In a new investigation into secret IRS documents, ProPublica reveals how American billionaires manage to pay little or no income tax — without breaking the law.

For months now, some scientists have been calling attention to the once-controversial idea that the coronavirus originated in a laboratory. Vox lays out what we know and don't about the lab-leak theory.

The growth of for-profit medical schools is raising questions about how the U.S. will train its next generation of doctors. NPR looks at the issue.

National Geographic's cartographers say they now recognize a fifth ocean: the Southern Ocean, which encircles Antarctica.