View source for Astronomy:UniverseMachine

{{short description|Computer simulated universes}}
{{Physical cosmology|experiments}}
The '''UniverseMachine''' (also known as the '''Universe Machine''') is a project carrying out [[Physics:Astrophysics|astrophysical]] [[Supercomputer|supercomputer]] [[Simulation|simulation]]s of various models of possible [[Astronomy:Universe|universe]]s, created by astronomer Peter Behroozi and his research team at the [[Astronomy:Steward Observatory|Steward Observatory]] and the [[Organization:University of Arizona|University of Arizona]].<ref name="UAZ-20190809">{{cite news |last=Stolte |first=Daniel |title=Virtual 'Universe Machine' Sheds Light on Galaxy Evolution - By creating millions of virtual universes and comparing them to observations of actual galaxies, a UA-led research team has made discoveries that present a powerful new approach for studying galaxy formation. |url=https://uanews.arizona.edu/story/virtual-universe-machine-sheds-light-galaxy-evolution |date=9 August 2019 |work=[[Organization:University of Arizona|University of Arizona]] |access-date=22 August 2019 }}</ref><ref name="MNRAS-20190502">{{cite journal |author=Behroozi, Peter |display-authors=et al. |title=UniverseMachine: The correlation between galaxy growth and dark matter halo assembly from z = 0−10 |date=3 September 2019 |journal=[[Organization:Monthly Notices of the Royal Astronomical Society|Monthly Notices of the Royal Astronomical Society]] |volume=488 |issue=3 |pages=3143–3194 |arxiv=1806.07893  |doi=10.1093/mnras/stz1182 |bibcode=2019MNRAS.488.3143B |s2cid=119385275 }}</ref><ref name="EA-20190809">{{cite news |author=University of Arizona |title=Virtual 'universe machine' sheds light on galaxy evolution |url=https://eurekalert.org/pub_releases/2019-08/uoa-vm080919.php |date=9 August 2019 |work=EurekAlert! |access-date=22 August 2019 |author-link=University of Arizona }}</ref><ref name="LS-20190822">{{cite news |last=Childers |first=Tim |title=Astronomers Create 8 Million Baby Universes Inside a Computer and Watch Them Grow. Here's What They Learned. - What can simulating 8 million universes tell us about the history of our own universe? |url=https://www.livescience.com/universe-machine-probes-dark-matter.html |date=22 August 2019 |work=LiveScience |access-date=22 August 2019 }}</ref><ref name="MD-20190810">{{cite news |last=Lea |first=Robert |title=Galactic Evolution Examined by 'Universe Machine' Researchers have turned to a massive supercomputer — dubbed the 'UniverseMachine' — to model the formation of stars and galaxies. In the process, they created a staggering 8 million 'virtual universes' with almost 10¹⁴ galaxies. |url=https://medium.com/@roblea_63049/galactic-evolution-examined-by-universe-machine-ec1ba2250e54 |date=10 August 2019 |work=[[Software:Medium (website)|Medium]] |access-date=22 August 2019 }}</ref><ref name="ET-20190823">{{cite news |last=Whitman |first=Ryan |title=Scientists Use 'UniverseMachine' to Simulate 8 Million Universes |url=https://www.extremetech.com/extreme/297093-scientists-use-universemachine-to-simulate-8-million-universes |date=23 August 2019 |work=[[ExtremeTech]] |access-date=23 August 2019 }}</ref><ref name="SPC-20190814">{{cite news |last=Rabie |first=Passant |title=Scientists Create Millions of Virtual Universes to Understand Cosmic History - Scientists created millions of universe replicas on a supercomputer. |url=https://www.space.com/virtual-universe-machine-reveals-star-formation.html |date=14 August 2019 |work=Space.com |access-date=24 August 2019 }}</ref> Numerous universes with different physical characteristics may be simulated in order to develop insights into the possible beginning and evolution of our universe. A major objective is to better understand the role of [[Astronomy:Dark matter|dark matter]] in the development of the universe.<ref name="LS-20190822" /><ref name="ET-20190823" /> According to Behroozi, "On the computer, we can create many different universes and compare them to the actual one, and that lets us infer which rules lead to the one we see."<ref name="UAZ-20190809" />

Besides lead investigator Behroozi, research team members include astronomer Charlie Conroy of [[Organization:Harvard University|Harvard University]], physicist Andrew Hearin of the [[Organization:Argonne National Laboratory|Argonne National Laboratory]] and physicist [[Biography:Risa Wechsler|Risa Wechsler]] of [[Organization:Stanford University|Stanford University]]. Support funding for the project is provided by [[Organization:NASA|NASA]], the [[Organization:National Science Foundation|National Science Foundation]] and the Munich Institute for Astro- and Particle Physics.<ref name="UAZ-20190809" />

==Description==
Besides using computers and related resources at the NASA Ames Research Center and the [[Organization:Leibniz-Rechenzentrum|Leibniz-Rechenzentrum]] in Garching, Germany, the research team used the [[Organization:University of Arizona|High-Performance Computing cluster at the University of Arizona]]. Two-thousand processors simultaneously processed the data over three weeks. In this way, the research team generated over 8 million universes, and at least {{val|9.6|e=13}} galaxies.<ref name="EA-20190809" /><ref name="MD-20190810" /> The UniverseMachine program continuously produced millions of simulated universes, each containing 12 million galaxies, and each permitted to develop from 400 million years after the [[Astronomy:Big Bang|Big Bang]] to the present day.<ref name="UAZ-20190809" /><ref name="LS-20190822" />

According to team member Wechsler, "The really cool thing about this study is that we can use all the data we have about [[Astronomy:Galaxy formation and evolution|galaxy evolution]] —  the numbers of [[Astronomy:Galaxy|galaxies]], how many [[Astronomy:Star|star]]s they have and how they [[Astronomy:Star formation|form those stars]] — and put that together into a comprehensive picture of the last 13 billion years of the universe."<ref name="LS-20190822" /> Wechsler further commented, "For me, the most exciting thing is that we now have a model where we can start to ask all of these questions in a framework that works […] We have a model that is inexpensive enough computationally, that we can essentially calculate an entire universe in about a second. Then we can afford to do that millions of times and explore all of the parameter space."<ref name="LS-20190822" />

==Results==
[[File:NASA-UniverseMachine-SupercomputerSimulatorOfDifferentUniverses.png|thumb|right|300px|Logo of the UniverseMachine]]
One of the results of the study suggests that denser dark matter in the [[Astronomy:Chronology of the universe#Early universe|early universe]] does not seem to negatively impact [[Astronomy:Star formation|star formation]] rates, as thought initially. According to the studies, galaxies of a given size were more likely to form stars for much longer, and at a high rate.<ref name="ET-20190823" /> The researchers expect to extend the project's objectives to include how often stars expire in supernovae, how dark matter may affect the [[Astronomy:List of galaxies|shape of galaxies]]<ref name="ET-20190823" /> and eventually, by gaining better general cosmological insights, how life [[Biology:Abiogenesis|originated]].<ref name="MD-20190810" />

==See also==
{{div col|colwidth=30em}}
* {{annotated link|Computational fluid dynamics}}
* {{annotated link|Astronomy:Galaxy}}
* {{annotated link|Astronomy:Galaxy formation and evolution}}
* {{annotated link|Astronomy:Illustris project}}
* {{annotated link|Astronomy:List of cosmological computation software}}
* {{annotated link|Astronomy:Millennium Run}}
* {{annotated link|Physics:N-body simulation}}
{{div col end}}

==References==
{{reflist|30em}}

==External links==
* <!---temporary link for starters--->
* {{youtube|GNjuz6MO0eU|Video (86:49) – "Search for Life in the Universe"}} – [[Organization:NASA|NASA]] (14 July 2014)
* [https://www.eurekalert.org/pub_releases/2019-08/kift-alt082819.php Universe Model using Artificial Intelligence] (IPMU; 28 August 2019)

{{Dark matter|state=collapsed}}
{{Computer simulation}}

[[Category:Astrophysics]]
[[Category:Cosmological simulation]]
[[Category:Physical cosmology]]

{{Sourceattribution|UniverseMachine}}