Researchers are using the behavior of slime mold, a strange, single-celled organism, to help build a map the web of dark matter filaments which make up our universe. Scientists designed a computer algorithm inspired by the unique creature to try to trace the cosmic web, which is "the large-scale backbone of the cosmos," according to a NASA press release. They applied the algorithm to data that had the positions of 37,000 galaxies, which then created a 3D map of the cosmic web's "intricate filamentary network."
Slime mold is a curious organism — one that inspires a lot of interest from scientists and even the Paris Zoo. The blind, single-celled creature can build filamentary networks in a hunt for food, optimizing the pathways it takes in its search. Remarkably, they lack a "brain" but slime molds are able to perform incredible feats like finding the shortest path through a maze.
And strangely enough, the networks it builds resemble the web that gravity makes in shaping the universe, linking galaxies and clusters of galaxies along invisible bridges, hundreds of millions of light-years long.
The cosmic web consists largely of dark matter and is laced with gas. Astronomers have struggled to find the strands of the web, given the gas is so dim and difficult to detect. That's why they turned to the humble slime mold. Using a computer algorithm inspired by slime mold behavior, they're able to build a map of the filaments in the universe within 500 million light-years from Earth.
Researchers tested the algorithm against a computer simulation of the growth of dark matter filaments in the universe. Applying the algorithm to data containing the positions of 37,000 galaxies, they were able to simulate a 3D map of the underlying cosmic web structure.
It's a lot more complex than just writing an algorithm, however. Scientists then analyzed the ultraviolet light from 350 quasars documented in the Hubble Spectroscopic Legacy Archive. Using the quasars — extremely bright and remote black holes — researchers were able to light up the cosmic web, seeing the gas that makes it up.
"It's really fascinating that one of the simplest forms of life actually enables insight into the very largest-scale structures in the universe," lead researcher Joseph Burchett of the University of California, Santa Cruz, said in the release. "By using the slime-mold simulation to find the location of the cosmic web filaments, including those far from galaxies, we could then use the Hubble Space Telescope's archival data to detect and determine the density of the cool gas on the very outskirts of those invisible filaments. Scientists have detected signatures of this gas for several decades, and we have proven the theoretical expectation that this gas comprises the cosmic web."
The survey supports research that denser sections of intergalactic gas is grouped into filaments that extend over 10 million light-years from galaxies.