2018-05-19

L'affaire Foote

Eunice Foote is a recent cause celebre: By all rights, Eunice Newton Foote should be a household name. More than a century and a half ago, Foote was part of one of the most important scientific discoveries of our time: revealing the role of carbon dioxide in the earth’s greenhouse effect. This is, of course, literally bollox. The proposal is to supplant Tyndall's name with hers. But Tyndall is not a household name, and therefore hers would not be either. While I'm on nonsense, mention should go to ThinkProgress's the concept of the greenhouse gas effect was discovered in the 1920s, by Joseph Fourier. Does no-one proof-read this stuff? More, is everyone who read it too ignorant (or, like me, too despairing) to point out the error to TP? But enough footling stuff. What of the substance?

The substance is her Magnum Opus, On the circumstances affecting the Heat of the Sun's Rays (side note: she appears to be part of a scientific family; her husband's somewhat longer paper on a similar subject preceeds hers in the same volume). She takes two jars, with thermometers in each, and exposes them to the sun, having done different things to each. Firstly, one has condensed air; in the other it is exhausted. It gets warmer in the condensed one. She concludes:
foote1
This is wrong. It is colder up mountains because the air is thinner because temperature decreases as air expands, not for radiative reasons. Indeed if anything the sun is stronger the higher up you go, because there is less air for it to be absorbed in. But this bit is uninteresting to the retrospective warriors, and certainly Foote's errors are not of interest to them, so we continue on.

Second, dry air didn't get as hot as damp air. Third, the one filled with CO2 got hotter than the one filled with common air (as she herself says, she had no way of assessing the pressures in the vessels, so there are uncertainties in all this). Oddly, despite tabulating 120 degrees (unspecified units) for CO2 and for damp air, she then claims that CO2 was the hottest, at 125. I don't quite understand that.

What did Foote actually see? Not the GHE, but most people seem uninterested by this. TP quotes Katherine Heyhoe: Due to the rudimentary set-up of the experiment, Foote “wasn’t measuring what she thought she was measuring, but she actually serendipitously ended up with an understanding that is correct today,” Which is very delicate, but completely side-steps the point, and not I think entirely true2. AFAIK the only person to even look is good ol' Eli; amusingly, TP provides a link to Eli under the misleading text that EF's work was "not definitive". From Eli I copy the interesting "why did Foote observed a stronger effect from CO2 than H2O?  The answer is that she had a much higher partial pressure of CO2 in her containers than H2O because water vapor is condensible at 25-30 C, about 30 Torr", which I think is (a) comprehensible and (b) a bit of a shame that all the revisionsists couldn't also quote. But for the rest: if you ask me to draw an illustrative diagram of the GHE then I can and have; however even after reading Eli's words I'm rather uncertain what EF actually saw. Never mind; no-one else cares so why should I?

Did EF's work actually have any effect, or was it ignored? One of the Justice Warriors says A few years later, Foote’s findings were reflected in the studies of physicist John Tyndall but notice the deliberately ambiguous words used. It implies to imply that Tyndall was influenced by Foote, but there is no evidence for this1.

Note: this isn't new. It first came up in 2011. I thought it was wrong then.

Update thought


On reflection, the fuss around EF most closely resembles that around Bob Carter after his death. Not, I stress, that this reflects in any way badly upon EF, but on her puffers. Just that those who puffed Carter as a great scientist had not the slightest interest in his actual work; refer to Cainozoic history of southern New Zealand: An accord between geological observations and plate-tectonic predictions.

Notes


1. As he says: “With the exception of the celebrated memoir of M. Pouillet on Solar Radiation through the atmosphere, nothing, so far as I am aware, has been published on the transmission of radiant heat through gaseous bodies,”. Roland Jackson writes The saga of Eunice Foote and John Tyndall which considers the possibilities; I think his most compelling evidence of a lack of connection is that Tyndall didn't start with CO2.

2. KH did better in 2016. But there was less sex around then.

Refs


CLIMATE WARS : THE SALT TALKS.
On the Principles of Economic Principles

9 comments:

Kiwi Griff said...

Reminds me of NZ's Richard_Pearse.
Wrong but wright direction.
Working in isolation on an idea whose time had come.

David B Benson said...

William, to bring "six impossible things before breakfast" to the present, your thoughts, riven as they are by some Austrian, on Brexit?

William Connolley said...

Richard Pearse? First I've heard of him; interesting. I went to Otago once.

Brexit, ah well. My opinion is that what I expected has come to pass: the various pols are incompetent to negotiate anything sane. It now looks like the short-term outcome will be to leave, but in a manner similar to staying in, but worse. This will make mainstream pols happy - because they can have lots of fun looking important doing things - and the Brexiteers not too unhappy - because we will have technically left, and they can work on "improving" the practical situation later.

Hank Roberts said...

So, how come nobody's brought this out as instructions to create a school science fair demonstration?

Surely the materials aren't hard to come by, and the electronics available today ought to handle making measurements.

Google tells me the "facetime" camera of the iPhone 4 doesn't filter out infrared, though the back side camera does.

CO2? Seltzer or dry ice are easily enough available.
Nitrogen? Harder to come by, welding shops maybe.

I recall a cheap aquarium pump can work as a cheap vacuum pump.

William Connolley said...

For the reasons that I gave: (almost) no-one knows what it is a demonstration *of*. Only Eli (and anyone who has bothered to read what he wrote carefully and understand it, which as far as I can tell is no-one :-) knows. Do you think you know?

Anonymous said...

I recommend anyone putting Foote's experiments and short paper forth as an unjustly neglected pioneering contribution to climate science

1) read Foote's paper
2) read Tyndall's paper
3) consult with a science historian
4) consult with a physicist, meteorologist, or metrologist who understands thermometry, convection, and radiant heating
5) reconsider their position

EliRabett said...

What she observed was absorption of sunlight in the near IR (shorter than 4 microns) which heated the gases. At this point it looks like she was the first to have observed IR absorption of gases. This is not the greenhouse effect but it is an important result in a developing field and could have motivated Tyndall, as the experiments of Melloni did
https://www.chemistryworld.com/opinion/mellonis-thermomultiplier/3008435.article

The two open questions at this point (seriously) are first, did news of her experiment reach Tyndall (a real possibility) and what type of glass was she using. The latter will tell us what the IR cutoff in her experiments were.

Hank Roberts said...

> Do you think you know?

Nope. That's why I'd like to see this described by someone who does know, as suitable for kids to do at the school science fair level.
Most science fair projects are replications of older scientific work, at best.
It'd be educational.

Infrared diodes are now commonly available specified by wavelength.
As Eli says, specify what kinds of glass container would be useful for making comparisons
Photocells that respond to infrared are ubiquitous in digital cameras nowadays.
And used in face recognition devices too.
Most electronic parts are available cheap-from-china
Edmundoptics sells infrared mirrors.
I recall nail polish works as a fairly effective cement for sealing tubes to be pumped down to soft vacuum ....

Hank Roberts said...

My goodness. 'Build your own terahertz source, see through clothes!
https://www.azosensors.com/article.aspx?ArticleID=654

"... an infrared laser beam of 50 Watt at a wavelength frequency of 10.6 micrometer.... is transformed into a terahertz laser beam by channeling it through pressured methanol. The resulting terahertz laser has a power of 150 milli-watt and a wavelength frequency of 119 micrometer...."