According to the predominant cosmological model, the first stars in the Universe formed roughly 100,000 years after the Big Bang. Known as Population III stars, these…
Researchers observed an ultra-rare particle interaction that reveals the half-life of a xenon-124 atom to be 18 sextillion years.
Circa 2022 😀
New mathematical formulation means huge paradigm shift in physics would not be necessary.
Our universe may be fundamentally unstable. In a flash, the vacuum of space-time may find a new ground state, triggering a cataclysmic transformation of the physics of the universe.
Or not. A new understanding inspired by string theory shows that our universe may be more stable than we previously thought.
Within the first microseconds of the Big Bang, the universe underwent a series of radical phase transitions. The four forces of nature — electromagnetism, gravity, the strong nuclear force and the weak nuclear force — were at one time unified into a single force. Physicists do not know the character or nature of this force, but they do know that it didn’t last long.
But black holes do have gravity, and they know how to use it. If a black hole has a stellar companion, and they orbit each other closely enough, the former can strip some of the gas from the star. The gas falling into the black hole heats up and shines in high-energy radiation. Astronomers have found more than 50 such systems in the Milky Way.
However, when a black hole and its companion star orbit each other at a greater distance, the star remains whole. The black hole is then dormant and much more challenging to spot. To find it, one has to search for wobbling stars whose peculiar motion could be due to an unseen dark companion.
This is how a team of astronomers discovered the newest black hole candidate, which they call Gaia BH1. (The study, which is under review, is available here). Although it isn’t the first proposed candidate of its kind, it seems to be the most compelling to date.
In the 20th century, many options abounded as to our cosmic origins. Today, only the Big Bang survives, thanks to this critical evidence.
Preview of NASA’s Double Asteroid Redirection Test, or DART, the first asteroid deflection mission.
Worm-hole generators by the pound mass: https://greengregs.com/
Infinity is back. Or rather, it never (ever, ever…) went away. While mathematicians have a good sense of the infinite as a concept, cosmologists and physicists are finding it much more difficult to make sense of the infinite in nature, writes Peter Cameron.
Each of us has to face a moment, often fairly early in our life, when we realize that a loved one, formerly a fixture in our life, was not infinite, but has left us, and that someday we too will have to leave this place.
This experience, probably as much as the experience of looking at the stars and wondering how far they go on, shapes our views of infinity. And we urgently want answers to our questions. This has been so since the time, two and a half millennia ago, when Malunkyaputta put his doubts to the Buddha and demanded answers: among them he wanted to know if the world is finite or infinite, and if it is eternal or not.
Issac Arthur play list.
SFIA looks at uses for black holes ranging from spaceships to artificial worlds to escaping the Heat Death of the Universe.
There is a lot of culture and philosophy built into the Big Bang theory as we understand it.
