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  "body": "\n## Summary\n\nA spherical code is a finite set of points on the unit sphere in $\\R^n$, judged by how far apart its points are.\nThe main question asks for the largest number of points with a given minimal angle.\nThe dual question asks for the largest minimal angle for a given number of points.\nKissing configurations are spherical codes with minimal angle $60^\\circ$, and the [[Tammes problem|9WD2TZ4ZB5]] is the case $n = 3$.\nUpper bounds come mainly from the [[Delsarte linear programming bound|7RPEDHAT7R]].\n\n## Explanations\n\n### L1 human\n\nChoose a number of directions in space, pointing from the centre of a ball to its surface, and try to keep any two directions far apart.\nSuch a choice is a spherical code.\nIn the plane the best choice is clear: space the points evenly around the circle.\nOn a sphere and in higher dimensions it is a hard problem, studied for its use in signal transmission and for its links with sphere packing.\n",
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