_Possible Tests of Universal Gravitation at Short Distances_, *Peter
Watson*,* */Carleton University -  /A number of recent theories have
suggested that the inverse-square law may be modified at short
distances. Current experimental limits show that it is valid down to at
least 150µ: but there are effectively no limits below 10µ. We show that
it is possible to obtain a very weak limit for shorter distances, and
suggest that it may be possible to use a “quantum pendulum” to go below 1µ.