h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

An interesting theory. I posted another one today as P50806.

I am impressed by the such concentrated thought being directed towards doors - very interesting. However if you watch Friends you should know that the purpose of doors is to prevent people seeing through into other room: "I can't see through it!"
"And so the inventer of the door is satisfied"
I realise this knowledge of Friends is somewhat tragic but I'm not sure those are the write words. Besides, I can't think of anything else to write related to doors.

I can't believe I wrote write instead of right! Now I'm just wasting space.

Then could we in fact infer that, since before the invention of the door there must simply have been just large holes, and now the hole is tiny (a keyhole), there must have been some intermediate states where the hole was moreorless the same size as the door. Is the average stable door an example of this - half door, half hole? Maybe our discussion will unlock the secret.

I find it also intreguing that the thickness of the door (or LATD) has no actual effect on the transporting powers (i.e. a thick door can not transport more people than a thin one). Also the seethruieness (a better word anyone?) of the door is not lessened by the thickness. Why, then, in the middle ages dit everyone have thick doors with iron bolts through them.

There must be some diference between having a thick door and a thin one. Simple conduction theory tells us that a thin object will have a higher resistance (in terms of electricity or heat). If as you say, olden doors were of thick metal, they would have had a very low resistance. Nowadays low resistance doors are de rigeur. This enables various conclusions: 1) the doors have become more efficient, and require less energy to work, 2)the door-openers amongst us have become weaker, and don't have the strength to open thick doors (witness: automatic doors, especially in futuristic TV shows), 3) concern over our heads' well-being has meant we have softened up the door to prevent serious damage when opening it rashly.

I feel led to the conclusion that not being able to see through them is the sole purpose of the door.... The only other thing I can think of is connected to the human wish for "privacy" and "space" - the door acts as a screen between themselves and the outer world creating the impression of security and safety.
The thickness of the door issue may indicate a wish not to have conversations overheard or may be merely a result of inefficent central heating during the "mega-thick" door era meaning that they were just an extra form of insulation.

I have still not figured out the point of having doors with holes in them, or at least ones that have glass in the spaces. Surly this defeats the whole idea of the doors for privacy and so therefore points at the purpose mainly for reduction of heat loss. As well as the general thinning of the doors some people have resorted back to adding metal features to descuise the thin door as a boneie-fide ye olde door. Whereas others have gone the whole hog and compleatly made the door out of glass. This has the rather humorous effect of tricking people into thinking there isn't a door there and then walking into the glass.
Nick

My father actually did walk through our entirely glass back door......

Hay. That's funny.

Indeed it does seem so - in retrospect.

Doors come in various types :

The door with a window : meant to make the neighbours go green with envy or to invite burglers into the place because the insurance has been tampered with.

The plain door : privacy, heatloss-prevention, you said it.

The virtual door(a.k.a. the hole).