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Big sim’s – visualizing the universe!

Taking all-sky surveys / maps to another 10^n level of visualization …

So much of modern cosmology depends on the discovery of the cosmic microwave background (CMB) radiation in 1965.

Wiki: “Any proposed model of the universe must explain this radiation.”

Since then, advances in the tools to measure and analyze that faint, relic radiation have refined our perspective on cosmic origins. Studying the most subtle fluctuations in the CMB. Evidence of the Big Bang model. A consistency check (challenge) for the Standard Model.

Wiki: List of cosmic microwave background experiments [link]

Supercomputers and simulations to the max. Beyond galactic simulations in this case (below), which uses data from the Planck spacecraft.

Wiki: Planck was a space observatory operated by the European Space Agency (ESA) from 2009 to 2013, which mapped the anisotropies of the cosmic microwave background (CMB) at microwave and infrared frequencies, with high sensitivity and small angular resolution.

Planck has defined the most precise measurements of several key cosmological parameters, including the average density of ordinary matter and dark matter in the Universe and the age of the universe.

This article provides an overview of how Planck’s 2015 data release [link] has been used to simulate a virtual universe. The various derived cosmological parameters [link].

No, not something like the quintillions of worlds (planets) of the No Man’s Sky video game’s procedurally generated universe; but data visualization of large-scale structures. The cosmic shape of dark matter.

Data reduction and analysis of the CMB is complicated – both the physics and math and computation. The chain of dependencies and well-established assumptions in this model are far beyond my ken. Yet, a useful vehicle for exploring some fundamental questions. Communicating the cosmos.

• > “Largest virtual universe free for anyone to explore” by Center for Computational Astrophysics (September 10, 2021)

[Article includes YouTube video.]

(quote) Uchuu (meaning “outer space” [universe] in Japanese) is the largest and most realistic simulation of the universe to date. The Uchuu simulation consists of 2.1 trillion particles in a computational cube an unprecedented 9.63 billion light-years to a side.

Uchuu focuses on the large-scale structure of the universe: mysterious halos of dark matter that control not only the formation of galaxies, but also the fate of the entire universe itself. The scale of these structures ranges from the largest galaxy clusters down to the smallest galaxies. Individual stars and planets aren’t resolved, so don’t expect to find any alien civilizations in Uchuu. … Uchuu simulates the evolution of matter over almost the entire 13.8 billion year history of the universe from the Big Bang to the present.

… the research team used high-performance computational techniques to compress information on the formation and evolution of dark matter haloes in the Uchuu simulation into a 100-terabyte catalog. This catalog is now available to everyone on the cloud in an easy to use format

• Skies & Universes > Uchuu Simulations

See also:

• Universe Today > “Researchers Generate an Entire Virtual Universe and Make it Available for Download (if you Have 100 Terabytes of Free Hard Drive Space)

Related posts

Star bright, first light — fingerprint hunt

Age of universe — implications?

Defining a universe — how many constants?

Cosmological fact and fiction

4 thoughts on “Big sim’s – visualizing the universe!

  1. Does the universe have a color?

    Looking at the range of electromagnetic radiation, not just the visible spectrum, “the researchers used a color-matching computer program to convert the cosmic spectrum into a single color visible to humans.”

    • > “What color is the universe?” by Harry Baker (August 25, 2021) – “Cosmic latte” …

    (quote) In 2002, Baldry [Ivan Baldry, a professor at the Liverpool John Moores University Astrophysics Research Institute in the U.K.] and Karl Glazebrook, a distinguished professor at the Centre for Astrophysics and Supercomputing at the Swinburne University of Technology in Australia, co-led a study published in The Astrophysical Journal that measured the light coming from tens of thousands of galaxies and combined it into a singular spectrum that represented the entire universe.

    In 2002, Australia’s 2dF Galaxy Redshift Survey — which was the largest survey of galaxies ever carried out at the time — captured the visible spectra of more than 200,000 galaxies from across the observable universe. By combining the spectra of all these galaxies, Baldry and Glazebrook’s team was able to create a visible light spectrum that accurately represented the entire universe, known as the cosmic spectrum.

    The team determined that the average color of the universe is a beige shade not too far off from white.

  2. Seeing vs. realizing …

    Imagine looking out a window at a tree in the back of your yard. Perhaps taking a picture of the scene. At a later time, perhaps after some years, you look again; and the tree is noticeably farther away. A walking tree? Then sometime later, you notice it’s even farther away. So, you go outside; but, like in a strange dream, no matter how fast you try to reach the tree, you cannot do so.

    Such is the cosmos. The scale of the universe is mind-boggling. Even from what we can observe with ground / space telescopes across the electromagnetic spectrum. Distances elude us: original distances, apparent current distances, actual current distances.

    How far way can another galaxy still be observed? The size of the observable universe. What’s the oldest light than can be detected?

    (quote) From our vantage point, we observe up to 46.1 billion light-years away.

    If we can see it, would a light-speed spacecraft be able to reach it?

    (quote) Beyond distances of ~14.5 billion light-years, space’s expansion pushes galaxies away faster than light can travel.

    (quote) The present “reachability limit” has a boundary ~18 billion light-years away.

    How do these approximate light-year numbers arise: 46.1, 14.5, 18 billion?

    • Big Think > “94% of the universe’s galaxies are permanently beyond our reach” by Ethan Siegel (October 18, 2021) – Even if we traveled at the speed of light, we’d never catch up to these galaxies.

    [photo caption] Distant galaxies, like those found in the Hercules galaxy cluster, are not only redshifted and receding away from us, but their apparent recession speed is accelerating. Many of the most distant galaxies in this image are receding from us at speeds that appear to exceed the speed of light. We will never be able to reach any of the ones presently located more than 18 billion light-years away. (Credit: ESO/INAF-VST/OmegaCAM. Acknowledgement: OmegaCen/Astro-WISE/Kapteyn Institute.)

    • The universe is expanding, with every galaxy beyond the Local Group [that is, those not gravitationally bound to our galaxy] speeding away from us.

    • Today, most of the universe’s galaxies are already receding faster than the speed of light.

    • All galaxies currently beyond 18 billion light-years are forever unreachable by us, no matter how much time passes.


    • Redshift
    • Light year
    • Big Bang

  3. This is an interesting article regarding cosmological models. As well as an example of Sabine Hossenfelder’s work – since I recently finished reading her 2018 book Lost in Math, which explores (among other things) the role of assumptions in astrophysical theories. So, this is an example of research seeking to move beyond a common simplistic model.

    Namely, the Lambda-CDM [cold dark matter] model. And an application of the Mori-Zwanzig formalism – a method of statistical physics used, e.g., in fluid mechanics! For systems which form a Hilbert space.

    • > “Studying cosmic expansion using methods from many-body physics” by University of Münster (December 6, 2021)

    It is almost always assumed in cosmological calculations that there is a even distribution of matter in the universe. This is because the calculations would be much too complicated if the position of every single star were to be included.

    “Strictly speaking, it is mathematically wrong to include the mean value of the universe’s energy density in the equations of general relativity,” says Sabine Hossenfelder. … Some experts consider it to be irrelevant, others see in it the solution to the enigma of dark energy, … An uneven distribution of the mass in the universe may have an effect on the speed of cosmic expansion.

    “The Mori-Zwanzig formalism is already being successfully used in many fields of research, from biophysics to particle physics,” says Raphael Wittkowski, “so it also offered a promising approach to this astrophysical problem.” The team generalized this formalism so that it could be applied to general relativity and, in doing so, derived a model for cosmic expansion while taking into consideration the uneven distribution of matter in the universe.

  4. Perhaps a new computational record for cosmic simulations. Modeling the early universe, including dark matter as “the backbone of the cosmos.” Using the Vlasov equation.

    Neutrinos “have an outsize influence on the evolution of structures” – “to weakly influence the behavior [clumping] of dark matter.”

    • > “Massive simulation of the universe probes mystery of ghostly neutrinos” by Paul Sutter (12-6-2021) – “the universe is a little smoother than it would be without neutrinos.”

    A team of Japanese scientists has built the largest-ever cosmic simulation to include tiny “ghost” particles called neutrinos. To explore one of physics’ biggest unsolved mysteries, the researchers used a whopping 7 million CPU cores to solve for the evolution of 330 billion particles and a computational grid of 400 trillion units.

    If you change the neutrino mass just a bit in the simulations, it will change how the neutrinos influence the formation of structures over billions of years.

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