English Dictionary

gnomon

IPA（発音記号）

/ˈnəʊˌmɒn/

名詞

広義

An object such as a pillar or a rod that is used to tell time by the shadow it casts when the sun shines on it, especially the pointer on a sundial.

日本語の意味

日時計で、太陽の光によりできる影を利用して時刻を知るために用いられる柱や棒

The historian carefully measured the angle of the gnomon to restore the sundial's original timekeeping accuracy.

歴史家は日時計の指針の角度を慎重に測り、その日時計の本来の時刻測定精度を復元した。

意味（1）

An object such as a pillar or a rod that is used to tell time by the shadow it casts when the sun shines on it, especially the pointer on a sundial.

Let a Gnomon, being firſt ſharpened into a Point, be ſhaped, and faſtned in ſuch wiſe, that it no way hinder either the draught of the Horizontal Line, or the Point of the ſhadow from having free access to the Dial at all times of the Year. […] Upon the Superfices of the Dial, obſerve the Point of the Shadow of the Gnomon (making a mark at it) and the Sun's Altitude, both of them at the ſame inſtant of time.

意味（2）

An object such as a pillar used by an observer to calculate the meridian altitude of the sun (that is, the altitude of the sun when it reaches the observer's meridian), for the purpose of determining the observer's latitude.

This muſt be performed by help of a Spherick Gnomon, (as Blaew [Willem Janszoon Blaeu] calls it,) which is a ſmall Pin or Needle fixed perpendicularly into a ſmal Baſis with an hollow concave bottom, that it may ſtand upon the convexity of the Globe.

意味（3）

The index of the hour circle of a globe.

Index of a globe, the little style or gnomon, which being fixed on the pole of the globe, and turning round with it, points out the hours upon the hour circle.

意味（4）

(geometry) A plane figure formed by removing a parallelogram from a corner of a larger parallelogram.

If a Parallelogram be divided into four leſſer ones, by two Lines interſecting each other; and one of theſe Parallelograms be retrench'd, or taken away; the other three will make a Gnomon, ordinarily call'd a Square.

意味（5）

(mathematics, by extension) A number representing the increment between two figurate numbers (“numbers equal to the numbers of dots in geometric figures formed of dots”).

https://books.google.com/books?id=R0d76m-Be10C&pg=PA16 page 16 The figurate number's gnomon is therefore 1+nb in the general case. A trivial family of numbers, those for which b=0, might be called linear. […] https://books.google.com/books?id=R0d76m-Be10C&pg=PA17 page 17 Clearly, a figurate number of rank n is equal to the sum of its first n gnomons, and in particular the sum of the first n odd numbers is equal to n².

gnomons （ plural ）