I’ve been thinking about the differences between Eridian Radar and human sight and the things that Rocky and Grace would find amazing about the other’s abilities.
Rocky’s radar is amazing because he can “see” through walls, he can “see” the insides of bodies, and his sense is full 360 degrees all the time, unlike eyes which have to be pointed a specific direction. He has a much better sense of space and can easily find hidden objects. When eridians “watch” each other sleep, it’s different from humans watching something because they don’t even have to be in the same room as someone in order to watch them. Rocky could be in the next room, working on stuff, and still have sleeping Grace fully within his scope of radar.
But human sight! Sure, we can only see the surface of things, and if the light goes out we’re useless. But!!! We can see things that are 2D. That’s crazy to Rocky, that we can see things that can’t be touched or heard. We can see color, which gives us a wealth of information about things that eridians are entirely unaware of. Grace explains that humans can walk through a forest full of thousands of textures and easily spot out edible fruit because it’s a bright color. And the distance on sight! It’s incredible. Grace explains the concept of lighthouses, and how one small light can guide ships from miles away through a deafening storm. No eridian could hear that far, and even if they could, the noise of the storm would drown it out. And then there are the stars. Humans can see stars!!! Erid only learned about stars recently but humans have known about them since the very beginning because they can just look up and see across the vastness of space with no technological help. They can see the other planets in their solar system. They can see their own star so powerfully that they can’t even look directly at it. No eridian can hear their own star. And when they’re in space, Rocky is totally blind because sound doesn’t travel through a vacuum - but light does! Grace can see just as well in space as on Earth!
Also, and this is a big one: humans can turn off sight. Grace doesn’t think it’s that cool, but Rocky explains that there’s no way to stop using radar. There’s no way to block out sound completely. Humans can cover their eyes and see nothing if they want to. No distractions, no stimulation. That’s amazing.
I also love the idea of Grace explaining the concept of “see-through” to Rocky and telling him about all the types of transparent materials earth has developed over the years. And there are naturally transparent materials, too! Rocky is very excited to learn that water is transparent.
God I just love the fact that Rocky is just as amazed at human biology as Grace is with Eridian biology.


















