signalling apparatus
71Mirror — looking glass redirects here. For other uses, see Looking Glass (disambiguation). This article is about wave reflectors (mainly, specular reflection of visible light). For other uses, see Mirror (disambiguation). A mirror, reflecting a vase A… …
72List of IEC standards — In order to distinguish standards published by the International Electrotechnical Commission numerically from other international standards, their number range was shifted in 1997 by adding 60000. So what used to be called IEC 27 is now… …
73Origin of language — The origin of language is the emergence of language in the human species. This is a highly controversial topic, empirical evidence being so limited that many regard it as unsuitable for serious scholars. In 1866, the Linguistic Society of Paris… …
74Dual gauge — Track gauge by size Broad gauge Sta …
75Radio Electronic Token Block — is a system of railway signalling used in the United Kingdom. It is a development of the physical token system for controlling traffic on single lines. How it works On arrival at a token exchange point , the driver reports his/her position to the …
76No-communication theorem — In quantum information theory, a no communication theorem is a result which gives conditions under which instantaneous transfer of information between two observers is impossible. These results can be applied to understand the so called paradoxes …
77Lever frame — Mechanical railway signalling installations rely on lever frames for their operation to interlock the signals and points to allow the safe operation of trains in the area the signals control. Located in the signal box, the levers are operated by… …
78Safety coffin — A safety coffin or security coffin is a coffin fitted with a mechanism to prevent premature burial or allow the occupant to signal that he has been buried alive. A large number of designs for safety coffins were patented during the 18th and 19th… …
79RGS20 — Regulator of G protein signalling 20, also known as RGS20, is a human gene.cite web | title = Entrez Gene: RGS20 regulator of G protein signalling 20| url = http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene Cmd=ShowDetailView TermToSearch=8601|… …
80Honey bee — For other uses, see Honey bee (disambiguation). This article refers collectively to all true honey bees; for the common domesticated honey bee, see European honey bee. Honeybees Temporal range: Oligocene–Recent …
