T-shirt: How to explain your research at a party.

My new t-shirt reward for renewing my subscription to Science arrived. I wore it proudly yesterday.

How to explain your research at a party.

I have probably used all of these techniques at one point. Diagram, Lecture, Demonstration, Embellishment, Puppet Show, Interpretive Dance.

One might have just as easily titled this "the six stages of increasing desperation when explaining your research at a party."

Measuring Shellpot Creek Stream Flow with a Leaf

Before today's rain, the Shellpot Creek has been so low due to the lack of rain that it has contracted down to flowing through a few inch wide cleft in the rocks on the stream bed in the middle of the picture below.

Here is the cleft:

The width is about 3.25 inches:


The depth is 2 inches, the ruler I used goes to 16 inches on the right side and 14 inches is just visible below.


I realized that such a controlled situation would allow me to measure the stream flow with a ruler and something like a leaf floating in the water to get the flow velocity of the surface. I used my camera and flip video to capture the measurements and as a timer for the flow. I repositioned the ruler and used an imaginary line drawn from the cleft in the rock to the ruler edge. This distance is 5.25 inches. I then used the flip video snapshot function to find the exact frame the leaf first crosses the imaginary line at the cleft in the rock and the exact frame the leaf just touches the ruler at the other end (leaf and red lines below).


There are 30 frames/second in the video. I got 10 successful measurements from 14 leaf drops, ranging from 23 frames to 40 frames, corresponding to an average of 5.59 inches/second +/s 15% for the velocity of the leaf and thus for the velocity of the top of the water.

I pieced them all together in the following video.

Without doing the extra work that would be required given the fluid mechanics of the situation we are going to assume that the channel is rectangular and that I have measured the maximum velocity of the fluid. That corresponds to the right hand side of the chart below.

If we assume a linear velocity profile the average velocity is 5.59 inches/sec multiplied by a 2 inch depth and a 3.25 in width to get 36.3 cubic inches/sec for the flow. In reality the velocity profile is more parabolic like the right hand side of the diagram above and the average velocity is higher. Also, the channel is not smooth on the sides or the bottom, because of pebbles and stones and even the cross section will not be regular. Close examination of the video of the leaves floating by shows that they often go fast on the right hand side of the flow of the creek and slower on the left hand side, giving another clue that the velocity profile isn't simple.

Thus I feel like I have measured more of a lower bound for the flowrate. What would my readers do differently?

Babies and monkeys laughing at unpopular names

Sometimes the most recent good stuff is over at Childhood Antics:

A study of baby, monkey and primate laughter shows evolution of laughter seems to follow the evolution of primates.

A study of name popularity indicates a correlation between unpopular names and juvenile delinquency. Do I wish I knew that before we named our son?

Science - is there nothing it won't do?

Two comics today that perfectly capture the hubris of science and engineering.


(via Savage Chickens)

I also like the contrast between normal person and doctor or engineer, it doesn't appear that you can be both.

(via Saturday Morning Breakfast Cereal)

Some years have lots of acorns and some don't

Several articles in the press and out on the web today have sensationalist titles like "Where are the acorns?", "Acorns disappear across the country" and "Acorn Watchers Wonder What Happened to Crop". Even Topix has a a forum topic devoted to it. Then the various articles ring the climate alarm quite vigorously. Others use the false analogy of disappearing acorns to disappearing bees. Once again eye catching headlines win out over even reasonably thoughtful study.

The acorns and other edible parts of woody plants like tress are call mast. These acorns are a food source for many animals in a forest from squirrels, to mice to deer. Pig farmers sometimes let their pigs loose in forests to fatten up on acorns. The important thing to realize is that these trees don't produce acorns every year in the same quantity like a fruit tree or like a farmer farms wheat. There are good years and bad years. Good years (here is an example in California last year) are called mast years, in fact. The cycle is reported to be 3 to 4 years and tied to a wet or a dry spring (this abstract reports other factors as well). The article sometimes points this out but then go on to say no one knows to heighten the mystery. The lack of acorns discussed in the Washington Post is centered around northern Virginia. Not all areas report the same thing.

I wonder if this boom and bust cycle has ever happened anywhere before. A precursory search using google (which I imagine any reporter could do) reveals several free articles on the topic, one with a very good chart. Other articles would cost money, but I am sure that a newspaper might even be able to purchase an article if they needed it.

One the article has an interesting chart (click the chart for larger) with some data that I have adapted by stretching and lining up the years, that shows boom (1994) and bust (1995, 1998) cycles for oak trees in California, Missouri, and Massachusetts and over several years. Some years have no acorns at all, some have plenty. Even different species seem to produce or not to produce in synchrony. I guess an article reporting that some years there just aren't any acorns doesn't get the hits of one with a dire end of the acorn death knell.

From the figure caption from the article: Fig. 1 Example time series of mast production. (a) Hastings Reservation (California) site, Q. agrifolia, (b) Hastings Reservation, Q. douglasii, (c) Missouri, Q. coccinea, (d) Missouri, Q. alba, (e) Massachusetts, Q. rubra. In (a–b) each line represents values for individual trees; in (c–e), lines represent yearly means for each plot. Heavy lines represent yearly grand means.

Another article has an appendix with line after line of articles with historical levels of acorns and other mast over many years, some as long as 31 years. I would love to have the data from that article because I think it would put this issue to rest even better than the small amount shown above. Here is a chart (click for larger) of acorn production for different oak species in Florida (source abstract, source .pdf). Some years show almost no production, and even some synchrony between species.

It is interesting that people at least notice their environment somewhat, but noticing only the negative events and lacking the scientific curiosity to determine if the phenomena is fleeting or cyclic or permanent almost defeats the benefit of being observant in the first place.

The acorns will return.

Ph.D. Thesis Interpretive Dance Competition

Back in graduate school, as the pressures of getting ready to defend my thesis grew, my lab partner and I would come up with more and more fanciful ways to avoid working on it. One of our best suggestions was to forgo the traditional thesis defense in favor of using interpretive dance to convey my thesis topic "Solid Dispersions in Surfactant Solutions". Think of the possibilities of dancing wormlike micelles and particles in rainbow colored colloidal crystals. Add lasers for the laser light scattering and shooting soap foam and bubble machines for the surfactants and it would have been quite a production. Alas it never came to be.

Almost a decade later John Bohannon sent out a request for students, scientists and postdocs to interpret their Ph.D. Thesis using only dance, no words or images. The results of the contest with videos are available at Science. Participants were given 60 seconds before the performance to summarize their Ph.D. thesis topic for the judges, so it wasn't a complete free-for-all. The judges really were looking to see if the performance really represented the research.

The dances are all very charming and some are quite good and everybody looks like they had fun. I can't directly link to the videos because they are on the Science magazine site, but scroll down the article page to see them for yourself.

The winner, Brian Stewart, wore a loin cloth and enacted in dance the hunting of an antelope (played by a colleague, archaeologist Giulia Saltini-Semerari) and then topped it off with the touching gift of the hide to a tribe member to present "Refitting repasts: a spatial exploration of food processing, cooking, sharing and disposal at the Dunefield midden campsite, South Africa".


Some other fun performances were:

"The eventful life of galaxies in low density environments" by Ruth Gruetzbauch was charmingly portrayed as a tango ending with the two dancers (as galaxies) locked in an embrace.


How would you perform a thesis entitled "Analysis of thymic nurse cells in the chicken"? Professor Josef Penninger did the chicken dance, what else!


Nicole-Caudia Meisner won the postdoc catagory by tap dancing her way through "mRNA Stability Regulation as a Drug Target: mRNA Stability Cross-Screening and Molecular Mechanisms in Post-Transcriptional Regulation resolved bu Quantitative Biology."



There are many more and all are worth watching.

Are you a Nerd? Of course you are, you're reading this.

You always knew you were a nerd, but just what kind are you? As always the Internet comes to the rescue with a fun quiz.

My results may not be typical, use with caution.




(via Marc A. Murison)

Are you smarter than an 8th Grader?

Remember all that stuff that was taught to us in school? Even I, lover of science and knowledge that I am, must admit that not all of that stuff is useful at all times. So it seems I have forgotten some myself.

I always did work just hard enough to get an A (minus in this case) but no harder. Post your scores in the comments.

Overly sensitive radioactivity detectors - no radiation is too small?

As more and more public venues put in radiation detectors in the aftermath of 9-11 and the general terrorist scare, it appears they are catching more patients with residual radiation left over from medical tests than terrorists.

BoingBoing and others are picking up this story as new, but in a post from March of last year I described a personal experience with this phenomenon from when I was in graduate school. It was at the NIST laboratory (complete with nuclear reactor) rather than a public venue with radiation detectors but the humor is the same. From the previous post:

"You must pass through radiation detectors to enter and leave the room where the experiments are performed to make sure that no radioactive material leaves the room for safety reasons. The detectors start by stepping in them or when they detect any radiation, this last property was the source of the fun.

During one of our trips to NIST, where the experiments were performed, one of the group had just undergone a medical test similar to the one of the woman above that involved injecting a radioactive tracer. The sensitivity of the radiation detectors at NIST was so high that this newly radioactive group member could set them off from 40 feet away. His residual radioactivity was so high that he could make you fail the test (proclaimed with loud alarms and flashing lights) while you were in the machine and he was far away. It was great (if a bit geeky) fun."

That recollection was inspired by a story about a woman driving who set off detectors intended to catch mobile radioactive terrorists.

Will someone please do the economics on this stuff: How many false alarms and the costs associated with them are equal to the prevention of the hypothetical attack? Keep in mind that the false alarms are many and the probability of attack is extremely tiny.

tags: science, radiation, neutron