Susan Eyre invites visitors to view her cloud chamber which was used to capture footage of the ephemeral trails of cosmic rays as seen in the video Cosmic Chiasmus: crossing the universe currently showing in the Carbon, Carbon Everywhere exhibition co-curated by Indira Dyussebayeva-Ziyabek and Maria Hinel.
Cosmic rays are fast moving particles, blasted across space, spiralling along magnetic field lines to end up entangled with carbon in our bodies. They are raining down on Earth all the time. Although they are called rays they are not like photons of light as they have mass but they do travel at nearly the speed of light. At ground level two to three cosmic particles pass through your hand every second, deep underground this is reduced to about once a month.
Not only is all life physically permeated by cosmic rays with the potential for nuclei collisions but some cascading particles smash into atoms of nitrogen to create carbon-14. Carbon-14 then combines with oxygen in the atmosphere to create radioactive carbon-dioxide - this is ingested by plants and animals through the food cycle. Plants absorb it during photosynthesis, and it is incorporated into their carbon skeleton which we then eat. When an organism dies no more Carbon-14 is absorbed and that which is present starts to decay at a constant rate. By measuring the radioactivity of dead organic matter, the current carbon-14 content can be determined and the time of death established. Cosmic ray activity gives us carbon dating techniques.
