The morning after

This is an addendum to last night’s post.

I should let everyone know that I was using an unusual definition of “my”. Usually, my is the first person possessive pronoun. But occasionally, it has other meanings. In the case on yesterday’s title, for example, I used the little known definitions of “my”, such as: my=a; my=an uncontrollable; or my = a scheming foxy, willing-to-let-me-think-I-actually-figured-her-out.

For the better part of a week, everything was perfect, blissful, the Cs barely twice the instrumental background and Rb only a few times larger. I’m still not sure exactly what happened. Perhaps I got complacent, and started taking my cps for granted. Or maybe the alkali wild spirit can never really be tamed by a lab coated man, and resumed its contaminated machine on its own schedule, without regard to the wants and desires of the laboratory staff.

Whatever the reason, in the cold light of dawn, it became evident that the Friday morning backgrounds were an order of magnitude higher than the rest of the week. I was back to square one, with no consolation or explanation to ease my loss.

Fortunately, by that time the moon people had finished their analyses. In fact, I eventually tracked down the source of the contamination. A couple of Germans from Edinburgh* had been using the machine to looks at refactory glass and carbonates. That was fine, but what ended it for me and my alkali backgrounds was their decision, late in the day, to run just a couple of volcanic sanidines (is there any other kind?). The ablation of trace element-enriched K-spar must be what brought on the contamination.

I’m not really sure what to do now. Staring at the wiggly signal lines, it feels like I’ve lost something special, something irreplaceable. The calculating pert of my mind tells me that I’ll solve the problem of getting the low backgrounds soon enough, and I think I know how to keep them, but that doesn’t stop me from worrying.

A more interesting question, however, is why the Germans are in Edinburgh. I suspect it is a result of natural selection. Researchers from Mexico, China, or Italy would not be able to survive in Edinburgh. They would starve to death. So only it is reasonable to suspect that any scientists who can thrive there must come from countries with a cuisine sufficiently bland that Scottish food is not too painful an adaptation.

Rubidium is my Bee-otch

The Alkalis are the most tempestuous of elements. Willing to drop their unfilled S shell at the drop of a hat, they shamelessly lure anions away from more respectable metals, giving up their unpaired electron like a thermal ionization source in heat.

They are also filthy little atoms, dissolving into almost any aqueous solution, and easily evaporating under fairly reducing conditions. This, along with their ubiquity, makes them infamous contaminants in ICP mass spectrometry, and their background concentrations under standard conditions can be equivalent to thousands of ppm.

Special analytical techniques, such as soft extraction, have been developed to get around the pernicious easy-going electron-induced ionization of alkali caused by premature charge separation. But these techniques lead to reduced sensitivity, uneven backgrounds, and higher detection limits.

An alternative method, which has kept me out of trouble for the past six months, is to prevent these ionic Jezebels from getting into the cones in the first place. Although this “absence-based” protocol sounds easy, actually quarantining the gas expansion region of our machine from the alkali has been a bit of a chore, and only last month (and just in time for the conference) have I had any luck getting results from this technique.

On Tuesday, I finally managed to kick some group one ass. For some planetary post-Goldschmidt visitors, I let them open fire on lunar minerals with a 15 ppb detection limit for Rb on a 70 micron spot and minimal laser power. Now, the moon isn’t exactly alkali heaven. A dry, degassed, volatile-depleted wasteland, it has one of the lowest assumed mantle K/Th ratios of any known planetary body. So even in the compatible phases Rb is going to be low. But thanks to my trusty new tuning glass, half a year of assiduous record keeping, and a bit of good old-fashioned luck, these guys have a chance at getting something other than “bdl” to put in their papers when they’re done.

Playing the name game

Tonight, I bring you the tale of two papers. The first paper, Zr budgets for metamorphic reactions, and the formation of zircon from garnet breakdown, is by H. Degeling, S. Eggins, and D. J. Ellis. The second paper, In situ U–Pb dating of zircon formed from retrograde garnet breakdown during decompression in Rogaland, SW Norway, is by H. S. Tomkins, I. S. Williams, and D. J. Ellis. Aside from the third author (and really, who cares about third authors?), the subject matter, the methodology, the samples, and the overall geologic framework, these two papers have something else in common. Something rather important, that neither Web of Science nor Google Scholar can discern (I also tried Georef, but it crashed my work comp, and I don’t have a home subscription).

Both papers are written by the same first author, who for the purposes of this blog will referred to as either Dr. Tomkins, or Helen*. As you might be able to surmise from the publication dates, Helen got married in 2003 +/-2 AD (1 permil precision is good enough for geochronologists), and changed her name. But as far as the system is concerned, she is no longer the same person. And neither index seems to list both of her papers as being written by the same person. Why is this?

I offer three hypotheses:

1. Computers are stupid, and a single person with more than one name is more than they can handle.
2. Married women aren’t worth listing because...
2a. Once they’re hitched, women have no future in scientific research.
2b. Real, hard-core science chicks are all feminist zealots who would never consider a name change.
3. The scientific indices are run by a bunch of lazy dumbasses.

Test of hypothesis 1:
Go to imdb.com, a large on-line database. Search for “Jamie-Lynn Siegler”. Then try “Jamie-Lynn DaScala”. If television database is smart enough to recognize that both names refer to the actress who plays Tony’s daughter in The Sopranos, is it really too much to ask for a scientific database to display the same level of competence? After all, the Web of Science certainly charges more for subscriptions.

Test of Hypothesis 2:
Consider the career of Marie Sklodowska. Married at the age of 28, she took her husband’s name, and first published under it three years later, with “Rayons emis par les composes de l'uranium et du thorium”. Over the next 37 years, she added to her scientific credentials with
-The discovery of polonium and radium.
-The Nobel Prize for physics, in 1903
-The Davy Medal of the Royal Society in 1903
-The Nobel Prize for chemistry, in 1911
All in all, Marie Curie didn’t do too badly.

Test of hypothesis 3:
The best way to test this is to see how long it takes the various indices to get their acts together.

Now, I’m a rogue, not a feminist, so I ain’t gonna campaign for any sort of systemic change. I will simply offer two bits of advice to Dr. Tomkins:
1. If future editors ask you for the name of a referee for future papers, why not suggest Dr. Degeling?
2. Make sure you reference her work many times, as the citation indices probably think you two are independent researchers.

* ‘cause that’s her name.

Melbourne III

Some more highlights (more general, less scientific):

-Seeing old friends who have been overseas for 3, 5 sometimes even 7 or 8 years. It is kinda scary how easy it is to lose touch with people for half a decade or more when living on the bottom of the world.

-The quality of the science presented. The vast majority of talks were well thought out, and presented significant, interesting research results. My only complaint was that with so much good science, there were a lot of simultaneous sessions for talks I really wanted to go to.

-Dragging a bunch of lily-white geologists out to Footscray for real Ethiopian food. It is interesting how the whole corporate hospitality industry brags about how many dollars it brings into the city, and then does everything possible to make sure that all of those dollars are spent on it. So it’s fun to actually pry people away from their grip on city centre and actually go to establishments owned and operated by humans.

-Lab visitors. People on their way to or from the conference have been floating into lab with interesting samples, methodologies, or ideas. Also, some of the geochemical community’s analytical hot shots- people who generally aren’t let out of their own labs for substantial periods of time, have been wandering through, and it is great to learn from the masters, and trade ideas, protocols, and general lab talk.

Anyway, that’s about it for Goldschmidt thoughts. Hopefully I’ll have some nitty-gritty analytical posts ready sometime next week, but for now, good night all.

Iridium anomaly as historical artifact

Everybody knows that way back in 1980, Alvarez et al. showed that Italian sediments deposited on the Cretaceous / Tertiary boundary (and NOT the Cretaceous / Paleogene boundary, I might add) are enriched in the element iridium. The term “Iridium anomaly” was thus coined as a quick and dirty way to identify extra-terrestrial impactors.

The idea is simple: when the Earth differentiated into core and mantle, the PGE elements (Ru, Rh, Pd, Os, Ir, and Pt) partitioned into the core, since they are soluble in metallic iron, but excluded from silicates. Thus, undifferentiated material has a much higher PGE content than the silicate Earth, allowing anomalously high concentrations of these elements to be used as an indicator of undifferentiated material.

What this idea does not explain, though, is the following:

Why Iridium? Why don’t we all learn about a platinum anomaly or a ruthenium anomaly in first-year geology?

The answer to that question is actually quite simple, but it involves nuclear physics, not geology. Iridium was the PGE detected by the Alvarez study because it is the only PGE that can be identified in sub-ppb concentrations using neutron activation. Prior to the refinement of ICP mass spectrometry in the 90’s, neutron activation analysis was the most sensitive analytical technique available to geologists. But because it is a nuclear, and not a chemical or ionic technique, its applicability depends on whether or not any isotopes of a given element happen to have high cross-sections that capture neutrons to form unstable, gamma-emitting products.

It just so happens that the two naturally occurring iridium isotopes have relatively large cross sections, and form short-lived, gamma-emitting products. The other PGE’s do not. So the iridium anomaly was detected simply because it was the most detectable, using the technology available at the time.

Here in the 21st century, it is generally cheaper, easier, and safer to dissolve a sample and run solution ICPMS to get all six PGE’s. Unless, of course, you give yourself osmium poisoning from mishandling your spike.

Melbourne (II)

Highlights from Goldschmidt:

Watching A. Hoffman erupt, strombolian style, when C. Spandler presented his new olivine diffusion data, cutting orders of magnitude off the re-equilibration time of melt inclusions.

E. Hendy’s description of what happens to coral during a bleaching event, as determined by synchrotron tomography, personalized the pain of losing one’s autotrophic symbiotes in a way I’ve never experienced before. I don’t know how I’ll ever calcify without them.

S. Ader’s fifteen extra minutes of fame- due to a scheduling mishap, she got 20 minutes of question time instead of three, and the discussion and back-and-forth between her and other researchers working on correlated strata was awesome in its earnestness and spirit of co-operation and learning.

Names on papers are actually people: It turns out that Prof. Kirschvink, the guy who first introduced the snowball Earth hypothesis back in 1992, is a feisty Californian named Joe, who seems to suspect that we are all actually Martians. It can be kinda odd when a name that exists only in bibliographies suddenly turns into a human being.

Sponges! In the Cryogenian! If G. Love’s paper is as detailed as his talk, it will be a classic.

Xenon isotope people are seriously smart. I had no idea how S. Crowther transformed her isotopic ratios the way that she did, but it all made sense in the end.

There is such a thing as a stupid question. I should know. I asked far too many of them.

RIP Steve Irwin

The crocodile hunter Steve Irwin was killed while filming a nature documentary today. Mr. Irwin was better known outside of Australia than here in his home country, where his success has often been greeted with embarrassment and derision. But his impact on the promotion and education of the natural sciences should not be underestimated.

Academics, like many professionals in demanding careers, seem to automatically assume that the skill set needed for their work is something that the entire population must enjoy. For researchers, the most basic skill set is learning. Thus the vast majority of science media and education material produced starts with the assumption that learning is fun. For vast numbers of people, this is simply not the case.

What made Steve Irwin a great educator is that he was able to reach beyond the narrow subset of people who learn for kicks, and appeal to those people who aren’t interested in books, or study, or arcane facts that have no relevance to their own immediate experience. This is a skill very rarely seen in natural science education, but it is very important.

The planetary system does not affect people differentially, based on their willingness to go to school. The Love and Rayleigh waves produced by the next major quake will not bob and weave to avoid the houses of people who are scared of math. Global warming will not only cook that small segment of humanity which appreciates radiative energy balance. We all live on the same planet. So an Earth scientist who says that the incurious deserve what they get is just as narrow-minded and callous as a plumber who thinks that homeowners ignorant of a good Teflon winding deserve to have their toilet overflow.

On a personal level, have to admit, I was stunned. In the lead-up to the 5 o’clock news, the teaser went something along the lines of “A famous naturalist dies doing what he loves.” I automatically assumed that David Attenborough had passed on, so when the full story played 20 seconds later, I was completely shocked. My parents hadn’t even met when JFK was shot, and I can barely remember when Diana died, but this afternoon I was turning around the east corner of parliament drive after picking up my wife from work when I heard the bitter news.

New uses for grad students. . .

. . . as seen at the Melbourne Goldschmidt.

1. Babysitter.
I saw one mid-career academic telling the kids to behave, be quiet, and ask her grad student if they needed anything, shortly before the professor walked into a session. The poor grad student was just trying to sink into her laptop in a dark corner behind the kids. Imagine having to sort out crayons during your first chance at meeting the experts in your field and lining up a post-doc.

2. Session chair.
Obviously, you have to wonder why a session is being put together if nobody actually wants to convene it. But if you get stuck with the job, skyving and leaving your first year student at the helm is a bit rude to the presenters who submitted to the conference wit the expectation that someone would care. Especially if the student hasn’t yet learned how to successfully disguise boredom.