November 05, 2005
In which we are out of sight in the night, out of sight in the day
Just before sitting down to a drink at a sidewalk café along the Embarcadero, I found myself wondering about which jobs society deems "tip-worthy" and how restaurants, especially, are able to regularly under-pay their staff because of the collective anticipation of tips. 10%? 12% 20%? A sawbuck on top of a benjamin? Tip on the cost of drinks, or $1 per, plus the percentage of the food? How does it work? Why ca'n't restaurants around here pay a living wage, and not force the ignominy of a tip jar on every coffee-shop counter from the Haight to Potrero?
"Excuse me, I didn't realise you had a degree in medicine. Are you a doctor? Are you a doctor? Answer me, please. Are you a doctor? Okay, then you admit you do'n't know what you're talking about." This is such a great movie. I saw it by myself at the Pittsburgh Playhouse in autumn of '92.
November 04, 2005
In which we defend against the rainy season
As the rain begins falling in San Francisco, some comments on fenders:
Kent Peterson and his amiably-recycled coroplast; Drew on wooden fenders, cheerfully recycled from discarded window-frames; the River City Bicycles' Full Wood fenders are beautiful to behold.
November 03, 2005
In which it is a selective sort of engineering
arup and co. are taking none of the blame for the designed-by-committee Millennium Bridge shenanigans: the current fashion blames the pedestrians on the bridge of collusion in causing structural instability through collective synchronisation. Not quite as dramatic as Galloping Gertie, perhaps, but frightening nonetheless.
Revealed: Why London's Millennium Bridge wobbled
Wed Nov 2, 2005 6:08 PM GMT
By Patricia Reaney
LONDON (Reuters) - A natural phenomenon rather than a design fault caused London's Millennium Bridge to wobble and sway, forcing its closure just two days after opening in 2000.
The elegant pedestrian walkway was conceived as a blade of light linking the south bank of the River Thames to the City of London.
But as large crowds walked across the steel structure on opening day in June 2000, the 320-meter long bridge swayed from side to side because of a phenomenon known as collective synchronisation.
"The phenomenon was that people who were walking at random, at their own favorite speed, not organized in any way spontaneously synchronized," said Steven Strogatz, of Cornell University in Ithaca, New York.
"That's the phenomenon. Why did they all start moving in step? They did it unconsciously. That is what nobody had thought about and engineers did not anticipate."
The applied mathematician and expert on the phenomenon said collective synchronisation is now something engineers will have to consider when designing bridges.
He and colleagues at Cornell and other universities in the United States, Britain and Germany have devised a theory based on what happened to the Millennium Bridge to estimate how much damping or stabilization is needed in footbridges.
Their findings are published in the science journal Nature.
"We think our theory will provide some guidance to help engineers avoid the problem," Strogatz said in an interview.
Certain coincidences must occur for collective synchronisation to occur. In the case of London's wobbly bridge, it was large crowds walking across a flexible footbridge that vibrated at a frequency of one cycle per second, which just happened to be the same frequency as humans walking.
"The people were resonating with the bridge," said Strogatz.
As the bridge started to move, people would get in step with the sway to steady themselves. They widened their stance to make it more comfortable to walk and inadvertently made the wobbling worse.
"A lot of people were blaming it on the beautiful innovative structure, the design of the Millennium Bridge itself, which was a radical design," said Strogatz.
"But that is not true."
Collective synchronisation occurs in nature when crickets start chirping in unison. In some parts of the world, fireflies blink on and off in perfect synchrony like a Christmas tree. The monthly cycles of women living together have also been known to synchronize.
"It is always very striking and almost spooky because it is like order coming out of chaos," said Strogatz.
After 5 million pounds worth of modifications to steady the structure and 20 months of closure, the Millennium Bridge successfully reopened in February 2002.
Lady Chatterly's Lover
In a rush on the way out the door this ack emma, I grabbed a hardbound book from the shelf. I sat down in my seat on the bus to find out that it was the stupefyingly dull "Lady Chatterly's Lover," which I had last attempted to read while spending an afternoon in Rockridge (indeed, a receipt from a nice wine-bar in that area served as the bookmark). And I again got about sixty pages into the book and could not suppress my boredom any longer. I turned out the window and watched traffic flow past.
November 02, 2005
In which I day-dream about automobiles
Cars I once thought I would like to own:
1971 Mercedes 280SEC
1956 Nash Metropolitan(and it probably would have its hood up most of the time!)
1984 Toyota LandCruiser FJ60
Volvo 122 waggon (I did have a 1984 Volvo 240GL waggon, which is also quite splendid)
I did (briefly) drive a burgundy-and-black Mercedes, aka Blinky, which "smelled like money" according to one of my neighbours: now all I have left is the three-cone pininfarina air horn and a single fog lamp (the other flew off somewhere on the road between Breezewood and DC); the Volvo, known during its brief life as Moby; and Winnie the Poopmobile, a handsome brown FJ60 which spent more time on the back of a tow-truck than actually off road anywhere.
In which multicast is our king
Stuart Cheshire, designer of Zero-Configuration Networking (that's RFC 3927 to you IETF fans out there) quoted Antoine de Saint-Exupéry today with respect to protocol design: "You know that you have finished not when there is nothing left to add to the protocol, but when there is nothing left to take away from the protocol." Saint-Exupéry was an aviator, and I suspect that he was referring specifically to aircraft design when he said that "La perfection est atteinte non quand il ne reste rien à ajouter, mais quand il ne reste rien à enlever." I think the same applies to bicycles!
November 01, 2005
In which I jump the turnstile and you have to pay the fee
October 31, 2005
In which we sing the Internationale
Two of my colleagues stood outside my office, poring over the bicycle parked in front. They finally came in and commented on "What an international bike you have!" 'tis true: an American-designed, Chinese-built frame hung with a French chainring and crankset, Japanese cog on an American hub laced to a much-beloved French wheel (with an Italian tyre in the rear, French on the front). The pedals are a Japanese copy of the classic Italian track pedal, with French leather straps. My California panniers mount to a gorgeous lightweight German rear rack. The stem and bars are a mix of Italian and Japanese components, mounted on an American headset. The corks stuck in the handlebar ends are American and French. And the saddle is, of course!, English.
October 30, 2005
In which raccoons appear, again
More raccoons, courtesy ritchey, who is in a different part of the Golden State entirely . Last night Anna and Matt saw the little ring-tailed beggars scampering across the street, looking about as tidy as the other Lower Haight denizens wandering about in their amazon costumes.