On more than one occasion, Rocky makes an observation like this to Ryland: “You face is leaking.” 25.259 The first time this occurs, Ryland explains that it is a “human thing.” 25.259

It makes sense from a biological standpoint that Eridians would not be familiar with the concept of crying. We know that they obtain all their water needs from food (see #205) so they may, like many terrestrial desert-dwelling organisms, conserve as much water as possible. Eridian bodies are almost always completely closed to the outside environment (see #196), so any opening to release tears might become a vulnerability.

There are three distinct types of tears found in leaky space blobs such as ourselves:

• Basal tears, ever-present for lubricating our eyes
• Reflex tears, for removal of irritants
• Emotional tears, in response to various emotions

Humans appear to be the only organisms who cry emotional tears, though there remains much research to be done on the neurobiology of this unique behaviour.

As humans who were deeply impacted by this novel, we also agree on a personal level that face-leaking is a distinctly human thing.