Infinite Orbit is twenty engraved instruments, each one a real diagram or experiment from the history of how we learned the sky moves: Kepler's equal areas, Newton's cannonball, Foucault's pendulum under the Panthéon, the rose that Venus draws over eight years, the frame Voyager sent back from six billion kilometres out.
The laws
A planet sweeps out equal areas in equal times. Kepler, Astronomia Nova, 1609.
Newton's thought experiment, drawn for A Treatise of the System of the World (1728): an orbit is a fall that keeps missing the ground.
The least-energy path between two orbits, worked out by Walter Hohmann in 1925. To Mars, about 259 days.
Lagrange worked them out in 1772. Jupiter's Trojan asteroids share its orbit, 60 degrees ahead and behind.
For every orbit of Ganymede, Europa makes two and Io four. The lock is what keeps Io volcanic.
The Sun pulls the Moon about twice as hard as the Earth does, so the Moon's path round the Sun never loops back on itself.
The proofs and the instruments
Paris, 1851, the first direct proof that the Earth turns. At that latitude the swing plane turns 11.3 degrees an hour.
3 June 1769: Cook's party on Tahiti timed the crossing at 6 hours 5 minutes 37 seconds; Maximilian Hell at Vardø timed 6 hours 29 minutes 34 seconds. Halley's method turned those 24 minutes into the distance to the Sun.
A Greek astronomical calculator of the second century BC, found in a shipwreck in 1901. The oldest known geared computer.
The loop is our own motion seen from a moving Earth. Copernicus explained it in 1543.
One turn takes about 26,000 years. Thuban was the pole star of the pyramid builders; Vega will take its turn around AD 14,000.
The Moon turns once on its axis for each orbit, every 27.3 days. That is why we only ever see one face.
The visitors and the voyages
Back every 76 years or so. At perihelion in 1910 and 1986; next on 28 July 2061.
Found on 19 October 2017. Its orbit is not closed, so it came from another star and is leaving.
14 February 1990, about 6 billion kilometres from home.
Cassini's 22 final orbits passed between the cloud tops and the innermost ring. It plunged into Saturn on 15 September 2017.
35,786 kilometres up, where one orbit takes exactly one day. Arthur C. Clarke proposed it in 1945.
One orbit about every 92 minutes, so about sixteen sunrises a day.
Their balance point lies outside Pluto, so both of them circle empty space.
Thirteen orbits of Venus take almost exactly eight of Earth's, so the pattern repeats every eight years.
Formats
Every piece comes as a Comfort Colors tee on Black or Pepper, a heavyweight hoodie with the artwork across the back and a small emblem on the chest, an organic cotton tote, and a gallery canvas in three sizes. Printed to order and shipped to the US, Canada, the UK, the EU, Australia and New Zealand (canvas to all but New Zealand).
See the whole Infinite Orbit series · The Lunar Eclipse series