Alderson disk

Common card · No. 330527

An Alderson disk (named after Dan Alderson, its originator) is a hypothetical artificial astronomical megastructure, similar to the ring in Larry Niven's Ringworld and the Dyson sphere. The disk is a giant platter with a thickness of several thousand kilometers. The Sun rests in the hole at the center of the disk. The outer perimeter of an Alderson disk would be roughly equivalent to the orbit of Mars or Jupiter. A big enough disk would have more mass than its Sun. The hole would be surrounded by a thousand-kilometer-high wall to prevent the atmosphere from drifting into the Sun. The outer rim would not require a wall. The mechanical stresses within the disc would be far beyond what any known material can stand, thus relegating such a structure to the realm of exploratory engineering until materials and construction science become advanced enough. Building a megastructure of this size would require far more material than is found in the Solar System. Life could exist on either side of the...

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