New Delhi—The most widely discussed talk at the Indian Science Congress, a government-funded annual jamboree held in Jalandhar in January, wasn't about space exploration or information technology, areas in which India has made rapid progress. Instead, the talk celebrated a story in the Hindu epic Mahabharata about a woman who gave birth to 100 children, citing it as evidence that India's ancient Hindu civilization had developed advanced reproductive technologies. Just as surprising as the claim was the distinguished pedigree of the scientist who made it: chemist G. Nageshwar Rao, vice-chancellor of Andhra University in Visakhapatnam. "Stem cell research was done in this country thousands of years ago," Rao said.

His talk was widely met with ridicule. But Rao is hardly the only Indian scientist to make such claims. In recent years, "experts" have said ancient Indians had spacecraft, the internet, and nuclear weapons—long before Western science came on the scene.

Such claims and other forms of pseudoscience rooted in Hindu nationalism have been on the rise since Prime Minister Narendra Modi came to power in 2014. They're not just an embarrassment, some researchers say, but a threat to science and education that stifles critical thinking and could hamper India's development. "Modi has initiated what may be called ‘Project Assault on Scientific Rationality,’" says Gauhar Raza, former chief scientist at the Council of Scientific and Industrial Research (CSIR) here, a conglomerate of almost 40 national labs. "A religio-mythical culture is being propagated in the country's scientific institutions aggressively."