It’s Day 16 and the underground astronauts at Rising Star have managed to “hangout” (virtually, via Google) with classrooms from around the world: with little kids as young as five, to university students! In these classrooms, learners get to ask us questions ranging from the experiences of the excavation, to what we know (or hypothesize) about our strange relative, Homo naledi. I have recently written about how I became a part of the project more generally, but today I want to focus on some of my favourite questions, which many people might be interested in, but may be too shy to ask. I am focusing a bit more on the experience questions (of caving) because I think there will be plenty of opportunity to discuss and flesh out the debate about the small hominin in years to come.
1. What kinds of animals live there?
The farm on which the Rising Star Cave System is found has quite a bit of wildlife. Some of it, like the Nguni cattle (two cows and a bull), the blesbok (three babies were born during our stay!), springbok and impala were recently purchased. But we also see mice and steenbok and other little creatures on the farm. At the mouth of the cave, birds (two fledglings learning to fly through the top of Command Center), porcupines (we use their pointy, but soft quills to excavate out more delicate specimens), dassies and snakes have made a few featured appearances. Deeper into the cave, near Superman Crawl, we have found wandering toads (which Marina has rescued) and spiders (including a long-dead “crystal spider” where the body, on it’s web, was encased in dripping lime). But as we get to Dragon’s Back, the only friends we find are insects and bats. In the Chamber, it is almost only ever us and the occasional bat.
Angharad Brewer Gillham’s (trainee) excellent drawing of our Blesbok males chasing each other around the farm, featuring Marina Elliott (original), Keneiloe and me (trainees).
2. How small do you have to be to get to the Dinaledi Chamber?
When the original call was made for excavators, it was clear that it would be ideal if individuals chosen were relatively small in order to get through spaces: in particular one 18cm pinch point which occurs somewhere in the chute. This was initially a psychological barrier to me applying. I was small by most human standards, but there was certainly no way I could fit through 18cm! Luckily, this pinchpoint was such that there are multiple ways to manoeuvre around it. Once I arrived at Rising Star, however, it was clear that I wouldn’t be that unusual in dimension: the other astronauts present (in the 2018 expedition) are smaller than I am, but the cavers are pretty tall men, one with a little build. Don’t get me wrong! You cannot be too robust if you hope not to get stuck, but the majority of the problems one is likely to encounter is mental, rather than physical.
3. Did you ever get hurt/stuck?
Yes and yes. In the first week of excavation I climbed out of the chute, traversed Dragon’s Back, climbed down a ladder off of Dragon’s Back and then twisted my ankle… on flat ground… Which just goes to show that flat surfaces are super dangerous! But, after a couple of days of rest, I was right as rain and could continue caving, albeit with a strappy boot for slight ankle support. Safety is emphasized over and over again at Rising Star. Marina Elliott (lead excavator) emphasizes safety at each morning briefing; Lee Berger always says “Stay safe” as we are about to descend; we harness up when climbing the Dragon’s Back and are encouraged to take our journey in and out of the cave slowly and carefully. The safety cavers are on standby both at the front of the cave (at Command Centre) and at the top of the chute (right by the chamber), and any injury in the Chamber itself has a protocol that’s already been detailed. We also have (much needed) safety helmets and overalls. In general, I feel pretty safe, as long as I remain attentive. But the physical nature of the journey in and out of the cave means that each day I leave with fresh new bruises on my legs, sensitive knees and some scratches on my arm.
As for whether we get stuck? Learning to navigate through caves, especially if you are not used to it (as Kenni, one of the other trainees, and I were not), is difficult. You are tempted to tackle spatial problems like you would in a mall. However, this is practically not possible in the three dimensional space of a cave. Learning to twist your body, moving sideways, or crouching and crawling in strange ways is something that takes a little time to become intuitive. During orientation, we were taken through a path that included areas named “Upside-down-turnaround” (the name says it all) and “ballerina’s passage” (where tilting sideways like a ballerina is encouraged), which resulted in a little snag for all of us. But reevaluating the space, taking a deep breath and trying again, ultimately led to success! Every day I go up or down the chute, something snags at my pocket, or my thighs get lodged into a narrow section temporarily. But a good pull up or breath out gets me dislodged quickly enough.
4. How do you pee?
The journey into the cave is only really 200m, but it’s quite a complicated one (through narrow passages, Superman’s Crawl, the climb up Dragon’s Back -harnessed- and a 12m climb down the rocky chute). Then we are down in a pretty confined, humid space. This means that, once we are down in the Dinaledi Chamber (where we excavate), it is a bit of a mission to go to the… uh… bathroom. Apparently in previous excavations a rule needed to be made to take out whatever you made… if you catch my meaning. Our strategy? Hold it in. No-one wants to confuse water and pee bottles.
5. What does it smell like down there?
Kenni had the perfect response to this question: “It smells like the wet.” The Dinaledi Chamber is a consistent 18 degrees Celsius, with 99% humidity. Every rock you touch is slightly damp, as is the sediment we move as we excavate. Just like all excavation sites, there is certainly an earthy smell as well once we start digging (also, our faces are closer to the ground). Think about the smell that you get when you pass an active construction site, where they pile on sand and clay into heaps. I think we settled on wet, muddy clothes as the final “smell” of the Dinaledi Chamber. Not unpleasant, but certainly distinctive.
It’s probably also worth mentioning sound and sight. The Chamber, without our lights and headlamps on, is pitch black: any light is merely your brain trying to make sense of the void. When we do not speak and try not to move, there is no sound at all…
We have been asked so many cool and interesting questions which have made us think more broadly about our experiences and about the science, that it is impossible to address them all. (“When did you know you wanted to be a” -slight pause- “ologist?” was also a great one). I hope you enjoyed these questions as much as I did! And don’t be shy to message or tweet me any more!