Grrr. Cecil was using the approach I pooh-poohed in my earler post - adding up all the energy in the universe, blah blah blah. Sure, it’s a maximum, but just for this universe. Absolute zero is absolute zero in any universe - either atoms are moving or they’re not - so I don’t think this upper limit is of the same caliber.
And as far as I’m concerned, all the argument on this subject just proves my point - it’s a stupid question. I don’t like questions that devolve into arguments about how to define the question, because then there’s no real answer. But that’s just me.
I guess it is an “ambigously” worded question. It implies that “cold” is a quantifiable measure. Hmmm I wonder if that generalises to other things quantities. E.g. if I have a stick that’s 1 meter long, and someone else has one that’s twice as long, that’d be 2 meters. But if there’s one that’s “twice as short”, would that be 1/2 a meter? Or how about an interval “twice as short” as 1 hour?
It’s ambiguous not because “cold” isn’t quantifiable, but because it’s unclear which scale to use. To use linear math with temperature, you have to use an absolute scale such as Kelvin or Rankine, or it doesn’t make sense. However, the question is worded such that a normal scale such as Celsius or Fahrenheiht is implied, where “twice as cold” doesn’t make sense.
A stick “twice as short” as a meter is 1/2 meter- everything’s fine because the smallest distance is zero meters- i.e. it’s an absolute scale. If you defined 0 meters as the length of a standard meter stick, and -1 meters as zero length, then you’d have the same trouble with “twice as short” as “twice as cold”.
Crafter_Man gave the exact same answer my Chem teacher gave us in class.
Apparently they asked the same question on the radio one day, and about 10 science majors phoned in with the same answer. Yes, my Chem teacher was the one that got through on the radio, hence the somewhat unrelated story in my class (ok, we were discussing temperatures in kelvin).
…even though his post didn’t adequately address the difference between “heat” and “temperature”. Here’s my argument which nonetheless supports his answer.
q = Cp(T),
Where q = Heat (thermal energy) at constant pressure (in Joules),
Cp = heat capacity at constant pressure (J/K), and
T = temperature (in Kelvins).
I couldn’t readily find the heat capacity of air, but run-of-the-mill nitrogen gas is 29.1 J/K and oxygen is 29.3 J/K, so I just picked 29.1. At 0°C (assuming the jokester is talkin’ metric), there are 7.95 kJ of heat energy in the air. Taking “twice as cold” to mean “half as hot”, we just take half of 7.95 kJ (=3.97 kJ), plug it back into the equation for heat energy and solve for T. The answer, as sayeth C_M is 136.575 K, or -136.575°C.
So, yeah–I know it’s a joke… but it does have an answer and that’s it. (File this one under “more evidence for my wife’s claim that I am gradually losing my sense of humor”.)
Thanks for all your considered replies. I’m continually amazed by the number of intelligent people that post to this board…
Yes, of course it’s just a joke. But we can also have a sense of curiosity and think…hey…that kinda works?!? It’s not something I lose sleep over but it is interesting to ponder…
