In 19th-century France, the young chemist challenged the theory of spontaneous generation and discovered an invisible world of airborne microbes. Credit...Antoine Maillard Supported by By Carl Zimmer ...

Unlike germs, however, it can be seen under a blacklight, enabling Rober to track how it spreads through his day-long experiment in a classroom. The teacher was doused with the invisible powder prior ...

In order to demonstrate the importance of practicing good hygiene and help prevent the spread of <a href="https://www.menshealth.com/health/a31158940/coronavirus ...