Tuesday, August 15, 2017

Robert Gould Shaw and the Massachusetts 54th Regiment Memorial



The Massachusetts 54th Volunteer Infantry was the first African American regiment formed in the US Civil War.  Lead by Robert Gould Shaw the regiment endured heavy casualties and fought with valor. Shaw was killed in the attack on Fort Wagner South Carolina in 1863.  Sgt William Carney was the first African American to earn the Congressional Medal of Honor for his bravery in that fight.

Dedicated in 1897, the monument was created by August St. Gaudens and paid for by private donations.  The relief shows Shaw and the troopers marching off to a war that would free their countrymen from chattel slavery.  It sits opposite the State House on Beacon Street in Boston.

At the dedication
The military units present began to march past the Memorial, led by 65 veterans of the 54th Regiment. Some of the officers wore their Civil War uniforms, but most of the enlisted men were in their best frock coats. Black veterans from the 55th Massachusetts and the 5th Cavalry were also present. Among the men of the 54th, Sergeant Carney carried the American Flag. The sight of him elicited cheers from the onlookers who knew of his exploits. The 54th veterans laid a large wreath of Lilies of the Valley before the monument. All of this deeply moved Saint-Gaudens:

"Many of them were bent and crippled, many with white heads, some with bouquets... The impression of those old soldiers, passing the very spot where they left for the war so many years before, thrills me even as I write these words. They faced and saluted the relief, with the music playing 'John Brown's Body'…. They seemed as if returning from the war, the troops of bronze marching in the opposite direction, the direction in which they had left for the front, and the young men there represented now showing these veterans the vigor and hope of youth. It was a consecration."


Monday, August 07, 2017

Making the Elephant Dance as Performed by Ned Nikolov and Karl Zeller

As John von Neuman put it
With four parameters I can fit an elephant, and with five I can make him wiggle his trunk.
and, as fate would happen, along comes Ned Nikolov and Karl Zellner with "New Insights on the Physical Nature of the Atmospheric Greenhouse Effect Deduced from an Empirical Planetary Temperature Model".  It's basically 22 pages of word salad and Eli may later return to pointing out some of the more amusing light fingered moves, but here the Bunny will only provide a small amuse bouche with the "interesting" exercise in fitting five numbers with four free parameters, two unphysical constants and a free choice of fitting form.

So briefly, what goes on is to fit the five average surface temperatures of five plants or moons (Venus, Earth, the Moon, Mars, Titan and Triton.  Wait you say, that's six, not five, but they leave Titan out of the mix because  (Eli told you this would be yummy) to an arbitrary functional form

y = a exp(bx) + c exp(dx)

Wait you say again, ok, that is four parameters and the functional form plucked out of thin air, but what is x and y.  That's kind of interesting and more than a bit light fingered but you have to watch the moving cup.  The independent variable is a ratio of pressures (Ps/Pr).  Ps is the pressure at the surface, Pr, well that's interesting, Pr starts out as the "minimum air pressure required for the existence of a liquid solvent at the surface, hereto called a reference pressure (Pr)" but about a page further on it morphs into 
For a reference pressure, we used the gas-liquid-solid triple point of water, i.e., Pr=611.73Pa [38] defining a baric threshold, below which water can only exists in a solid/vapor phase and not in a liquid form. The results of our analysis are not sensitive to the particular choice of a reference pressure value; hence, the selection of Pr is a matter of convention.
The alert out there have noticed that the minimum air pressure required for the existence of a liquid solvent at the surface kind of depends on the temperature of the surface, and would vary widely from planet to planet. Of course worry bunnies like Eli might ask:  What liquid?  Water exists as water on the surface of the Earth, if there was any as steam at Venus and as ice at all the others if it exists there at all.  For Venus maybe CO2, but at the surface of Venus CO2 is a supercritical fluid and you can't tell the difference between liquid and gas.  At Titan, there are oceans, but oceans of methane, so any useful Pr is going to be wildly different for all of these bodies and, in the case of the Mars, and Triton some pretty fancy liquids are going to be needed.

Selection of water as the solvent of choice is then both arbitrary and unphysical.  But why do Nikolov and Zeller insist on using it? Turns out their elephantine trunk waving depends on using dimensionless variables, but restricting Pr to an inappropriate value independent of the planet is equivalent to stripping the units off of the surface pressure Ps.

How about y.  y is defined as the ratio (Ts/Tr) with some really serious trickery buried in TrTr is defined as a reference temperature,
the planet's mean surface temperature in the absence of an atmosphere or an atmospheric greenhouse effect.
At this point no bunny should be surprised to find that that ain't quite that.  Whoa.  Where that come from.  Old timers may remember Eli's old friends Gerlich and Tscheuschner who were also in the business of trying to falsify the greenhouse effect, by as was pointed out, not understanding what the greenhouse effect was.  As Science of Doom put it
 Gerlich & Tscheuschner have written an amazing paper which had the appearance of physics yet failed to address any real climate science.
Eli and several distinguished bunnies had a run at G&T, but, of course, as such things go, the majicians never give up, and one may anticipate a visit from Nikolov and Zeller too.  Good times to be had.

Anyhow, one of the results was a nice arXiv article by Arthur Smith explaining how the surface temperature of a rotating planet varies with the rotational period and the heat content of the surface, which for the earth is basically that of water.

The parameter λ for the Earth is 0.04 and describes the ratio of the energy absorbed from the sun in a day to the heat capacity of the surface.  The effective temperature is the temperature determined by emission from  the surface on a non-rotating body needed to maintain thermal equilibrium.  Depending on your model Arthur showed, as was well known, that the average temperature of the surface of a rotating planet without greenhouse gases has to be less than the effective temperature.

Nikolov and Zeller reproduced Smith's results in another paper with one very strange twist.  In their model  they insist that every planet without an atmosphere will have the same surface as the moon.  (Basically λ =20 in the figure above.)  Using the bare moon Tr now Tna, is, again arbitrary, but let's go ahead and look at the fit which is all John von Neuman told you it would be

Further hand waving ensues.  Nikolov and Zellner will soon be here to entertain you.  Eli warns the bunnies they are indefatigable and will tell you to read the paper.  Eli's advice is if you want some laughs go ahead.  Scott Denning has been trapped into the endless circle, so be sure to take some survival rations for him.



Friday, August 04, 2017

The face of a champion




Context (link here if the video doesn't work, just scroll down):

Wednesday, August 02, 2017

Tyler Cowen and defensive innovation: reasonable idea, problematic execution

Tyler Cowen has an interesting point about "defensive innovation" meant to prevent future problems, wherein he describes climate change as a future problem and Tesla as a defensive innovator that solves the future problem without necessarily improving human lives over baseline conditions.

It's a reasonable point viewed in isolation, that we may overestimate how technology improves lives over the baseline condition when it just solves problems we anticipate. The problem is overplaying the point. One example is Cowen referencing a cure to Alzheimer's as a defensive innovation - yes it's true that Alzheimer's will likely become far worse of an affliction as our population ages in the next few decades. OTOH, it's already a tremendous problem today - as an economist, Cowen should appreciate the tremendous, current economic cost in treatment and decreased earnings from Alzheimer's today, let alone the negative utility from human suffering (and to be fair, he doesn't completely ignore this).

Climate change is a comparable example - for one thing, it's already harming us. For another, environmental impacts are rarely unique - the pollution that causes climate change has many other negative impacts on health and the environment.

A thought experiment:  compare a modestly optimistic future for our Earth in the year 2050 relative to Earth 2 in another universe, exactly like ours except some quirk in physics or technology keeps greenhouse gases from building up in their atmosphere. Earth 2 will be still be using coal and petroleum in 2050, with resulting air quality health impacts and devastated environment from mining and spills. They'll talk about switching to wind and solar, but those technologies will be expensive because Earth 2 hadn't spent many decades subsidizing research in those fields. Earth 2 will also be poorer than us because fossil fuel energy there will be more expensive than cheap renewables here.

Other than the climate impacts, Earth 2 will be worse than Earth. Climate mitigation is making Earth a better place.

One final point - from a policy perspective, it doesn't matter whether an innovation is defensive or an improvement over current conditions. If it fixes a problem in the future at an acceptable cost, then it doesn't matter whether that problem exists in the present or just in the future - you should still fix it. Climate change exists in the present, but regardless, the future catastrophe is well worth preventing.