After decades of wondering, an NPR reporter finally figures out how her husband's family dog knew when the school bus would arrive every day. She did some digging — and now it all makes scents.

The appeal of pumpkin spice has a lot to do with how we associate smells and flavors with fall — despite the fact that the flavoring doesn't contain any actual pumpkin.

Using machine learning and artificial intelligence, researchers hope to document — and later recreate — historical scents and smell-scapes from as far back as the 16th century.