November 28, 2013
Non-Astronomy Scientists May Help Answer Cosmology Conundrum
April Flowers for redOrbit.com - Your Universe Online
Measuring the invisible and intangible is a challenge for sure, but scientists have made inroads on one front: the study of dark matter and dark energy, two of the most mysterious substances in the cosmos.
Although dark matter is intermixed with normal matter, it gives off no light, making it impossible to see. Dark energy presents even more challenges, yet researchers believe it works against gravity to pull our universe apart at the seams.
In order to find and develop better tools for investigating dark energy and dark matter, an innovative competition has begun for the third time. The GRavitational lEnsing Accuracy Testing 3 (GREAT3) event is sponsored by NASA's Jet Propulsion Laboratory (JPL) and a European Union Network of Excellence called Pattern Analysis, Statistical Modeling and Computation Learning 2 (PASCAL2).
The challenge is designed to spur scientists, including those outside the field of astronomy, to develop new insight into the problems of measuring dark matter and dark energy. Using millions of images from NASA's Hubble Space Telescope, the contestants are asked to solve galaxy puzzles that could lead to a better understanding of the "dark side of the cosmos." These insights may reveal new information about the very fabric and fate of our universe.
The first two challenges were successful. They attracted new researchers to the field from disciplines as diverse as particle physics and machine learning -- which involves programming computers to learn on their own using actual data from the real world. Machine learning has several important applications, such as facial-recognition software, medical diagnostics and spam filtering, to name a few.
"Other data scientists have been thinking about the same type of algorithms we need for our cosmology tools for a long time," said Jason Rhodes of JPL. "We want to acquire that knowledge and see this field grow."
Currently, one of the most powerful tools for studying dark matter and dark energy is gravitational lensing. Gravity from dark matter can warp the light of a distant galaxy when the dark matter lies between us and the galaxy. Scientists map dark matter, despite its invisibility, by measuring the warping of that light. They are also able to get a better handle on dark energy and how it battles gravity to slow the growth of galactic structures by looking at the distribution of dark and normal matter in the universe.
Some galaxies appear "wacky," or as if they were being viewed through a funhouse mirror in gravitational lensing. They might also appear multiple times. These anomalies are called strong lensing. In the majority of cases, called weak lensing, the warping effects are tiny and impossible to see by eye.
Improved methods for measuring weak lensing in preparation for future dark matter/dark energy missions, such as the European Space Agency's Euclid, in which NASA plays an important role, and the National Academy of Science's highest priority for NASA, WFIRST -- also known as the WFIRST-AFTA mission, which stands for Wide-Field Infrared Survey Telescope-Astrophysics Focused Telescope Assets, are the aim of the GREAT3 challenge.
The millions of Hubble images available to the contestants show galaxies that have been artificially warped via weak lensing. The participants are asked to figure out precisely how the galaxy images were warped. This complex task involves pattern recognition and sifting out the effects of artificial warping caused by telescope optics and the atmosphere.
The winner, announced in May 2014, will receive computing equipment worth $3,000 -- the perfect gift for programmers hoping to crack more cosmic codes.
"With these contests, we have seen new ideas seeping into our field," said Rachel Mandelbaum of Carnegie Mellon University, Pittsburgh, who is working with Rhodes and Barnaby Rowe of UCL (University College London), England, to organize the challenge, along with a special committee. "It's a fun problem to work on and it's a problem that needs to be solved."
How would you fare in such a contest? NASA has put a visual quiz online involving lensed, or warped, galaxies to allow you to find out.