- Binary Star § Astrometric binaries (Wikipedia)
Astronomers have discovered some stars that seemingly orbit around an empty space. Astrometric binaries are relatively nearby stars which can be seen to wobble around a point in space, with no visible companion. The same mathematics used for ordinary binaries can be applied to infer the mass of the missing companion. The companion could be very dim, so that it is currently undetectable or masked by the glare of its primary, or it could be an object that emits little or no electromagnetic radiation, for example a neutron star.
- Do Androids Dream of Electric Sheep? (Wikipedia)
Do Androids Dream of Electric Sheep? (retrospectively titled Blade Runner: Do Androids Dream of Electric Sheep? in some later printings) is a 1968 dystopian science fiction novel by American writer Philip K. Dick. It is set in a post-apocalyptic San Francisco, where Earth’s life has been greatly damaged by a nuclear global war, leaving most animal species endangered or extinct. The main plot follows Rick Deckard, a bounty hunter who has to “retire” (i.e. kill) six escaped Nexus-6 model androids, while a secondary plot follows John Isidore, a man of sub-par IQ who aids the fugitive androids.