# Mathematical terms in popular usage

James A. Landau JJJRLandau at AOL.COM
Wed Apr 21 22:14:26 UTC 2004

```To Mark Mandel:

(This is a continuation of an off-line discussion)

You asked for terms which are both 1) originally from mathematical usage but
now in popular usage and 2) which have different meanings in the popular
usage.  Your examples were:
least common denominator
exponential (as in "exponential growth", in popular usage merely
meaning "fast")

After going through Jeff MIller's MATHWORDS page, my list is not much longer
than yours:

digital, speicifally digital clock---there used to be sold a type of clock on
which the numbers were on revolving drums, as in a car spedometer that has a
mechanical readout.  There were called "digital clocks" but in my opinion were
actually analog clocks, since there was a noticeable period of time in which
at least one digit was moving from one position to the next, causing the exact
time to be ambiguous.  (Yes, this is a quibble)

fuzzy logic---when used as a polemic about some opponent's ideas

googol---when spelled "google", means either the Web search engine or as a
verb "to use Google".  It is not a verb in math

order of magnitude---sometimes used in popular usage as a long-winded synonym
for "approxiimately" whereas the meaning in math and science is "how many
digits are in the number being discussed"
I once read (perhaps in Stewart Alsop _The Center_) that Secretary of
Defense McNamara used "order of magnitude" correctly, but this term was picked
up as a bureacratic buzzword by numerous people who did not know the proper
meaning.

series---in the sense "time series" etc.  is actually what mathematicians
call a "sequence" (a series is a particular type of sequence).  This is a quibble
since "time series" is a well-established term in statistics

tangent, as in "off on a tangent".  This is really reaching, but the math
meaning of "tangent" is the direction the curve were going at a specified time or
point, and could remain quite close to where the curve is currently going,
whereas the popular usage implies "going in a quite different direction".

- Jim Landau

```