Prolonged Absence

The cessation of regular blog posts has prompted a number of folks to ask if I still live and breathe. Several reasons contribute to the silence. Primarily, most of what I set out to do and say on Do the Math has been covered. How many times can I calculate total tidal power available? I’ve expressed views on our precarious trajectory with respect to finite resources, touched on the psychology of major change and sacrifice, and shared personal explorations in reducing energy/resource footprints at home. While some of this continues (look for a post on nickel-iron batteries soon), for the most part it’s already all there.

The second factor is that the research, education, and administration components of my life (i.e., my job) are demanding significant attention. This has generally been true all along, but the administrative burden has skyrocketed of late due to my role as vice chair of the physics department at UCSD since July 2013. Perhaps as I climb up the learning curve, I’ll find more “hobby” time in the months ahead.

While I am sharing personal news, two things of note: 1) My efforts to write and speak about energy and resource use to a broad audience has resulted in UCSD awarding me the Outstanding Faculty Sustainability Award for 2014. This despite the fact that I don’t know what sustainability means (suspecting that none of us really do), and that very little of my efforts have been directed at the UCSD campus.  All the same, I am as pleased as I am surprised by the recognition.  2) While not related to Do the Math, I encourage you to check out this stunning photo taken by Dan Long capturing our recent laser ranging efforts during the April 15 lunar eclipse.  This is a real photo, taken through a C-11 telescope with a focal reducer (700 mm, f/2)—the outgoing laser beam has not been artificially superimposed. Normally it is really difficult to get a picture of our faint beam heading toward the Moon, because the Moon is so glaringly bright. The eclipse provided a great photo-op, and also a means to test the hypothesis of dusty reflectors. To me, this shot is just gorgeous. But I have more invested in it than the average Joe: this picture serves as a visual representation of a key focus in my life over the last 14 years—so of course I’m enamored.

15 thoughts on “Prolonged Absence

  1. I’d suspected you’d either run out of physics or that your Ford C-Max (with Sync by Microsoft!) had been requiring as much attention in the shop as mine has!

    Congratulations of being too busy to blog, Doc. It is a good thing.

    • Still very happy with the C-Max: seldom use gas around town. Not jubilant about Microsoft Sync, but no serious shop time, aside from the odd minor recall.

  2. If you’ve covered everything you wanted to cover, have you spoken to any agents about wrapping it up into a book? Or self-publishing it? I suspect converting your content from a non-ordered series of posts into an ordered series of chapters with your perspective introducing an dtying them together would appeal to many. More importantly, I suspect it would reveal to you or lead you to clarify and write overarching thoughts we, your readers, mostly get, but would get more seeing written out plainly.

    That is, each time you did the math, I think the point wasn’t just to do that calculation but to find out what it meant and how it affected us. In each post you commented on that result. I think all the posts together reveal more than what you get just reading the posts alone. While most publishers would probably say too many (any) equations limit a book’s readership, I bet the results would appeal to a wider audience than just the scientifically-literate.

    Not that writing a book doesn’t take more time and effort than writing a blog.

    • I agree. I was just about to write exactly the same comment myself. Tom, turn the blog into a book! With all the material readily available, this can be done pretty easy. And, as a personal wish from me; print it on hemp paper. :)

      Btw. Will you continue to write posts?

    • I would like to second this idea of writing a book. I would like to have your works in a reference volume I could (re)read as I sit outside smoking my cigars and I also suspect that if you went this route you probably would add in some addition thoughts to tie your various blogs together.

  3. I think the fact wasn’t simply to do that computation yet to figure out what it implied and how it influenced us. In each one post you remarked on that come about. I think all the posts together uncover more than what you get simply perusing the posts alone. While most distributers would presumably say too much (any) mathematical statements restrict a book’s readership, I wager the outcomes might speak to a more extensive crowd than simply the experimentally proficient.

  4. Your work deserves and your audience would appreciate a book.

  5. I’ve had that photo as my screen backdrop since it appeared on APOD(*). Many thanks for it.

    If you do decide to produce a book, I can introduce you to a publisher that specialises in that sort of area – he publishes David MacKays book “Sustainable Energy – Without the Hot Air” amongst other works.

    (*) If anyone isn’t familiar with APOD, you really should be. It’s a wonderful site.

    • Now that’s a good recommendation! Do The Math is quite similar to MacKay in many ways.

  6. Thank you for your insightful blog.

    To answer your question: can an advanced society be sustained on terrestrial renewable resources? No.

    Proof (sketch): Consider 2 adjacent terrestrial areas of equal size, one with an ecosystem and the other with an advanced civilization running off of renewable energy collected in that area. By definition the area of advanced civilization contains high thermal gradients (computers, transport, smelting, manufacturing, etc..). Now by the first law of thermodynamics both areas conserve energy over a sufficient period of time. Thus the industrial civilization produces less entropy per unit time and unit area when compared to the ecosystem which has smaller temperature gradients. So in the long run almost surely the industrial civilization must collapse back to an agrarian civilization.

    Lemma: The evolution of agrarian civilizations is constrained by the opposing processes of increasing entropy with increasing crop yield and decreasing entropy with increasing thermal gradients in the urban and agricultural heat islands.

    Corollary: Tropical agrarian civilizations are not stable because tropical jungle entropy production is nearly maximized.

    The whole of the evolution of human society, past, present, and future follows trivially from the partition function of the theorem. It is left as an exercise for the reader to derive the evolution.

    • One can apply similar logic to prove that civilization will stop extracting fossil fuels long before they physically run out. Briefly, when the net entropy produced (per unit area unit time) from self sustaining fossil fuel extraction is close to the net entropy produced through agriculture and ecosystems then eventually almost surely fossil fuel extraction will decline.

      But the emperors where I live have no tolerance for being told they are naked.

    • I caution against using entropy and second-law thermodynamic arguments to set constraints on the human endeavor. See my post on entropy misunderstandings. I am comfortable using thermodynamics to illustrate what continued growth does to our thermal budget, but hesitate to invoke entropy and the second law, as the solar input flux (among other possibilities) gives us substantial leeway with respect to the second law.

      • Thank you, your cited that post does illustrate the common misunderstandings of entropy. I have encountered the same misunderstandings you illustrate when some have tried to claim that geological hydrocarbons are a low entropy state. They are in a high entropy state compared to extracted, processed, and refined hydrocarbons. Of course the entropy is offset by…burning hydrocarbons to extract, process, and refine new hydrocarbons. One can easily deduce the limitations on net entropy production from self sustaining hydrocarbon reserves, just as one can do the same for a burning log of wet wood.

        The point I was trying to illustrate was that civilization collects energy and dissipates over a smaller surface area. QED by the Stefan-Boltzmann law the temperature of that thermal dissipation is higher. It follows that for the same amount of energy dissipated, civilization dissipates the energy at a lower entropy than natural ecosystems.

        In the last 250 years civilization overcame this constraint by dissipating the chemical potential stored in hydrocarbon bonds. Which as we both know is a very finite resource.

        • I just re-read your piece on tidal power, which jogged a few questions.

          At what temperatures do the following forces dissipate their driving energies: wind? solar? tidal? hydro-geological? Geothermal?

          The follow-up question is then, can the human race do better and dissipate those energies at lower temperatures? Probably not and still maintain a complex industrial society.

          Put another way, if there was enough entropy available in deep ocean vents to evolve base energy gathers as complex as trees it would have happened after a billion or so years.

          FYI, the answer for entropy maximized space based solar collection is 3/4 solar black body temperature, or the Earth emitting 81/256 the flux of the solar surface. This tells us that if civilization entered a “breeder” phase for space based solar collection eventually we would cook the planet at ~4200K. Provided society does not also make the phase change towards Dyson sphere civilization.

          And if you buy those arguments, I’ve got a handful or martingales I’d like to sell you.

  7. Sorry one more point of clarification. I’m not arguing that the second law precludes society from building a large capacity for renewable energy capture. Rather I am arguing that in the long run the second law precludes society from maintaining renewable energy capture using only renewable energy capture, as natural processes dissipate the same energy sources at higher entropy than civilization can.

    In short, which I am never, except in height, over time the incurred damages to renewable energy infrastructure would outpace our ability to conduct repairs using only the energy derived from the renewable sources.

    This leads to the next question, what would be the half life of a renewable power source maintained only using renewable power?

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