First, many people who are blind still have some usable vision. So, although I’m blind, I can still see the moon to verify it’s existence.

Second, we live in a sighted world, and are well aware that sighted people see more than us. So if all the sighted people I know and trust talk about seeing the moon, I can be reasonably confident that the moon is there. I’m not seeing it firsthand, true, but have enough consistent secondhand accounts to take it as true.

Otherwise, we take plenty of things as true that we can’t verify with our own senses. The roundness of the Earth. The existence of bacteria, DNA, molecules and other tiny tiny things. The existence of other galaxies. All of these, we have verified through experimentation and specialized equipment, and cannot experience with our unaided senses, but still take as true.

Sight is a concept we only have vague notions of in a certain sense. I personally know what bright lights look like to my eyes, but that was due to a set of extraordinary circumstances when I got older and understood what it was supposed to be like from a scientific point of view only. I don't experience any of the details of that light and even if it's bright it appears very dim to me. At least I think. It's like how an astronaut can tell us how it feels to be weightless for an extended period of time, but because the rest of us have never had that experience, or anything like that, we just have to take what he said at face value. If we know he hasn't lied about something, or most astronauts can relate the same experience then we take that as truth. In the case of the moon and stars, we can never see them, and we also can't touch the light, but because the rest of the world has in depth knowledge of these things and everyone lying at the same time would be extremely improbable, we can come to the conclusion that the moon exists, however we don't have any knowledge of how these things look over the planet. We just have knowledge from other sources. so let's say we had to give an exact description of things like that. We might get a few details wrong or have it positioned in the wrong way. As kids we generally try and get as much informational and descriptive knowledge as we can to fill in the gaps, but it's definitely not enough to give a clear and accurate picture since we lack the fundamental knowledge to form it. One of my favorite books as a kid was a book called "Touch the Stars" it had as a forward, a discription of what the sky looked like. That was new knowledge to me. Also something that hasn't been talked about much is that representations can help fill in the gap a bit as well and generally are used so that someone can experience, for example, what the phases of the moon look like in the sky, but because they are representations they have limited usefulness because they are not the real thing. I will give one more example. Let's say you have a representation of a duck, but the duck is in profile, and the duck you're feeling is just molded plastic. There will be some details you can get from the duck, but others will be wrong and not something found on a real duck. So until you get to feel a real duck, the thing that get's conjured in your mind is the plastic duck and the sound of a duck because you've heard that before. That's what it's like in our world. If sighted people didn't exist, there would be things the world wouldn't have figured out as easily. Things get even more crazy if you take the scale of some things into account. For example, I have never climed a tree or felt a fallen one, so I have know knowledge of how the branches feel when they are still on the tree, and have little knowledge of how the trunk changes to accomodate them. I am not taking the risk of climbing up the tree to find out either. So that knowledge is something I won't have for the foreseeable future. It's the same for the sun and moon. I can feel the affects that both have on the Earth with the sun's heat warming my area and when it sets the area cools down but I have know way to imagine what a sunset looks like. That doesn't mean I don't have an image for it, but it's not sight. It's just imaginary and not accurate. I also strugle with imagining parts of a scene that I wouldn't be able to touch in reality, so like a house will be small so I can touch every part of it and if it isn't, the tactile sensation of the part I can't reach isn't there and the image is vague. Even sound and smell generally are within arms reach unless I force myself to try imagining things to scale. Even that is never successful. Sorry for the lon post but I wanted to try and explain things in a way that would help you explain this idea we've all been hitting on better in your book, because I don't think it's exactly like the scientists thing. They have photos and magnification. We don't even get that luxury, so it's more like how some people convert to a different religion. Someone explained something in a way that fills in a gap in knowledge and it fits, so you accept it as truth due to overwhelming evidence.

Much of science has to be taken on faith. It's strange using those two words together, considering faith and science are often at odds, but it's true.

A bit of perspective here - human beings can't see much. We perceive the vibration frequencies of photons reflected off of surfaces as colors and forget how little we're seeing. Nearly all of the Universe is dark. Photon density in the Universe is estimated at less than 1 per cubic meter. Any particle that vibrates at a wavelength greater than 750 nanometers or less than 350 nanometers is invisible to us. We can't see radio waves, microwaves, x-ray, gamma ray, infrared, or ultraviolet wavelengths. The visible spectrum is far less than 1% of the entire electromagnetic spectrum. Then, just to make it worse, half of everything is hidden behind our own heads and outside our field of vision.

Human beings are lousy cosmic observers. Almost anything outside of this little blue rock we call Earth is imperceptible to us. We evolved here and developed eyesight well suited to living here, but we specialized in adequately seeing the visible spectrum at the expense of seeing the rest of the electromagnetic spectrum.

Even those of us with the sharpest eyesight are still limited in what we can see.

I've read that human beings actually glow in the dark, but human eyesight is about 30 times too weak to see it. The article said cats can see our glow. It makes sense - they evolved from nocturnal hunters.

Back to the question.

I've never seen Iceland but I know it exists. I've never seen gravity. I've never seen electrons, oxygen, or the molten iron core at the center of the Earth. But that's okay. I know gravity exists every time I drop a brick and it falls down instead of up. I know electrons exist every time I flip the fan switch on. I know oxygen exists when I hold my breath until I experience the effects of oxygen deprivation. And I know the iron core is there because shock waves travel through molten iron at a certain speed, and an earthquake that happens in the Indian ocean is detected by sensors around the world after precisely enough time has passed for the shock wave to travel through molten iron and no other material.

Science includes inference, and inference requires faith. I have to have faith the engineers aren't lying to me when they say shock waves travel through different mediums at different speeds. I have to have faith the clocks at the seismographic stations around the world are accurate. I have to have faith the world isn't flat. I can't personally see any of this but I don't have to to believe it. Airplanes fly through air nobody can see, elevators go up and down on cables passengers don't see, the color of a girl's eyes is determined by genes she can't see.

My point is blindness isn't a barrier to accepting science because vision isn't a requirement to believing science.

When I was a kid, my mom used to take me outside and have me show her where the heat of the sun was on my body. This was to teach me that the sun moves across the sky. I have no way of experienceing what the moon and stars look like, so I have to rely on people's word on there existence.

I only use color as something to describe things to sighted people. For example, I might tell someone the color of a car if I am looking for a ride.

The one big thing my parents taught me, was that when I turn while standing in a room, the room does not room with me. I have met some totally blind people who do not understand this. If they are in the middle of a room, they can actually lose track of themselves in space. It is hard to explain, but I have watched someone walk across a room and drift towards the right edge and run in to the wall.

The thing that helped me with the scale of objects growing up was books. My mom started reading to me before I was two, and when i got older, I continued to read everything I could get my hands on. Today, I still prefer a good book to a movie.

u/Tarnagona Has covered it, really. I've never had usable vision, but just as I was able to hear higher frequency sounds as a child that I can no longer perceive as an older adult, or as personal experimentation has proved to my own satisfaction that wireless communication is real, I just have to take it as read that things are out there beyond my sensorium. I really struggled with some concepts as a child. The sun made sense, because I could feel its heat. But the sun being obscured by a cloud was a trickier one (the lack of sunshine doesn't necessarily imply a cloud, after all).

To this day, colours are just arbitrary labels people put on things which hold very little relevance to me, in the same sort of way I might choose to buy a specific weight of meat to feed the family, I will elect to pair up specific colours to ensure my clothes match.

So I was blind from birth and I don't often think about sight I just take it as granted that I won't understand it. But I imagine it's just like any other sense that there's the looking component and that's similar to hearing, smelling, touching tasting, and then there's the staring seeing component and that's similar to listening, feeling, sniffing, savouring. What I mean is that there's a passive part and an active part.

"existance of moon"

Because we import cheese from there.