Apr 25, 2023 03:39 PM
How “bound together” is our Universe?
https://bigthink.com/starts-with-a-bang/...-universe/
KEY POINTS: At a fundamental level, our Universe is composed of indivisible, elementary particles embedded in the backdrop of the spacetime in our expanding Universe. But what we observe isn't simply a collection of independent particles, but rather a series of bound structures: atomic nuclei, atoms, molecules, planets, stars, galaxies, and more. When we add it all up, how bound together is our actual Universe? The answer might surprise you and being both more, and less, than you ever imagined... (MORE - details)
The Universe sucks: The mysterious Great Attractor that’s pulling us in
https://arstechnica.com/science/2023/04/...ing-us-in/
EXCERPT: Our Milky Way galaxy is speeding through the emptiness of space at 600 kilometers per second, headed toward something we cannot clearly see...
[...] Cosmologists continue to debate the exact contents and location of the Great Attractor. We can only infer its mass and location based on relatively sparse surveys within the Zone of Avoidance and reconstructions of the movements of those galaxies (which is slightly difficult because we can’t watch anything move in real time given the enormous scales involved).
The supposed location of the Great Attractor already contains an immense assemblage of mass known as the Norma Cluster, which is located over 200 million light-years away. Our own [ul=https://en.wikipedia.org/wiki/Shapley_Supercluster]Virgo cluster[/url] and all its surrounding galaxies are on the move toward Norma, which sits at the center of the flow of all the galaxies within Laniakea.
Recent studies have revealed more complexity. Norma itself appears to be moving toward another supercluster, the Shapley supercluster, which might be even larger than our own Laniakea, indicating that while Norma sits at the bottom of our local gravitational well, there is an even deeper well nearby. Other reconstructions of our local Universe indicate that yet another supercluster unrelated to the Great Attractor, the Vela, contributes to some of our own motion.
Unfortunately, all of this is temporary. Gravity’s great engines of creation shut off over 5 billion years ago. The cosmic web, with its vast and interconnected filaments of clusters and superclusters, will never be completed.
The culprit is dark energy, that bastard of the cosmos. Astronomers do not understand what dark energy is, but they do understand what it does. Whatever it is, it’s causing the expansion of the Universe to accelerate. Over time, any galaxies that are not already gravitationally bound to each other will find themselves flying apart at ever faster rates... (MORE - missing details)
https://bigthink.com/starts-with-a-bang/...-universe/
KEY POINTS: At a fundamental level, our Universe is composed of indivisible, elementary particles embedded in the backdrop of the spacetime in our expanding Universe. But what we observe isn't simply a collection of independent particles, but rather a series of bound structures: atomic nuclei, atoms, molecules, planets, stars, galaxies, and more. When we add it all up, how bound together is our actual Universe? The answer might surprise you and being both more, and less, than you ever imagined... (MORE - details)
The Universe sucks: The mysterious Great Attractor that’s pulling us in
https://arstechnica.com/science/2023/04/...ing-us-in/
EXCERPT: Our Milky Way galaxy is speeding through the emptiness of space at 600 kilometers per second, headed toward something we cannot clearly see...
[...] Cosmologists continue to debate the exact contents and location of the Great Attractor. We can only infer its mass and location based on relatively sparse surveys within the Zone of Avoidance and reconstructions of the movements of those galaxies (which is slightly difficult because we can’t watch anything move in real time given the enormous scales involved).
The supposed location of the Great Attractor already contains an immense assemblage of mass known as the Norma Cluster, which is located over 200 million light-years away. Our own [ul=https://en.wikipedia.org/wiki/Shapley_Supercluster]Virgo cluster[/url] and all its surrounding galaxies are on the move toward Norma, which sits at the center of the flow of all the galaxies within Laniakea.
Recent studies have revealed more complexity. Norma itself appears to be moving toward another supercluster, the Shapley supercluster, which might be even larger than our own Laniakea, indicating that while Norma sits at the bottom of our local gravitational well, there is an even deeper well nearby. Other reconstructions of our local Universe indicate that yet another supercluster unrelated to the Great Attractor, the Vela, contributes to some of our own motion.
Unfortunately, all of this is temporary. Gravity’s great engines of creation shut off over 5 billion years ago. The cosmic web, with its vast and interconnected filaments of clusters and superclusters, will never be completed.
The culprit is dark energy, that bastard of the cosmos. Astronomers do not understand what dark energy is, but they do understand what it does. Whatever it is, it’s causing the expansion of the Universe to accelerate. Over time, any galaxies that are not already gravitationally bound to each other will find themselves flying apart at ever faster rates... (MORE - missing details)
