I once got so claustrophobic just by reading a book about caving that I had to put it away: Blind Descent by James Talbot. It describes the quest of a couple of maniacs to explore the deepest caves on earth under hellish circumstances. No light for weeks, no communication with the surface, camping against vertical walls in the dark, hurricane level winds, tight sumps full of dark water, disease, panic attacks... Man, who in his sane mind does things like that?

The parent comment has a typo in book author name. The book is actually "Blind Descent: The Quest to Discover the Deepest Cave on Earth" by James M. Tabor.

https://www.amazon.com/dp/0812979494

(Curiously, Google search for "James Talbot Blind Descent" points to this very Hacker News thread.)

Reading this feels as claustrophobic. This description gave me anxiety... and it's third hand information. Maybe I need therapy.

> who in his sane mind does things like that?

The usual estimation is that 5% of the population is insane, and I guess they do fill a purpose :)

I remember reading that book! There were lots of deaths in those expeditions. As the author said, "supercave" exploration is like extreme mountaineering, but even more dangerous and complicated.

Honestly it's this kind of thing that really makes me marvel at the human brain. Most people see 'the grass is greener' as meaning that you will always want what you don't have.

I see it as meaning that you can honestly get used to anything, given enough time. It's inspiring really, when I'm at my worst and darkest times, to think - hey, if someone can deal with being tortured for years and get through it, I can make it through this.

> if someone can deal with being tortured for years and get through it, I can make it through this.

I understand what you're saying, but being tortured for years leaves physiological and psychological scars that never go away.

William Sampson, A Canadian who was tortured for 31 months in Saudi Arabia, died at 52 after suffering four heart attacks in six months.[1]

Three of these were after the torture ended.

[1] https://www.thestar.com/news/insight/2012/04/01/william_samp...

An experienced caver buddy of of mine tells stories about doing chest compressions to get through really small spaces. You know, because the hole is too small for you to pass through with lungs full of air. So you exhale it all and hope there's space ahead for you to breath in again.

No thanks, man. I'll stick with kayaking.

Reading this gave me a mild panic attack. That just seems mad. I'm very glad there are people who are not affected by or have overcome fears to go and do these things though :)

When I was kid I did some splunking, and squeezing through narrow spaces, especially with even a bit of water running near your mouth which is common = 100% hated it. Don't splunk at ALL anymore. Diving in cynotes in mexico though is stunning - so still have enjoyed doing that.

Running water in a place like that makes me double nervous. A sudden shower breaks out while you're in the cave and a path like that can flood out in an instant.

Caving can be incredibly fun as well, tight squeezes can come with the territory but there's plenty of horizontal walking/borehole opportunities. It is pretty geographically dependent.

This one always gets me a bit:

https://gfycat.com/responsibleboweddalmatian-exploration-cav...

I'm wondering if there's not a second entrance or something that sumped and connects, in the US some tracks are a mile or so back but several hours? Sounds significant.

It's funny - I've only caved a bit, but I watch that video and think "wow that looks fun." There's something so exciting about getting right up to the edge of what's possible for a human to do.

I know what you mean, I went through a fairly simple cave except for ~90 feet with 3 90 degree turns in between which required me to be completed stretched out (Superman style) and push with only my toes/fingertips. It was terrifyingly exhilarating.

when I was a kid a crawled into half collapsed etruscan tombs often (which in hindsight was not a good idea) and it felt ok but this video gave me instant claustrophobia.

It's incredible that people can do this as a hobby :)

I’m going to have nightmares after seeing that gif. How can these people be ok with that?

Also, does the notion of eventually needing to turn around never stymie them?

That's why the send the cameraman first.

Cave exploration is sometimes like that

https://www.youtube.com/watch?v=FAY-t32vyds

Yeah, I've seen this one. This is an "alternative entrance" to a decently-sized cave with a normal access elsewhere off camera.

That's not to say there aren't examples of some truly disturbing spelunking - https://i.imgur.com/BkmpH9v.jpg

Oh man, that poor guy didn't make it:

https://www.deseretnews.com/article/705347362/Man-trapped-in...

I saw that picture and read up more on the story a while back... absolutely horrifying situation. Stuck upside down underground for hours, unable to move or escape even though there are others right behind you that you can communicate with until you eventually die. Somewhat unrelated, but that is part of what made me decide to not further pursue my cave diving certification

Damn that's frightening. They need semi-autonomous robots (spider-like?) to crawl ahead with a camera before going head-first into a place like that.

That image is simply terrifying.

Some people are even claustrophiles. Isaac Asimov was a famous one. Being in tight spaces makes them feel safe, although being actually stuck may not have the same effect.

Thanks for giving me a word that describes my instinct. I do tend to prefer small spaces.

This said, there are limits - in places like that caving gif upthread, I'd freak the hell out.

And the Maya didn't have LED headlamps with lithium-ion batteries, either.

They went in there with torches.

I was going to say this. I mean, we freak out at the idea of doing it now. Imagine some guy 1000 years ago who found a crevice... in the dark... and decided to crawl through it. That... both impresses and terrifies me.

Now overlay that with the belief that your are literally descending into the underworld.[1]

It must have made for a very transformative experience.

[1] https://en.wikipedia.org/wiki/Xibalba

What bothers me about pictures like that isn't so much having to cram through the tight space. It's the cave collapsing and being squished to death with a 0% chance of survival.

Do other people who are semi-claustrophobic fear the literal tight place, or dying from something going wrong that's out of your control? The same thing applies to heights. I have no problem with heights at all but ladders bother me a lot because I'm always thinking the ladder will fail at any second.

I did some spelunking as a teen (lived in an area with 100+ caves), and you sometimes heard about stone blocks ramming down with climbing speleologists in large underground halls, higher levels of carbon dioxide preventing breathing or sudden flash-floods preventing escape. Not so much about sudden cave collapses (I guess in earthquake areas that's always a possibility).

When I was in the dark, squeezing through tiny holes in various angles, I felt a bit like having an "out-of-body" experience, where my brain visualized my whereabouts in some kind of 3D map and internally I was looking at the whole 3D map "from outside"; like viewing an autonomous robot making its moves. It was quite fascinating. I guess sensory deprivation allowed the "3D mapping signal" to be perceivable and dominant.

Also, given there is no smell inside caves, if you spend a few hours/days inside, then climb back to surface, upon entering ground you are hit by a wall of smells you never perceived before. Suddenly you can distinguish individual flowers, trees, grass, soil etc. That however only lasts a few seconds :-(

Your visualization experience sounds very interesting!

I actually believe it is possible to consciously 'do' what you describe to at least some degree. It would be nice to hear more about your experience in detail, may I ask you some questions?

Was it as vivid and sharp as daylight open eye view or was it rather blurry / fuzzy?

Where the colors saturated or rather gray?

Was every action instant or was there a time lag?

Did the shapes stay stable or did they deform or fade after a time [of no new inputs (from touch I guess)]?

What did it look like to touch a wall?

How would you describe the field of view you had in your visualization? Normal? All-Round-View onto the 3D map?

Did you have a feeling for the volume where the field of view of your body would be?

How did you visualize your body? Abstractly or more like you might look in daylight?

Could you move as observer in your visualization or was that out of your control?

Well, it's not like I didn't perceive stuff with my eyes, it's just that I also internally had another view (I still have some fragments fairly vivid in memory), where I could kinda rotate my view, e.g. being inside a tunnel with irregular slopes hinting at some abyss through cracks at the bottom and I viewed it inside as a certain irregular shape I could rotate, localize me (where "me" was some uncertain blob and my pose was how my body was reporting to me, but my overall shape was just fuzzy/unimportant) and do some planing. As for colors, again unimportant, not sure if there was even a concept of color in my internal representation. Actions as such were instant, but the feedback was basically tactile/otolithic, updating my location/pose estimate. FOV was variable, changing as I needed and as I moved inside visualization. It might have been inspired by some speleology mapping tools that at the time started to become 3D, so my brain might have used a similar representation.

I guess it was really dampened sensory inputs, not dominating perception as usually, that allowed this kind of planing/internal model to come out. Without spelunking I'd probably use it only subconsciously in sports like when hitting a tennis ball at 120mph and planning all moves in advance, serving a sneaky ball in volleyball etc. I had a similar feeling once when a car that was joining my road almost rammed into me and I just remember that my brain switched to 100% focus and almost automatically did all the crash avoidant tasks where I felt more like an observer, and the calculation was perfect (i.e. no crash).

Thank you that was a very interesting read. It sounds similar to how I imagined it.

Sometimes I ask myself if this is similar to how blind people visualize their world. I remember reading from Hellen Keller (deaf-blind from birth) that she also had a visual representation of the world around here. Something along the lines of the human brain is just build for this kind of representation.

I think that there is some common underlying representation that everyone uses. When seeing something through the eyes this representation is overlayed with salient visual sensor input in eye fov and our internal fov just focuses on this for convience and because it is so damn salient. I think it is possible to detach the internal fov from the eye fov and see how the brain models the other regions.

Your suggestions that sensory deprivation brings out the underlying internal representation is very intersting. It makes a lot sense! Really gotta try that sensory deprivation chambers some time =)

You live in a universe where astronomical events lightyears away can obliterate life on earth with no advance warning whatsoever. Being in control is an illusion.

The fact that all life on earth could theoretically be snuffed out without warning doesn't mean there aren't more mundane terrestrial factors that we can control, and should, assuming you're into things like comfort and survival.

Oddly, this reminds me of my mild fear of driving. I can't ignore the fact that at any moment while driving, I or anyone driving near me could apply a few paltry newtons of force in a way that causes massive injury and destruction, changing or ending lives. Every time I get behind the wheel, I have to wonder at how casually I'm about to pilot a huge mass at lethal speeds around hundreds of other people casually doing the same thing. There's nothing I can directly do to affect the mistakes of others, but I accept the risk of freak accident and resolve to do what I can to at least reduce the risk of disaster (drive defensively). Analogously, we all accept the (demonstrably small) risk of annihilation by, e.g., gamma-ray burst, and go about our lives.

> Being in control is an illusion.

It is a very useful illusion though. I take it as a sort of veneer that the brain hoists over our eyes to make day to day life bearable. There is some truth to the saying "Ignorance is a bliss".

Aw, this one's easy; the passage isn't even underwater! It's the flooded passages so narrow you have to take your scuba gear off and pull it behind you that are really terrifying.

Maybe not wired differently. It could be that they've gained knowledge and experience that makes this seem normal/safe.

A bit of a tangent but it never occurred to me before I went caving: The helmet keeps you safe from getting your head stuck.

It's slightly bigger than your head so if anything attached to your neck is going to get stuck, it'll be your helmet, which you can remove.

Actually, if you look at the pictures, it would seem the artefacts themselves a larger than the crack we see in your image.

That was mysterious to me until I saw the rather large electric lighting fixture on the cave floor. So there must be some larger passage somewhere.

So wait? Ancient people carried valuable things through those enormously inconvenient tiny little holes and then created small hoards deep in the caves?

Was there maybe an easier route that has fallen away through the centuries and this is what's left?

Or was there perhaps a religious belief here because honestly, if you were trying to hide things, burying stuff sounds just as effective and quite a bit less dangerous.

The fit may have been easier for them, due to:

1. Shorter / thinner stature compared to today's explorers 2. The caves having compressed / become narrower, even slightly, in the last 1000 years

Should they not be using remote-controlled drones first and 3D-map the tunnels first before going in with humans?

Cool idea, but what drone would you actually be able to use for spelunking?

That is the actual question: Why aren't there spider-like (or some other suitable form) drones by now, for exploring enclosed environments with uneven terrain? Or are there?

Nothing AFAIK. And that's not surprising to me; the locomotion requirements are very tough.

It has to be able to fit anywhere a small adult can fit. It has to be able to climb anything an adult can climb. There has to be a workable communication strategy (wirless, wired) through tunnels of solid rock. And it has to all that well enough not to need frequent retrieval.