An example of the use of metaphor (and rhetoric) in popular science writing:
"Stars are born in groups. This is pretty obvious from what I have already said, because you wouldn't expect the large-scale eddies and clouds that form within the interstellar gas to end in the making of just one single solitary star. Rather do the clouds break up into into a shower of individual condensations, each one becoming a star.
Fred Hoyle (1960) The Nature of the Universe (Revised ed.), 1960
I must emphasis that the whole process is going on all the time. With binoculars you can find lots of these star showers lying along the bright band of the Milky Way. Many hundreds of stars have been born during the last million years within the great gas cloud in the constellation of Orion."
There are a number of terms being used metaphorically here.
Read about metaphor in science
Read about examples of science metaphors
Many examples of science metaphors are listed in 'Creative comparisons: Making science familiar through language. An illustrative catalogue of figurative comparisons and analogies for science concepts'. Free Download.
Hoyle does not here offer a strong argument for why stars form in groups, but rather suggests (a) it follows from previous text (presumably the slight variations in gas density) and that (b) this should be obvious enough for a reader to have anticipated it (subtext – you must be pretty dumb if you are not following?) He emphasises how obviously unlikely it would be a for only one star to form by tripling the counting (one, single, solitary star), and using the qualifier 'just' to suggest something exceptional.
