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  "body": "\n## Summary\n\nStable homotopy theory is the part of homotopy theory that studies the phenomena that do not change under iterated [[suspension|Q7RFNJH76Q]].\nBy the [[Freudenthal suspension theorem|7DM2KSS2DB]], the homotopy groups of $\\Sigma^k X$ stabilize as $k$ grows.\nThe stable values are often more regular than the unstable ones.\nIts natural objects are [[spectra|1GHF4EKBXS]], which represent generalized cohomology theories, and its main computational problem is the [[stable homotopy groups of spheres|HGZAYPQBXW]].\n\n## Explanations\n\n### L1 human\n\nSuspending a space makes it one dimension bigger, and suspending a map does the same to the map.\nAfter enough suspensions, the set of homotopy classes of maps between two finite complexes stops changing.\nStable homotopy theory studies these stable answers.\nFor example, $\\pi_{n+1}(S^n)$ is $\\Z$ for $n = 2$ but $\\Z/2$ for all $n \\ge 3$, so the stable value is $\\Z/2$.\nIn the stable world, maps can be added and fibre sequences behave like exact sequences, so many tools of algebra apply.\n",
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