Even one preoccupied has to make room for his obsessions. (Further obsessive tendencies revealed here.)
For quite a while I have been persuaded by experience that my Nigel Rudolph mug retained heat better than any other mug in our cabinet. I asked Nigel and his wife Cheyenne about that recently and they could offer no reason why that should be. These are not, you should know, ceramic hacks. Nigel and Cheyenne know much about the science of clays, and as far as they knew, there was nothing in the mug itself to bring about my perceived result.
So, making tea for a guest the other night, I decided to put my perceptions to the test.
I selected three mugs, a tall skinny Hope Presbyterian Church mug, a wide mouth Nigel Rudolph mug, and a medium girth Krispy Kreme mug. I put 7 ounces (by weight) of hot water in each, and took measurements every minute for ten minutes, then every five minutes, and then at 60 minutes.
This was a very efficient use of time, as our guest, Barb, and I sipped our tea and talked while the measurements were being recorded.
Our guest, though, laughed at me. We love her anyway. I have been accused by friends in Los Alamos, NM (having, in my estimations, more PhDs per square inch than anywhere else on the planet) of suffering from LAPD, (Los Alamos Personality Disorder). Diagnosis is, no doubt, hereby confirmed.
What we discovered was that my perceptions were wrong. The wide-mouthed, Nigel Rudolph mug lost heat at a greater rate than the tall and skinny-mouthed Hope mug. Our conclusion was that the surface area of liquid exposed to the air is the variable which determines rate of cooling.
I also concluded that I simply need to drink my coffee faster. All science aside, I’m not giving up the aesthetic and personal pleasure of using Nigel’s mug!
MagistraCarminum
LOL! LAPD duly confirmed. Not too surprising!
David
Nice experiment, but you failed to put error bars on your measurements. Also, did you calibrate your thermometer before your test? Why the difference in the temperatures at time zero? Did you take the temperature of the mugs before liquid was added; were the mugs preheated? Inquiring LAPD minds want to know!PS skinny is always best!
Randy Greenwald
Error bars: not necessary – I don't make errors.Thermometer was calibrated at factory. However, actual temps were not as important as rate of decline.Each mug was at room temperature when liquid was added. I suppose each would have immediately absorbed an initial amount of heat, depending on the mass of the mug. That is why I started measurements at 1 minute, and then tracked the decline. My deficiencies are duly noted. My LAPD is obviously not sufficiently advanced.
Seth
The question is this: is the rate of decline linearly proportional to the surface area of the hot liquid? While the larger cools faster, does it's drop in temperature slow over time? I would assume that the transfer of heat into the atmosphere would slow as the liquid nears equilibrium. Is the rate ofchange of the rate of change a constant? As we can see from this experiment, LAPD is a genetic trait.
TulipGirl
You crack me up.
Nigel and Cheyenne Rudolph
so, actually, the real test as to the heat retaining qualities of the clay itself would best be determined not by how wide-mouthed or shallow-girthed the mug is, but by the use of several different clay bodies at their vitrified state. one would also need to consider the thickness of both the clay walls as well as the type and thickness of each glaze. of course, each mug would need to be the precise equal (in form) of the others being tested…let me know what you come up with in your second round of testing.
Randy Greenwald
Such testing, of course, cannot begin until I have a whole supply of said mugs from the supplier…