November 20, 2008: Whole Lotta Hole

xoxoxoBruce • Nov 20, 2008 1:31 am
Just like getting a BJ from grandma... don't look down.
Hold on to your specs while peering down here. You'd have a long climb to the bottom if they fell off.
This rocky chasm in China is one of the world's deepest underground shafts. It stretches down for an astonishing 3,100ft, or 1,026 metres.
An international team of cave explorers who discovered the cave, near the village of Tian Xing, are seen descending into the abyss.


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The picture was taken by photographer Robert Shone, 28, of Manchester, who spent two months with the climbers documenting-their explorations. Camping underground for four to five days at a time, the team were able to explore the extensive network of caves and tunnels.Though unimaginably deep, the Chinese caves are actually dwarfed by others across the globe.
The world's deepest cave is Krubera in Georgia, which is 6,822ft deep (2,080 metres), followed by Lamprechtsofen in Austria (5,354ft or 1,631 metres) and Gouffre Mirolda in France (5,335ft or 1,626 metres).


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Link
Kolbenfresser • Nov 20, 2008 4:35 am
Amazing. I'm gonna start a second career as a cave explorer right away.
Is this the cave where the Chinese Government dumps all the executed people? It shouldn't be that deep anymore...
ZenGum • Nov 20, 2008 5:43 am
Should we tell Sheldon there is a giant vertical shaft in the IotD?


I just did some calculations, and if I got them right, if you tossed a stone into that shaft it would take 14.5 seconds to hit the bottom. There would be another three seconds before the sound reached you back at the top.
When it hit it would have been doing 510 kph (317mph) less wind resistance.
footfootfoot • Nov 20, 2008 10:53 am
I thought terminal velocity was around 200mph?
sweetwater • Nov 20, 2008 10:57 am
Obviously the work of a big Horta with locomotion difficulties.
glatt • Nov 20, 2008 11:00 am
It's really cool how smooth/straight that hole is. I'm no geologist. There's probably some simple explanation for how it was formed, but I can't imagine what that would be.
lumberjim • Nov 20, 2008 11:02 am
THIS THING:
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Cicero • Nov 20, 2008 11:16 am
I just want to throw a hot dog down there. Zen can calculate it for me. And Sheldon could laff.
Sheldonrs • Nov 20, 2008 11:23 am
ZenGum;506021 wrote:
Should we tell Sheldon there is a giant vertical shaft in the IotD?...


I've been aware of you for some time. ;-)
Cloud • Nov 20, 2008 11:37 am
spelunking will NOT appear in my obituary
Sheldonrs • Nov 20, 2008 12:03 pm
Cloud;506177 wrote:
spelunking will NOT appear in my obituary


But "Horrendous personal pleasuring device accident' will. :D
Cloud • Nov 20, 2008 12:04 pm
oh, one can only hope!
HungLikeJesus • Nov 20, 2008 12:23 pm
ZenGum;506021 wrote:
Should we tell Sheldon there is a giant vertical shaft in the IotD?


I just did some calculations, and if I got them right, if you tossed a stone into that shaft it would take 14.5 seconds to hit the bottom. There would be another three seconds before the sound reached you back at the top.
When it hit it would have been doing 510 kph (317mph) less wind resistance.


I got slightly different numbers, but I didn't account for bouncing off the walls on the way down.
SteveDallas • Nov 20, 2008 12:36 pm
What about terminal velocity? I guess you couldn't figure it unless you knew the exact size & mass of the stone and figured out the air resistance.
HungLikeJesus • Nov 20, 2008 12:38 pm
All you really need is the mass, frontal area and drag coefficient.
Clodfobble • Nov 20, 2008 1:09 pm
How can the air be any good way down at the bottom? I would think they'd need breathing apparatus at some point in their explorations.

Also: better hope the bulbs don't burn out on those flashlights.
Cicero • Nov 20, 2008 1:10 pm
I like it when HLJ talks dirty. :)
barefoot serpent • Nov 20, 2008 2:03 pm
glatt;506145 wrote:
There's probably some simple explanation for how it was formed, but I can't imagine what that would be.


Limestone rock (soluble) + water (slightly acidic) + time (millions of years) = karst topography
dar512 • Nov 20, 2008 2:10 pm
SteveDallas;506205 wrote:
What about terminal velocity? I guess you couldn't figure it unless you knew the exact size & mass of the stone and figured out the air resistance.

And whether they have coconuts tied on.
HungLikeJesus • Nov 20, 2008 2:57 pm
Perhaps someone in Argentina dug a hole to China.

Here's an elevation map of the cave from 2002 (from here). (I think it's the same cave. The link is to the explorers' journals.)

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footfootfoot • Nov 20, 2008 3:25 pm
glatt;506145 wrote:
It's really cool how smooth/straight that hole is. I'm no geologist. There's probably some simple explanation for how it was formed, but I can't imagine what that would be.


Tunnelling like that is usually caused by small clumps of baking soda or baking powder which weren't properly sifted. That is why it is important to sift all your dry ingredients, especially if they are clumpy.
Undertoad • Nov 20, 2008 3:38 pm
I would guess that layers of permeable and impermeable rock are created over ages, and then pushed around as a part of tectonic plate collision, with some layers being pushed close to vertical, and then a process of erosion occurs and the impermeable parts don't crumble in for some reason. That's just a guess.
glatt • Nov 20, 2008 3:53 pm
It's clearly water doing it, but I don't understand why the water eroded straight down instead of making a more horizontal cavern with stalactites and stalagmites. Those caverns are in limestone too.

It's so perfectly straight in the photos and we all know that water almost never goes perfectly straight. It winds and meanders all over the place following the path of least resistance.

Barefoot's karst topography link makes a lot of sense the way it's drawn, but I'm not fully convinced. This shaft reminds me of peeing into a snow bank. Dogs, I mean, not me. You would never catch me peeing into a snowbank.
Wombat • Nov 20, 2008 6:48 pm
Not just any water... falling water. Water does go in a perfectly straight line when gravity makes it fall straight down and there is no wind.

Makes me think of Gandalf and the Balrog...
Ibby • Nov 20, 2008 7:15 pm
HungLikeJesus;506255 wrote:
Perhaps someone in Argentina dug a hole to China.

Here's an elevation map of the cave from 2002 (from here). (I think it's the same cave. The link is to the explorers' journals.)

Image



they named all the different parts after... Doctor Who?

that. is. so. COOL.
footfootfoot • Nov 20, 2008 8:52 pm
Sheldonrs;506192 wrote:
But "Horrendous personal pleasuring device accident' will. :D

You can't really dust astroglide for fingerprints, can you?
Gravdigr • Nov 21, 2008 8:43 am
Looks kinda like the asshole of the earth. And here I thought it (the a-hole of the earth) was in a trailer park here in Kentucky.
Diaphone Jim • Nov 21, 2008 4:11 pm
No comments on the "grandma" quip in the intro, but I'm not sure why. One time I think of it I laugh out loud, the next time I shudder. Is it an old IOTD standby? Or just something xoB managed to sneak in?
Speaking of IOTD standbys, when I was in Vietnam there was a nearbly unit called the 174th Assault Helicopter Company, with the motto or handle "Dolphins and Sharks." The dolphins were the "slicks" or troop carriers and dustoffs and the sharks the gunships (Cobra, e.g.). Have they come up in the d/s bandinage here?
dar512 • Nov 21, 2008 5:20 pm
Bruce is just a witty guy.
Sundae • Nov 21, 2008 7:41 pm
Diaphone Jim;506656 wrote:
No comments on the "grandma" quip in the intro, but I'm not sure why.

I thunked it. But I have a quota of snarky comments per day, and I was saving them up for Flint.
spudcon • Nov 21, 2008 10:58 pm
We have a bigger hole than that here in the states.
It sucks up trillions and trillions of dollars annually,
[FONT=Tahoma][SIZE=5][COLOR=blue]Never to be heard from again[/COLOR][/SIZE][/FONT][FONT=Tahoma][SIZE=4][COLOR=blue]! [/COLOR][/SIZE][/FONT]