This change ‘is analogous to changing the direction of a new battleship in a few minutes,’ researcher Gerrit Schellenberger said.
Category: cosmology – Page 71
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00:00 Intro.
I found this on NewsBreak: Astronomers Just Calculated The Spin Speed of a Supermassive Black Hole #Astronomy
Inflation: The leading theory for the universe’s earliest moments, cosmic inflation, proposes that the universe underwent a brief period of exponential expansion an instant after the Big Bang. This process would have enlarged a minuscule volume of space to a tremendous size, much larger than our observable universe. Inflation neatly explains the flatness and uniformity we observe. But it also suggests that our entire observable universe is a tiny bubble in a vast inflated expanse.
Infinite replicas: If the universe is truly infinite, then everything that occurs within our observable universe must recur an infinite number of times beyond our cosmic horizon. The number of possible particle configurations in any finite volume is large but limited. In an infinite expanse, each configuration, no matter how unlikely, will be realized somewhere, and not just once but an infinite number of times. There would be infinite copies of our observable universe, infinite Milky Way galaxies, infinite Earths, and even infinite versions of you pondering this article. It’s a dizzying but inevitable consequence of an endless cosmos.
From 13 billion light-years across the gulf of space and time, we’ve just caught a glimpse of the most distant black hole merger discovered yet.
Using JWST, an international team of astronomers has discovered two supermassive black holes, and their attendant galaxies, coming together in a colossal cosmic collision, just 740 million years after the Big Bang.
This discovery could be a clue that helps us piece together where supermassive black holes came from, and how they grew so large, so early in the history of the Universe.
Black holes are intriguing astronomical objects that have a gravitational pull so strong that it prevents any object and even light from escaping. While black holes have been the topic of numerous astrophysical studies, their origins and underlying physics remain largely a mystery.
The NA64 experiment started operations at CERN’s SPS North Area in 2016. Its aim is to search for unknown particles from a hypothetical “dark sector.” For these searches, NA64 directs an electron beam onto a fixed target. Researchers then look for unknown dark sector particles produced by collisions between the beam’s electrons and the target’s atomic nuclei.
Apologies for the (hopefully now somewhat less) clickbait-y title. Now, of course, I know that the Big Bang did not happen at any point connected to a single point in our current $3$-dimensional observable universe by a one-dimensional causal curve. I also know that at any point in the universe, all other points seem to be moving away from that point. However, according to our current understanding of physics, the universe is (at least) $4$-dimensional. Just like how in the classical “balloon” analogy for an expanding universe, the points do in fact all move away from a common point on the interior of the balloon, all spacetime points do move away from the Big Bang, or at least some kind of cosmological horizon which surrounds it — this is how I understand going forward in time, at least. Does it make sense to think of this as a sort of “center” for the full, $4$-dimensional spacetime? Or are there further subtleties to this situation?
Black hole singularities defy the laws of physics. New research presents a bold solution to this puzzle: Black holes may actually be a theoretical type of star called a ‘gravastar,’ filled with universe-expanding dark energy.