He couldn’t see any of them, but he knew there was a bustling electric world below his feet. “It was a moment I can still close my eyes and go back to,” he tells me. “It was the most amazing experience I’ve ever had, and I’m so sad I’m not there right now.”

As the writer Marcel Proust once said, “The only true voyage…would be not to visit strange lands but to possess other eyes…to see the hundred universes that each of them sees.”

He reminds us that seeing more colors isn’t advantageous in and of itself. Colors are not inherently magical. They become magical when and if animals derive meaning from them. Some are special to us because, having inherited the ability to see them from our trichromatic ancestors, we imbued them with social significance. Conversely, there are color

We have used technology to make the invisible visible and the inaudible audible. This ability to dip into other Umwelten is our greatest sensory skill.

In the three-dimensional world of the deep ocean, above and below matter as much as in front and behind.

Nagel wrote. “Yet if I try to imagine this, I am restricted to the resources of my own mind, and those resources are inadequate to the task.”

Distinguishing self from other isn’t a given; it’s a difficult problem that nervous systems have to solve. “This is largely what sentience is,” neuroscientist Michael Hendricks tells me. “And perhaps it’s why sentience is: It’s the process of sorting perceptual experiences into self-generated and other-generated.”

I’m reminded of Hamlet’s plea to Horatio that “there are more things in heaven and Earth…than are dreamt of in your philosophy.” The quote is often taken as an appeal to embrace the supernatural. I see it rather as a call to better understand the natural.

The senses transform the coursing chaos of the world into perceptions and experiences—things we can react to and act upon. They allow biology to tame physics. They turn stimuli into information. They pull relevance from randomness, and weave meaning from miscellany. They connect animals to their surroundings. And they connect animals to each other