I was asked for
thoughts on BIG things (though i'm not sure which big things)
See, this is actually quite an interesting question. What actually is a big thing? Let's start with an easier question, and think what isn't a big thing. An electron is not a big thing. It's sufficiently small that it doesn't even have a size, because it's too effected by quantum doodahs. An electron is tiny.
So then we move up the scale, and we see an atom. Now, most people would say that an atom is fairly small, and yet it's many thousands of times bigger than an electron. If I were an electron then an atom would seem like a very big thing indeed.
And then we go many thousands of times larger again and we see a cell. Or rather, we don't see a cell, because it's still too small to be seen unaided by the human eye. But if you're a chemist, then a cell is huge. It contains a vast array of chemical reactions far too complex to accurately track. A cell may be tiny, but a cell is big too.
Bigger still and we get to people. On a human scale, a person is neither particularly big or particularly small. In fact, on a human scale, an average human is approximately one human high. We are our own frame of reference. And while some of us may be 4'11" and some of us may be 6'8", we are all approximately the same size, which, when we come down to it, isn't all that big.
So let's go larger still and consider London. London is big. Unless you happen to be a stereotypical American tourist, you will realise that thewre is more to see and do in London than could possibly be achieved in a single human lifetime. That counts as big, right?
Well not really, because on a global scale London is little more than peanuts. Zoom out so that you see the whole of Britain, and London really only covers a fairly small speck of it, and then when you realise that Britain is just a miniscule little island, that could quite easily go unnoticed by anyone looking at a globe, you realise that the earth is truly vast.
Then consider the galaxy. Or rather, don't consider the galaxy, because it's so stupidly huge as to be beyond human comprehension. Imagine a map of the galaxy the size of the room that you're in now. Then imagine that you set out across the galaxy at light speed, travelling for the rest of your life, and a line of your progress was drawn on the map. By the time you die, your line probably wouldn't even be visible, or if it was it would be very short indeed.
Then beyond the galaxy is the rest of the universe. The size of the universe is so incomprehensible, that I can't even comprehend just how incomprehensible it is. It makes the galaxy look like a walk to the post office. It's big.
And then, depending on what sort of theology or cosmology you subscribe to, there may be gods, or there may be an entire multiverse. Needless to say, that anything bigger than the universe is going to leave people dribbling and babbling incoherently if we try to think about them for too long.
So the question is, which of these things can actually be called "big". The answer, of course, is all of them. That a universe exists at all is quite incredible. That its physical constants are finely tuned to allow atoms to exist is amazing. That these atoms can come together to form cells, to form people, to build London are all incredible facts. Thinking about the atom for a minute will blow your mind just as much as thinking about the universe. Size really doesn't matter.