Sugar The sugar contents of common fruits and vegetables are presented in Table 1. The fructose to fructose plus glucose ratio is calculated by including the fructose and glucose coming from the sucrose. Due to rising demand, sugar production in general increased some 14% over the period 2009 to 2018. The largest importers were China, Indonesia, and the United States. In 2016, global production of sugar beets was 277 million tonnes, led by Russia with 19% of the world total (table). The sugar beet became a major source of sugar in the 19th century when methods for extracting the sugar became
Proper time arc length of world lines in four-dimensional spacetime. From the mathematical point of view, coordinate time is assumed to be predefined and we require an expression for proper time as a function of coordinate time. From the experimental point of view, proper time is what is measured experimentally and then coordinate time is calculated from the proper time of some inertial clocks. Proper time can only be defined for timelike paths through spacetime which allow for the construction of an accompanying set of physical rulers and clocks. The same formalism for spacelike paths leads to a measurement of proper distance