Our paper on tie knot classification is finally officially published: Hirsch D, Markström I, Patterson ML, Sandberg A, Vejdemo-Johansson M.(2015) More ties than we thought. PeerJ Computer Science 1:e2.
Besides the paper and its supplementary code, there is also a random tie knot generator and a tutorial by Mikael about how to read the notation.
The classification of tie knots is not in itself important, but having a nice notation helps for specifying how to tie them. And the links to languages and finite state machines are cool. The big research challenge is understanding how knot façades are to be modelled and judged.
Over on Practical Ethics I blog about how to handle production of opiates from bioengineered yeast.
The basic problem is that opiates seem to be unusually harmful (rather nasty dependency, social withdrawal and risky methods of administration), yet restricting access looks hard in the long run. I don’t subscribe to the view that mere exposure will turn all people into addicts (it looks like it is a subset of people who are vulnerable), but there is a fair bit of harm here that likely is not outweighed by cheapness and better quality. Yet proposed methods restricting access to the modified yeast are unlikely to work in the long run, and may some bad effects on their own.
My own solution is to recognize that in 10-20 years it will be possible to brew many strong drugs discreetly at home, and that we need to reduce the harm from this by developing other technologies that make them less problematic. It might sound wussy and complex compared to the more easily actionable targets suggested in the article, but I think it has a greater chance of actually reducing harms in the long run than policies that merely delay the broad arrival of microbrew drugs.
I recently discovered Alex Wellerstein’s excellent blog Restricted data: the nuclear secrecy blog. I found it while looking for nuclear stockpiles data, but was drawn in by a post on the evolution of nuclear yield to mass. Then I started reading the rest of it. And finally, when reading this post about the logo of the IAEA I realized I needed to mention to the world how good it is. Be sure to test the critical assembly simulator to learn just why critical mass is not the right concept.
Another awesome blog is Almost looks like work by Jasmcole. I originally found it through a wonderfully over the top approach to positioning a wifi router (solving Maxwell’s equations turns out to be easier than the Helmholz equation!). But there are many other fascinating blog essays on physics, mathematics, data visualisation, and how to figure out propeller speeds from camera distortion.
Francesca Minerva and me have a new paper out: Cryopreservation of Embryos and Fetuses as a Future Option for Family Planning Purposes (Journal of Evolution and Technology – Vol. 25 Issue 1 – April 2015 – pgs 17-30).
Basically, we analyse the ethics of cryopreserving fetuses, especially as an alternative to abortion. While technologically we do not have any means to bring a separated (yet alone cryopreserved) fetus to term yet, it is not inconceivable that advances in ectogenesis (artificial wombs) or biotechnological production of artificial placentas allowing reinplantation could be achieved. And a cryopreserved fetus would have all the time in the world, just like an adult cryonics patient.
It is interesting to see how many of the standard ethical arguments against abortion fare when dealing with cryopreservation. There is no killing, personhood is not affected, there is no loss of value of the future – just a long delay. One might be concerned that fetuses will not be reinplanted but just left in limbo forever, but clearly this is a better state than being irreversibly aborted: cryopreservation can (eventually) be reversed. I think our paper shows that (regardless of what one thinks of cryonics) the irreversibility is the key ethical issue in abortion.
In the end, it will likely take a long time before this is a viable option. But it seems that there are good reasons to consider cryopreservation and reinplantation of fetuses: animal husbandry, space colonisation, various medical treatments (consider “interrupting” an ongoing pregnancy because the mother needs cytostatic treament), and now this family planning reason.