A dying star is like a high-rise building collapsing in on itself. The core compresses to unimaginable density, while the outer layers fall onto it at speeds of tens of thousands of kilometers per second. At that moment, neutrinos are born — particles that barely notice ordinary matter and carry energy away. But sometimes they don't just fly off; they interfere with the course of the explosion.
Neutrinos come in different types, and in the dense core they start rapidly transforming into one another. This process is like a crowd suddenly changing direction: some energy stays in the center and heats up the infalling matter. For some stars, such heating is a lifesaver: the explosion gains strength and blows the star apart. For others, it's the opposite — neutrinos carry away too much energy, and the explosion fizzles out.
Scientists tested this on computer models of stars of different masses. It turned out that for the lightest star, neutrino transformations accelerate the explosion and make it more powerful. For heavier ones, they slow it down. And the key parameter here is the rate of matter falling onto the core. When it's low, neutrinos heat the matter more efficiently because they become "harder"—like water that boils at a higher temperature. When the rate is high, that gain is more than offset by losses.
So tiny ghost particles, which pass through Earth every second, turn out to be the conductors of the most powerful explosions in the universe. And without them, the starry sky would look very different.
Neutrinos interact so weakly with matter that they can travel through a light-year of lead without hitting a single atom.
In Stanisław Lem's novel "Solaris," the planet's ocean communicates with humans via neutrinos — particles that are nearly impossible to catch.