Can dogs smell time?

Anyone with a dog knows that they can tell time—but how? Alexandra Horowitz is a professor and Senior Research Fellow at Barnard College with a PhD in Cognitive Science. She runs Barnard's Dog Cognition Lab, which studies what it is like to be a dog. It also sounds like an extremely cool place to work. Horowitz proposes that dogs tell time using their noses.

In her book Being a Dog: Following the Dog Into a World of Smell, she writes:

As each day wears a new smell, its hours mark changes in odors that your dog can notice. Dogs smell time. The past is underfoot; the odors of yesterday have come to rest on the ground. Carried by the morning's first breath or sloughed off the backs of nighttime animals, the message lies on the doorstep with the folded newspaper. The odor of the future is carried from around the corner, reaching the dog's nostrils before reaching our eyes. Smell rubber-bands time for dogs, pulling some of the past and future into the now.

Unfortunately, Horowitz and the Dog Cognition Lab have not tested this theory experimentally, which seems like an enormous oversight. However, for the documentary series Inside the Animal Mind, the BBC did a very unscientific test that is nonetheless worth watching.

Here is another fact that I learned from Horowitz's book, which is not related to telling time but needs to be shared:

Dogs can use their nostrils separately and differentially: when sniffing something new and "nonaversive"—neutral or likeable odors—they begin with the right nostril, then switch to the left.

If a dog sniffs you with its right nostril, it is likely suspicious of you. However, maybe don't get close enough to a strange dog that you can tell which nostril it is using.

Previously: Japanese robot dog sniffs your feet and faints if they're smelly