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The most important thing for a successful business is location, location, location. The most important thing for as successful experiment is calibration, calibration, calibration. That having been said, location can also be critical in an experiment.
For instance, at our house, we know that if we set the thermostat, which is located in the living room, at 71 degrees, that the room temperature in the family room, where we spend most of our time, will be a comfortable 70 degrees. However, if one day I decide to do my reading in the living room, and start using the lamp next to my favorite chair, then we’d soon find that the house was routinely staying too cold. Why? Because said lamp is within a foot of the thermostat, and the increase in average temperature at the position of the thermostat renders the previous calibration useless.
When you work in experimental physics, you have it drilled into you that without proper calibration, at the end of the experiment you will have, as my professor one time screamed at me, no data. (I’ll get to that story in a minute.)
When I was working with Dr. Van Zytveld to measure the thermopower of liquid rare earth elements, recalibration of our instruments had to be done all the time. One reason for this was that the thermocouples we used to measure temperatures were essentially consumed after each experimental run. Even if not visibly damaged, after one use where they were called upon to measure temperatures above a thousand degrees C for many hours, they were unlikely to survive a second run, let alone remain accurate. Also, we frequently rebuilt the ovens we used to achieve those high temperatures. After each experimental run, I would have to experiment with my rebuilt rig and make sure it would track along the same curve as the previous runs had. That is, I had to calibrate it with the previous work.
When doing experimental physics, the test rig used to make measurements is a separate experiment in its own right. If you haven’t experimented with your test rig enough to know exactly how it works, you will never be satisfied that the measurements you make with it are valid, or at least you shouldn’t be.
For my junior year laboratory requirement, I measured the speed of light in gases. The methodology for this experiment was quite clever. I had to fill a small cylindrical chamber with various gases, then pass a laser beam through it, the chamber being in one arm of an interferometer. When the split laser beam was recombined, it formed an interference pattern. As the gas was slowly pumped out of the chamber, I could see fringe shifts in the interference pattern, and the number of shifts allowed me to calculate the speed of light in the gas.
The experiment was an interesting mix of high tech with low. The interferometer has been around since the 1800s, the laser since the 1960s, and to count the fringe shifts I used a very modern (for the 1980s) trace storage oscilloscope attached to a light sensor. To measure the pressure, I used a U-tube mercury manometer, which goes back to the Middle Ages.
The way you read a manometer is to measure the difference in height of the mercury column between the right and left sides. What I did was to measure the height on one side from the unpressurized position and then double it. I thought I was saving time. Unfortunately, this method would only be valid if the right and left sides were volumetrically uniform, and they were not.
I was a bit slow in accepting that all my labor might be worthless, at which point Professor Van Baak screamed at me, “You have NO data!” (Fortunately, there was a simple, albeit tedious, way to recover my data and so save my experiment.)
As embarrassing as it was at the time, now, 25 years later I’m glad I made that mistake and learned that lesson. It greatly sensitized me to the need to examine all the assumptions that go into a measurement, and helped me notice when others were less than punctilious about it.
Speaking of less-than-punctilious measuring, I’d like to call your attention to a report available at SurfaceStations.org entitled “Is the U.S. Surface Temperature Record Reliable?” The short answer is NO. And along with the unreliable data goes much of the case for global warming.
The report is written by Anthony Watts, who has been doing broadcast meteorology for 25 years, both on TV and radio. He is currently chief meteorologist for KPAY-AM radio and also runs the website wattsupwiththat.com. The site provides a welcome dissenting side in the global warming debate and I encourage you to check it out. Watts founded SurfaceStations.org in 2007, “a Web site devoted to photographing and documenting the quality of weather stations across the U.S.”
Why do this? The answer to that is stated in the executive summary:
The reliability of data used to document temperature trends is of great importance in this debate. We can’t know for sure if global warming is a problem if we can’t trust the data.
The official record of temperatures in the continental United States comes from a network of 1,221 climate-monitoring stations overseen by the National Weather Service, a department of the National Oceanic and Atmospheric Administration (NOAA). Until now, no one had ever conducted a comprehensive review of the quality of the measurement environment of those stations. (Pg. 1)
The story of what prompted Watts to begin this study is interesting in its own right. As Watt says, “It began when I set out to study the effect of paint changes on the thermometer shelters, known as Stevenson Screens, used by the National Oceanic and Atmospheric Administration’s Weather Service (NOAA/NWS) to track changes in the climate of the U.S.” (Pg. 4)
From 1890 until 1979, Stevenson Screens, which are just wood-slatted boxes, were specified to be coated with whitewash. In 1979, this was changed to semigloss latex paint. In 2007, with some time on his hands, Watts decided to find out if this change in coating affected the temperature readings inside the Stevenson Screens.
He went about it this way (although I can’t show the picture of Figure 2, it looks as described): I purchased three new Stevenson Screen thermometer shelters, shown in Figure 2. One is bare wood, unpainted, as a control; the middle one is painted with latex, as sent by the supplier; and the third is painted with a historically accurate (for early twentieth century) whitewash mixture that I obtained (both materials and formula) from the head chemist at the National Lime Company. Whitewash was mixed after conferring with chemist Richard Godbey of the Chemical Lime Company in Henderson, Nevada, and after reading a paper he authored on the history and home creation of whitewash. (Pg. 4)
I must point out that this account represents a level of attention to detail, particularly with respect to the whitewash formula, that should be emulated in any kind of experimental replication, but seldom is. This is what Watts found:
This test showed that changes to the surface coatings did make a difference in the temperatures recorded in these standard thermometer shelters, shown in Figure 3. I found a 0.3º F difference in maximum temperature and a 0.8º F difference in minimum temperature between the whitewash and latex-painted screens. This is a big difference, especially when we consider that the concern over anthropogenic global warming was triggered by what these stations reported was an increase of about 1.2º F over the entire twentieth century. (Pg. 5)
Having discovered that the switch did significantly affect temperature readings, Watts “set out to determine if the Stevenson Screens of the U.S. network of temperature-monitoring stations had been updated to latex paint as required by NWS specification changes in 1979.” There were three stations relatively close to his home base of Chico, California. Here is what he found. “The first station, at the Chico University Experiment Farm, had been converted to latex, but it also contained a surprise. It had two screens, one of which was converted to automated radio reporting. I was surprised to find NWS had installed the radio electronics just inches from the temperature sensor, inside the screen.”(Pg. 5) The second station, in Orland, California, was well maintained and properly painted with latex. Unfortunately, this is what he found at the third site: “The third station, however, in Marysville, California, revealed the Chico University station was not a fluke. As I stood next to the temperature sensor, I could feel warm exhaust air from the nearby cell phone tower equipment sheds blowing past me! I realized this official thermometer was recording the temperature of a hot zone near a large parking lot and other biasing influences including buildings, air conditioner vents, and masonry.” (Pg. 5)
The rest is history. Two of the three stations Watts visited were not measuring what they were supposed to be measuring. As he puts it for the Marysville station, “Yet here we had an official climate-monitoring station, dubbed part of the ‘high-quality’ USHCN (U.S. Historical Climatology Network) network that provides data for use in scientific studies, actually measuring the temperature of a parking lot with air conditioners blowing exhaust air on it, and missing more than half of its data for the month of July!” (Pg. 6) So it was obvious there was a need to survey the rest of the stations in the USHCN, and the Surface Stations project was set up to “create a network of volunteers to visit USHCN climate-monitoring stations and document, with photographs and site surveys, their quality.” (Pg. 8)
What the Surface Stations Project found is deplorable. The report details, with lots of color photos of actual stations in the network, just how haphazard and inept our attempts to accurately measure the surface temperature record in the U.S. have been. For instance, there are guidelines for how close a measuring station can be to a parking lot or other “artificial heating or radiating/reflecting heat source.” The Surface Stations Project surveyed 70% of the stations in the U.S. This is what they found: “(W)e found that 89 percent of the stations—nearly 9 of every 10—fail to meet the National Weather Service’s own siting requirements that stations must be 30 meters (about 100 feet) or more away from an artificial heating or radiating/reflecting heat source. In other words, 9 of every 10 stations are likely reporting higher or rising temperatures because they are badly sited.” (Pg. 1) The report concludes, “the raw temperature data produced by the USHCN stations are not sufficiently accurate to use in scientific studies or as a basis for public policy decisions.” (Pg. 17)
Obtain the report, read it, dissect it, and refute it if you can, or accept it if you can’t. That’s the honest thing to do. I have long wondered why most of my fellow physicists haven’t been as skeptical of global warming alarmism as I have been. I think one reason, perhaps even more important than their politics affecting their judgment, is that they naturally assume other scientists are as careful in how they obtain data as physicists are. I’ve been a global warming skeptic for some time now, and it didn’t even occur to me that most of the time the thermometers would be “sited next to a lamp.” What’s really ironic is that, if someone claims to see a flying saucer, which hurts no one and costs nothing, debunkers come out in force. But let a former vice-president claim environmental apocalypse is upon us, and suddenly we’re appropriating billions and changing our lifestyles.
Cripes.
Copyright © 2009 Jeffery D. Kooistra
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