Shapley concentration, the supercluster we live in. © Valade et al., Nature 2024
In 2014, Helen Courtois, Daniel BomaredeR. B. Tully and others made a resounding announcement: They have determined that the Milky Way is gravitationally bound by 100,000 other galaxies spanning a distance of 500 million light-years. Having made part of their ten-year observations on Mauna Kea, in Hawaii, they gave the poetic name Lāniākea to this cosmic group to which we belong.
Laniakia and the cosmic filaments that make up galaxies and their velocities. The red dot represents our position: *”We are here.” © Courtois, Tolle, Boumaredi and others (Nature)
Laniakia means “Infinite Paradise” And countless means “which cannot be measured”. It's a shame, because these scientists spent a decade measuring the speeds and directions of all these galaxies. In this regard, Hélène Courtois and Daniel Bommardé followed the recommendation to the letter Galileo To measure everything that can be measured and make the unmeasurable measurable.
Astronomy has the potential to dramatically reduce the scale of our problems…
They also honored astronomy as well as the luminaries Carl Sagan Who saw this science as a way for man to know his place in the universe. Thanks to Laniakea, we learned more about where we are and what we are. We can now take a startling look at our existence. Humanity is that little pile of carbon and oxygen atoms on a little blue planet in a little galaxy carried away by a flood of other galaxies.
The different structures we belong to. © Andrew Z. Colvin
Our neighboring giant galaxy clusters (the Virgo Supercluster), most notably the Ophiuchus supercluster, in yellow, towards which we are heading. © Andrew Z. Colvin
Yes, but now our address has changed. Or rather, perhaps today we can add a line to our planetary calling card, because we exist in a larger giant group. This first-hand information was provided by almost the same team as Laniakea. Let's summarize…
Humanity lives on Earth, in the Solar System, in Orion's Arm, in the Milky Way, in the Virgo Cluster, in the Virgo Supercluster, in Laniakia and in the Chapley Concentration.
Gravitational currents that connect galaxy clusters. What's more, it's awesome. © Valade et al., Nature 2024
Watershed technology.
It was necessary to study 38,000 galaxy clusters and 56,000 galaxies to determine this new gravitational connection. This is the program of cosmic flows 4. The parts farthest from us due to the expansion of the universe are transported at a speed of about 30,000 km/s! However, indirectly, we are still connected to them.
Space is distorted by the masses located there and the concentration of the latter. Think of a formula John WheelercooperatingEinstein : “Matter tells space how to bend, and space tells matter how to move forward.” Thus groups of galaxies slide towards each other at hundreds of kilometers per second. So, “The 'Local Group' of the Milky Way and Andromeda is moving at a speed of 630 kilometers per second towards the Centauri cluster, and these streams then direct us towards the cluster in the constellation Ophiuchus.”said Daniel Bomaredi, one of the authors of this article published on nature.
On the left, the Great Wall of Sloan, which is 1.35 billion light-years across. © Valade et al., Nature 2024
This new volume is about 10 times larger than Laniakia, but is still much smaller than the largest known gravitational structure in the universe, the Great Sloan Wall, which also consists of galaxies in clusters and spans approximately 1.5 billion light. Years!
When we expand the universe
It should be noted that our supercluster still seems to be attracted to another superstructure, but that is another story that leads to other discoveries. Let's savor this and consider that 500 years ago, for 99% of humanity, the world – the universe – was limited to Earth. Then, thanks to Galileo and the astronomical telescope, it expanded into the solar system and beyond, and then the universe became the Milky Way.
Just 100 years ago, astronomers gathered for a great debate discovered the unthinkable: there were thousands, millions, and then billions of other galaxies. On this day in 1924, the universe expanded as never before seen in human minds. Hey, one of the debaters has been called Harlow Shapley…
As a gift, here is an animated video of the story of the creation of the world according to Hawaiian legend:
“Professional food nerd. Internet scholar. Typical bacon buff. Passionate creator.”
