The Atom is a superhero created in 1941 for All-American Comics, and recreated in 1962 in a self-named title, a part of DC Comics' Silver Age of Comic Books.

Golden Age Atom

The original Atom, Al Pratt, had no super powers; instead, he was initially a physically diminutive college student and later became a physicist. He was depicted as a tough guy, a symbol of all the short kids who could still make a difference. He would become a member of the Justice Society of America, and, after the atomic age began, would get a new costume.

The Modern Atom

The current version is physicist and university professor Raymond "Ray" Palmer (named for science-fiction writer Ray Palmer, who was himself quite short). Ray Palmer created a costume from what was initially depicted as white dwarf star matter, which allows him to shrink down to subatomic size. He has been a member of several incarnations of the Justice League.

Neither character appears regularly in comics, and even in their heyday were mostly supporting characters, although Palmer has had several short-lived series (including Sword of the Atom, in which he abandoned civilization and became a Conan-like figure, hero of a tribe of microscopic yellow-skinned humanoid aliens in the jungles of Central America). He was later rejuvenated to a teenager, and became a mentor of the Titans; he subsequently regained his original age and memories.

Palmer was suspected of murdering Sue Dibny, the wife of Elongated Man, during Identity Crisis . However, his ex-wife Jean Loring had used his costume to hurt her, unintentionally killing her, to win him back. Loring was also responsible for the deaths of Captain Boomerang and the third Robin's father. Palmer had her imprisoned at Arkham Asylum and, as of this writing, had quit the Justice League.

A third Atom, Adam Cray, appeared in the pages of Suicide Squad; Cray was widely believed to be Palmer in disguise, and was murdered for that reason.

Al Pratt was murdered in 1994's Zero Hour miniseries.

A fourth version of the Atom has been featured in stories set eighty-three thousand years in the future, in the 853rd century, as seen in DC One Million .