# chrono-, chron-

#### (Greek: time, times; sequence of times)

synchronograph

An automatic recording telegraph worked by an alternating electric current, with a synchronously moving strip of perforated paper.

synchronology

Combined or comparative chronology; arrangement of events according to dates, those of the same date being placed or treated together; a comparative chronology.

synchronous

1. Existing or happening at the same time, simultaneously; coincident in time; belonging to the same period, or occurring at the same moment, of time; contemporary; simultaneous.

2. Relating to or treating of different events or things belonging to the same time or period; involving or indicating contemporaneous or simultaneous occurrence.

3. Recurring at the same successive instants of time; keeping time with; going on at the same rate and exactly together; having coincident periods, as two sets of vibrations or the like.

4. Of a satellite: rotating round the parent planet at the same rate as the planet rotates.

5. Of an orbit: such that a satellite in it is synchronous.

2. Relating to or treating of different events or things belonging to the same time or period; involving or indicating contemporaneous or simultaneous occurrence.

3. Recurring at the same successive instants of time; keeping time with; going on at the same rate and exactly together; having coincident periods, as two sets of vibrations or the like.

4. Of a satellite: rotating round the parent planet at the same rate as the planet rotates.

5. Of an orbit: such that a satellite in it is synchronous.

synchrony

The simultaneous appearance of two separate events.

synchrotron

In nucleonics, a machine that accelerates charged particles in circular orbits by varying the frequency of the accelerating voltage and also magnetic field so as to maintain a circular orbit.

tautochrone

That curve upon which a particle moving under the action of gravity (or any given force) will reach the lowest (or some fixed) point in the same time, from whatever point it starts.

A tautochrone or *isochrone* curve is the curve for which the time taken by a frictionless particle sliding down it under uniform gravity to its lowest point is independent of its starting point. The curve is a cycloid, and the time is equal to π times the square root of the radius over the acceleration of gravity.

tautochronism

Occupying the same time; pertaining to, or having the properties of, a tautochrone.

tautochronous

Having the character of a tautochrone; occupying the same time, isochronous.

tephrochronological

tephrochronology

The dating of volcanic eruptions and other events by studying layers of tephra.

Related **"time"** units:
**aevum, evum**;
**archaeo-, archeo-**;
**Calendars**;
**horo-**;
**pre-**;
**Quotes: Time**;
**tempo-**.