“There are precious few fossil relics of the early Universe,” Brian Keating, Chancellor’s Distinguished Professor of Physics at UC San Diego, and author of Think Like a Nobel Prize Winner,” told The Daily Galaxy. “Just after the Big Bang,” Keating explained, “came the epoch of Big Bang nucleosynthesis, ending a few minutes later. The Cosmic Microwave Background, the universe’s oldest light, came about 380,000 years later. Then the great cosmic darkness began. That darkness had to end, or else we would not be here asking what caused the Universe to be so dim.
One of the major problems in understanding the formation of galaxies is that approximately 80% of the baryons that make up the normal matter of galaxies is missing, expelled over eons from galaxies into inter-galactic space by the galactic winds created by stellar explosions.
“Something like the diffuse glow of gamma ray background that permeates our Milky Way Galaxy could conceivably be evidence for dark matter,” researcher Mark Krumholz, a theoretical and computational astrophysicist at Australian National University, told The Daily Galaxy.
“Planet Earth Report” provides descriptive links to headline news by leading science journalists about the extraordinary discoveries, technology, people, and events changing our knowledge of Planet Earth and the future of the human species.
It’s possible that the universe isn’t uniform past what we can see, and conditions are wildly different from place to place, says Caltech astrophysicist Sean Carroll. “That possibility is the cosmological multiverse. We don’t know if there is a multiverse in this sense, but since we can’t actually see one way or another, it’s wise to keep an open mind.”
Determining the age of a star can be one of the trickiest measurements an astronomer can make. Stars don’t obviate their age like humans do — with wrinkles around the eyes, grey hair, or brittle bones. Instead stars give hints at their age through things like their motion, rotation rate, chemistry, and placement in the Galaxy. Finding “extrema” on the age spectrum for stars — the oldest and youngest — is much easier than trying to find middle aged objects like our Sun. In this article, we reveal four fast facts about the oldest stars in the Galaxy.
An enormous amount of gravity from a cluster of distant galaxies causes space to curve so much that light from more distant galaxies is bent. This “gravitational lensing” effect has allowed University of Copenhagen astronomers to observe the same exploding star –SN Requiem–in three different places in the heavens, and may help solve the mystery of cosmic expansion and reveal the nature of dark matter and dark energy.
In 2019, astronomers accidentally discovered the faint, shimmering blob of a monster galaxy cloaked in dust and a lot of mystery in the early universe. Like a cosmic Yeti, the scientific community generally regarded these galaxies as folklore, given the lack of evidence of their existence, but astronomers in the United States and Australia managed to snap a picture of the beast for the first time. The discovery provides new insights into the some of the biggest galaxies in the universe.