A metaphor is a figure of speech used to suggests some similarity with a more familiar entity or feature:
- cells are cities buzzing with activity
- some comets are pilgrims
- some antiaromatic molecules have been tamed
- water voles are the missing Mars bar of the food chain
Cells are not cities; comets do not engage in pilgrimages; aromatic molecules were never wild and have not been tamed; and moles are not mars bars. But the author/speaker using these comparisons hopes to communicate something through the metaphor.
Read about metaphor in science
Some examples of metaphors in science
Metaphors can become so widely used that they are no longer figurative and so becomes accepted as the literal meanings (such as with 'charge' in electricity). These are referred to as dead metaphors (and a good deal of everyday language can be considered to comprise dead metaphors).
Terms that are used metaphorically within a specific area of activity (such as a scientific field) may become dead metaphors within the discourse of that domain, without being widely understood outside the domain. We might say these metaphors are phantoms – dead to the experts using them because the meaning has solidified through repeated conventional use, but seeming to still be meant metaphorical to someone who is not an expert in that domain.
Read 'Beware of phantom metaphors'
This is an issue for science communication, as the lexicons of scientific fields have many terms which were originality used as metaphors, but have in effect become technical terms – but which may be taken as everyday language (with its fluidity of meaning) by a non-initiate.
Here are some suggestions of terms that may seem to be meant metaphorically by the novice learner or non-expert member of the public:
chaperone proteins (molecular chaperones)
assembly of hemoglobin requires the presence of chaperone proteins
there is little cross talk between haemoglobin genes
globin genes are completely silent in most tissues
