has been  used to find voids in pyramides: https://physicsworld.com/a/muons-reveal-hidden-void-in-egyptian-pyramid/ Basically, if you get more muons coming from a specific direction it indicates there is less rock in that direction. Unfortunately it needs the detectors underneath the void

Not me. I was warm and dry on Thursday but in the streamway on Sunday. 

OFD is open and was actually quite busy last weekend As suggested is does flood quite quickly after rain. 

Hi, I have a partial upper plate with my three front teeth. [Consequence of an RTA whilst a teenager] I've done a decent amount of dives (400ish) almost all open water but fairly technical so I've had to swop regs under water.  Always dived with my plate in and never had a problem [If you...

The cable is used for comms which could be for diver support but is also to give a communication link to any trapped group

Access arrangements at :https://www.swcc.org.uk/joomla-swcc/caving/local-caves-access/2-uncategorised/79-access-to-ofd Most visitors are with a club with an annual permit

yes : because it gets pulled out again

Yup : bang on.    Happy days from 2018.....

We probably should not be caving.  The biggest issue is that if an accident /rescue is required then that with put an extra strain on a system already under extreme pressure.  Nobody (I presume) goes caving thinking that they will need rescuing but nevertheless a small percentage end up...

For Ogof Dan Y Lleuad Wen,  I found the grid reference on http://www.ogof.org.uk bang on last year.  This has          SN 75794 18665 whereas  CCR is SN 75801 18645 there is not much difference in these but it is in a quite shallow shake hole (with much bigger and more obvious shake holes...

I've never seen the traverse protected. The survey is actually very good however the cave is very complex and 3-D in this Area.  There are several layers of passages. The survey represents this in colours.  The normal route is the darker yellow of the survey. The paler/greeny yellow is the...

How about https://www.youtube.com/watch?v=JIWA6E8PK-g

( -202 Sqrt[2] - 135 Log[3 - 2 Sqrt[2]]  )/16 ..thats quite a PIN!

There is no minimum age for entry to OFD as far as I know [I was DO at SWCC this month..] and loads of younger cavers do indeed go caving there.