They look like tiny batteries, round metal cells that hide a measuring instrument and a little bit of memory-space. They are (relatively) cheap and very robust. They are called iButtons and they are more valuable to me than an iPhone. This is a post about a measurement device, but one that definitely deserves some lyrical reviews.
The best thing about them is their unrivaled survival skill. Just put them a few centimeters beneath the soil surface (maybe wrapped in some parafilm) and let them log the temperature for as long as you want.
We will leave them behind in fields all over the world, from Sweden to Chile and in all my gaps in my Belgian experiment. On their own, these iButtons will help me answer several important research questions about mountain ecology and the effects of disturbance. They can bring my PhD to a whole new level of importance for science!
Just imagine how much they can tell us! They can show the temperature gradient in the mountains, they can reveal the influence of the roadsides on this temperature gradient and they can help tracking the exact perfect location for plants to grow! They cover the whole year, the cold winter snows and the peaks on a sunny summer afternoon. The best thing is: you can leave them behind in the field without any problem as they are strong enough to survive most outside adventures, but cheap enough to survive the losses.
When my PhD becomes successful, it will to a large degree be thanks to them. Some of the most exciting parts of future fieldwork will be to search for these little instruments where I left them behind, to find them back in the vastness of nature and download their important content.
In brief: this iButtons are magical!