I keep experimenting with different approaches to building and expanding the knowledge base, because no one of them works all the time. I had about given up on a bottom-up approach, but I thought I'd give it another try.
There is a lot to be said for simple appreciation of nature. Going for a walk outdoors, seeking the sky clouds, sun, moon (if it's up), trees, grass, birds, bugs, and small animals, the breeze... All these are ways of experiencing and appreciating nature. Every day, even every hour, brings its own new experiences. All the various parts and facets of nature seem to be woven together, almost in one seamless web., and this overall, or holistic view, is an important part of understanding and appreciating nature.
But, for the purposes of science, it's necessary to focus on one thing at a time, and by convention it's useful to group things that are similar in some way together. The trees, grass, birds, bugs, and small animals, we recognize as living things. Even the sticks of wood that have fallen from the trees, we recognize as once having been living, and for a time we focus on them and call the subject biology.
The ground we walk on, the clouds, the breeze, and any streams that may happen to be flowing nearby, we recognize as nonliving, and are part of earth science.
The sun and moon belong to astronomy.
There are two more branches of science, which are less obvious: The substances things are made of is considered as part of chemistry, and heat and warmth, and light and darkness, and sound are considered to belong to physics.
What's often missing in education is the ability, once we have isolated and analyzed all these things and taken them apart, is bringing them back together and appreciating the whole.
Also, there is the fact that the study of nature is a human activity, performed by people, acting in society. The tools, ideas, and occupations that scientists use and follow, the social institutions, the communities and peoples that produce them, and the history of the whole scientific enterprise are also connected, so that the whole can be overwhelming to contemplate. So, I go back to looking at one small piece at a time.