Meet the 18-year-old Nikola Veselinov whose new mathematical theorem earned the top prize at the world's biggest student science fair While many science fair winners build robots, develop medical technologies or tackle climate challenges, one 18-year-old student from Bulgaria impressed judges with something far less visible but equally powerful: pure mathematics. Nikola Veselinov, a student at the Sofia High School of Mathematics, developed a new mathematical theorem that explains when certain equations cannot be solved using basic mathematical functions. His research earned him the prestigious $75,000 Regeneron Young...