Young children jump and twirl and play. An adult puts the baby they are carrying down for a moment. We can see their prints in the sand. This happens every day at the beach, right? Well apparently, it also happened 23,000 years ago in White Sands, New Mexico. The accepted theory was that humans didn’t make their way to the Americas until around 13,000 years ago—certainly no earlier than 16,000 years ago. Scientists may have to rethink the how and the when of our arrival. How do we know how old the footprints are? By grass seeds found in the same layers as the footprints. All living things absorb carbon while they are alive and once they die the carbon-14 decays at a measurable rate. The footprints themselves were never alive, of course. But the seeds were…and they’re talking.