Yma Sumac

When I was a kid, my dad had an album by Yma Sumac, called Voice of the Xtabay. I remember she seemed so mysterious and exotic. This video certainly doesn't change that impression:

Clifford Brown

There is a clip of Clifford Brown on YouTube:

This is apparently the only video record of Clifford Brown in existence. There is a poignant message from Clifford's nephew to that effect in the clip's comment section. YouTube does serve a purpose.

Global Warming Calculator

Update: See Part II.

I thought it would be fun to create a calculator to compute Global Warming. You can find it here: Global Warming Calculator. The method uses conservation of energy and the climate dynamics shown in the figure here, and in the Wikipedia article on the Greenhouse Effect.

The figure itself (by Robert A. Rohde, Creative Commons Attribution NonCommercial License applies) is based on the work of Kiehl & Trenberth, in their well-known article "Earth's Annual Global Mean Energy Budget" Bull AMS 78(2) Feb 1997, 197-207. The baseline data for the calculator was also taken from Kiehl and Trenberth's publication.

The method works by finding the steady state corresponding to the percentages you enter into the calculator. The default values are the ones from Kiehl and Trenberth shown in the figure. The only "difficult" part is figuring out the total flux from the ground (Eg) as a function of incoming solar flux (Es). The formula is


where Pas is the portion of atmospheric radiation sent into space, Psg is the portion of solar radiation reaching the ground, and Pgs is the portion of ground flux radiated into space. Here "ground flux" includes radiation into space and the atmosphere, as well as energy transfer via evaporation, thermals, etc.

Although quite simple compared to other climate models, that doesn't mean it's not sound as far as the physics goes. Of course, it's only as good as the information you put into it.

It is interesting to see how sensitive the degree of warming is to changes in the percentages. Remember that the IPCC prediction of warming over the next 100 years is anywhere from 1 to 5 degrees.

Who Knows Science?

You try to pay some attention in science class. You watch nature shows on T.V. You try to keep up with scientific advances. However, for everything you know, there are a million things you don't. For example, would someone please explain to me how tomorrow's lunar eclipse can be visible until 08:24 am EDT here in Massachusetts, when according to the weather almanac, sunrise is at 06:04 am EDT?

What is Science?

When I was in grade school, our class was taught the Scientific Method. This method, which we were told guides all scientific research, involved the following steps:
  1. Observe some phenomenon in nature.
  2. Form a hypothesis to explain or model the phenomenon.

  3. Design an experiment to test the hypothesis.

  4. Carry out the experiment, recording all input data and output measurements.

  5. Analyze the results of the experiment.

  6. Determine whether or not the results support the hypothesis.

Suppose you are interested in determining the population of ancient Troy from its founding through it's abandonment. You consult historical records. You examine the ruins of the city, to determine its extent. Perhaps you conduct some experiments, carbon dating say, to determine the age of certain artifacts. From this collected data you make an estimate of the city's growth and decay. Is this science? In my opinion, it isn't. It's Quantitative History, but it isn't science. There is no experiment being made that can be verified with a new collected data set. There is no natural phenomenon that is being modeled and explained. While some of the steps in the Scientific Method fit to a certain extent to the process described, overall it doesn't really fit the working definition of science.

It is said that the "science is settled" about Global Warming. That the Earth has warmed 0.6C in the past century is practically written in stone. But was this conclusion based on science? In fact, it was based on the statistical analysis of temperature data taken at weather stations and ships at sea since 1860. It was not based on laws of physics from the theory of heat transfer and fluid dynamics at all. There was no repeatable experiment conducted. There is no ability to predict the future from the data; it is not even tied to an increase of greenhouse gasses. Like the analysis of Troy's population, this is quantitative history, not science.

The Earth may indeed have warmed over the past century. But when I hear that the "science is settled," I think to myself "what science?"

Sober in the Sun 2007

I'll be playing flute as part of a Celtic/Bluegrass band at the Sober in the Sun Festival next Sunday. It's just a short bit, about half an hour or so, but it's enough to get me nervous. Mostly I'm doing it because my friend Bob really enjoys playing (fiddle) in public, and I want to help him out. It should be some fun, as long as I don't mess up. I will be getting $25 for my efforts though. How cool is that? My first professional gig! I won't be quitting my day job, believe me.

Mortgage Bailout

I agree completely with Michelle Malkin about the idea of a mortgage bailout. Boston home prices are sky high, and I attribute much of that to banks lending out too much money. It has fueled the speculative bubble. Banks even announced, to much fanfare, that they would begin granting mortgages to "undocumented workers." How can you justify the risk of granting a 30 year mortgage to someone who is not even in the country legally if not as speculation? Now it looks like the bubble is about to burst, and I and the rest of us renters are going to be "asked" to bail out those who acted irresponsibly and borrowed beyond their means. It's not enough to give folks a tax deduction on mortgage interest? They want to do away with the alternative minimum tax too, so they can get even more. Adding insult to injury, all this means that I'll be paying a higher than free market price for a house if I can ever afford one. How about we bail these people out, then tax their "windfall profits?"

Turkey Day

There was a commotion outside the other day. Several neighbors were standing around looking at something. When I went outside, I was amazed to see a flock of turkeys surrounding our house. No, not the neighbors. Real wild turkeys! There are many around the Brookline area, and they are becoming a nuisance. When Turkeys Attack: Bostonians Battle Wild Birds. I like them though. Better than those damn Canada geese. Here are a few pics I took.

Creative Destruction: Should a professor require students to attend a teach-in?

My Old Chum C.W. answers a question I sent him anonymously:
Creative Destruction: Should a professor require students to attend a teach-in?
I agree with him for the most part. What put this situation beyond what I think is reasonable was the requirement that students either pay the cost of attending or "earn" their attendance by working for the organizing group. It seemed just barely reasonable to me without that bit; I have doubts that this particular teach-in would provide a balance of views.

On another note, as I recall from earlier posts, C.W. has expressed his belief that as a professor, one of his roles is to provide views that his students would otherwise not hear. I agree with that, although my impression is that very few students will be willing to engage in a lively honest discussion with a decided professor on matters political. There is little incentive to do so, and in the mind of the student there is always the possibility that it will affect his or her grade. So in general, the idea that a professor who appears non-neutral on an issue can foster classroom debate seems a bit naive.

Confession about Reading

I don't read novels. Indeed, I almost never read a book cover to cover. This is not to say I don't read, of course. I read all the time; a substantial part of my day is spent reading. For pleasure I mostly read articles on the web, but also some magazines and the occasional newspaper. For work I read journals and text books. But the fact is that I rarely enjoy reading book fiction. Every once in a while I try to read a novel, because it's one of those things I'm "supposed to do." I lose interest after 100 pages or so. Give me a good movie instead. A novel to me is like a 24-hour long movie. No story is that good. I don't think that political persuasion has anything to do with it though:

Pat Schroeder never seemed too bright to me. I once saw her lose terribly on Jeopardy, playing against Al Franken and another guy. Al tried to give Pat an opportunity to answer a question, under the category "Congress," pausing before finally giving his answer: "What is cloture?" He then paused and said "you know... one of us was actually in Congress..." Burnnnnn!

Climate Cryptography

Here's an intentionally provocative post. Suppose you have temperature data T(x,t) over space x and time t, and the slope of your regression line indicates an average rate of increase of 0.6 degrees per 100 years. Suppose you need to allow others to verify that 0.6 number, but for whatever reason, you would not like to give out the raw data T. What to do? Choose a "private key" g(x), a function of space alone, which you keep secret. Publish and release to the public only "temperature anomaly" data T1(x,t) = T(x,t)-g(x).
http://lwf.ncdc.noaa.gov/oa/climate/research/anomalies/anomalies.html http://www.cru.uea.ac.uk/cru/data/temperature
You can claim that T1 is a normalization of the data, accounting for local climate variations, or some such. It's clear that T can not be recovered from T1 without g. So your data is safe. However, it's also clear mathematically that the regression line through T1 will yield that same 0.6 number you obtained. Cryptography has allowed you to keep your data private, while permitting others to "verify" your results!

Update 9/8/2008 : more detail.

Atmospheric "Saturation"

There was a debate recently between the RealClimate folks:
and Lubos Motl, on his "Reference Frame" blog:
regarding whether or not the marginal increase in global warming should lessen as more and more greenhouse gasses are added to the atmosphere. I made a few calculations on the subject for myself, eventually coming to agree with RealClimate that it need not. And yes, it pains me to say so. A slightly mathy write-up, in pdf format with spiffy imbedded links, is here:
Check it out if you are interested. It's intended to be self-contained for the most part.

Hello World!

I think I'll try this blogging thing... I don't know how long the urge will last, but it's best to get it out of my system. Welcome to my blog!