An Alderson disk (named after Dan Alderson, its originator) is a hypothetical artificial astronomical megastructure; like Larry Niven's Ringworld, or a Dyson sphere. The disk is a giant platter with a thickness of several thousand miles. 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. According to the proposal, a sufficiently massive disk would have a larger mass than its Sun.