All sizes of needle in that overcrowded haystack

Sir

The few lone top quarks that have been discovered are “60 needles in a pretty large haystack” according to your News in Brief story “Fermilab team finds top quark going solo” (Nature 444, 983; doi:10.1038/444983a 2006). Just a few pages further on, a Book Review tells us that the discovery of a body in the Kuiper Belt is “a classic case of finding a needle in a haystack” (“The beginning of wisdom” Nature 444, 1006–1007; 2006). That sure is a good few orders of magnitude for a metaphor.