December 2, 2023

Brighton Journal

Complete News World

The largest simulation of the universe ever can finally reveal how we got here: ScienceAlert

The largest simulation of the universe ever can finally reveal how we got here: ScienceAlert

How did we get here? It’s not just us humans, moving on a pale blue dot, hurtling around a star, hurtling around a supermassive black hole, hurtling through the local cluster. But how did the point, the star, the black hole, and the cluster get here?

How incomprehensibly massive Everything From all of this to arrive at what we are now, from nothing unimaginable, billions of years ago?

That’s all, really, a matter of questions. In the largest project of its kind to date, astronomers are trying to find answers – by running computer simulations of the entire universe.

They are called Flamingo Simulations (simulating the full large-scale hydrostructure with full-sky mapping to interpret next-generation observations), are performed on Supercomputer at DiRAC facility in the UK.

This simulation is intense. They are designed to calculate the evolution of all known components of the universe.

This means ordinary matter: stars; Galaxies. All the things we can touch (they might kill us, but we can); dark matter – the mysterious mass that creates strange extra gravity; Dark energy – the mysterious force that accelerates the expansion of the universe.

The largest of these simulations contains 300 billion particles equivalent to the mass of a small galaxy, in a cubic volume of space whose edges are 10 billion light-years across.

“To make this simulation possible, we developed a new code, SWIFT, that efficiently distributes the computational work over more than 30,000 CPUs.” Astronomer Matthieu Schaller explains From Leiden University.

A slice of the largest simulation, with a zoom in on some of the features. (Josh Burrow, Flamengo and Virgin League)

The preliminary results were published in three papers: the first Description of methodsthe second Provide simulationsThe third is the results Description of the structure is extensive The universe is in cold dark matter.

See also  Luna 25: The Russian lunar lander crashes into the lunar surface

In particular, the third paper sought to address what is called 8 sigma, or s8 tension. This is based on a measurement of the universe called the cosmic microwave background — the faint microwave radiation filling the universe from the epoch immediately following the Big Bang. Analysis of this light suggests that the universe must be like this now Grouped together more Of what she has.

Since this tension represents a great challenge to Cold dark matter model About the universe in which clumping must occur, researchers hope FLAMINGO can provide some answers.

So far, they haven’t been able to resolve this tension — that would be huge news for cosmology — but they have something going for them about running simulations: both ordinary matter and neutrinos are essential for accurate predictions.

“Although dark matter dominates gravity, the contribution of ordinary matter can no longer be neglected.” says research leader and astronomer Job Shay from Leiden University, “because that contribution can be similar to deviations between models and observations.”

Simulations involving normal matter are difficult to run. Dark matter is known to interact with the universe only through gravity; Natural matter also reacts to pressure, such as radiation pressure and galactic winds, which are unpredictable and difficult to model. It takes a lot of computing power to run, so we’ll have to wait a little longer for answers on the S8 Stress of flamingo.

However, the researchers ran a series of simulations tracking the composition of the universe’s structure across dark matter, ordinary matter, and neutrinos, varying the parameters of all three to see how this affects the final result.

See also  “Vortices” and space-time storms

“The effect of the galactic wind was calibrated using machine learning, by comparing predictions from many different simulations of relatively small sizes with observed galaxy masses and gas distribution in galaxy clusters,” explains astronomer Roy Coghill of Leiden University.

The team has not yet made the FLAMINGO data publicly available, as it is several petabytes in size. Anyone interested is encouraged to make a polite inquiry With the corresponding author.

The research was published in Monthly Notices of the Royal Astronomical Society. All three sheets can be found here, hereAnd here.