Physics Photo of the Week

Physics Photo of the Week December 23, 2022 The Christmas Tree Nebula - Photo by Donald Collins with the College View Observatory Merry Christmas Everyone! The Christmas Tree Nebula, part of NGC 2264 consists of a cosmic cloud composed of dust and hydrogen in the constellation Monosoros - just east of Orion.  This gas/dust cloud is a busy center of extensive star formation.  The dust and hydrogen gas have been contracting due to their own self-gravity and clumps become extremely dense and begin to form new stars in the centers of the dust cloud.  Like the nearby Orion Nebula ( PPOW for February 8, 2019 ), this nebula is a stellar nursery where hot, giant, blue stars are "born".  The Christmas Tree cloud resembles a dust "pillar", which is also seen in the Orion Nebula as a dark shadow.  The bright halo surrounding the Christmas Tree cloud is a massive cloud of hydrogen that glows red and emits the red glow characteristic of a hydrogen lamp - a glass tube filled with

Physics Photo of the Week        December 9, 2022 Slinky Defies Gravity My grandson Jay is holding a yellow plastic "Slinky" at one end is about to drop it.  We recorded a slow-motion video for the falling slinky.  When you watch the video (see link below) be sure to pay attention to the bottom of the yellow slinky - it seems to defy gravity and doesn't fall until the rest of the slinky "catches" it and the collapsed slinky continues is descent to the floor.  Shouldn't the whole slinky fall at once?  The bottom edge of the stretched-out slinky simply "floats" at the level just below Jay's knee while the top of the slinky falls due to gravity.    Press this link to see the slow motion video. Why does the base of the slinky remain suspended motionless while the top of the spring falls rapidly?  Shouldn't the whole stretched out slinky fall at once? The answer lies in the fact that gravity is not the only force acting on each of the coils of t

  Slow Motion Video