Be specific is solid advice to give to a fiction writer. I don’t feel very connected to a character who lives in “the city.” Not as much as I do when they live in Chicago or Astoria, Queens. And how marvelous when a surgeon drives a green Aston Martin DB4 to the hospital at dawn instead of “his English car.”
The flip side to the specificity coin is that mathematical specificity has little place in narrative prose. Though many people anchor their lives around the wondrous reliability of measurable distances, times, and temperatures, these people are the last ones you’d want telling stories at your dinner party. The world needs these people, but the literary world does not.
Specificity taken into the numeric realm is generally poisonous to prose. “A few feet to my right sat the mayor and his wife.” That’s tolerable, because it may be crucial whether or not our narrator can hear the mayor, or is close enough to see who he’s texting without throughout the opera. But get too numerical, and suddenly we have the voice of a nerdy obsessive: “Four feet to my right sat the mayor and his wife.”
The thing to do when you feel an impulse to grab the tape measure or ruler is to measure things instead in story terms. “The mayor sat close enough that I could recognize him, but far enough that he didn’t notice me.” Rather than, “It was a sunny day, temperatures in the mid 50s,” you might say, “It was a brilliantly sunny day, but still chilly, it being late October, and going out the door, I grabbed my jean jacket and a hat for the concert that evening.”
How fast and hard is this rule? I can see a golfer telling a buddy that he missed a four-inch putt. I can imagine a clothing designer asking her assistant to hand her the 5 MM thread or the 9-gauge scissors or something I have no clue about. So be sensible and don’t enact a total ban. There are situations when numbers derive from life and make for excellent telling details.
One problem with numbers might be that you cannot be assured every reader will comprehend the value the way you intend. The meaning of the distance or volume or whatever depends on knowing its relative value, and that judgement could be subjective. I think that’s true even of the mayor being four feet away. Is four feet close? It might seem obvious to you. But while one reader might hear keenly at that distance (and might also work in espionage), another reader might have spent his teens standing before the towering speaker cabinets of every major hair band of the time.
Furthermore, when it comes to mentioning more arcane things like decibels, wattage, amperes, pounds per square inch and so on, it’s just not safe to assume any base level of knowledge.
“Nancy,” the sage writer writes, “in her jealous rage, hooked her passed-out ex-husband Larry up to the generator, giving him enough electricity to stop his heart every day for the coming month.” That was clever, perhaps. I got my point across about her intent without counting joules, volts, or anything else. Even though the generator probably has its rating printed on the side, I left it out.
Before dashing off some hasty and erudite conclusion, one must consider the argument of a case such as Tim O’Brien’s wonderful novel The Things They Carried. This is a special case — and I mean that both factually and flatteringly. It clearly made fantastic use of items such as a rifle scope weighing “6.3 pounds.” In this work, the moral burden of soldiering, being far from home, and enlisted to kill is spoken of figuratively through the many items in a private’s possession.
The rule stands for most fictional prose, however: be specific, but unless it really suits your character or plot, don’t be mathematical.