How do stars actually shine—and could one ever burn out like a lightbulb? In this episode of Explain It Like I’m 5, Alex breaks down the science of stars in fun, simple language. We explore what a star really is (a massive sphere of hot plasma), how gravity forms stars from huge clouds of gas and dust, and how nuclear fusion in the core powers them for billions of years.

You’ll learn how hydrogen fuses into helium, why Einstein’s E = mc² explains the enormous energy stars produce, and how a delicate balance between gravity and fusion pressure (hydrostatic equilibrium) keeps stars from collapsing or exploding—at least for a while. We walk through the life cycle of a star, from protostar to main sequence, then to red giant, and finally to white dwarf, neutron star, or black hole, depending on its mass.

The episode also highlights different types of stars (red dwarfs, blue giants, binary systems, neutron stars, black holes), cool facts about our own Sun, and how stars create the elements in our bodies, meaning we are literally made of stardust. Along the way, Alex touches on how stars shaped navigation, mythology, and culture, and explains why stars can’t shine forever, even though some will outlive the universe as we know it. By the end, every “twinkling dot” in the sky becomes a powerful cosmic nuclear engine sending you a postcard from across time and space.