Caves, real and virtual

When I was younger I did a bit of caving, spelunking, potholing, call it what you will. This mainly consisted of donning smelly boiler suits or wet suits and crawling, and in some cases, swimming through muddy, dusty, or wet caves, and later downing a few pints at the pub.

I and my friends visited caves in England and South Wales. Some cavers went further a field to places like Ireland, and places in Europe. I expect that most countries have caves of some sort, either limestone caves carved by streams and rivers, or sea caves blasted out of the rock by the waves, or even lava caves created by volcanoes.

We always wore hard hats and carried lamps, and sometimes we would carry ropes and coiled ladders for the bits that we could not otherwise free climb. (This is not meant to refer to the technical sport of climbing without aids – in caving, the climbing is secondary to the prime purpose of exploring the cave).

Lamps varied from the usually reliable “carbide” lamps, through various type of “miner’s” lamps to sophisticated battery powered lamps. All were worn mounted on the helmet.

The carbide lamps, usually reliable, burned acetylene created by dripping water onto calcium carbide. Starting them up was occasionally difficult and involved opening the water valve and lighting the gas thus generated. They were usually reliable (unless clogged with mud) and gave a bright light. However there were problems with the disposal of “spent” calcium carbide and many people didn’t like the idea of carrying a lighted flame on their head!

The “miner’s” lamps were usually second hand, sourced from coal mines. They could be recharged many times, but because they were second hand, they could be fickle and could discharge rapidly, leading to the user relying on his/her companions for light. They also contained lithium hydroxide, which is pretty powerful chemical and this could leak from the old rubber seals, possibly resulting in burns.

The newer lamps were electric, with batteries that could be recharged and I see that the newer ones can have battery packs that are mounted on the helmet, which could be useful. I suspect that one could take spare power packs and plug them in as needed. The older “miner’s” lamps had a cable that allowed the battery pack to be strapped around the waist.

Of course, all the lamps had a limited range. This did not matter too much as the view tended to be restricted to the back of the person in front for most of the time. When the group entered a larger cavern however, a caver’s view of it depended on the power of his/her headlamp.

In general a headlamp could not easily distinguish details in the distance in a cave, but a group of people in a cavern could illuminate it pretty well, or enough to spot the things that needed a closer look, like cave formations and stalactites and stalagmites, and the next bit of the intended route.

Nevertheless, the beauty of some of the formations in a cave is breathtaking. Huge stalactite flows, hanging curtains and sheets, rimmed pools of mirror like water in glorious colours can be seen. I’ve several times seen delicate helictites, which are rarely to be seen in show caves.

“Real” cavers scorn the show caves, but I’d guess that all have visited them at some time or other. For a “retired” caver they are a reminder of all those hours spent underground. The cave formations are pretty ordinary as compared to those found in the more natural caves, and the lighting and concrete paths, stairs and indeed the touristy commentaries by the guides seem laughable to those have experienced “real” caving.

When you visit a cave, at least those that have formed in limestone, they have been carved out of the rock by water (“phreatic”) and therefore have a distinct slope. There are exceptions but in most caves you go down into them and up out of them.

When you are exploring a cave, you generally don’t have a map, but in most cases you will be following someone who has already visited that part of the cave that you are exploring. You look forwards and down going in, pointing your headlamp at place, generally, below you. On the way out you look upwards, pointing your lamp in the direction of the exit.

You look into interesting nooks and crannies which points your light into them. Interestingly, when I have visited show caves I have looked into nooks and crannies and unconsciously expected them to light up. Of course they don’t as show caves don’t supply helmets with lights on them!

I’ve played the game Minecraft quite a bit, and that has a feature which resembles caving. When you dig a mine in Minecraft you generally dig downwards. At first you might just hammer rocks to clear your way, but sooner or later you will hit a void in the ground. The trick here is not to fall into it.

You may hit the void or cave at any point – the bottom, the middle or the top. In any case you will initially see only darkness with maybe a a few blocks dimly visible in the gloom. To proceed further (and find all the desirable ores and minerals) you will need to get down to the bottom and root around.

This generally means that you carefully cut steps around the edges of the void until you reach the bottom. I generally leave torches attached to the walls of the excavation as I go, as a sort of “breadcrumb trail“. Eventually one reaches the bottom of the void and can go exploring.

At the bottom of a void, it is much like the bottom of a cave. A jumble of blocks and the occasional pitfall await. The only difference is that the blocks that form the virtual cave are all cubes and don’t move as you walk over them, whereas in a real cave there are all sorts of shapes, and they can move under your feet.

Interestingly coming upon a gaping void in Minecraft induces the same gripping tension as entering a large, unknown chamber in a real cave, at least to some extent.