## The puzzle of the two switches (harder)

See “the puzzle of the two switches” for a seriously hard logic puzzle. This is a variation of the same puzzle to make it even harder. The puzzle is exactly the same, except that you can no longer assume anything about the initial state of the two switches. Each switch could be off or on. […]

## The puzzle of the two switches

You are one of ten clever people about to be locked in a strange prison controlled by a computer. You will each be sent to individual isolated cells with no possibility of communication. Randomly, one cell door will open and the prisoner will be allowed access to a central room that contains two on-off switches, […]

## A Framework for Ethics

Just ran across this link http://faculty.plts.edu/gpence/html/kohlberg.htm Kohlberg describes the following.

## How expensive is desalination actually?

Couple of people have asked me about this, and I did a little research. The quoted energy usage for early model reverse osmosis desalination plants is around 6 Watt-hours/litre. More modern plants appear to be more efficient and the quoted figures for WA and Vic are 4.1 and 4.6 respectively. A kilolitre of water costs […]

## The Puzzle of the Five Cards

Andy and Bert have worked out a neat card trick, but they need your help to do it. The puzzle for you is to figure out how the trick works. The essence of the trick is that you shuffle a normal pack of 52 cards thoroughlyand give 5 cards to Andy. Andy keeps one card, […]

## Three Gods: the “Hardest Logic Puzzle Ever”

This statement of the puzzle comes from Wikipedia. There are subtle variations, but only one puzzle. Three gods A, B, and C are called, in some order, True, False, and Random. True always speaks truly, False always speaks falsely, but whether Random speaks truly or falsely is a random matter. Your task is to determine […]

## Pest toast please ignore

If you really have nothing better do then click the link. Don’t say I didn’t warn you.

## Are you a Rational?

Many people have had taken a Myers-Briggs Type Indicator (MBTI) or Jung style of psychological test. What you get back is a 4 letter category such as ENTJ, which is supposed to be an assessment of how you perceive the world and how you like to make decisions. http://en.wikipedia.org/wiki/Myers-Briggs_Type_Indicator Here is a free one you […]

## The chemistry of methylamphetamine

From a strictly scientific/chemical point of view, I’ve often wondered what actually goes on inside a “meth lab”. This article explains all, and provides enough info to roll your own. Obviously this is something you should not try at home. http://sbillinghurst.wordpress.com/2009/08/13/pseudoephedrine-acetate/ The essential components are: Pseudoephedrine (Sudafed cold tablets) Red phosphorus (road flares) Iodine (medical […]

## Private jet is cheaper than Bugatti Veyron

According to Autocar, an anonymous Bugatti Veyron owner has found maintenance on his 400 km/h hypercar so expensive he trailers it to his favorite roads, then flies there in his private jet to save money. Apparently, the English Bugatti owner was tired of paying \$21,000 for a routine service, \$38,500 for a set of four […]