DARK MATTER by Benjamin Skuse Axion The search for an almost invisible and wholly hypothetical elementary particle is on! D ark matter: It's the elephant in the astrophysical room. Astronomers think it makes up about 84% of all the mass in the universe. And they're bending over backwards to find it. "Some days I'm doing pencil-and-paper theory, other days it's simulations, and still others I'm analyzing astrophysical or laboratory data," muses Benjamin Safdi (University of Michigan). "To be honest, I'm not completely sure how to classify researchers like myself . . . perhaps 'dark matter hunters' is an appropriate term." 16 JANUARY 2 021 * SK Y & TELESCOPE Safdi and others like him are unusual in the physics community, where experts rarely straddle the boundaries between experimental, observational, and theoretical research. But their "Renaissance man" approach is born out of necessity: Decades of expensive and drawn-out experiments have come up empty, so scientists need creative new ideas for directly detecting dark matter. For some, this means building more complicated and sensitive lab experiments and space-based searches in a last-ditch attempt to discover the most popular dark matter GOLDEN WIND / SHUT TERSTOCK.COM Huntershttp://www.SHUTTERSTOCK.COM