24 hours, no more no less? I doubt it.
March 20, 2009 1:24 PM Subscribe
Examples of suspiciously round numbers that have, in all probability, been fudged up or down? Extra points for cases where those numbers can be safely discarded in favour of a different, more realistic figure.
posted by onshi to Grab Bag (29 answers total) 4 users marked this as a favorite
We just had a refrigerator delivered and we are advised to let it "stand" for 24 hours before plugging it in. The interwebs confirm this as a widely invoked rule of thumb, the rationale being that in a fridge transported horizontally, oil from the compressor seeps into places it doesn't belong such that the fridge mustn't be switched on until the oil has time to settle back into the compressor. If plugged in too soon, the oil tends to block refrigerant lines (negatively affecting cooling performance) and could potentially cause the compressor to fail completely.
I accept this explanation, and am willing to adhere to the 24 hour guideline just to be safe, but I find it incredibly unlikely that a full day (not one hour more or less) is really required for this process; instead, I would suppose the "true" time it takes would be 12-18 hours at most -- potentially far less -- with the remainder added as a safety margin and to account for idiosyncrasies across brands and models. Instead of providing an accurate figure with each model, a nice, round, extra-safe number that's easy to remember is promulgated by the entire industry.
Another example that springs to mind is the maximum recommended dosage information for non-prescription drugs (e.g. not to exceed 1000mg every 4 hours), which must be set well below the "true" toxic dose for safety reasons and to compensate for the low granularity in the "adults" and "children" doses as opposed a more accurate dosage based on body mass (e.g. 300mg per kg per hour). This fudged number -- say, 40% of toxic for a body mass 1 standard deviation below the mean for an adult or child -- would probably be further rounded down to a multiple of the quantity of drug in each tablet. Alternatively, the tablet size would be adjusted to be a factor of the various fudged dosage guideline(s).
So my question to you: which fudged numbers have you come across? Why do you think they are fudged? What factors would need to be taken into account to determine the corresponding "true" number? Anecdotes where you have personally shown the fudged number to be so? Thanks!