Graham help!

[CaverA]

What does this word mean? I've searched the on line dictionary and they don't know.

Ponor - I've included the full sentence.

"Morphological investigations show that from the early Holocene onwards, Niedzwiedzia Cave belonged to a closed system, and contact to the surface only existed by ponors. (Don,1989 in Pflitsch, 2003, p4) 

Tar. 

 

[Peter Burgess]

Google is your friend.

http://www.speleogenesis.info/glossary/glossary_by_letter.php?Authors=p

(Slavic.) 1. Hole or opening in the bottom or side of a depression where a surface stream or lake flows either partially or completely underground into the karst ground-water system. A seaponor is where sea-water flows or is drawn into an opening by a vacuum in karstified rock [20]. 2. Hole in the bottom or side of a closed depression through which water passes to or from an underground channel [10]. Synonyms: (British.) swallet, swallow hole, stream sink; (French.) ponor, aven, gouffre, perte; (German.) Schlund, Saugloch, Schlinger, Ponor; (Greek.) katavothra; (Italian.) inghittitoio, capovento; (Russian.) ponor; (Spanish.) sumidero, ponor, perdida; (Turkish.) su yutan; (Yugoslavian.) ponor, utok, poziralnik, pivka. See also swallow hole.

 

[graham]

Its foreign for "swallet", basically.

 

[cap n chris]

Well done, Graham; you're an encyclopaedia of arcane caving knick-knackery.   

 

[graham]

Who needs Google, eh, Chris

 

[CaverA]

Got another one for you. Just can't get my head around it.


Wigley and Brown devote a lot of space to relaxation lengths, defining them as "with the difference reducing to 1/e, where e = 2.781 of its initial value after one relaxation length."

That's just 

The on-line dictionary defines it as:

the time that it takes for an exponentially decaying quantity, as radioactive particles or transient electrical currents, to decrease to 36.8 percent of its initial value. Now it kind of makes sense, kind of.

The second definition is better, I think?

 

[cap n chris]

Whether you express it as 1/2.781 or 36% surely makes no odds, though?

 

[CaverA]

Your right Cap'n, been surfing through academic journals for the last two days....my brain is very fried. The second definition I would class as being more user friendly, I'll go with that.

Thanks for pointing that out.

 

[kay]

Depends who the user is. 36%? Now where the heck did that come from? e I can understand. I can even recognise 2.718 as being e, but 1/e is not a number that sticks in my brain.

 

[Elaine]

What is 'e'? Is it an electronvolt? I can't remember.

 

[Piglet]

It's all complete gobbledegook to me!!! 

 

[Peter Burgess]

Anne, you need to read

http://www-groups.dcs.st-and.ac.uk/~history/HistTopics/e.html

Come back tomorrow, and we'll see how well you have done your homework.

Whether it's anything to do with the original question is another matter.

 

[Dep]

Depends who the user is. 36%? Now where the heck did that come from? e I can understand. I can even recognise 2.718 as being e, but 1/e is not a number that sticks in my brain.

1/e is a factor in any exponential decay equation but more usually written as e-1
Jees! my maths is rusty 

 

[Piglet]

I have a strange feeling this might be why I failed my maths 'O' level!!!  :blink:

 

[paul]

I have a strange feeling this might be why I failed my maths 'O' level!!!  :blink:

Is that why you wear your helmet at a "jaunty angle" (see avatar photo...)?

 

[Elaine]

What is 'e'? Is it an electronvolt? I can't remember.

Of course, e is a constant - I can't believe that I put that dumb comment.

I know what big E stands for - Elaine.