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Look around. An electric light is probably on in the room. Perhaps the space contains a chair or a desk. Maybe there’s a laptop or tablet in view.
If you’re at home in the kitchen, you may see a box of juice on the counter. If the TV is on, you might see images and hear voices or music. Most of us take these things for granted. But all these things — each of them — is the solution to a problem and the end product of the engineering process.