You Are in the Middle of a Borderless Nothingness
Push your attention to the very edge of what you can see and try to find where it ends. Vision, sound and even space have no border you can touch. The edges meet nothingness.
You are in the middle of a borderless nothingness. Let me show you.
Keep your eyes on these words. Without moving them, notice your hand... now the wall behind the screen.
Now push your attention out, to the very edge of what you can see. Find where it ends.
Is there a line? A frame? A black border?
There isn't. The colours don't stop at an edge. They merge into nothingness, and since we're talking about colour, we can call it the colourless. You can never point to where it begins. You're inside a screen of your own, and it has no border.
And behind your head? It isn't black. It's colourless. You can't see from your elbow, and you can't even imagine what that would look like.
The edge of sound
Now try it with sound. Hum, "Aaaaah", and listen for where it ends.
It doesn't hit a wall of silence. There's no place where the sound stops and the soundless begins. And even the "Aaah" itself has a boundary, just like your vision. Yet you never find where it ends.
Space is just another experience
So if every experience has a border that touches nothingness, each in its own dimension, then where is everything?
We say: in space. But space is just another experience, like sight, or sound, or smell. We use it as a place to hold everything together, so these borderless experiences make sense.
So try this. You may be inside a room, but you can still sense the space behind the wall in front of you. Let your attention go out into it. Just like at the corner of your eyes, there's no border it can touch. Space itself is an edgeless nothingness. Only the feeling of a solid world out there keeps us from noticing.
Edges everywhere
And once you see it, edges get strange everywhere. What came before the Big Bang? What letter comes before A, or after Z? What was the very last moment you felt, before you fell asleep?
Every time you go looking for the edge, you find the same thing.
The edges are mysterious, because they meet nothingness.