Radioactive: Study 1


In short: The half-lives of all known radioisotopes on a clock-face (with a log-scale). The colors show the type of the decay and the further out the more energy used to bind the atom’s nucleus.

Description: The aim of this study is to take on proper meaty science data, and to take an established graph on the wall of every science classroom in the world (seen here for example) and show it in a different, more beautiful, way.

The image shows the half-lives and binding energy of all known decays for each radionuclides, with the color channel indirectly signifying the method of nuclear decay. The half-life is plotted on a clock face starting at 10 ns to ~320 years on a log scale. The distance from the center is the “Mass Excess” which is the difference between the nuclide’s actual mass and the mass of its constituent nucleons (protons, neutrons…etc) i.e. how much energy is binding the nucleus. The colors signify the method of decay as the nuclear changes its atomic number (Z) and atomic mass (A). As each isotope is undergoing a change in its nuclear makeup, the image is designed to be vibrant and convey motion, and allowing the colors to bring out an underlying decay processes. Not many of us are experts in particle physics, but this starts to give us a picture of how atoms are made and how they break apart, and how similar groups of radioisotopes do similar things.

Point of interest:  Aside from the great blue brush-strokes introduced by the radionuclides that only have a lower-limit on their half-life, one of the interesting features is the yellow and blue groups that spiral out from the center of the image. They are presumably linked as an nuclide decays into another unstable state. I’m no particle physicist, but it seems a reasonable assumption for nuclides with small binding energies.

Technical: All 4125 known nuclides and some isomeric states taken from the US Nuclear Data Program available at Each nuclide is plotted according to the half-life (angle, log scale) and Mass Excess (distance from center, linear scale) for all isotopes with half-life between 10^-8 and 10^10 seconds. The size of each point is determined by the uncertainty on the half-life measurement (when only a upper or lower limit is known the point is smeared out); and the size away from the center linearly scales with Atomic Mass (A). The method of decay is represented by the color scale with the Red-channel inversely scaling with the increase in Atomic Number (Z); the blue-channel inversely scales with the decrease in Atomic Number (Z); and the green channel scales with change in Atomic Mass (A). Spontaneous Fission and Isomeric Transfer are not included. Alpha-decay shows up red, Beta as a shade of blue (depending on the other modes of decay).

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