Empty premises

“We had a search warrant for this empty premise where we found all these goods,” said Singh.

Will they next start searching through empty promises, too?


Seeking fresh vegetables

If you live in Germany, you’ll certainly have seen posters for Parship.de, a dating website based in Hamburg. Their posters all bear the tagline “Alle 11 Minuten verliebt sich ein Single über Parship” (A single falls in love every 11 minutes through Parship), and usually feature an attractive person (mostly women) on each poster (examples).

In recent months they seem to have gone all-out with the advertising campaign, and almost every bus or tram stop seems to have at least one ad. The repetitiveness of it has inspired some ideas for how they could branch out into other lucrative markets….

(Disclaimer: I am not associated with nor derive any profit from either parship.de or parsnip.de. This is purely for my personal amusement.)

Bad consumer product ideas

More business ideas that will probably never get off the ground, following on my previous post. That said, if anyone needs a designer for a very reasonable price, do get in touch.



“Snalt – Banish winter from your driveway”

Snow salt – not for human consumption.



“Nature’s calling for a number two!”

All-natural laxatives.



“Where hipster Mexicans plot their next move”

Trendy taco restaurant.

Plotting data as ratios? Think again

We are often interested in ratios between two quantities. As an example, let’s use data from a study on the sugar content of soft drinks, where the the sugar content declared on the drink label was compared to the actual sugar content measured in the laboratory (Ventura et al. 2010, Obesitypdf). The paper includes a nice table summarizing their measurements, which I have adapted to produce the plots shown here.

How can we present this data to get the most insight? In my opinion, presenting such data as ratios can obscure useful information; showing scatterplots of the two quantites can make it easier to spot patterns.
Continue reading

Standards of evidence

Science and the law, and their respective practitioners, may seem to be as different as chalk and cheese, but they are both very much concerned with the evaluation of evidence. Scientists like to think of themselves as dispassionately weighing the objective facts arising from their experiments and observations, and using these to validate existing theories or to propose new ones. However, as any practicing scientist knows, we don’t always apply the same standards when weighing evidence.

For example, my field, environmental microbiology, relies heavily on observations and measurements made on wild organisms, rather than experiments on cultivated ones. The positive side is that there is so much diversity in wild organisms that there’s always something new to discover. However, not having them in cultivation means that whole classes of experiments, such as making knockout mutants to study particular pathways, are simply not possible. If I wanted to demonstrate that a particular microbe I’m studying is using a certain metabolic pathway, I can marshal all sorts of indirect evidence: the presence of key genes in the genome, expression of the corresponding mRNAs, chemical measurements of metabolic compounds unique to that pathway, and so on. Whereas with a “lab rat” organism like E. coli, I would have a more direct route: show that the key phenotype is affected in a targeted knockout, clone and heterologously express the gene. If I am working with such a “lab rat” for which genetic manipulation is possible, the indirect evidence that was acceptable previously would no longer be acceptable to most of my peers. They would instead demand the more stringent “gold standard”.

In American legal jargon, the “preponderance of evidence” is the burden of proof required for civil cases, whereas a stricter standard, “beyond a reasonable doubt”, applies to criminal ones. We sometimes hear people saying that scientists have “proven” this or that, but my impression from biology at least is that most scientific papers make their arguments from the preponderance of evidence, much less rigorous proof. In some types of experiments or analyses, it is possible to construct a formal statistical model to evaluate the probabilities. Does the preponderance standard correspond to P > 50%, as some sources suggest? And what is a reasonable doubt? If I am 99% sure, is that reasonable enough? Or is 95% sufficient? Rhetoric is important. That elusive quality, “relevance”, is conjured up by putting pieces of evidence in the frame of a larger narrative to hint at some deeper understanding in the works.

Does this mean that we should be stricter in what results we allow to be published, or that scientists should have argue like prosecutors in a death penalty case? I don’t think so. A single scientific project, whether on the scale of a PhD thesis or a large scale collaboration like the Large Hadron Collider, is usually an accretionary process. The pieces of the puzzle come out one at a time, and quite often we slot them together wrongly in the beginning. Ideally, each step of the way we strive towards reducing uncertainty. Artificial rigor would, in the words of the Street-Fighting Mathematician, induce rigor mortis and instead be a hindrance to scientific work.

Toddling in the snow

Snow has been falling heavily in the past few days after an unseasonably warm December, that misled some trees into bloom. Can we even tell if it has stopped falling? The wind still blows sprinkles off the roofs.

The snow has drawn out a childish feeling, even for someone like me, who never saw any until adulthood. Maybe it’s the association with childhood books and TV imported from far away? Or the surreality of seeing familiar streets look so strange?

I don’t think it is really about seeing. It’s the awkward toddling walk we are forced to adopt, looking down at our feet as we take steps one at a time through the drifts. It’s the pillowy heaps of snow by the paths – usually only children have the privilege of tumbling over without serious injury. I think that snow brings out the inner child kinesthetically, as it humbles our arrogant bipedalism.