Chronometry, or horology, is the science studying the measurement of time and timekeeping. Chronometry enables the establishment of standard measurements of time, which have applications in a broad range of social and scientific areas. Horology usually refers specifically to the study of mechanical timekeeping devices, while chronometry is broader in scope, also including biological behaviours with respect to time (biochronometry) as well as the dating of geological material (geochronometry).
Horology is commonly used specifically in reference to the mechanical instruments created to keep time: clocks, watches, clockwork, sundials, hourglasses, clepsydras, timers, time recorders, marine chronometers, and atomic clocks are all examples of instruments used to measure time. People interested in horology are called horologists. That term is used both by people who deal professionally with timekeeping apparatuses, as well as enthusiasts and scholars of horology. Horology and horologists have numerous organizations, both professional associations and more scholarly societies. The largest horological membership organisation globally is the NAWCC, the National Association of Watch and Clock Collectors, which is US based, but also has local chapters elsewhere.
Records of timekeeping are attested during the Paleolithic, in the form of inscriptions made to mark the passing of lunar cycles and measure years. Written calendars were then invented, followed by mechanical devices. The highest levels of precision are presently achieved by atomic clocks, which are used to track the international standard second.
Etymology Chronometry is derived from two root words, Ancient Greek () and (), with rough meanings of "time" and "measure".Bauer, W. (2001). A Greek-English Lexicon of the New Testament and Other Early Christian Literature (Third Edition). University of Chicago Press. The combination of the two is taken to mean measurement of time.
In the Ancient Greek lexicon, meanings and translations differ depending on the source. , used in relation to time when in definite periods, and linked to dates in time, chronological accuracy, and sometimes in rare cases, refers to a delay.Liddell, H & Scott, R. (1996). A Greek-English Lexicon. Oxford University Press, USA. The length of the time it refers ranges from seconds to seasons of the year to lifetimes, it can also concern periods of time wherein some specific event takes place, or persists, or is delayed.
The root word is correlated with the god Chronos in Ancient Greek mythology, who embodied the image of time, originated from out of the primordial chaos. Known as the one who spins the Zodiac Wheel, further evidence of his connection to the progression of time.Vrobel, S. (2007). The Kairos Syndrome. N.p. However, Ancient Greek makes a distinction between two types of time, , the static and continuing progress of present to future, time in a sequential and chronological sense, and , a concept based in a more abstract sense, representing the opportune moment for action or change to occur.
() carries little emphasis on precise chronology, instead being used as a time specifically fit for something, or also a period of time characterised by some aspect of crisis, also relating to the endtime. It can as well be seen in the light of an advantage, profit, or fruit of a thing, but has also been represented in apocalyptic feeling, and likewise shown as variable between misfortune and success, being likened to a body part vulnerable due to a gap in armor for Homer,Murhchadha. F.O. (2013). The Time of Revolution: Kairos and Chronos in Heidegger. Bloomsbury Academic. benefit or calamity depending on the perspective. It is also referenced in Christian theology, being used as implication of God's action and judgement in circumstances.Strong's Greek: 2540. καιρός (kairos). (n.d.). Retrieved 2 October 2020, from https://biblehub.com/greek/2540.htmMark 1:15 Greek Text Analysis. (n.d.). Retrieved 2 October 2020, from https://biblehub.com/text/mark/1-15.htm
Because of the inherent relation between and , their function the Ancient Greek's portrayal and concept of time, understanding one means understanding the other in part. The implication of , an indifferent disposition and eternal essence lies at the core of the science of chronometry, bias is avoided, and definite measurement is favoured.
Subfields
Biochronometry Biochronometry (also chronobiology or biological chronometry) is the study of biological behaviours and patterns seen in animals with factors based in time. It can be categorised into circadian rhythms and circannual cycles. Examples of these behaviours can be: the relation of daily and seasonal tidal cues to the activity of marine plants and animals,Naylor, E. (2010). Chronobiology of Marine Organisms. Cambridge University Press. the photosynthetic capacity and phototactic responsiveness in algae,Bünning, E. (1964). The Physiological Clock: Endogenous diurnal rhythms and biological chronometry. Springer Verlag. or metabolic temperature compensation in bacteria.Menaker, M (Ed.) (1971). Biochronometry: Proceedings of a Symposium. National Academy of Sciences, USA.
Circadian rhythms of various species can be observed through their gross motor function throughout the course of a day. These patterns are more apparent with the day further categorised into activity and rest times. Investigation into a species is conducted through comparisons of free-running and entrained rhythms, where the former is attained from within the species' natural environment and the latter from a subject that has been taught certain behaviours. Circannual rhythms are alike but pertain to patterns within the scale of a year, patterns like migration, moulting, reproduction, and body weight are common examples, research and investigation are achieved with similar methods to circadian patterns.
Circadian and circannual rhythms can be seen in all organisms, both single and multi-celled.Edmunds, L.N. (1985). Physiology of Circadian Rhythms in Micro-organisms. Elsevier.Gillette, M.U. (2013). Chronobiology: biological timing in health and disease. Academic Press. A sub-branch of biochronometry is (also chronomicrobiology or microbiological chronometry), the examination of behavioural sequences and cycles within micro-organisms. Adapting to circadian and circannual rhythms is an essential evolution for living organisms. These studies, as well as educating on the adaptations of organisms also bring to light certain factors affecting many of species’ and organisms’ responses, and can also be applied to further understand the overall physiology, this can be for humans as well. Examples include: factors of human performance, sleep, metabolism, and disease development, which are all connected to cycles related to biochronometry.
Mental chronometry Mental chronometry (also called cognitive chronometry) studies human information processing mechanisms, namely reaction time and perception. As well as a field of chronometry, it also forms a part of cognitive psychology and its contemporary human information processing approach.Abrams, R.A, Balota, D.A. (1991). Mental Chronometry: Beyond Reaction Time. Cambridge University Press. Research comprises applications of the chronometric paradigms – many of which are related to classical reaction time paradigms from psychophysiologyJensen, A.R. (2006). Clocking the Mind: Mental chronometry and individual differences. Elsevier. – through measuring reaction times of subjects with varied methods, and contribute to studies in cognition and action.Meyer, D.E, et al. (1988). Modern Mental Chronometry. Elsevier. Reaction time models and the process of expressing the temporostructural organisation of human processing mechanisms have an innate computational essence to them. It has been argued that because of this, conceptual frameworks of cognitive psychology cannot be integrated in their typical fashions.Van der Molen, M.W, et al. (1991). Chronopsychophysiology: Mental chronometry augmented by psychophysiological time markers. John Wiley & Sons.
One common method is the use of event-related potentials (ERPs) in stimulus-response experiments. These are fluctuations of generated transient voltages in neural tissues that occur in response to a stimulus event either immediately before or after. This testing emphasises the mental events' time-course and nature and assists in determining the structural functions in human information processing.Coles, M.G, et al. (1995). Mental Chronometry and the study of Human Information Processing. Oxford University Press.
Geochronometry The dating of geological materials makes up the field of geochronometry, and falls within areas of geochronology and stratigraphy, while differing itself from chronostratigraphy. The geochronometric scale is periodic, its units working in powers of 1000, and is based in units of duration, contrasting with the chronostratigraphic scale. The distinctions between the two scales have caused some confusion – even among academic communities.Harland, W.B. (1975). The two geological time scales. Nature.
Geochronometry deals with calculating a precise date of rock sediments and other geological events, giving an idea as to what the history of various areas is, for example, volcanic and magmatic movements and occurrences can be easily recognised, as well as marine deposits, which can be indicators for marine events and even global environmental changes.Elderfield, H (Ed.). (2006). The oceans and marine geochemistry. Elsevier. This dating can be done in a number of ways. All dependable methods – barring the exceptions of thermoluminescence, radioluminescenceErfurt, G (et al.). (2003). A fully automated multi-spectral radioluminescence reading system for geochronometry and dosimetry. Elsevier. and ESR (electron spin resonance) dating – are based in radioactive decay, focusing on the degradation of the radioactive parent nuclide and the corresponding daughter product's growth.
By measuring the daughter isotopes in a specific sample its age can be calculated. The preserved conformity of parent and daughter nuclides provides the basis for the radioactive dating of geochronometry, applying the Rutherford Soddy Law of Radioactivity, specifically using the concept of radioactive transformation in the growth of the daughter nuclide.Rasskazov, S.V, Brandt, S.R & Brandt I.S. (2010). Radiogenic isotopes in geological processes. Springer.
Thermoluminescence is an extremely useful concept to apply, being used in a diverse amount of areas in science,McKeever, S.W.S. (1983). Thermoluminescence of solids. Academic Press. dating using thermoluminescence is a cheap and convenient method for geochronometry.Price List – CHNet. (n.d.). Retrieved 25 October 2020, from http://chnet.infn.it/en/price-list/ Thermoluminescence is the production of light from a heated insulator and semi-conductor, it is occasionally confused with incandescent light emissions of a material, a different process despite the many similarities. However, this only occurs if the material has had previous exposure to and absorption of energy from radiation. Importantly, the light emissions of thermoluminescence cannot be repeated. The entire process, from the material's exposure to radiation would have to be repeated to generate another thermoluminescence emission. The age of a material can be determined by measuring the amount of light given off during the heating process, by means of a phototube, as the emission is proportional to the dose of radiation the material absorbed.
Time metrology Time metrology or time and frequency metrology is the application of metrology for timekeeping, including frequency stability. Its main tasks are the realization of the second as the SI unit of measurement for time and the establishment of time standards and frequency standards as well as their dissemination.
History