- How Animals See the World (artsandculture.google.com)
Each type of animal on Earth has evolved a range of senses and skills which allow it to live successfully in its environment. Many of these adaptations are very different from how humans have evolved, and compared to humans some of these adaptations feel like they belong in a superhero comic. Senses such as ultraviolet vision, extra color receptors, and echolocation are very hard for humans to imagine, yet are part of the everyday life of hundreds of species of animals.
- 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.