Thermodynamic Temperature

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Physics (Episode 5): Thermodynamic Temperature.

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What is the temperature of outer space? way out there between galaxies ... where there is only about one hydrogen atom per cubic meter? Can an individual atom be hot or cold? Can it even have a temperature? It sounds a little silly to say an atom is 27 degrees Fahrenheit or something.

PARTICLE TEMPERATURE: But temperature is really a measure of the motion energy of an atom if the atom is motionless then it is at zero Kelvin. Now it can never be really motionless so it can never be at exactly zero Kelvin. And it moves pretty fast pretty fast as the temperature rises. At a tiny fraction of a degree above absolute zero, (700 nK (1 nK = 10−9 K)) the atom is already moving at about 1 centimeter per second.

For subatomic particles the energy is often measured in MeV or GeV. An electron with 1 GeV of energy is moving close to the speed of light. And that corresponds to a temperature of ... 11 thousand billion kelvins.

AVERAGE TEMPERATURE: For a collection of atoms or molecules like a gas or a crystal lattice, the temperature of the collection is just the average temperature of the group. But of course because of collisions and interactions at the molecular level, a group of atoms or molecules will distribute the total motion energy pretty evenly among the individuals in the collection.

HEATFLOW: And if two or more systems are brought together, some motion energy from the hotter system will flow to the colder system until they are both at the same temperature. When you measure your body temperature using a thermometer, your body cools down a tiny bit and the thermometer heats up until the two are at the same temperature. Then reading the thermometers temperature also reveals your body temperature since the two are the same.

PRESSURE AND VOLUME: If we take a quantity of gas and enclose it in a container, the individual molecules in the gas constantly bang into the walls of the container creating a pressure on the walls. We can do three different things to increase the number of wall-collisions:

-- Increase the number of atoms in the container by adding more gas.
-- or increase the motion energy of the atoms already in the container by heating the gas. This makes them go faster and increases the number of times that each atom hits the wall.
-- or we can make the container smaller decrease the volume so that individual atoms have shorter distances to go to collide with the wall. This leads directly to the ideal gas law relating temperature, volume, pressure, and quantity of gas: p = nRT/V

Snuck that one in on you didnt we :)

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[bionicdemon36]

wtf? "snuck that one in on u, didnt we. hehehehe." that is wierd.

[bla34112]

oh man im glad i subscribed.

[ronathangator]

Temperature is not a property of individual atoms but is defined by the motion of a collection of atoms relative to each other.

On Earth the average velocity of molecules to be around 700 m/s at room temperature. Now suppose that an astronaut orbiting the Earth at 50 km/s looks at the velocities of molecules relative to the spacecraft. The velocities would be 50 km/s. The observer would conclude the Earth was very hot.

Temperature is defined as an average velocity about the center of mass.

[KimmyPossible]

I fucking love The Cassiopeia Project

[greentiles2]

Love the weird laugh at the end :)

[Shockszzbyyous]

@CptBarimba since atoms have mass the can't move at the speed of light thuss never reache "absolut heat "

[Deeredman4]

ah I see so Pressure = number of atoms times temperature of those atoms divided by the volume of the container (times the amount of gas molecules that are always present at any giving time)?

[dyslexicdays]

@23GrandMasterK Please don't use religious dogma in the eyes of Science.I hope you are just goofing on the god thing.

[TheFiberone]

@vintageozarks I am working on it too.

[bmdeerwester]

@Typho0n86 Crickey!

[Typho0n86]

@bmdeerwester Americans are retarded

[bmdeerwester]

11 thousand billion kelvin? why not just say 11 trillion?