The world is obviously quite complicated, often almost hopelessly so.
If you want to understand how things work, you look for patterns. You find many classes of such patterns—some involving complex interactions behind the scenes.
Ask where ice cream comes from. One child will explain the pattern he has found: put 3 quarters in a vending machine and an ice cream cup falls into a tray at the bottom.
That answer may not entirely satisfy you. If you dissect the vending machine you find a finite stack of ice cream cups, and will discover that these need to be replenished.
The origin of the ice cream turns out to be a delivery truck. Or maybe not—on dissecting the truck and tracking its operation you find that the real origin is in a factory.
Dissect the factory and you find you have to start making some distinctions. What you choose to call ice cream has its origin in a vat—and it is made of other ingredients that are not ice cream themselves, and which come from elsewhere.
Looking closely into that vat you learn what mix of air and cream and sugar and flavorings and cold makes the ice cream.
Now you have an explanation that should satisfy you, and answer your initial question.
You can dissect further, but at the price of no longer talking exactly about ice cream. For example you can ask why fats congeal this way, and study that aspect of chemistry, or how the flavors effect the tongue, or how the textures effect the tongue, or how the cold effects the mouth. You could even try to learn if people have genetic predispositions to prefer one flavor over another.
All these represent aspects of ice cream, but no longer represent the totality of it. That doesn’t make them valueless--quite the contrary--but they are no longer big picture studies. Maybe they’ll help improve ice cream, but there’s work to be done putting the pieces together first.
Suppose we take a more traditional example from elementary physics class—the famous soporific inclined plane that trips up so many with its force decomposition diagrams.
Before you place the block on the slope you have to make sure of Rule 0:
"One of these days in your travels, a guy is going to show you a brand-new deck of cards on which the seal is not yet broken. Then this guy is going to offer to bet you that he can make the jack of spades jump out of this brand-new deck of cards and squirt cider in your ear. But, son, do not accept this bet, because as sure as you stand there, you're going to wind up with an ear full of cider."
Rule 0: Make sure nobody is doing something else with your apparatus. If you put a toy car on an inclined plane you don’t expect it to roll uphill—but it might. Think “wind-up car.” If somebody else has plans for your apparatus, you won’t be able to measure what you want to.
This means that you cannot directly study intentions with science. You have to exclude them as a complicating factor—you can’t do experiments unless the materials involved operate through their own motions with no human, angelic, or divine intervention. Or … “There's a story about a psychologist who was studying the intelligence of a chimpanzee. He led the chimp into a room full of toys, went out, closed the door and put his eye to the keyhole to see what the chimp was doing. He found himself gazing into a glittering interested brown eye only inches from his own. The chimp was looking through the keyhole to see what the psychologist was doing."
Interventions, motives, and goals are not part of the field of view of science by construction. Some careless folk claim that since science doesn’t study them, they don’t exist. Chess doesn’t include the concept of a full house, but poker exists anyway.
When you let the block slide down the slope to try to study gravity and force balancing, you try to keep friction to a minimum, air resistance to a minimum, and don’t use wheels. Once you understand sliding you can study friction; once you know both you can study rolling; once you understand those you can study friction in the axles; then go on to air resistance, and so on.
Study the properties of springs in isolation, of gears in isolation, and ratchets, and so on.
Once you understand these in isolation you can model their combinations, and try to understand the operation of a wind-up toy car. That’s the “integration” part of science and technology. The final system is very complex, but each of the dissected forces is easy enough to understand in isolation. The science lies in the dissection and modeling of the simple aspects. The engineering art lies in assembling these into a design.
Technologies take models—usually fairly high level models—and design ways to use these. Typically an engineer does not care about the crystal structure of a steel beam when he is designing a bridge—unless he cares about the limits of his model and what the effects of metal fatigue and creep are likely to be. Then he does need a deeper, more fundamental, model of matter.
A structural engineer won’t need to worry about quantum effects, but an electronics engineer probably will, if only to understand the limits of his tools.
Remember—you don’t understand your measurement until you understand the limits of your measurement.