Also called PM2.5 or particulate matter pollution, it’s the mix of solid and liquid droplets floating in the air, according to ... problems and a variety of heart problems.

Tucked in the basement of the Mayo Building on the University of Minnesota’s Twin Cities campus sits a detached, beating pig’s heart floating in clear liquid. Graduate and undergraduate students ...

Pasteur was on a hunt, he later wrote, for “the floating germs of the air.” For this 1885 portrait, Pasteur posed with a rabies-infected piece of rabbit tissue that he was using to develop a ...