Not simply nothing, dark matter searches near ‘neutrino fog’

Dark Matter and its Role
• Dark matter, the invisible part of the universe, makes up most of the mass.
• It is the simplest contender for the make-up of dark matter, which doesn’t interact with photons and lives for at least 14 billion years.
• The question is whether dark matter ever touches us, or if atomic nuclei and electrons scatter dark matter particles when they come close.

A Sail to Catch the Wind
• In 1985, physicists Mark Goodman and Ed Witten proposed a new strategy to measure the unknown mass of the dark particle and the unknown rate at which atomic nuclei scatter dark matter particles.
• The goal of the experiment was to measure two quantities: the unknown mass of the dark particle and the unknown rate at which atomic nuclei scatter dark matter particles.

‘The Neutrino Fog’
• Scientists have ruled out dark matter-nucleus cross sections of 10-44 cm2, a million times smaller than the GW limit.
• Future detectors will also register much more noise from the scatters of other ghostly particles, especially neutrinos forged in the Sun’s interior and in the earth’s atmosphere.

Every Last Drop
• Scientists are actively pursuing other avenues of research, such as detecting dark particles that are lighter than atomic nuclei.
• The hunt for dark matter unites many talents, drawing every last drop of human ingenuity.