What's the biggest thing you can think of? At the limits of my imagination, really pushing my understanding, I can get as far as a large village or a small town.

I mean, really feel the size. I figure my local village is about 100,000 times larger than me in each direction. Visualising myself in that kind of space; really feeling that kind of size, it certainly seems like the maximum size I can sensibly conceive of is about a million times the size of myself.

1mm in 1km kind of makes sense (I can see them on the same scale). 1mm in 1000 km, not a chance. There's a limit of understanding there. 1:1000,000 roughly. So what I want to know is:

  1. Is this true?
    Do you have a scale limit of 1 in a million?
  2. Is it physical?
    Imagine something that is a million times longer than it is wide. Is that the limit you can actually see? Any longer, would it be invisible at the ends? Any narrower, would it be too thin to see? Is the limit of our understanding the same as the diffraction limit at our eye? If our eye were different, could we then perceive larger scales? If our eye were different, would it in fact see larger scales (perhaps it couldn't)?
  3. Is it lack of experience?
    Perhaps it's because if things differ in size that much, we've never needed to interact with them concurrently. You don't regard a grain of sand when building a pyramid; you interact with a mass of sand.
  4. Nature or nurture?
    If it is|was just experience, has that now become part of us? Is our brain incapable of regarding larger scales now? Has our eye not needed to become capable because we've never needed it to? Or is it just us, and we can train ourselves to understand?

So many questions. Enlighten me, or just tell me what the biggest thing you can think of is.