I personally think the similarity between a neuron and the universe is coincidental, but the picture was relevant to what OP asked. As for god, nope, no invisible sky fairy to be found.
I believe it is entirely possible entire worlds exist on micro and macro scales, however they won't exist like our world. I don't believe we are "atoms" of giant humans... that's just silly -Yuri
The visible spectrum can only show so much to the naked eye. The flesh is the boundary of our body, so why not the crust the boundary to the earth? Scales are relevant to the viewer but objective insight is all in the mind.
Even within our current understanding of life there are vast differences that size has on the way an organism is able to adapt and survive. For instance humans and tiny insects have much different physiological workings (think an ant lifting many many times its body weight) And there are even more differences between humans and microbial life - some microbes we are still discovering today. That being said, an organism operating on an astronomical scale would be so radically different from any life on earth that we'd struggle to recognize it if we had a way of detecting it... Which is why some people will say this idea is silly or unimaginative. In my opinion I think people are just trying to express the feeling that they are a part of something bigger, and I agree with that notion in that we are apart of the universe, which as a combination of living things is an organism in its own way regardless. What's unique to me is how many people can come to a similar independent thought.. Sent from my iPhone using Tapatalk
That might be a 4th (another) dimension, where size doesn't matter (or it might be out of illusionary dimensions we perceive (space and time)) . You can be as big or as small as anything. The size is curved like the Earth is round. It doesn't have an end. We humans are just out of this dimension and cant perceive it. So we see big objects and small objects. But these are paradoxes. What is the smallest thing or what is the biggest thing. As long as we have math and can divide and multiply on paper, we wont find the biggest and the smallest particle or whatever. So, may be, the question was asked the wrong way or we just out of the zone of understanding it. 8)