Supercomputer Turns Back Cosmic Clock for Insights Into One of the Most Important Mysteries in Modern Astronomy

Evolution of the Universe Schematic Diagram

Schematic diagram of the evolution of the Universe from the inflation (left) to the present (right). The “reconstruction method” winds back the evolution from right to left on this illustration to reproduce the primordial density fluctuations from the current galaxy distribution. Credit: Institute of Statistical Mathematics

Astronomers have tested a method for reconstructing the state of the early Universe by applying it to 4000 simulated universes using the ATERUI II supercomputer at the National Astronomical Observatory of Japan (NAOJ). They found that together with new observations the method can set better constraints on inflation, one of the most enigmatic events in the history of the Universe. The method can shorten the observation time required to distinguish between various inflation theories.

Just after the Universe came into existence 13.8 billion years ago, it suddenly increased more than a trillion, trillion times in size, in less than a trillionth of a trillionth of a microsecond; but no one knows how or why. This sudden “inflation,” is one of the most important mysteries in modern astronomy. Inflation should have created primordial density fluctuations which would have affected the distribution of where galaxies developed. Thus, mapping the distribution of galaxies can rule out models for inflation that don’t match the observed data.

Supercomputer Turns Back Cosmic Clock

(1) The simulations start from a galaxy distribution based on primordial density fluctuations and (2) performs gravitational many-body calculations to evolve to the current galaxy distribution. (3) Then the reconstruction method is used to work backwards to the earlier galaxy distribution. (4) Finally, the reconstructed galaxy distributions and initial conditions are compared. This research found that the statistical properties of the reconstructions are very similar to the initial conditions. Credit: Masato Shirasaki, NAOJ

However, processes other than inflation also impact galaxy distribution, making it difficult to derive information about inflation directly from observations of the large-scale structure of the Universe, the cosmic web comprised of countless galaxies. In particular, the gravitationally driven growth of groups of galaxies can obscure the primordial density fluctuations.

A research team led by Masato Shirasaki, an assistant professor at NAOJ and the Institute of Statistical Mathematics, thought to apply a “reconstruction method” to turn back the clock and remove the gravitational effects from the large-scale structure. They used ATERUI II, the world’s fastest supercomputer dedicated to astronomy simulations, to create 4000 simulated universes and evolve them through gravitationally driven growth. They then applied this method to see how well it reconstructed the starting state of the simulations. The team found that their method can correct for the gravitational effects and improve the constraints on primordial density fluctuations.

“We found that this method is very effective,” says Shirasaki. “Using this method, we can verify of the inflation theories with roughly one tenth the amount of data. This method can shorten the required observing time in upcoming galaxy survey missions such as SuMIRe by NAOJ’s Subaru Telescope.”

Reference: “Constraining primordial non-Gaussianity with postreconstructed galaxy bispectrum in redshift space” by Masato Shirasaki, Naonori S. Sugiyama, Ryuichi Takahashi and Francisco-Shu Kitaura, 4 January 2021, Physical Review D.
DOI: 10.1103/PhysRevD.103.023506

8 Comments on "Supercomputer Turns Back Cosmic Clock for Insights Into One of the Most Important Mysteries in Modern Astronomy"

  1. The universe continually repeats itself if only to a lesser degree as it ages so that’s where the answers to all the questions lye. It’s not easy if it was everybody would do it so hats off to the crazy people that dedicate there existence to finding the answers we all seek to find so to them I say thanks for your hard works. Now that the ass kissings over let’s get atter lol. Someone run the snowball early universe please if only to rule it out thxx.

  2. Think really big snowballs of pure hydrogen so big that the pressure at the core transforms the hydrogen into different forms. And hopefully it leads to the hot big bang from giant hydrogen snowballs across the universe?

  3. The reason I comment a lot on these matters is because all scientists go through school and read the same books. I’m not saying all the books are wrong what I’m saying that all the books can’t be right. And if everybody reads the same thing then they will all start there own works based on the same info and if only 1or 2or3 of these works ended up being wrong then so is the work that comes from them. So a fresh perspective should always be welcome in any type of study such as these. Anyway just thought I would explain a little why I comment as there mostly theories that I comment on. Theories are like well you know everybody got one lol.

    • Torbjörn Larsson | February 18, 2021 at 5:03 pm | Reply

      “The reason I comment a lot on these matters is because all scientists go through school and read the same books.”

      That’s not how science works – it is not handed down from authority.

      Different universities have different specializations, courses and textbooks (even if the better textbooks are more spread). And different reseach groups work on mostly different things.

      There is literary zero likelihood that ideas among general public are useful in science – there are no papers that refer to such sources. But if you are interested there are now citizen science projects – new area with old roots, see the last quote below – where public can help scientists crunch data. And in those principled contexts there have been genuine discoveries that people got credit for.

      “Citizen science (CS; also known as community science, crowd science, crowd-sourced science, civic science, or volunteer monitoring) is scientific research conducted, in whole or in part, by amateur (or nonprofessional) scientists.[1] Citizen science is sometimes described as “public participation in scientific research,” participatory monitoring, and participatory action research whose outcomes are often advancements in scientific research by improving the scientific communities capacity, as well as increasing the public’s understanding of science.[2][3][4]”

      “In February 2020, Timber Press, an imprint of Workman Publishing Company, published “The Field Guide to Citizen Science” as a practical guide for anyone interested in getting started with CS.[26]”

      “They conclude that as CS continues to grow and mature, a key metric of project success they expect to see will be a growing awareness of data quality. They also conclude that CS will emerge as a general tool helping “to collect otherwise unobtainable high-quality data in support of policy and resource management, conservation monitoring, and basic science.”[45]”

      “A study of Canadian lepidoptera datasets published in 2018 compared the use of a professionally curated dataset of butterfly specimen records with four years of data from a CS program, eButterfly.[46][47] The eButterfly dataset was used as it was determined to be of high quality because of the expert vetting process used on the site, and there existed a historic dataset covering the same geographic area consisting of specimen data, much of it institutional. The authors note that, in this case, CS data provides both novel and complementary information to the specimen data. Five new species were reported from the CS data, and geographic distribution information was improved for over 80% of species in the combined dataset when CS data was included.”

      “Japan has a long history of citizen science involvement, the 1,200-year-old tradition of collecting records on cherry blossom flowering probably being the world’s longest-running citizen science project.[254”

      [ ]

      For an article discussing why your “snowball hydrogen” idea do not work against current observation and theory, see the link to cosmological order of events.

      The nut is inflation predicts that the universe at the start of hot big bang is homogeneous and isotropic to 10^-5 parts nonuniformity (as seen in the cosmic background spectra). Leaving no place for much clumped matter (and hydrogen is not present early on – it is created in the hot big bang nucleosynthesis).

  4. So the reason I like the hydrogen snowball theory is? In the beginning of the dark universe there would have been little of so called gravity as in GR’s (Einstein) theories. But if he was correct than the snowball universe makes a lot of sense the bigger the snowball the bigger the gravity well in the fabric of spacetime. Where in having trouble is the snowballs transformation did they melt into liquid or gas before the banged. ( trying to fit ur BBang theory in here works with or without the theory) so as the snowballs of hydrogen increase in size the more mass they will gather the more mass the more energy etc. Snows sticky no matter what the snows made of and that would help explain how the universe found the fabric of space and so called gravity yes? But how big would a hydrogen snowball have to be to transform itself into the matter we see around our neighborhood as the universe itself wasn’t created in the bang just the matter in it. Do you get whAt I’m getting at here the universe wasn’t hot in the beginning it was extremely cold and then the temperature changed and so what changed the temp the snowballs changed the temps once they transformed from snow to lighting up the neighborhood. We should stop thinking all we see came from a singularity more like countless singularities all across the uni and they don’t all have to ignite at once it might still be happening just to far away. The idea came from Jupiter if u must know.

  5. Why are there ads on my comments? When do I get the cheque from these companies soon I hope. You can contact me for the info you need.

  6. Torbjörn Larsson | February 18, 2021 at 4:21 pm | Reply

    Planck still rules, but this method show promise.

    “The main result of this paper is shown in Table I. For the local-type PNG, we find that the post-reconstructed galaxy bispectrum can constrain fNL with a level of 13.3 by using existing galaxy sample. The size of error bars is still larger than the latest CMB constraint [4], but it issmaller than the current best constraint by quasars [41].”


    The press release describe a context not in the paper, and it gets the ordering wrong. “Just after the universe came into existence 13.8 billion years ago, it suddenly increased more than 1 trillion trillion times in size in less than a trillionth of a trillionth of a microsecond, but no one knows how or why.” :
    “Inflation came first, and its end heralded the arrival of the Big Bang. There are still those who disagree, but they’re now nearly a full 40 years out of date.”

  7. Don’t waste money and efforts on the wrong big bang theory any longer because it is based on Einstein’s relativity which has already been disproved. Relativists assume that a clock can directly record pure time without using the status change of a physical process. We know time is a concept abstracted from the status changes of physical processes such as the change of the view angle of the sun, the increase of the height of a tree, the distance that a car has driven, the biological age of a person, the number of cycles of a clock, etc. All the changes of the statuses of physical processes are the products of time and changing rates. The effect of time can be shown only through these status changes, and there is no pure time keeper in the world which does not need a physical process. Any physical clock records the number of cycles of a periodical process and use this number to indirectly calculate the elapsed time. The number of cycles is the product of time and frequency. In special relativity, when observed from a stationary frame, relativistic time of a moving frame does become shorter but the relativistic frequency of a clock on the moving frame becomes faster to make the product of relativistic time and relativistic frequency unchanged compared with that of the stationary clock. That is, relativistic kinetic time dilation won’t be found on any physical clock or the twin brothers or any other physical process. Time dilation is just the property of the relativistic time, nothing to do with the physical clock. As we all use physical clocks to observe physical phenomena, clock time is the real physical time. Thus, relativistic time is just a fake time without physical meaning and special relativity is wrong. What do you think?

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