Monday, July 30, 2007

Nappies- disposable vs reusable

I while back I mentioned that Mrs. Lemming, Littlest Loveliest Lab Lemming, and I were trying a variety of different nappy types. For the first 11 weeks or so of her life, LLLL used a couple of different reusable nappies and disposables.

The first sort of nappy that we used on our daughter was the standard, terry-towel cloth nappy. This is the chondrite of diapers, an undifferentiated square of cloth with no functional adaptations. The hospital where LLLL was born provides only cloth nappies, and encourages new parents to also use them at least until the meconium changes and any potential jaundice passes. I think the idea is that it is easier to count and keep track of eliminations if they aren’t all sucked into the silica gel of doom.

Cloth nappies were fine for those first few days, but after the first week they started suffering containment failures, and the size we had at home was too big anyway.

For the next 10 weeks, we used two other nappy options on our daughter. After 11 weeks, she grew out of newborn sizes, so everything changed.

The disposable option was huggies. Everyone we talked to said that they had the best containment, and we found that the newborn size worked quite well.

The reusable nappies were bummi wraps from Green Mountain Diapers in the US. These consist of a water resistant nylon outer wrap which holds a cloth diaper in the appropriate position. With urination and small poos, only the cloth insert needs to be changed, while with large poos everything gets messy.

Both systems leaked about once a week or so, and the reusables generally soiled the (inside of) the outer wrap one or two times a day. For the first month, we alternated each system for a few days at a time, because using either all disposables or all reusables for more than a few days gave her nappy rash, which changing systems got rid of.

After the nappy rash past, we usually used the reusable nappies at home and the disposables for going out, or for overnight. In terms of grossness, time consumption, or difficulty I don’t think there is that much difference, except for doing the extra load of washing, which takes a while. The reusable covers are definitely cuter, but since it is the middle of winter they aren’t often visable.

During my last week of paternity leave I considered calculating a partitioning coefficient between bottom and nappy for both types, but sleep deprivation and inconsistent fecal texture stymied this project.

In terms of waste, the disposables generally meant one more trash bag per day*, while the reusables meant an extra load of washing every day or two. We wash the nappies in the washing machine on the “biologicals” cycle, with an additional vinegar rise cycle afterwards.

After 11 weeks, LLLL grew out of the infant size and also changed from 4 medium poos per day to one megashit every 24-36 hours. We found the infant sized female huggies and baby love disposables to be fairly ineffective at containing megashits, but the mamia brand from Aldi seems to be doing OK. The reusables contain well, but the whole package needs to be changed, not just the insert.

Did anyone have any particular questions about the advantages or disadvantages of one system over the other?

* We use plastic grocery bags as our garbage bags, and filled 2-3 per week before the baby.

Friday, July 27, 2007

Abiotic snake oil

I usually don’t bother with antiscience. It’s kinda like researching and dobbing in companies that advertise Mexican sex drugs- debunking takes way more effort than spewing crap, so it is hard to win. But Sabine pointed me to a recent article on abiotic oil that is a textbook case of argument from ignorance.

An argument from ignorance generally works like this:
1: “I have no idea how much I don’t know. In fact, I think I know everything worth knowing.”
2: “I have no understanding of X, and since I know everything worth knowing, X can’t be important or correct”
3: “Because X is not important or correct, any arguments based on X must be irrelevant or wrong.”

In this article, we have:

“Kerogen, it turns out, is not a chemist's term. Kerogen is a loose, geological term…”

“Kerogen is not a term typically found in chemistry textbooks or specifically used by professional chemists. Use of the term kerogen is generally a signal that you are dealing with a petroleum geologist or engineer, not a chemical scientist.”

“A petroleum geologist, not a chemical scientist.” The obvious implication is that geology is not a science, and that any arguments based on geological knowledge are suspect.

This is NOT the same as arguing that geological processes must conform to the rules of chemistry. It is arguing that knowing the rules of chemistry excuse us from having to learn geology when studying geological processes.

The article continues to attack the concept of kerogen, saying that, “Chemical textbooks typically do not provide chemical formulae for kerogen.”

Does this mean that it isn't made of molecules? After all, it isn’t in the book! This is like saying that dirt doesn’t have a chemical formula that you can look up in a textbook, so it can't be studied.

Of course, the purpose of chemistry is not to list in rote format every reaction that exists. So the complaint that:
“We have yet to find a chemistry textbook that refers to "kerogen" or describes any combination of ancient algae, tiny Mesozoic sea animals, or dinosaurs as necessary or sufficient ingredients in the formation of common saturated hydrocarbons such as methane, ethane, propane or butane.”

…Is ignorant of the idea that the types of reactions shown in chemistry textbooks can be applied to natural materials of variable compositions with predictable results. After all, a real chemist would suggest that the same processes that allow hydrocarbons to be derived from whales or pigs ought to be applicable to dinosaurs as well. The author’s argument suggests that since we don’t know the chemical formula for pigs, they can’t possibly produce natural gas.

Luckily, the internet is slightly less ignorant. Wikipedia and the British chemguide both explain, in general terms, how thermal cracking occurs, and many more detailed studies are available.

In fact, the author doesn’t even seem to realize that crude oil is a mixture of all sorts of fairly heavy hydrocarbons. But it only gets worse from there.

He references an abstract that shows a wustite/calcite/water system will generate methane at mantle P and T to suggest that:
“The observation of methane formation at mantle pressures is significant because it demonstrates the existence of abiogenic pathways for the formation of hydrocarbons in the Earth's interior”

Once again, this is an argument from ignorance. In this case, it is ignorance of the composition of the earth- Wustite is not stable in the presence of magnesium silicates, which are what comprise the mantle. Discovering a reaction between arbitrary minerals that occurs in the (very large) P, T range of the mantle tells you nothing about the actual mantle unless that mineral assemblage is realistic.

It also assumes that because something can happen, it did happen. As it turns out, abiotic methane can be produced during serpentinization. But this gas is not mined. Doing so would not be economic. The natural gas that we actually pump out of the ground to cook stirfry with happens to be from dead bugs.

This post is already too long, so I’ll ignore the planetary non-sequiturs and the butchery of thermodynamics. I’ll also stay away from the entire field of biomarker geochemistry, which uses molecular fossils contained in hydrocarbons to determine the type of organism from which they are derived.

Instead I’ll just skip to his last question:
“Has anyone ever taken a flask of downed flora or dead protoplasm and produced a hydrocarbon fuel out of the mixture, or is this a process for alchemy?”

Of course they have. We call that hydrocarbon fuel “biodiesel”. Most of it is made from plant oils, but there is a New Zealand company that is now producing biodiesel from the natural algae found in sewerage plants.

Thursday, July 26, 2007

Greenhouses, Girls, and a River in Egypt

There’s a great new blog over at sciborgs, where the Hoofnagle brothers describe the psychology and tactics of denialist argument. I think that their main aim is the funded disinformation campaigns of interest groups and extremists, but I am beginning to suspect that the underlying psychological basis for inventing justifications is more widespread.

For example, the denial tactics used against global warming research are familiar to everyone who has worked in Earth sciences, and the denialism blog describes these well. But recently, I have seen the same pseudo-arguments appear in an entirely different context.

The institution I recently left has a terrible record at hiring women for senior positions (e.g. mass extinctions and Wilson cycles are more common). And it seems that recently, faculty has actually realized this, and decided to think about what, if anything, should be done. But although nobody has come out and said that the school is better off with 100% male professors and 60% female students, there have been a number of arguments against action that could have been torn right out of a coal lobbyist’s play book, or the denialism deck of cards.


Too expensive: We don’t have the money to hire anyone, so we’ll have to wait and see (3 spades).

Too damaging to (scientific/economic) output (6 hearts): Hiring the best women instead of the best people means lowering standards (and thus, presumably, quality of life).

Too daunting: the existing faculty makeup simply can’t be rebuilt overnight.

Wait and see (3 spades): The recent increase in female geoscience participation just needs time to work its way through the system. There is no problem (2 clubs), we just need to let time sort itself out.

Further study (5 spades). I think they wanted to interview all female alums to see what turned all of them off. Dunno if that actually went ahead, though.

Mere inconvenience (2 spades), no harm (3 hearts), no problem (2 club): Thankfully, nobody has mentioned these yet, so at least there is progress.

Wednesday, July 25, 2007

Acacia georgina

(Simul-blogged with Molecule of the Day.)

Much of our exploration area is loacated in gidgee country. Gidgee is a slow growing acacia tree that forms scrub, savanna, or low woodland in the claypans, stream beds, and dolomite areas of the basin.

From the bushcraft point of view, gidgee is the perfect firewood. It burns easily, hot, and long, with few sparks or pops. It was not unusual for us to put a log on at dinner and use the coals to heat the billy for coffee water the next morning. Cattlemen, however, are less fond of the tree.

At certain times of the year, or in periods of stress, Acacia georgina can contain high levels of fluoroacetic acid, the sodium salt of which is the poison 1080. Molecule of the Day gives more information on the chemistry and toxicity of this substance here, but the effect in the field is that cattle with gidgee poisoning are very prone to stress, and can drop dead when startled or disturbed. Annual cattle losses in the NT from gidgee are on the order of a couple million a year, and there are stories of helicopter-based geophysical surveys wiping out small herds just by overflying them. This is one reason that cattlemen don’t like helicopter work.

The other reason that cattlemen don’t like helicopter work is that healthy normal cows in eventually get used to overflights after a little while. This is great for the cows, but it is not ideal for the station manager when he plonks down several thousand bucks to rent a chopper for muster. The acclimated cows won’t run from a mustering chopper. They’ll just look at it, look at each other, and go back to eating the grass around the gidgee trees.

Monday, July 23, 2007

Just Keep Truckin’

In the outback, a vehicle is important for survival. Every summer there are tales of tourists who expire after leaving their vehicle in order to walk for help, without appreciating how far from anywhere they are, or how fast they dehydrate under the Australian sun. While it is important to stay with a vehicle if it breaks down, better yet is to not break down in the first place, or to carry supplies and know how to fix the problem. Therefore, I recommend that any traveler prevent his vehicle from degenerating into this sort of condition (click image for larger version):

Note that the operational status of this particular vehicle has been concisely described by somebody with a cutting torch. If the first couple letters of said description are not easily legible in this photo, try reading the antishadow in the wheel well instead.

Sunday, July 22, 2007

Where on (Google) Earth? #37

This has to be the easiest woge since the LGM ice caps slid into the sea. While the Schott Rule still applies (one hour per previous win), people waiting for the clock are welcome to name as many glacial features as they can make out in the picture.

Kent got it last night, bit I'll put up Yami's clues anyway, since they are interesting.

Oblique Google Earth view, looking south from small western plateau:

Actual view from same location:

All about the baby

By far the hardest part of the new job is that it requires me to be away from my wife and daughter for extended periods of time. In fact, this last trip ended up being something like 20% of LLLL’s entire life thusfar. And there were plenty of changes to be observed when I got back.

First of all, she is huge. Her head was bigger, and although her hair was longer, it seemed to give a similar amount of coverage. From this observation, I surmise that her rate of hair growth is the square of the rate of head circumference increase, assuming a constant number of follicles.

Her cries developed syllables. This must be the beginning of speech.

She went up a nappy size, and has transitioned into larger, less frequent poos (Mrs. Lemming gave me the opportunity to change a nappy in the airport change room immediately after getting off the plane).

She smiles much more convincingly, and laughs, and gurgles.

Despite all the changes, she is just as cute as ever.

Saturday, July 21, 2007

Australian residency for geoscientists

The state government of Western Australia is currently offering skilled migration visas to geologists and geophysicists in order to meet the skills shortage caused by the continuing resource boom. The STNI scheme is a two year working visa, successful completion of which culminates in permanent residency. Applicants under this scheme must live in Western Australia and work for a WA company. Details on the visa are found here. The deadline for the current visa conditions is 17 August 2007.

Needless to say, most of the earth science job shortages are in the minerals industry. However, defection of people from other geoscience areas (e.g. people like me) means that there may be other types of employment available. You won’t know until you look. So if you are a geologist or geophysicist, you want to try the Australian lifestyle, and you meet the criteria (see link), check it out.

Note: I am not a migration agent. I strongly recommend that anyone interested in these schemes contact a professional for accurate information on how they work.

Thursday, July 19, 2007

Blogger and gmail problem

I can't upload images larger than about 150k, even though available space is huge. I seen to have the same limit on gmail attachments. If any of y'all have seen this problem, or know a solution, please tip me off so that I can show off field pics...

Tuesday, July 17, 2007

Thank God for geophysics

Can you imagine defining targets in this sort of terrain without it?

p.s. Apologies to any Midwesterners who get homesick from the relief in this terrain.

Sunday, July 15, 2007

Where on (Google) Earth? #33

There's nothing like winding down after a field posting by knocking off a woge as a distraction from trying to find a route that doesn't bog the truck so much. So for everyone back on break, here's another picture of our beautiful planet. The geological theme for this episode is structurally controlled drainage. The environmental theme is clearcutting.

In order to open the contest up a bit, I will ask previous winners to wait 24 hours before answering.

Wide Open Spaces

Hopefully the next line of the song will not apply...

p.s. I apologise for the low image quality, but blogger won't take anything over 200 kb for some reason...