Our PLANET is mind-numbingly big. If you don’t believe me go to the grand canyon and look down. Did I say go to the grand canyon? Make that HIKE to the grand canyon from yellowstone national park. Still not convinced? ROW across the ocean to china. Bonus points if you can hit Japan without a gps.
So in a twisted sort of sense, the milky-way galaxy is less mind-bogglingly big, because our [or at least my] built-in distance-comprehension hardware shorts out so quickly when attempting to deal with the milky way galaxy we don't really even notice it and so we switch to rigorous numbers which do not have this short-circuiting problem.
I think that shorting out effect is what is meant by "mind-bogglingly".
People have walked from yellowstone to the grand canyon. I couldn't do it myself, but I can read their accounts and understand them.
Earth is big, but our minds are amazed, not boggled. It's with the galaxy that we just start thinking "system error".
Another month has passed and here is a new rationality quotes thread. The usual rules are: