zoom.
- In Injustice: Gods Among Us video game, Flash, Superman and Cyborg attempt to use the cosmic treadmill in an attempt to retrieve Green Arrow, Wonder Woman, Aquaman, Green Lantern, Batman and Joker from a parallel universe where Superman rules the world. However, this only results in Cyborg being sent to the alternate Earth.
- In the video game, DC Universe Online, the Flash uses the treadmill to send players to alternate timelines in order to resolve time paradoxes and prevent Lex Luthor from altering the origins of Batman and Superman.
- In TV series The Flash, a similar treadmill built by Cisco Ramon (Carlos Valdes) is used to test Barry's (Grant Gustin) speed limits, monitor his vitals and other factors related to his speed. In "Rogue Time", Barry attempts to travel through time by running on the treadmill, in an effort to recreate his experience in the previous episode. He is unsuccessful, and Dr. Wells notes that the ability to time travel might depend on one's mentality, not the speed itself.  This treadmill makes brief appearances in the fourth, seventh and twenty-first episodes as well.
Silver Age/Bronze Age
- The Flash #125 (December 1961): "The Conquerors of Time" written by John Broome, art by Carmine Infantino and Joe Giella.
- The Flash #139 (September 1963): "Menace of the Reverse-Flash!" written by John Broome. Art by Carmine Infantino and Joe Giella.
- The Flash #179 (May 1968): "The Flash--Fact or Fiction?" written by Cary Bates. Art by Ross Andru and Mike Esposito.
- The Flash #350 (October 1985): "Flash Flees," written by Cary Bates, art by Carmine Infantino and Frank McLaughlin.
- Crisis on Infinite Earths #10 (January 1986) written by Marv Wolfman, art by George Pérez.
- Flash #79 (August 1993): "The Once and Future Flash", written by Mark Waid, art by Greg LaRocque and Roy Richardson.
- Flash #112 (April 1996): "Future Perfect," written by Mark Waid, art by Anthony Castrillo and Hanibal Rodriguez.
- Flash #145–150 (February–July 1999): "Chain Lightning", written by Mark Waid and Brian Augustyn, art by Paul Pelletier and Vince Russell.
- Flash #196 (May 2003): "Helpless", written by Geoff Johns, art by Paul Winslade.
- Flash #220–225 (May–October 2005) "Rogue War", written by Geoff Johns, art by Howard Porter and Livesay.
- "Impulse" #25 (May 1997)
- "Rogue Time - Flash 1x16".
- Hyperborea's article on the cosmic treadmill
- Crimson Lightning - An online index to the comic book adventures of the Flash.