Time Capsule
Another World Is Possible Community Archive
Buried at The Goat Farm Arts Center in Atlanta, Georgia 2024
Somewhere beneath the earth at @thegoatfarm, with the help of a few good friends (thx @alliebashuk & @markfielddinatale ), I buried a time capsule to mark this moment in time.
The capsule consists of three chambers, two intersecting tesseracts, one of which houses the third chamber. In the first chamber, a digital archive of my personal work, some personal artifacts and all of the collective works of @theyoungneversleep studio friends and collaborators across more than a decade or so of imagining, creation and world building.
The capsule was 3D printed by @ellex_swavoni The material choice was intentional as a ln acknowledgement of the current Anthropocene where human activity will leave an indelible impression in geologic time marked by materials like plastics. Considering how the longevity of plastics in the environment could be used in somewhat positive ways, by archiving the human experience. Subsequent versions of this capsule will use other materials. It’s sort of an experiment, the results of which I will likely not live to see.
The smallest chamber, which doubles as a camera obscura, contains water, one of the most significant mediums in the story of technological evolution. In addition to being a carrier of information about a given time or place via microorganisms and through its molecular structure and chemical composition, water has been studied and applied as a source and a medium for computation. There are many historical and modern day examples of this kind of water-based time keeping and “elemental computing”, one notable example from MIT in 2018.
Coupled with the Another World is Possible Experiment, the Time Capsule acts as an optical quantum clock, the most precise timekeeping device available with current technology, surpassing that of even traditional atomic clocks.
Optical lattice clocks
In an optical lattice clock, thousands or tens of thousands of neutral atoms (e.g. strontium, ytterbium, mercury, cadmium, mercury, magnesium, thulium) are first laser-cooled to ultra-low temperatures. Then, they are trapped in a periodic potential created by interfering laser beams, the “optical lattice” (Atom laser cooling and trapping), at a “magic wavelength” such that the trapping light shifts the two clock states equally and does not perturb the clock transition. The clock transition with sub-Hertz linewidth is probed spectroscopically with the clock laser. Since many (“N”) atoms are interrogated in parallel, the statistical signal-to-noise, which scales with N-1/2, is improved and pushing down the uncertainty, which also scales with the averaging time t like t-1/2, rapidly.
Optical trapped-ion clocks
Most optical trapped-ion clocks are realized in the following way. Atoms are photo-ionized with lasers and usually one of the resulting ions is confined by rf fields while being laser-cooled to near its motional ground state. A clock laser is then frequency stabilized to the narrow sub-Hertz optical transition of this clock ion (Yb+, Sr+, Ca+, Al+, In+, Lu+, and others). Compared to optical lattice clocks, using only one ion comes with a reduced signal-to-noise and consequently the uncertainty (proportional to N-1/2×t-1/2) improves much slower but can also reach values on the order of 10-18 for long averaging times. On the positive side, ions can be trapped stronger and longer than atoms, have zero or lower interaction-induced shifts, and systematic effects can often be quantified more reliably. Latest publications report on systematic uncertainties (accuracies) of optical trapped-ion clocks in the region of a few ×10⁻¹⁹.
Some special trapped-ion clock versions are
- Al+ clock, because Al+ can be hardly laser-cooled. Hence, a second ion (Ca+ or Mg+) is co-trapped together with the single Al+ clock ion and used for sympathetic laser-cooling as well as quantum logic detection of the Al+ clock ion.
- Ion clocks that use not only one but several clock ions (e.g. Sr+, In+, Ca+) to improve the signal to noise ratio and hence promise faster averaging down to low uncertainty values. Note, the use of x-times more ions leads to x-times faster averaging down.
- A Lu+ ion clock is expected to work well also with many ions and not only with a few ions due to a favorable combination of atomic properties.
- Multi-charged ions are just starting to enter the field but promise outstanding performance (e.g. low systematic effects) and scientific relevance (e.g. for studying fundamental physical like potential time variation of the fine structure constant).