weirdo

Edited to say:

because thinking about them clothed is less fun, presumably.

Do people really tend to walk in circles when they're lost?

I know it happens sometimes and it is a bit of an adventure/survival telly program cliche, but does it happen more often than chance?

New Scientist ran an article on movement of animals/humans/etc. and how they seemingly follow random routes, but are in fact following a pattern. It's on their website (for a subscription fee, however):

http://www.newscientist.com/channel/being-human/mg19225791.800-locating-locating-locating.html

This subconscious way of moving may not quite be the same when you're paniking or if you can't see where you are going, but it explained the way Ikea and car parks make you lost- they make more money that way.

Mr Fuller, fraid I don't have an NS subscription but remember reading years ago about animal foraging patterns, some of which define a spiral.

 Re planning of shops etc, someone told me that if allowed to wander around a maze, most people end up making more turns to the right than the left, and that supermarkets are designed with this in mind. IKEA just seems designed to reduce people to sobbing relief on eventually finding the way out!

Here is one for you John

When using a screw on top gas stove - i.e. a Micron or pocket rocket. What is the best way to keep the canister warm:

a) insulate it from the grond with, say, a piece of foam mat.

or

b) put foil under it to reflect the heat of the pot and burner.

???? 

Hi FB,

good practical question that would probably be best answered by someone who has tried it! I use an old Whisperlite on Coleman white fuel so haven't had much experience of this design of stove. But in theory...

I would say that insulating from the ground using foam could be a bit risky. I imagine that contact with the hot metal parts could melt the foam and give off some pretty noxious gas. And foam is a good insulator against conduction but I don't think this would be the primary mechanism of heat loss.

Foil under sounds both safer and, probably, more effective; you are trying to prevent heat loss downwards. As the gas canister stays relatively cool, this is mainly going to be from radiant heat from the hot parts near the flame. (There isn't much you can do about convective heat loss except to shelter the stove from the wind). Foil will take care of the radiant heat loss. It is for this reason that my Whisperlite came with a foil skirt.

Not sure about melting the foam John.  If the canister gets hot enough to do that you are in serious danger of it exploding and turning into a fireball.  Roger Caffin in Backpackinglight.com thinks people tend to worry too much about this happening, but gives the rule of thumb that if the canister is not too hot to hold comfortably with a bare hand there is no danger.

My main concern about the foam would be flammability. Most plastic foams will burn quite readily and this would be very risky if cooking under a porch. The most spectacular example I have seen is this:-

http://www.ccnr.org/browns_ferry.html

Andybr

The cannister gets cold because of the latent heat of vapourisation taken up as the gas inside it boils off. Consequently, the cannister can be at a lower temperature than its surroundings. This will usually be the case using a 'remote' type gas stove; for the type that screws directly onto the cannister, heat conduction from the burner will heat the cannister up. If the cannister is colder than its surroundings, any insulation around the cannister won't be keeping it warm - on the contrary the insulation will be slowing the cannister's absorption of heat and so keeping the cannister cold.

Therefore, foam insulation under the cannister can actually be counter-productive.

Foil underneath will encourage a little more radiant heat to reflect back to the cannister. This will have some positive benefit, but I suspect very little and not enough to be significant.

with a remote canister (a la my Epigas Alpine, rubber hose etc), one way to warm up the canister is to stuff it inside you clothing. Bloody cold though. So, the science question;

Would heat lost from the body via this technique be greater than or less than, or even equal to, the heat gained from having a hot cup of coffee? 

Given that you get far more energy from burning the vapourised gas, and assuming that most of the energy is transferred to the coffee, you should get a net gain in energy.

Yeah but what happens if you let it go cold?

FB...

it would depend how much sugar you put in the coffee!