illuminating science

This is faintly creepy - a cat that can predict deaths in a hospital. It’s not quite like a feline Grim (ala Harry Potter) where the cat turns up and they just die - rather that the cat somehow senses when they’re almost ready to go and will curl up with them in bed. Apparently, they now call the patient’s family if the cat starts purring at the door, and it has given some families time to say goodbye they wouldn’t have otherwise had! The most likely explanation is some change in either the scent or sound of the patient (e.g., relaxed breathing) which the cat can detect, but it’s quite fascinating nevertheless.

(Of course, reading it, I couldn’t help but at least consider which way the causality runs here. It’s the old problem - correlation doesn’t imply causation. It could be the cat visits them because he senses they’re dying; but it could also be the cat, for example, aggravates their sinuses and tips them over the edge! I think that’s pretty unlikely though!)

Have you seen the incredible Water Powered Clock? Amazingly, it’s a clock that runs entirely on water! That’s right, just add water - that’s all you need! There’s also a water powered calculator and soon our cars, planes and computers will all run on water! Fantastic!

Not convinced?

I can’t really imagine how water could act as a fuel directly, and their explanation that “The internal converter extracts electrons from the fluid molecules and provides a steady stream of electricity to generate power for the calculator.” is vague to say the least.

I can only assume that it works like an ordinary battery and has something like zinc and copper electrodes that, in the presence of water, are slowly corroding and freeing electrons to power the calculator. If this is the case, the calculator would be powered by nothing more than a built in battery, using water as an electrolyte, and will eventually stop working. You wouldn’t be “extract[ing] electrons from the fluid molecules”, and to say that it is “earth friendly” and “powered by most any liquid” is misleading to say the least, and pseuodoscience at the worst - not at all up to the usual standards of Steve Spangler Science! (Which just has really cool stuff!)

In the interest of upholding my scientific dignity (and when a bit of googling didn’t immediately turn up better explanations) I’ve rattled off an email to Steve Spangler Science, and we’ll see what happens!

My life is over.

The PhDComics guy, George Chan, is coming to Australia in September. And I’m planning to be away, travelling around the Northern Territory doing science shows. I mean, the latter is good, but I’ve been wanting to see him for YEARS! *sigh*

Apparently he’s going to be at UQ on the 20th of September. If you’re a Brisbane person, definitely worth checking out. If you’re in the USA, just invite him!!!

[Here’s my take on the Hat Problem, collating a couple of different problems.]

Three brilliant mathematicians have been kidnapped by Dr Evil, who is forcing them to play the Hat Game! He lines them up, blindfolded, one after the other, facing a wall, so that C can see B and A, B can see A, and A can see nothing:

| A B C

He explains (despite Scott’s protests…) that he has two white hats and three blacks, which he will put on the mathematicians. And, he promises to let them go if at least one person can guess their hat colour correctly. But, he warns them, if anyone guesses incorrectly, he’ll have them all killed anyway.

Version 1:

Simply put, will the mathematicians be able to escape? How should Dr Evil arrange the hats?

Version 2 (leading questions):

When he removes the blindfolds, mathematician C quickly pipes up his hat colour. What was it?

Dr Evil, thinking it could just have been a lucky guess, blindfolds them again and gives them new hats. This time, when he takes off the blindfolds, there’s a pause - and suddenly mathematician B announces his hat colour. What was it?

Frustrated, Dr Evil blindfolds them again and changes the hats. Whipping off their blindfolds, he giggles evilly while they sit silently. Then, mathematician A happily announces his hat colour. What was it?

(Just for the record, Dr Evil threw them all into a pool of sharks with laser beams on their heads anyway.)

To celebrate the upcoming release of Harry Potter Book 7, I thought I’d write about something that always bugged me. At the end of Harry Potter and the Philosopher’s Stone (which I’ve just re-read) Harry and Hermione are trapped in a room, and have to solve a riddle to find out which of seven potions to drink. One will move them onwards to stop Voldemort from getting the Philosopher’s Stone. One will send them back to (relative) safety. Two will do nothing, and three will kill them. Hermione (brains of the operation) of course figures it out, but, frustratingly, we (the readers) apparently don’t have enough information to solve it ourselves! Here’s the riddle:

Danger lies before you, while safety lies behind,
Two of us will help you, whichever you would find,
One among us seven will let you move ahead,
Another will transport the drinker back instead,
Two among our number hold only nettle wine,
Three of us are killers, waiting hidden in line.
Choose, unless you wish to stay here forevermore,
To help you in your choice, we give you these clues four:
First, however slyly the poison tries to hide
You will always find some on nettle wine’s left side;
Second, different are those who stand at either end,
But if you would move onward, neither is your friend;
Third, as you see clearly, all are different size,
Neither dwarf nor giant holds death in their insides;
Fourth, the second left and the second on the right
Are twins once you taste them, though different at first sight.

The catch is that the third clue tells us that “neither dwarf nor giant” bottles are poison - and we’re not told which of the seven bottles they are.

So, I started wondering - what, if anything, can we deduce from this riddle? It’s actually a neat little problem, with a clever problem solving twist. Have a go yourself, then read on for my solution and how it connects to one of my favourite logic puzzles!

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