Sit. Rep. #85: System Temperature vs Heat

1– Albert Einstein and Stephen Hawking did what they called “thought experiments.”  They used this process to take physics to a higher level.  Both are extremely fun to read about and study.
But where I want to go is to do a thought explanation of the difference between heat & temperature.  I had to figure this out when I read about the Parker Solar Probe going so close to the Sun.  This also applies to earth weather.    The units and sizes do not matter but I will stick to metric.  So here goes.

2- Say we have 2 atoms in system of a perfect 1 meter cube with a temperature of 50 degrees C.  ( Or we could have 2 trillion atoms at 50,000 degrees C – does not matter for this thought process )  That gives us X amount of heat per system (the cubic meter).

Next: We keep the number of atoms the same but now let us expand the system to 2 cubic meters.  And keep the temperature the same for both of the atoms.  BUT we have X/2 (half) heat per cubic meter.  Because we have doubled the size of the system – from 1 cubic meter to 2 cubic meters.

2B- The Parker Solar Probe will be exposed to 1,400 to 1,650 deg. C at the heat shield.  The individual particles that hit the heat shield will be several million degrees hot.  Because there are so few particles the amount of heat that is actually transferred to the probe’s heat shield is minimal.  The probe will fly (roughly) to within 6.4 million Km of the Sun’s surface.  Note:  The heat shield is about 4.5 feet thick.  And Sol is ~152 million Km distant from Earth.

Note:  Here on earth we have about 100,000,000,000,000,000,000 molecules per cubic centimeter.   In outer space there only are a few molecules per cubic centimeter.  There are a few more molecules inside the Solar System (closer to Sol ) than in deep space.  Another way to think about it;  You could easily hold in your hand the total amount of material in a cubic kilometer of space.

3- How does that also apply to our weather here on earth?  Let us examine what we already know.  The atmosphere is thinner at altitude than at sea level.  IE: There are fewer molecules per cubic centimeter.

3B- There is the term in weather circles “adiabatic” or “adiabatic winds.”  These are the winds on the windward side of a mountain or mountain range.  They cool as the winds progress up the mountain.  Why?

3C- Let’s assume that the individual molecules stay at the same temperature.  But the “system” expands ( fewer molecules per cubic centimeter ) so there is less heat in a given cubic centimeter at altitude.  It feels and is cooler because there is less heat.  Note: there are fewer Oxygen (O2) molecules at altitude.

3D- Adiabatic winds are also on the leeward side of the mountains and perform exactly the opposite of the windward side winds.  As they rush down the mountain the winds warm up.

M- What do you call a cloistered priest eating potato chips?
N- A chip monk.

4-  When I talk about maps I will mostly talk about United States Geological Survey Topographical Maps.  USGS is one abbreviation and Topo is another that I will use.  Remember that our Federal Tax Dollars paid for the surveys.  But individual maps cost if you order them.  Or you can print them at no cost.  Here is the USGS Map Store.