El Nino assignment

Author Subject: El Nino assignment
Angela Bartczak Posted At 23:08:15 10/23/2000
Angela Bartczak
X-Game : Chasing El Nino

Folklore: When doors and windows stick, it will probably rain.

I feel this folklore can be tested scientifically through investigation and experimentation.

The constraints are pretty small in this investigation. Basically what needs to be considered is finding windows and doors to do the investigation. No cost or safety, except maybe safety of not breaking any windows.

Question: When window or door sticks, how likely is it, that is will rain soon?
Prediction: I think that this folklore is one that can be considered credible. The increase in moisture in the air to do oncoming rain could cause sticking of windows and doors. The debatable issue is whether how reliable the sticking is, or does other factors influences a window to stick.

a. Variables include the weather, different windows or doors.
b. Data I need to help the experiment is to know the weather conditions, especially the amount of humidity. How hard the window or door normally is to open or how it normally sticks. What type of window or door.
c. The data used to support my prediction will be the weather, rain and humidity. Also the experimentation of opening the windows on different days and different weather conditions to see if there is a difference. By using a recording system to see how loud the noise it makes when opening and a scale system to list how hard I thought it was to open.
d. I will collect the data by opening the windows and doors rating their stickiness. Then I will obtain the weather info., rain and humidity and graph the days and the amount of humidity comparatively. My data will be presented on graphs and or charts.
e. I will need a few windows and doors, a tape recorder to see if I can get different sounds and pen and paper to record how sticky they became. Also a computer to graph and chart the info. to present.
f. I will do the experiment, record my findings and then make my findings presentable to the class.

Keri Re: El Nino assignment (Currently 0 replies)
Posted At 00:49:24 10/24/2000

Your proposed experiment sounds like it will work. It was well-presented and I believe that you will be able to show if this folklore saying is true. Hopefully the weather will cooperate and provide the conditions necessary to observe. Although we are entering the rainy season, the biggest constraint to all of our possible experiments will be the cooperation of the weather or lack thereof. Good luck and I look forward to finding out if it worked. :)
Dallas Campbell Re: El Nino assignment (Currently 0 replies)
Posted At 01:08:01 10/29/2000

One reason why doors and windows stick when the weather is wet is because of the change in the dimensions of their wood frames. Wood is composed of cellulose fibers that have voids or air pockets in them. Because our climate is so dry, the moisture that would normally be in the voids evaporates out, which causes shrinkage of the wood, especially in the width dimension.
When storms approach, the relative humidity in the air increases and the wood fibers begin to absorb moisture because of the increased number of water droplets in the air. As the fibers absorb moisture, they swell which causes the wood in the door or window frame, and its wood casing, to expand. The gap between the door or window and its casing is reduced and, in some cases, disappears. That contact makes them harder to open because they rub against their casings.
Because both surfaces, the door and the casing, are usually painted, it is even harder to open, as the paint tends to bond or adhere. In effect, it is glued shut. After a shower passes and the air begins to dry, the moisture in the wood begins to evaporate out, the door shrinks and no longer contacts the casing and sticking stops.
A control for the experiment would be a metal door and casing, which do not absorb moisture and do not expand. Another way to measure the change in the distance between the door and casing, in addition to the method you propose, would be a feeler gauge, which takes an internal measurement of distance between two proximate objects. A tape measure could also be used to measure any changes in the dimensions of the door or window itself.
I can contribute anecdotal data to the experiment. Thursday evening, about two hours prior to the start of the rain storm, a door in my house began to stick. In addition, the redwood gate to my backyard also began to stick. (Redwood is very soft and expands a lot when it absorbs lots of moisture.) The door continued to stick until Friday afternoon, when the humidity had dropped. The wood on the gate is thicker and will lose its moisture slower.
Good luck

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