There was a recent post on the Museum Audience Insight blog about “Historical cooties”. In a similar vein, I want to think about history being radioactive. By this I mean considering history as having a “half-life” – and thinking about how this influences what we tell and how we tell it in our museums and heritage sites.
I started thinking about this late last year, in response to Susan Cross’ blog post about Remembrance Sunday. At the time I saw a distinction between events that occurred within living memory (i.e., things we lived through ourselves), events within family recollection (i.e., it was before our time but we know an older relative who was directly connected to it), and events beyond the reach of this living recollection (where the past really is a foreign country). I guessed the limit of this living connection to be about 100 years. Once you get much beyond this, distinctions between eras and events start to diminish and smooth out, a bit like the decay curve above. So 20th century history has an immediacy to it that (say) the Victorian era no longer has. Fewer shared cultural touchstones and assumptions survive that length of time. So, things that would have been self explanatory to the Victorians need re-interpreting for a 21st century audience (an important thing to recognise when interpreting objects and sites from this period). Even more so when we go further back – such as the medieval period or the Roman empire (both of which span several centuries in themselves but are now considered to be more or less homogeneous from this temporal vantage point).
More recently, a discussion with Gretchen Jennings on the Museum Commons blog got me thinking about the other end of the decay curve. When events are so new, so raw, so contested, that museums decide they’re too hot to handle. Gretchen describes how US museums are engaging (or more to the point, not engaging) with the 10th anniversary of the Iraq war as a case in point. Getting back to the radioactivity metaphor, museums might be collecting the hot, unstable material of current events, but then they are “burying” it – until such time as the “stable isotopes” of history (less dangerous, less contested) can be safely recovered and interpreted.
So if history were a radioactive isotope, what would its half-life be? I’d be interested in your thoughts on this. Currently I’m thinking it’s somewhere in the order of a single generation – say 25-30 years. It’s interesting that this is the time period for which most Cabinet records are sealed, suggesting the most “hot” phase has passed by this time. But it might take 2 or 3 half lives before a period becomes a “stable isotope” – something like World War II. This is not to suggest that “stable” history is not contested either – as in the curve above, the “hot” parts of a story might fade with time, but they never completely disappear.