Professor Carlos Frenk, Ogden Professor of Fundamental Physics at the Institute for Computational Cosmology, at Durham University, said: “It is immensely exciting to see the familiar structures that we know exist around us emerge from a computer calculation. At the centre of the simulation is perhaps the most important structure, a pair of galaxies, the virtual counterparts of our own Milky Way and our nearby massive neighbour, the Andromeda galaxy. This means that the familiar structures within our Local Universe, such as the Virgo, Coma and Perseus clusters of galaxies, the ‘Great Wall’ and the ‘Local Void’ – our cosmic habitat – are reproduced in the simulation. By using advanced generative algorithms (models how the data was generated in order to categorize a signal), the simulations are conditioned to reproduce our specific patch of Universe, thus containing the present day structures in the vicinity of our own galaxy that astronomers have observed over decades. The simulations carried out in this study are different. When simulating a virtual cold dark matter universe, most cosmologists follow a ‘typical’, or random, patch, one that is similar to our own observed Universe, yet only in a statistical sense. Over the past 20 years, cosmologists have developed a ‘standard model’ of cosmology – the ‘Cold Dark Matter’ model – which can explain a plethora of observed astronomical data, from the properties of the heat left over from the Big Bang, to the number and spatial distribution of galaxies we observe around us today. Overtime, haloes grow large enough to host galaxies like our own Milky Way. Dark matter is a hypothetical form of matter thought to account for a large amount of all matter in the Universe.įirst, the dark matter coalesces into small clumps, called haloes, and the surrounding gas is gravitationally attracted towards these clumps, eventually fragmenting into stars to form galaxies. These ‘cosmological simulations’ developed by the team used relevant physics equations to describe how dark matter and cosmic gas evolve throughout the Universe’s lifetime. The simulation was performed on the DiRAC COSmology MAchine (COSMA) operated by the Institute for Computational Cosmology at Durham University. The simulation covers a volume up to a distance of 600 million lightyears from Earth and is represented by over 130 billion simulated ‘particles’, requiring many thousands of computers working in tandem over several weeks and producing large amounts of data. While the level of this underdensity is not considered to be a challenge to the standard model of cosmology, it could have consequences for how we interpret information from observed galaxy surveys. It was found that our local patch of the Universe may be somewhat unusual as the simulation predicted a lower number of galaxies on average due to a local large-scale ‘underdensity’ of matter. The team meticulously compared the virtual Universe to a series of observational surveys to find the correct locations and properties for the virtual analogies of the familiar structures. The simulation, named SIBELIUS-DARK, is part of the “Simulations Beyond the Local Universe” (SIBELIUS) project, and is the largest and most comprehensive ‘constrained realisation’ simulation to date. The findings are published in the Monthly Notices of the Royal Astronomical Society. An international team of researchers, led by the University of Helsinki, and including members from Durham University in the UK, used supercomputer simulations to recreate the entire evolution of the cosmos, from the Big Bang to the present. Scientists have produced the largest and most accurate virtual representation of the Universe to date. Grants for Studies in Astronomy and Geophysics. GCSE Poster Competition 2022 – Sponsored by Winton.Geophysical Journal International (GJI).Although the idea of virtual representation may seem paternalistic and undemocratic, it is perhaps the breadth of application rather than the concept itself which is offensive to modern susceptibilities: all modern societies accept it, in effect, in respect of children. Thompson have partly conceded this point by claiming that policy had to take some cognizance of the interests of the urban poor because of their capacity to riot, a form of anticipated reactions directly relevant to, for example, the Roman Empire, but also to the United States and United Kingdom in our own times in respect of people who do have the right to vote. Twentieth‐century social historians like E. That the disenfranchised were virtually represented in Parliament was an argument often put by opponents of franchise reform in England in the nineteenth century. The essential idea of virtual representation is that one can be represented by a decision‐making process without being able to vote for those who make the decisions.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |