An international team of researchers not only created an entire virtual universe. He made it available free of charge to everyone with Internet access.
Uchu, a word meaning cosmos in Japanese, is the most realistic simulation of the universe ever seen.
The project was developed by the National Astronomical Observatory of Japan (NAOJ) in collaboration with the Astrophysics Institute of Andalusia (IAA-CSIC), the Centro de Supercomputación de Galicia (Cesga) and the Spanish academic and research network Radiris.
Other research groups from Japan, the US, Argentina, Australia, Chile, France and Italy also participate in the initiative.
simulation will allow us the study of the evolution of the universe With an unprecedented level of detail and information, practically since the Big Bang to the present.
“Uchu is basically how the universe formed, the whole structure, a re-creation of everything we’ve seen since the universe,” said cosmologist Francisco Prada, a professor at the Spanish Higher Council for Scientific Research. Andalusian Institute of Astrophysics to BBC News Mundo.
“We were able, with a supercomputer deeply devoted to the project, to reconstruct all the physics involved, basically Einstein’s gravitational equations and the energetic and physical components of the universe, as well as numerically all the processes involved. For.”
The simulation, which is already available in Sesga’s cloud, will allow scientists to focus on different moments in the history of the universe and facilitate the understanding of events such as the evolution of galaxies and the formation of black holes.
super computer
The simulation was made possible by the ATERUI II supercomputer, the most powerful supercomputer dedicated exclusively to astrophysics, which belongs to the National Astronomical Observatory of Japan.
“Other large computers like the Mare Nostrum in Barcelona may have many more processors. But the advantage of ATERUI is that it is dedicated to a few projects in astrophysics,” says Prada.
“And it allows you to have exclusive use over a long period of time to be able to emulate something that would otherwise be impossible. We were lucky enough to exclusively use ATERUI for 48 hours every month throughout the year. This one It’s a huge privilege.”
Tomoaki Ishiyama, from Chiba University in Japan, was responsible for developing and executing the code that made up the simulation.
According to Efe, the result is “three petabytes of data, which is equivalent to about 1 million photos from a 12-megapixel mobile phone.”
CSIC says the simulations show that the 9.6 billion light-year virtual cube contains 2.1 billion particles, which is equal to half the distance between Earth and the most distant galaxies.
All data for analysis is stored in the composite center of CESGA, CSIC and Junta de Galicia, and can also be downloaded online via IAA servers.
galaxy evolution
Uchuyu will allow scientists to study in detail various moments and scenarios in the history of the universe over 13 billion years.
“For the first time we can study in a single simulation both very small objects and massive objects, galaxies whose masses are smaller than ours. Galaxy And very large galaxy clusters, or even giant voids, keeping similar resolution. This was not yet possible in the same simulation.”
“It’s like in any other simulation you can only study cars. But with our simulation we were able to study everything from a skateboard to a plane or a supertanker, and we could also see that all these objects How is distributed either over the plain or in the Himalayas or in ocean waters, is very different from the density of matter in the atmosphere.”
“The galaxies in the universe are distributed in what we call a large-scale structure: there are large voids, where there are very few galaxies, there are filaments, there are clusters like the Milky Way and Andromeda, and then there are larger objects like ours. A thousand times more massive than the Milky Way.”
The simulation allows us to see, for example, how smaller galaxies aggregate (merge) throughout history and become larger, in what is called the hierarchical formation of the structure of the universe, Prada explains.
“That’s how the galaxy formed. It’s ‘eating’ many smaller objects and it’s part of the galaxy’s formation history.”
The simulation will also allow studying the collision of two galaxies that have very large black holes that can generate gravitational waves.
“Massive galaxies like the Milky Way contain a black hole. Understanding the evolution of these structures is essential because it is also related to the rate at which black holes are added to how they form.”
‘Dark Matter Glasses’
A key feature about Uchu is that it symbolizes not only visible matter, but also the mysterious dark matter and dark energy.
Ordinary matter made up of atoms represents less than 5% of the total energy of the universe.
Dark matter, a form of matter that does not interact with light and can only be detected by its gravitational influence, represents about 25%. The rest, 70%, is what scientists call dark energy.
In view available in Uchu youtubeFor example, if you look at dark matter and how it is distributed in a supermassive object, how can it be a large cluster of galaxies.
“Our simulations have all the ingredients, all the parameters we know today in the correct proportions,” Prada said.
Uchu’s images are the equivalent of “putting on special glasses” to visualize dark matter.
“There was a time in the history of the universe when gravity had to compete with dark energy because if you only had gravity, all matter would collapse.”
“However, there comes a time in the history of the universe when this dark energy begins to dominate that we don’t know what it is, but we practically know it’s like a repulsive force, like a pressure against gravity. Is.” Prada explained to BBC News World.
“One of the big challenges for Uchu is being able to simulate the entire structure of the universe and compare it to all the data we’ve seen — for example, how many clusters of galaxies we have, how big There are vacancies, how galaxies are clustered—we’ll be able to better explain the nature of dark energy and dark matter, which to date we don’t know what it is.”
“It is understood that dark matter is an elementary particle, but we don’t know what it is. It is what causes this accelerated expansion.”
Francisco Prada explains: “This image shows four moments in the history of the universe, the present is below and the past is above. And the three pillars correspond to different regions of the universe.”
“For example, the one on the right is very interesting because it shows the process of creating a great void.”
“If we go to the present, you’ll see that there’s a very low density of galaxies, there are large regions that have a deficit, a void of galaxies, so we can go back in time and see how it formed.” “
“In the first column you see an object similar to the Milky Way; it’s like putting glasses on the sky and looking at dark matter.”
“If I instead give you a picture that can only be seen by binoculars, it would be a beautiful galaxy like the Hubble images, but we all see dark matter, because there must be thousands of smaller objects in our own galaxy that are dark matter.”
“And in the middle you see a cluster of galaxies that is an object a thousand times more massive.”
from Argentina and Chile
Scientist Sofia Alejandra Cora of the Astrophysics Institute of La Plata in Argentina is also taking part in the Uchu project.
Cora is an independent researcher at the National Council for Scientific and Technical Research (CONCET) and Associate Professor in the Faculty of Astronomical and Geophysical Sciences at the National University of La Plata.
“The main objective of my participation in this project is to produce a catalog of galaxies from data from the Uchu simulations, which consider only dark matter.”
“To do this, information about the properties of dark matter halos and how they grow and fuse over time is taken as a basis,” she explained to BBC News Mundo.
“And a semi-analytical model of galaxy formation and evolution is applied, taking into account the various physical processes that determine the properties of galaxies,” he continued.
“A quasi-analytical model consists of a set of simple analytical recipes that model the various physical processes that affect the gas and stars that make up galaxies.”
“The latest version of the model used by our working group in Argentina is described in an article in the Royal Astronomical Society’s Montali Notices. This work is under development.”
Researcher Cristian Vega Martínez from the Department of Astronomy and the Institute for Multidisciplinary Research in Science and Technology at the University of La Serena (ULS) in Chile is also participating in the project.
“One of Uchu’s biggest challenges was managing and publishing the huge amount of data that this category of simulation can generate.”
“This type of simulation can easily generate hundreds of terabytes,” Vega told BBC News Mundo.
“Therefore, we are actively working to design techniques to manipulate this data, provide a direct way to share it, and provide tools for its use.”
He brings his experience in the field of galaxy formation and evolution simulation and his knowledge of high-performance computing.
“Published data should be provided in a way that is useful to the community,” he says.
“These kinds of simulations, which allow the modeling of large volumes of the universe [que simulam as estruturas que definem onde as galáxias se formam]Large modern experiments are needed to be able to contrast our physical theories of galaxy formation and evolution with the results of the universe. [telescópios]”.
‘Give access to other people’
For Francisco Prada, one of the main reasons for Uchu’s importance is its free availability.
“As a scientist, I believe in the responsibility of providing access to other scientists who may not have the possibility to do these simulations so that they can do high-level, state-of-the-art science,” he said.
“We make it public to all scientists in the world, not only to scientists, but to everyone who has access to the Internet.”
“And in Galicia we also have data, so people can go there and analyze the data without having to download it at home. So we also provide computing capability, because usually this computing capability isn’t available to anyone. Is.”
The simulation, analysis and public dissemination of the data was funded by public institutions in Japan and Spain.
“The cost of this project is very high and there are only a few groups in the world that can do this project.”
“We are in the Big Data era, where what Uchu has generated is far greater than the amount of data stored by YouTube, Amazon and Google combined.”
“We were really able to make cutting-edge research available to society and scientists, and that’s what I find very encouraging.”
