There were very few calls worth recapping in the first hour. Oh, there were some interesting ones, but they’ve all been repeats of information I’ve already covered here. We have to solve this gas problem, at least so that Bill can get back to more interesting topics.
Andrew (an eighth-grader) in Lafayette asked Bill why his radio emits static when he places a fluorescent flashlight near the radio. Bill told him that the flashlight has an electronic circuit that creates a high-frequency energy wave that is used to light the bulb (this circuit is called a ballast, by the way). He also surmised that the flashlight didn’t have very much electromagnetic shielding, and so the high-frequency field was strong enough at close distances to affect the radio’s circuitry.
Also, other sources of radio frequency interference can include faulty light dimmers and heating pads.
At the top of the second hour, Bill read a quote from Science, July 2, 1993 p.40:
High Emitters
It is becoming increasingly apparent that most of the mobile source emissions are caused by a small percentage of the vehicles. The compelling body of remote sensing and roadside data shows more-or-less, regardless of locale, that about 50% of the carbon monoxide and hydrocarbon emissions come from 10% of the vehicles on the road.
....
This data came from an experiment that collected 4,400 vehicles at 60 locations throughout the state of California.
....
However, a relatively small amount of the overall emissions comes from the very old cars, because they contribute such a small amount to the total vehicle miles traveled. What was not expected, was the high emission rates detected in the worst 20% of more recent model cars.
Betty in Larkspur had bought a packet of shrimp that she saw glowing in the dark, and asked Bill why they had this property. This was one of the few cases where Bill didn’t have the exact answer, although he did say it could only be one of two things. Either the shrimp are of a species that is phosphorescent, or there was a phosphorescent or fluorescent material that was packed with the shrimp (perhaps as some sort of preservative?). The catch is that Bill knows that most shrimp are not phosphorescent, and didn’t recall having seen any of the shrimp which are typically sold commercially phosphoresce.
One of the last calls of the show was from Grant in Mission Hill, who said that the cause was probably a bioluminescent bacteria that does phosphoresce. This bacteria needs Oxygen to produce the light, and since Betty had said the light was diminishing over the course of a few days, Grant said that one way to test the shrimp was to add some water to the shrimp (which would add oxygen to it), and see if they started glowing after that. Bill then suggested to dip a glowing shrimp in some antibiotic to see if that stopped the glowing (in other words, kill any bacteria that might be causing the glowing).
Richard in San Jose wanted to know what the white streams are that high-flying jets trail behind them, and how the term came to be. The answer is that the contrails are formed from the water vapor expelled from the engines, which is left over after the fuel has been burned, but this only occurs at certain altitudes and atmospheric conditions. The low temperature at such altitudes causes the water to turn to ice crystals, forming a trail that is essentially a mini cloud. The term is a combination of condensation and trail.
Richard also wanted to know what the similar trails were that spiraled off the wingtips of aircraft. These are caused because there is a pressure drop over the surface of the wing (that’s how it gets lift), which under some circumstances, will cause the air cool enough (remember that lower pressures result in lower temperatures, all other input or output of energy being the same) that the suspended will form ice crystals, again forming mini clouds.
Paul in Sacramento wanted to know how gasoline engines work. Bill gave a brief description, repeated here, with some elaboration on my part:
A car engine contains cylinders which contain pistons that move up and down, with the bottom connected to a crankshaft which converts the cyclical vertical motion of the piston into a constant rotating motion of the shaft. What forces the piston to move is a mixture of vaporized gasoline and air, which is then ignited by an electrical spark from the cylinder’s spark plug. That ignition forces the mixture to rapidly expand in volume, with enough energy to force the piston down, rotating the crankshaft, which both propels the car forward and provides enough energy to other mechanisms in the engine (connected to the crankshaft) to operate the valves at the top of the cylinder which control the intake of the fuel mixture and expelling the burned mixture out to the exhaust pipe. This cycle repeats several thousand times per second.
Roger in San Francisco (yes, the infamous Roger the Liberal that’s well known on talk shows across the nation) asked about suggestions for travel in Northern California.
One trip Bill suggested was to drive up Interstate 80 to Reno, and get on Highway 395, which will take you to Modoc and Lassen counties, which are a high plains sagebrush area. If you want to see a lot of trees in the unspoiled part of the Sierra, take highway 70 up through Orville, through the Feather River Canyon, through cities including Quincy and Portola. If you turn off north on Highway 89, which runs along the spine of the Northern Sierra, through Plumas County and Mt. Lassen. If you want a real treat, Bill recommends a little restaurant on Highway 89 on the west side of Lake Almanor, with a porch that overlooks the lake. He wasn’t about to name the restaurant, but says it’s the only one nearby.
Another trip he suggested was to go south on 395 from Reno down to Southern California. He’s known visitors from Europe who have taken that route and thought it more beautiful than the Alps.
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