Last year (2008) we were starting to look at alternatives to our oil-fired burner for heating our house. The house is an almost rectangular 35x60 ft ranch a little over 30 years old, and came with a 1000-gallon buried oil tank, no longer allowed in town codes, so we knew we had to at least get rid of that some time. We finally got that taken care of a few weeks ago. How we're going to heat our house this winter we're still not quite sure. Anyway... one of the interesting options then (and now) was a geothermal heat pump system, and we had several contractors come in and give us quotes. Not cheap at all, mainly because we would have to switch from baseboard radiators to forced air, and putting in the ductwork and vents would take a lot of labor. But there's a 30% federal credit available so we may still go that route.
One of my more recent posts on the two-box model explored the space of possible underlying models for a given empirical fit by fixing heat capacities of the two boxes and varying the heat transfer rate. Keeping the time constants positive restricts the range of allowed heat capacities considerably, while forcing fraction (x) and temperature measurement fraction (y) also provide some constraints given the expectation they must lie between 0 and 1 (and must have actual solutions). Even among solutions satisfying those constraints, there is a further condition that the results look reasonable - as pointed out there and by Lucia here, some of the solutions produce wildly different response levels for the two boxes, which seems unrealistic for systems that should roughly correspond to sub-components of Earth's climate.
Buy high, sell low. Works every time. The other day I sold stock for $1800 that I had originally purchased for $12,000, and was happy to do it. Read on for the details!
Most of our "playground" investment portfolio (as opposed to the serious ones in retirement and college funds) is invested in renewable energy and energy efficiency-related company stocks. It's actually doing pretty well this year, up almost 85%. Of course, that doesn't quite make up for the 55% drop in 2008, but anyway... I'm fairly confident that these companies are doing things that are essential for the future of our nation and our world, so I'm happy to invest in them even when that investment ends up being at a loss. But Daystar Inc (DSTI) was a bit of a special case.
I've been discussing in some detail here a mathematical model of the response of Earth's climate to radiative forcings, trying to address some of the concerns expressed elsewhere on the need for such a model to be "physically realistic". In the case of the two-box model, a given fit of the response function to a two-time-constant decay curve could come from one of many different underlying physical models that correspond to a partitioning of Earth's climate system into two parts with different response rates. So the question has been whether any of these possible underlying physical models are in some way "realistic" or not. That essentially reduces to criteria on the magnitude of the various constants and partial outcomes in the model relative to real components of our planet.
The following proved a little long to be just an update to the previous post; I guess one should never say never. Nevertheless I don't anticipate a need for anything more on this model.
This will probably be my final post on this question - however I may append updates if other issues come up. In particular this post will look first at whether the fitted parameter values for two-time-constant fits to temperature vs forcing data for Earth's climate system have a collection of underlying physical two-box models that satisfy the basic physical constraints on such systems, and then whether the range of physical parameters in these matching models appears to correspond roughly with appropriate associated physical properties of the real Earth climate system.
CORRECTION: The following text has been modified significantly due to errors in the preceding post that nullify most of the original discussion here:
My summer project is pretty much done. I haven't done much carpentry in the past, and found the construction process surprisingly educational. Constructing the flooring, framing, siding, roof, and putting in the window and door all had their own unique challenges in measurement, cutting, joining, etc. I still have to build some shelving and bins and put up some hooks and other devices to hold our tools - can't do that yet though as the kids have installed a couch and turned it into a play house for now. Another couple of weeks though and our new shed should be fully operational!
Continuing from the previous post, suppose we want to look at solutions where the (s) box is close to the short-time-constant (τ-) solution, and the (o) box then close to the long-time-constant (τ+) solution. That suggests setting the corresponding inverse time constants perturbatively close to τ- and τ+, respectively. Define dimensionless small numbers εs and εo as follows:
Eq. 27: αs = (1 - εs)/τ-
Eq. 28: αo = (1 - εo)/τ+
Then from the definitions of ν+ and ν- (unnumbered equation between 22 and 23 in the previous post) we find:
This is essentially a continuation of the math in the previous post. The same warnings apply!
The previous analysis indicated we have 3 free variables to play with. Let them be αs, αo and Cs (the initial inverse time constants of the two boxes, and the heat capacity of the "surface" box).
Equations 9 and 12 of the previous post show a relationship between w+s and w+o depending on the α's, γ's and τ+, and equations 10 and 13 show the same relationship for w-s and w-o with τ- instead of τ+.
This will probably be painful for anybody who hasn't already been following this (which I'm sure is all but 1 or 2 readers, if that many). So skip this post unless you're really into solving systems of equations...
Ok, this time I'm going to start with the graph, and explain what's going on after. Seems to work for other folks... :
Kevin Kelly has a great new essay up, "Was Moore's Law Inevitable?", examining a series of examples of exponential growth in technological capability from a wide range of fields - and makes the very interesting point that all these examples are "prisoner[s] of physics, the periodic table, manufacturing technology and economics" - but some of them proceed rapidly and some do not. The interesting question is why?
I recently finished reading Victor Hugo's Notre Dame de Paris (i.e. the Hunchback of Notre Dame). Among his many long asides and discussions setting the tone for the time (it is set in Paris of the late 1400's, well over 300 years before he wrote) I particularly noticed his remarks on the remarkable transition just beginning at the time. As he put it: "The invention of printing is the greatest event in history." The copy of his book that I read was, however, not printed on paper, but electronically downloaded from Project Gutenberg - donated to the world through a scan of the public domain 1880 version translated by Isabel F. Hapgood. If the invention of printing was clearly the greatest historical event by the 1830's when Hugo first wrote those words, the 20th century revolution in information technologies is at least the start of something far greater.
Last night, as a holder of a few hundred shares in Sun Microsystems (JAVA is their stock symbol), I finally received voting instructions and an explanation of the proposed merger with Oracle. This is actually the second time I've had the opportunity to vote on a company's proposal to end itself through merger - the first was just last fall, when SpaceDev (SPDV stock symbol) was acquired by Sierra Nevada Corporation. In both cases it's been a somewhat mixed experience emotionally. The acquisition price has been a significant improvement on the recent market price for their shares (for Sun, the $9.50 price is significantly above the roughly $5 it was trading at a few months ago), so that's nice on the money side. On the other hand the reason I was holding the shares in the first place was because I believed the company had great potential for the future.
I recently corresponded with a colleague who has acquired a degree of "skepticism" regarding global warming. His comments to me specifically cited Freeman Dyson and Will Happer, distinguished physicists who are also well-known global-warming skeptics, and he contrasted their credentials with those of John Holdren (Obama's new science advisor) and Al Gore. The following is a lightly edited version of my response, which I'm posting here mainly as a place for some useful links on the subject.
This will necessarily be a somewhat rambling collection of my thoughts as I don't feel I've settled down to any solid conclusions on the matter. Perhaps just writing this down will clarify some of my thinking, or perhaps the ideas here will fetch some comments from others that will help point me in better directions. This is the development of some of the thinking from my earlier comments on measuring wrongness - the science I'm familiar with centers on measurement and quantification, and it certainly seems potentially fruitful to consider ways in which one could impose measures (of "wrongness" or "rightness" or just "uncertainty") on the world of ideas. In a sense that kind of measurement is what we impose under the banner of peer review, though the visible outcome is more a binary (publish/don't publish) than continuous measure.
Recently at work we've been making some minor changes to the handling of "auxiliary files" - movies, additional information, or data sets provided by the authors that go beyond the normal article text, figures and tables (all XML or PDF format) that we usually publish. The issue of archiving datasets in particular has been on my mind. One motivation is my own past experiences wondering what to do with large collections of (in my case computer-simulated) data generated in the process of doing research. I probably still have some of it, what I thought most significant, stored somewhere on the laptop I'm writing from now. Though I'm not sure what I would do with it after 20 or more years of neglect. Would it even be worth anything to myself or anybody else, to make it available? Recently advocates of scientific openness, for example Michael Nielsen's Physics World article, have made a strong case for sharing with the world.
One of the great puzzles I feel up against these days in several different contexts is finding a clear way to express how wrong certain expressed views are. This is not (at least usually not) an issue of moral wrongness, but in most cases just simple inconsistency of logic, disagreement with basic scientific understanding of issues, or perhaps abuse of the English language in ways that make no sense whatsoever. Last fall I spent an inordinate amount of time documenting the errors in an article by a climate-change "skeptic", but even then the simple count of the problems doesn't feel like it gives a true picture of the enormity of the misrepresentation of the facts provided by the article in question.
In keeping with the un-theme of this blog, I now present something completely different...
Belonging to a church with a lay clergy, it's my turn to speak once in a while to our ward, a congregation of about 130 on an average week. I seem to get called on every couple of years (more than I would like, but less than some!) Last Sunday (before Memorial Day) was my turn again, under the general topic of "unity". Following are some notes and quotes I gathered for the talk, for anybody interested. No, I did not use all this stuff in the talk... there's only so much you can say in 20 minutes!
Thanks to Michael Tobis I discovered a new report this week from the Congressional Budget Office that has the most dramatic illustration I've seen of projections of temperature for the remainder of this century (right - figure 1 in the report). The PDF of the 33-page report is available for download from CBO.