The School of Mechanical Engineering at the University of Bath where I work is one of the country's top teaching and research departments. We spend our days making aircraft fly further on less fuel, devising revolutionary new computer-aided design techniques, and worrying about why the car park is damp.
If you want to know about the aircraft and the CAD techniques, send me a stamped addressed A4 envelope for a free copy of the current Research Report. For now, I'm here to tell you about the car park.
It all started first thing on Monday 19 February. I parked, got out, knelt down, and crawled round to the front of my car. I'm a senior lecturer, so the security guard pretended hard not to notice; if I'd been a student he would have just thought this normal behaviour.
It was cold - I guess about four degrees - and sunny. The cars were all casting sharp shadows.
The tarmac where the shadows fell was bone dry. The tarmac in the bright sunshine was damp with dew.
Now this is the sort of thing that can get an engineer with no lecture to give first thing into a tizz. Or even into print. Sunshine heats the ground up. Shadows stay cold. The hot bit should be dry and the cold bit wet, not the other way round. I dabbed my finger in a shadow to see if the dry bit was actually unmelted frost. It wasn't.
I thought about this for quite a while. Then I got up, went to my office, and emailed my colleagues to see if any of them could come up with an explanation.
The result was a deluge of answers containing the sort of deep and subtle scientific insights that one doesn't normally see anywhere these days other than on The Girlie Show.
Steve Hampson (researching control systems) corroborated what I saw and yearned for the old country: "I too noticed this and thought it was just another strange thing that happens on this side of the globe. . . Steve (from New Zealand where life is simple)"
And there were I-dunno-but-here's-another-problem replies.
David Barker (the Computer Manager) said, "When the ground . . . is wet from dew then during the day it begins to dry, around each tiny stone there is a circle of dampness that remains . . . This can happen on even a windy day when you would think that because of the direction of the wind the damp patch would not surround the object equally, but it does. By the way, have you ever considered train spotting?"
Dr Derek Longmore (lecturer in Vibration and also Computing) manages efficiently to combine the study of both meteorology and natural history whilst also taking healthy exercise: "Returning from a run at dusk on a very cold day it was very easy to avoid treading in cow turds because they were white with frost whilst the grass had no frost on it."
My own idea here is that the bucolic turds are darker than the grass and so radiate heat into the evening sky more efficiently and thus get colder (though clearly they started out warm).
Dr Nigel Johnston (lecturer in Systems Engineering) pointed out that the plot - I use the term loosely - of a recent X Files hinged on a person's absorbing dark matter (you know - the missing bit of the universe needed to get its rate of expansion right) and then casting a shadow which made anybody upon whom it fell disappear. He said that he thought a similar phenomenon could be occurring in our car park.
This seemed to me like a solid, honest, straight-down-the-line theory. It could also explain why the X-filers always shine those somewhat ineffectual narrow-beamed torches into darkened rooms, rather than using what you on Earth call a light switch.
I also had about seven theories of varying degrees of seriousness, the joint runners-up being Janet Harvey (professorial secretary) with: "The wind had blown the surface of the tarmac dry, but the sun had drawn the dampness of the tarmac to the surface," and Dr Diane Mynors (researching metal forming by forging) with: "When the sun warms the surface of the asphalt the temperature of the water lying in the crevices also increases. As water at four degrees has a higher density than at other temperatures this heating causes the water to expand and hence appear on the surface."
So finally - Meryl, would you open the envelope, please - the first prize of a gift-wrapped gold-plated Ockham's razor goes to my colleague. . .
Bill Crowther (researching fault diagnosis), who said, "The ground in shadow was at or below zero degrees due to overnight cooling, whereas the ground in sunlight was considerably warmer. During a brief snow shower, ice crystals were blown across the car park. On the unshaded ground, the ice melted on impact, whereas on the shaded ground, the ice crystals were blown along by the wind. This would leave a dry patch in the shaded region."
So there you have it. As often, a mystery is more fun than an answer. But without answers, we'd still be terrified by every mystery.
Now I must sign off - I have to go and soak some Hula Hoops. I want to see if I can squash them to make them go square.
Does anybody know what colour a chameleon goes if you put it on a mirror?