Valentina De Romeri

At the center of a galaxy, gravity condenses dark matter into a dense 'spike.' Such a dark spike resembles a funnel of invisible particles around a massive body. But if both the center and the particles are primordial black holes, the picture breaks down.

Solar neutrinos are tiny particles born in the Sun's core by the trillions every second. They pass through Earth almost without noticing it, and for a long time they were considered absolutely stable. But perhaps they too can "age"—decaying imperceptibly, vanishing on their way to us.