Nuclear energy can power entire cities—or destroy them. Despite the risks, it is now considered one of the safest forms of energy and plays a vital role in the fight against climate change, as it is virtually carbon-free. Disasters such as those at Chernobyl, Fukushima Daiichi, and Three Mile Island continue to shape public perception to this day. However, crucial lessons have been learned from these incidents: modern plants are now considered significantly safer. Researchers are also working toward the vision of nuclear fusion—a potentially even safer and nearly unlimited source of energy.