An example of a teaching analogy:
"According to the Quantum Theory, an electromagnetic wave guides a flow of energy which is transported along the wave in bundles (photons) of size hf. A simplified view of the situation would be to say that if a wave was represented by a group of people marching in a line, the photons would be analogous to the backpack each person was wearing, and each of which contained a particular amount of material. This analogy could be extended to say that older, more energetic adults would carry a greater load in their backpacks than would children."
Source: Murray Hart, retired science teacher, previously posted at scienceanalogies.com
Read examples of scientific analogies
Many examples of science analogies are listed in 'Creative comparisons: Making science familiar through language. An illustrative catalogue of figurative comparisons and analogies for science concepts'. Free Download.