Microscopic scale

The microscopic scale () is the scale of objects and events smaller than those that can easily be seen by the naked eye, requiring a lens or microscope to see them clearly. In physics, the microscopic scale is sometimes regarded as the scale between the macroscopic scale and the quantum scale. Microscopic units and measurements are used to classify and describe very small objects. One common microscopic length scale unit is the micrometre (also called a micron) (symbol: μm), which is one millionth of a metre. Whilst compound microscopes were first developed in the 1590s, the significance of the microscopic scale was only truly established in the 1600s when Marcello Malphigi and Antonie van Leeuwenhoek microscopically observed frog lungs and microorganisms. As microbiology was established, the significance of making scientific observations at a microscopic level increased. Published in 1665, Robert Hooke’s book Micrographia details his microscopic observations including fossils insects, sponges, and plants, which was possible through his development of the compound microscope. During his studies of cork, he discovered plant cells and coined the term ‘cell’. Prior to the use of the micro- prefix, other terms were originally incorporated into the International metric system in 1795, such as centi- which represented a factor of 10^-2, and milli-, which represented a factor of 10^-3. Over time the importance of measurements made at the microscopic scale grew, and an instrument named the Millionometre was developed by watch-making company owner Antoine LeCoultre in 1844. This instrument had the ability to precisely measure objects to the nearest micrometre. The British Association for the Advancement of Science committee incorporated the micro- prefix into the newly established CGS system in 1873. The micro- prefix was finally added to the official SI system in 1960, acknowledging measurements that were made at an even smaller level, denoting a factor of 10^-6.