An example of an analogy used in popular science writing
"The most trivial, but probably also the most plausible, explanation of the origin of these high-energy particles moving with speeds of up to 99.999 999 999 999 99 per cent of the speed of light, lies in the assumption that they are accelerated by very high electric potentials presumably existing between the giant gas and dust clouds (nebulae) floating in cosmic space. In fact [sic], one could expect that such interstellar clouds would accumulate electric charges in a way similar to the ordinary thunderclouds in our atmosphere, and that the electric potential differences thus created would be much higher than those responsible for the phenomenon of lightning striking between the clouds during thunderstorms."
George Gamow (1961) One, Two, Three…Infinity. Facts and speculations of science, Revised Edition, Dover Publications, Inc., New York.
Gamow does not offer any details of how these phenomena are similar (this is presumably not a direct equivalence, given that the atmospheric processes surely involve much higher density of matter {and so 'frictional' interactions}, and depend on mixing due to convective processes that rely on the Earth's gravitational field and atmospheric heating by the Sun).
Read examples of scientific analogies
The usual meaning of 'floating' (at least in science) refers to a buoyant effect due to the upthrust on a fluid matching weight. As these forces are not relevant to gas and dust clouds found in cosmic space the use of floating here would seem to be a metaphor.
N.b. 'In fact…' seems to be a rhetorical flourish, as
- In fact, one could expect that…
- One could expect that…
offer the reader the same information content.
