Unnatural Science

I'm marking IB. Again. Trying to remember all the things that I knew lots about once. Amazing how it all comes if not flooding at least trickling back along with the sense of either hilarity, outrage or despair at what students write down. For some, hope indeed springs eternal, at least in the temporal time-warp of the exam-room. Physics is agonisingly, piercingly precise and there are people out there of strange persuasion who like to both make up exam questions then tell you what they think the answers should be. Such persons are known as Chief Examiners. I am constructing a mental picture of mine. I expect him to be conservatively dressed, probably in a grey suit with a plain shirt and tie, together with polished black shoes whose laces are exactly the same length. Little Mr Neat without the centre parting. Shortening his name to an affable “Mick" or "Dave” earns a frosty, disapproving glance. Probably from his wife, should he ever have summoned the nerve to acquire one. Assuredly, he is introverted to the point where he still blushes, slightly but distinctly sociopathic, perhaps obsessive (no perhaps about it), and certainly compulsive. A grown up version of Sheldon in "The Big Bang Theory". If anybody I happen to know should say "Ah" at this point, they can consider themselves unfriended from Facebook.

"Interesting. You're afraid of insects and women. A ladybug must make you catatonic."

In between banging my head against the wall it was quite nice to let what's left of my mind wander and think about when the immutable laws of nature got bent a little bit. Neglecting the halving of the angular velocity of the Earth in Judges 10, where a day became 48 hours, the thermodynamics of Pentecost sprang to mind, by way of example. Did the entropy in the Upper Room increase dramatically, I wonder? The tongues of fire – was anything actually ignited, or was the internal energy throughout the room just raised by a few kilojoules? After all, there'd've been plenty of oxygen from the 'rushing, mighty wind' to support combustion. And, what about calculating the average power during the Ascension. Let’s suppose the ‘ascensee’ had a modest mass of 60kg, hence a weight force just shy of 600N. Let us further suppose that to save a crick in the apostles’ necks, they only had to watch for a minute until clouds covered Him. If the cloud cover that day was at 1200m, that means an ascension rate of 1200m/60s or 20m/s. Power being force times average velocity, the average power would have been 600N x 20m/s or 12kW. Isn’t physics fascinating…

Finally – always save the best till last - what about this.

“March around the city once with all the armed men. Do this for six days. Have seven priests carry trumpets of rams’ horns in front of the ark. On the seventh day, march around the city seven times, with the priests blowing the trumpets. When you hear them sound a long blast on the trumpets, have the whole army give a loud shout; then the wall of the city will collapse.” 

(Joshua 6).

Excellent. Lots here to think about. Roman armies broke step on bridges so they wouldn’t collapse. A steady tramping round the walls for nearly a week might have set up a subsonic resonant vibration in the foundations. The citydwellers might have noticed a bit of subterranean rumbling, like a Tube train, perhaps the odd flake or two of mortar falling off the ceiling but thought nothing of it, after all the apartment was insured. Seven times on the last day, just to pound the foundations to pieces. Then, the good bit. If you’ve never heard a shofar being blown by an expert, it’s worth hearing. Now imagine quite a number of priests, well-practised and non-smokers, giving it large for an extended period. The Noise Abatement people would be knocking on the door within minutes. Long blasts would be like standing in Earl’s Court Road with a Guns N' Roses concert going on inside. People take cover, scuttling for their prized possessions as the walls require a different resonant frequency to the foundations and begin to vibrate, as the textbooks say, with ‘increased amplitude’. The wall of shouting does the rest and eventually, bricks and mortar being quite brittle, the whole structure just caves in. For those who don’t believe a word of it, watch what happened to the Tacoma Narrows Bridge. No shouting or marching feet this time, just a 'mighty rushing wind'. The bridge collapsed in November 1940 because of a resonant effect between the material of the bridge and the wind whistling down the gorge, rather like blowing a reed wind instrument to make a loud sound. So, ha. Thanks to my other blog for this. 
Postscript. Pentecost Sunday was last week and we were all asked to wear red. I was going to go as Santa Claus, but thought better of it.