Tuesday, March 10, 2009

Another way to waste important blogging time



Motivated by his last post and Real Climate's latest, Eli decided to go play with new toys and bunnies, did he find one, a web network mapper at Touch Graphics. It doesn't really work well with every site, for example this one. Here is the map for Real Climate

Don't stay up too late.

8 comments:

Magnus Westerstrand said...

My take on this is that one reason for the high traffic on the "bad" blogs is that they update much more... this is i think the most important thing to keep active blog hangarounds that link to you.

Barton Paul Levenson said...

Forgive me for posting this here, but the spam filter or something at Open Mind kept eating it. The poster I'm responding to was referring to events at Rabbett Run in the first place, though.

Saltator wrote:

Gerlich and Tscheuschner posed the following questions to Rabbett and have yet to receive a reply:

“1. What is the most general formulation of the second law of thermodynamics?

2. What is your favorite exact definition of the atmospheric greenhouse effect within the frame of physics?

3. Could you provide me a literature reference of a rigorous derivation of this effect?

4. How do you compute the supposed atmospheric greenhouse effect (the supposed warming effect, not simply the absorption) from given reflection, absorption, emission spectra of a gas mixture, well-formulated magnetohydrodynamics, and unknown dynamical interface and other boundary conditions?”


1.

dS = {closed-form integral} dQ / T

where S is entropy (measured in Joules per Kelvin in the SI), Q is heat (J) and T temperature (K). Obviously for a non-isothermal process you'd have to derive an equivalent expression, e.g. through the gas laws for a process involving gases.

2. "The mechanism by which greenhouse gases in a planet's atmosphere warm the planet's surface above the temperature expected from radiative equilibrium alone."

3. Try any of the following:

Houghton, J.T. 2002. The Physics of Atmospheres. Cambridge, UK: Cambridge Univ. Press.

Petty, G.W. 2006. A First Course in Atmospheric Radiation. Tucson, AZ: Sundog Press.

Goody, R.M. and Y.L. Yung 1989. Atmospheric Radiation--Theoretical Basis. NY: Oxford Univ. Press.

4. The question makes no sense and thus can't be answered. The greenhouse effect has nothing to do with reflection, magnetohydronamics, or dynamics. G&T have merely thrown technical-sounding words together here to intimidate people unfamiliar with physics. It's like asking, "How do you explain the rainbow, quantitatively, on the basis of relativistic wavelength-dilation, quantum tunneling, and the Zeeman effect?"

Arthur said...

Barton - not that these actually require further discussion, but your #1 is more the definition of entropy (and limited to a constant-temperature process) rather than of the second law. Second law is just dS/dt >= 0.

Anonymous said...

"Don't stay up too late" HA!

Cool toy.

Try www.heartland.org

--tiny rabit

Anonymous said...

Arthur - change the "=" to ">=" in Barton's statement and you have the Clausius Inequality, which is my own favorite compact version of the 2nd Law. I like it because I don't have to state whether my system is isolated, or open, nor do I have to embed my system in a larger one in order to get a super system that is effectively isolated. And I can avoid entirely talking about "the entropy of the universe", which is strictly speaking undefined. Just consider your system, and the heat that crosses the boundary of your system.

Robert P.

Anonymous said...

It's kind of funny and a little bizarre.

If you use that tool to graph "wattsupwiththat", you get Watts site at the center of a triangle with "Ghana", "Sudan" and "Eighteen hundred years and froze to death" at the vertexes.

I can understand the latter, but Ghana and Sudan????

Must be someone in Ghana (Sudan) sees action on global warming as a direct threat to their lifestyle (and I'm not talking about subsistence farming) Either that or they enjoy a good joke.

Anonymous said...

www.marshall.org

--tiny rabit

David B. Benson said...

Blogging time is important?