Sit. Rep. #106: Phases, Bottoms, & Ghosts

1- Maybe it is the Winter Solstice or maybe it is just because it is cold outside.  Most of the time when I think about HEAT I think about cooking or the thermostat for the house.  So I want to take a few moments to look at heat energy from an in-depth point of view.  There are 3 ways that heat moves or transfers between masses.

  1. Conduction:  Heat transfers between adjacent molecules or bodies.  Think about holding an ice cube.  Heat moves from your hand to the ice cube because they are touching.
  2. Radiation: Heat energy is transmitted across space to an absorbing object.  This radiation is usually infrared.  Think about sitting close to a campfire but not touching the fire or the logs yet you are being warmed.  Or think about the Sun radiating heat (across space) to the Earth.
  3. Convection: This is where heat energy is transferred to a fluid or gas by the movement of the gas or fluid.  So either gravity or a pump is required.  The hotter the fluid the less dense it is.  Therefore the hotter, fluid (or gas), rises in a gravity situation.  Cooler, denser gas or fluid takes up the vacated space and becomes heated and rises and the cycle continues until all the fluid or gas is equally heated.  Or until the heat stops.

C: Where can you find the ocean with no water?
D: On a map.

2- Phase Change: This means: the change of state from a solid to a liquid, or from a liquid to a gas.  A calorie is defined as the heat energy required to raise the temperature of 1 gram of water 1 degree Celsius.  Example: 36 C to 37 C of one gram of water takes 1 calorie.  Now let us move 1 gram of water from -1 C to 1 C, from ice to water.  The water takes 2 calories for the temperature change PLUS 80 calories for the phase change.  So the answer is 82 calories.

2B- The phase change of water from liquid to steam (vapor) is a bit different.  Again 1 gram of water changes from 98 C to 99 C takes 1 calorie.  Now, let us take 1 gram of water at 99 C and move it to 101 C vapor.  The calories for the temperature change is 2.  Plus it takes 540 calories to change from liquid to vapor.  So the answer is 542 calories for 1 gram of water to change from 99 C water to 101 C vapor.

NOTE: This is sometimes called the “small calorie.” It is denoted with a small “c”. and defined as 4.184 Joules.  The Large Calorie is defined as 1,000 (small) calories.  It is denoted with a capital “C.”  So 1 C = 1,000 * 4.184 = 4,184 Joules.  The word “calorie” comes from the Latin word “calor” which means heat.

E:  What did the bottle of water say to the spy?
F: The name is Bond. Hydrogen Bond.

3- In Scouts we talk about Leave no Trace.  I just learned another way to say the same thing – almost.  Camp Like a Ghost.  Field & Stream’s The Total Outdoorsman Manual puts it this way: “If it wasn’t there when Columbus landed, remove it.” It talks specifically about dispatching your fire ashes and unburned wood, remove ALL trash, rake the campsite with a branch, naturalize your site before you leave it, pack it in – pack it out, and then no one can tell you were ever there.  This is a courtesy to Mother Nature and all fellow campers.

Google Docs List for Low Impact / Leave No Trace Camping:

G: What do you say to boiling water?
H: You will be mist.

4- There are some bad places to set up a campsite.
Hilltops that are windy & may attract lightning.  Stay to the leeward side if possible.

Bottoms, depressions, valleys, & hollows where moisture and cold can collect.  These places tend to be real foggy and therefore hard to navigate in.  Also, think where mudslides and avalanches end up – at the bottom.  And that is where floods happen.

Game and people trails.  They are already established roads and highways for wildlife.  These locations for camping/campsites are both discourteous and unsafe.  Avoid cutting off wildlife from access to water.

Paratus Cogitare,

Scoutmaster’s Minutes by Thomas Mercaldo

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