- Canopus (stars.astro.illinois.edu)
CANOPUS (Alpha Carinae). As northerners drive south on winter vacations, if they are familiar with the sky they encounter something of a surprise. Just below the sky’s brightest star, Canis Major’s Sirius, is the SECOND brightest star, Canopus, 30 degrees and almost exactly south of Mirzam, one of Sirius’s announcing star.
- Mass (Wikipedia)
Mass is an intrinsic property of a body. It was traditionally believed to be related to the quantity of matter in a body, until the discovery of the atom and particle physics. It was found that different atoms and different elementary particles, theoretically with the same amount of matter, have nonetheless different masses. Mass in modern physics has multiple definitions which are conceptually distinct, but physically equivalent. Mass can be experimentally defined as a measure of the body’s inertia, meaning the resistance to acceleration (change of velocity) when a net force is applied. The object’s mass also determines the strength of its gravitational attraction to other bodies.
