Ever Been in a Cave When they Shut Off the Lights?
It's a standard 'surprise' on most cave tours. Kinda a strange feeling!
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ArishMell · 70-79, M
Oh yes, one one or two occasions. I don't think it's done in many show-caves though.
Absolute darkness - something we do not normally experience.
A lot of show-caves now limit the lighting to only that part of the passage your group is in, or to illuminate a particular feature. It's not to save electricity (though it will), but to minimise the growth of lamp-flora: algae, mosses and ferns germinating in the lamp-light, from spores carried in from outside on draughts or visitors' clothes. It used to be thought decorative but is now seen for what it is, a sort of pollution not at all natural to the surroundings.
I have been caving over the years and sometimes, if waiting somewhere underground for some reason, would turn my lamp off. I noticed this created a strange effect: if I held my hand up in front of my face it "appeared" as a shape apparently darker than the background. That is obviously impossible, and I assume what happens is that the brain "knows" the hand is there and tries to image it.
Absolute darkness - something we do not normally experience.
A lot of show-caves now limit the lighting to only that part of the passage your group is in, or to illuminate a particular feature. It's not to save electricity (though it will), but to minimise the growth of lamp-flora: algae, mosses and ferns germinating in the lamp-light, from spores carried in from outside on draughts or visitors' clothes. It used to be thought decorative but is now seen for what it is, a sort of pollution not at all natural to the surroundings.
I have been caving over the years and sometimes, if waiting somewhere underground for some reason, would turn my lamp off. I noticed this created a strange effect: if I held my hand up in front of my face it "appeared" as a shape apparently darker than the background. That is obviously impossible, and I assume what happens is that the brain "knows" the hand is there and tries to image it.
ArishMell · 70-79, M
@GerOttman Oh, yes, it is an odd experience, and of course you can't see your hand in reality. It's very possible that others would not have that "dark image" of the hand effect that I had.
One of my books on the subject does say that few cavers, even if very experienced, like to be in total darkness for long if they have to wait in one spot for something.
One of my books on the subject does say that few cavers, even if very experienced, like to be in total darkness for long if they have to wait in one spot for something.
SW-User
@GerOttman I experienced complete darkness when my friends and I climbed into a large drainage pipe in a town in southern California (one friend grew up there and had been in it many times as a kid). There's a point in the middle of the pipe where the darkness is absolute. It was really strange. 😯