Time’s effects on…time capsules

Of all the queries I receive as a conservator, my number #2 most hated is “we’re going to bury a time capsule, can you give us some advice?” (My #1 most hated is “we’ve just pulled up the lino and found some old newspapers and want to frame them. Can you give us some advice?”).

I don’t have anything against time capsules per se, it’s just that inevitably the time capsule is scheduled to be buried the next day and time capsules are something that benefit from a little forethought. So the ensuing conversation becomes very hard—because what can you really do to help, by tomorrow?

(NB Newspapers from under the lino I hate because they are usually already badly degraded and are therefore even more difficult to deal with than they might have been otherwise. Also, poor-quality newsprint doesn’t survive exhibition well. So I end up feeling like a massive killjoy).

To what hazards might a time capsule be subject, over the years? Time capsules are usually buried or sealed up in building cavities. Dry ground (or wall cavities) might be relatively safe—though not immune from floods, contamination, excavation and the like. Wetter soils will more actively attack anything buried within, promoting rust and biological activity—though of course we have on occasion retrieved amazingly preserved accidental time capsules from bogs, in the form of human remains. The unusual conditions within peat bogs—a lack of oxygen, low temperatures and acidic conditions—combine to effectively tan the skin and hair, leaving them relatively intact. (The bones, on the other hand, are often destroyed by the acidity of the peat). But earth is also home to bugs and worms and voles and things, which might also get into your capsule if it is not well-sealed.

So time’s effects on time capsules will be dependent on what your time capsule is made from, and how well it is made. An iron, wooden or cardboard box is unlikely to survive rain, flood, or rising damp. Some plastics might last the distance—the especially un-environmentally-friendly ones, that resist biodeterioration—but a time capsule is only ever as strong as its weakest point. If it’s not well sealed, water and bugs and bacteria will get inside and lay waste. Well-sealed copper alloys or stainless steel (welded shut, even) are often recommended.

Next—what’s going in this perfect capsule? What will the people of tomorrow’s tomorrow’s tomorrow find interesting? More importantly, what will they find interesting that isn’t already preserved in much better condition in some museum or library? I’m not sure I can advise here—I imagine I would enjoy digging up someone’s personal diary or notebook, lists of what was hot or not, what you hated/loved, some zines, a collection of Pokemon cards/figurines (or similar) and letters written by children about their hopes & predictions for the future—those are always good for some lols. Something that provides an insight into an earlier time that isn’t necessarily going to be on the public record—or failing that, an otherwise undocumented collection of Spanish coin that I don’t have to report to the authorities.

Newspaper clippings are often a popular choices for time capsules, but are they a good choice? OK, at least they aren’t technology-dependent—our descendants will still be able to read them without the aid of a CD or minidisc player, or even electricity. But newspapers don’t really last that well. They’re inherently unstable materials. Even worse, the noxious acids emitted by the newspaper clippings might start degrading other objects that have been sealed up in your tiny time tomb. A university lecturer of mine used to enjoy telling the story of a collection of lead coins that were stored in lovely oak drawers. After some years had gone by, someone opened the drawers to find little piles of lead-based powder. Ex-coins! See, many wood species give off organic acids, which eat away at susceptible metals. For time capsules, you don’t just have to consider the stability of the thing itself, you have to consider its effects on materials nearby. Would you put a xenomorph in a spaceship-capsule full of humans, even though xenomorphs are practically indestructible? No.

Anyway. I’m sure you’re starting to understand why I dread these conversations. They go on and on and the person on the other end begins to wish they’d never called, because it’s complicated and really let’s just bury it already, take a few snaps for the local paper, keep the boss happy and forget about the damn thing. Because that’s probably what will happen anyway.

Read the National Archives of Australia’s advice about preparing time capsules.

Issue two of Materiality (the TIME issue) will be published in late June or early July. Stay tuned!