Gordon’s Sun Clock: Instructions

‘Gordon’s Sun Clock’ is essentially a single-hand clock with a dial that changes daily, oriented to the rhythms of nature and the celestial bodies. It shows the position of the Sun and the starry sky. A new kind of time display that is not artificial like our conventional clock (with railway time and daylight saving time), but moves in harmony with the seasons.

NOTE: You can swipe back and forth between this guide and the dial.

–– Your view:

In the centre of the screen you see a horizontal line. This is the horizon (the Earth's surface). The pointed triangle in the middle is a spruce tree that you see from a distance (or a church). You are not looking down at it from above, but standing in front of it.

If you have not changed anything in the settings (‘Viewing direction: automatic’), you are usually facing south in the Northern Hemisphere (north in the Southern Hemisphere). Objects on the left of the screen are in the east, on the right in the west (reversed in the Southern Hemisphere). The respective cardinal directions are shown at the edge of the horizon.

The lighter band below the horizon indicates civil twilight. The large dark grey area symbolises the night (including nautical twilight). Objects located in this area are not visible.

At the top right you see the local time (optional), the altitude of the Sun in degrees in the sky (e.g. 27.6°), as well as your position as a numerical code (e.g. ‘cri-hs’) or a place name if you have entered one. Below that the light season and the unequal temporal hour display.

–– Sun:

The ☉ sun (at the end of the clock’s single hand) moves from left to right over the course of the day (reversed in the southern hemisphere). The further left the sun is on the screen, the more it is in the east; the further right, the more in the west (reversed in the southern hemisphere). The higher the sun appears on the screen, the higher it is in the sky.

The sun follows the drawn circular path along which it moves within a day. At the edge of this circle, hours are indicated (e.g. ‘12’ o’clock), so the circle also functions as a clock face.

On the clock face, for example, one can see how during daylight saving time the numbers shift, while the circular path remains the same. Or: how legal time at most places differs from local solar time, as 12 o’clock is not exactly at the top of the dial. Temporal hours do it differently: at the 12th hour (12ἡ), it is always sunset.

–– Moon:

The ● moon also has a circular path, shown in light grey. Since the moon takes more than 24 hours to complete one orbit, 1.5 hours from the previous day are appended in extra light grey. If one ‘lives with the clock’, one can nicely observe how the moon spirals higher and lower over the course of 27 days. One can also observe how at full moon it stands opposite the sun on the circle (distant); at new moon, however, it stands at the same position on the circle (close to the sun). It is rarely exactly the same position because the moon’s orbit is inclined relative to the sun’s path. It is exactly the same position only during a solar eclipse.

New moon is displayed for 48 hours because the crescent is usually not visible to the naked eye during this period. Full moon is shown for 24 hours. The recalculation of the sun and moon paths takes place at UTC 00:00.

–– Planets:

The five planets visible to the naked eye are shown, depending on the design either with photos as seen through binoculars or with their astronomical symbols. When you look at the real night sky, you can distinguish planets from stars by knowing that planets do not twinkle but shine steadily. They appear larger in the sky than the distant stars and are therefore less affected by atmospheric turbulence.

♀ Venus (pearl-coloured), ♂ Mars (reddish), ♃ Jupiter (striped), ♄ Saturn (with rings), ☿ Mercury (grey)

–– Stars:

In addition, the ten brightest stars are shown, represented by a letter in a square. While the planets move relatively orderly, mostly more or less near the sun’s path, the path of the stars is independent of the sun — after all, they are suns themselves. In the star symbols, two sides of the square are always drawn more strongly than the other two. This indicates the corner or quadrant of their path in which they are currently located. If the highlighted corner is bottom right, the star is (more or less) at the “end” of its path downwards and to the right. In its further movement it will mainly move upwards and to the left (often also outside the screen). If the upper side is stronger, the star is in front of you; if the lower side is stronger, it is behind you (provided you have not changed the direction of rotation).

[s] Sirius, [k] Canopus, [f] Alpha Centauri, [a] Arcturus, [w] Vega, [c] Capella, [r] Rigel, [p] Procyon, [b] Betelgeuse, [h] Achernar

–– Meteors:

Each year, Earth passes through dust trails of small celestial bodies. This produces meteors. During the eight main meteor showers, the area is marked where meteors are most frequently visible (though they can appear anywhere). When visibility is good, the search area is shown in red, and many meteors per hour are possible. The best time is usually the second half of the night, as Earth then rotates into the dust stream. A red square with letters marks the point from which they appear to originate. As with the stars, two sides are drawn more prominently; they indicate the direction of the search area (top = in front of you, bottom = behind you, relative to your viewing direction). Data vary slightly each year:

[Y] Lyrids (...), [E] Eta Aquariids (...), [D] Southern Delta Aquariids (...), [P] Perseids (...), [O] Orionids (...), [L] Leonids (...), [G] Geminids (...), [Q] Quadrantids (...)

–– Time Control:

If you want to move forwards or backwards in time, press the ⬌ button. Then press and hold in the centre of the screen and slowly swipe left or right. The vertical position determines the step size: at the top years, at the bottom minutes. Upon release, the dial is recalculated (duration 1–30s). With a tap on the right or left edge of the screen, you jump 1h forward or backward. Swipe at the very bottom or top to switch pages. If you want to go further back in time, e.g. to your birth sky, additional ephemeris data can be downloaded (years 1900–2050, see page 4).

–– Weather:

At the bottom left, a local weather forecast can be displayed (details: page 1 below). It presents the character of the day in a composed manner using symbols: for example, ... stands for actual rain (6–18 o’clock), not occasional drizzle (analogously: ... heavy rain, ... snow, ... uncertain, ... dry, ... sunny, ... lots of sun, ... calm, ... windy, ... storm, ... gale-force). No symbol means unremarkable weather conditions. From bottom to top: current temperature, daily precipitation data (χ = snow) and sunshine hours; weekday = tomorrow; grey = old data, ⁺ = current. The weather data are also used for atmospheric refraction and slightly influence the timing of sunrise and sunset.

–– History:

‘Gordon’s Sun Clock’ is the result of more than twenty years of engagement with the representation of time. The starting point was a mechanical organ clock with a 24 h dial and a month-dependent display of sunrise and sunset. From this emerged the concept of a Sun Clock, initially as a feasibility study and an ePaper wall clock; later, weather display and GPS were added. The idea of a location-flexible version culminated in this Android app.

The goal of the development is a representation of time that follows the course of the Sun and the natural daily and annual cycles – as a reconnection of humans with nature and with our inner, circadian time. May it provide insight and understanding.

Data

Current data³ for your location:

– Sun¹ –
Time: ...
Temporal hour: ...
Daylight: ...
Light season: ...
Solstice: ...
Equinox: ...

– Moon² –
Lunar night: ...
Illuminated: ...
Size: ... (85-100)
New moon: ...
Full moon: ...

– Brightness –
Venus: ... (83-100)
Mars: ... (52-100)
Jupiter: ... (87-100)
Saturn: ... (77-100)
Mercury: ... (0-100)

¹ Time: GPS = synchronised | Temporal hour: local, unequal hour (0,0–11,9) ‘ἡ’ of the day or ‘ν’ of the night. ‘φ’ night watch with unequal “minutes” (0φ00–3φ59) | Light season: see below | Daylight & Agnihotra: sunrise–sunset today [sunrise tomorrow], ⁺ = current GPS | ² Full and new moon: point in time (in days / days ago) | Lunar night: see below | ³ Calculated with JPL ephemerides (almanac accuracy) | ⁴ Weather: daily progression (☀ sun, ◴ progress, ₁₂₃ = current 3h block, ☂ rain clickable = radar, ✈ gusts). Now = next 3 hours, ◵ = older data. Display limited to 48h for reliability | Bottom daily values: min...max...[night min] (χ = snow)

–– Info:

Lunar night works like our date, but with nights: Μx·y (p/z) with x = lunar ‘month’ of the year, y = night of the lunar month. Μ1 is the first full moon in the light year (≈ Chinese New Year). Since lunar months have different lengths, z gives the total nights of the lunar month, p the full moon night. The night ends at sunrise.

The light year season divides the year into eight phases of increasing and decreasing light: 1. Waxing (...), 2a. Arrival in light (...), 2b. Light repose (...), 2c. Departure from light (...), 3. Waning (...), 4a. Arrival in darkness (...), 4b. Dark repose (...) and 4c. Departure from darkness (...). Short form: Ϟx·y (x = phase, y = % progress). Data change slightly each year.

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