Here's a fun eye test:
http://home.comcast.net/~carlfogel/download/eyetest.jpg
The picture shows the items listed far below. They're lying
on a smooth black plastic notebook in a well-lit room about
18 inches from a shaded 100 watt bulb.
One of WalMart's finest $15 digital cameras was used to
capture enough detail at 8 inches that you can make out the
heads on the dime and penny, as well as the blurred
"LIBERTY" on the left of the penny and the blurred "1977" on
its right.
See if you can identify which objects some people claim only
careless or near-sighted riders fail to avoid while riding
at 10 to 40 mph (15 to 60 feet per second).
Decide for yourself how often and how successfully you
swerve to avoid such debris, dangerous or otherwise.
Remember, you can't avoid them all on a cracked asphalt bike
path or marked shoulder only six feet wide, littered with
sand, pebbles, leaves, and so forth, particularly if lots of
light-colored pebbles were included in the asphalt mix.
A blink, sneeze, or sideways glance would probably cause you
to miss spotting them (much less avoiding them) at 20 mph
(30 feet per second).
And it's a good idea not to be too close behind another
rider--it's hard to see these little devils through his
backside.
6 goathead thorns (the 6th may be hard to spot)
2 elm seedlings (they're covering the roads here)
1 piece of a twig
1 locust tree leaf
1 wicked-looking, but harmless unidentified seed
1 whirligig leaf
2 pieces of glass extracted and saved from flats
2 pebbles larger than others extracted from flats
1 2mm spoke elbow
1 knurled Presta valve stem retaining nut
1 rusted bicycle chain pin
1 toppled green plastic Slime Presta valve cap
1 upright black plastic normal Presta valve cap
1 #5 lead sinker
1 #15 Eagle Claw fish hook
1 1-inch wood screw
1 Sara Lee Premium Bakery Bun sesame seed
no sand, although there's plenty of it on my roads
no cactus (never had a cactus flat)
no long-burr thorns (harmless)
no 9mm shell cases (occasionally spotted)
Feel free to submit guesses in any form. Can you spot all 6
goatheads? If there's enough interest, I'll post the
answers.
For anyone curious, here's a clean, classic goathead posing
on a dime like a Playboy model on a bean-bag chair:
http://home.comcast.net/~carlfogel/download/Goathead.jpg
For foreign currency holders, a dime is about 18mm, and a
penny is about 19mm.
Real goatheads rarely choose shiny, well-lit backgrounds and
are often dirty, dark, and rounded down except for one
deadly spine. The six in the picture were obtained from the
soles of my sneakers after a fifty-foot walk, so they're
warranted to pierce 700c tires.
For fun, plant an object resembling any of the 6 goatheads
somewhere on a 15-mile ride and offer to buy a friend dinner
to spot it. Somebody will get a good meal out of it.
Happy squinting!
Carl Fogel