How dark is the universe? Optically – for visible light. Far away from star light and reflected dust. Here’s an interesting perspective on electromagnetic (EM) cosmic energy density – just for optical wavelengths. And without any clarification of fuzzy bounds for a galaxy’s reach. The entire electromagnetic spectrum is another story. • Live Science >… Continue reading How dark is the universe – optically?
The universe’s expansion history is one thing; but then there’s its structural evolution. In particular, how early did well-formed galaxies emerge? • Space.com > “Galaxies in early universe were surprisingly diverse, James Webb Space Telescope finds” by Andrew Jones (Jan 16, 2023) – high-redshift galaxies (galaxies as they were around 11 to 13 billion years… Continue reading How early did disk galaxies emerge?
Who would have expected the Hubble Space Telescope (often referred to as HST or Hubble) to still be in operation after being launched into low Earth orbit in 1990? So, NASA/ESA kickstarted its 30th anniversary with some majestic galactic photos. Wiki: Five Space Shuttle missions have repaired, upgraded, and replaced systems on the telescope, including… Continue reading Celebrating Hubble – 30th anniversary year
Popular media is abuzz today with news regarding research by NAOC (National Astronomical Observatories of Chinese Academy of Sciences) on the shape of our galaxy, the Milky Way, published in Nature Astronomy today. A peculiar disk. A new 3D model. Original article on Nature Astronomy: “An intuitive 3D map of the Galactic warp’s precession traced by classical… Continue reading The Milky Way’s shape — a peculiar disk
As I’ve noted elsewhere (Beyond the infinity of black holes), it wasn’t long ago — maybe a 100 years or so, that our view of the cosmos was much more circumscribed. Those who studied cosmology — physicists, astronomers, et al, viewed our cosmos in a much different way, at a much different scale — basically… Continue reading Beyond the Milky Way — a game-changing discovery
As I continue to ponder the spooky character of quantum physics (the 10^-n reality), this May 17, 2017, Space.com article addresses a question at the other end of the cosmic scale (the 10^n reality): How Many Stars Are In The Universe? So how do astronomers figure out how many stars are in the universe? The first sticky part is trying to… Continue reading How many stars?
