On a rooftop outside Madrid, Spanish researchers have demonstrated that a carefully engineered polymer can shed heat into the cold of space without consuming a single watt of electricity, exploiting a narrow window in Earth's atmosphere where infrared radiation escapes freely. The work, emerging from CSIC's Institute of Micro and Nanotechnology, addresses one of modernity's quiet burdens: the roughly one-fifth of global electricity devoted to keeping things cool. In a world where rising temperatures make air conditioning ever less optional, this material offers a rare kind of answer — one draw