Four articles this month, representing a fairly mixed bag of subjects. Here goes:

• Let’s start with a very simple but effective technological innovation that applies only to countries that have four seasons. Tech-On! features a report about a new type of glass that would block sunlight in the summer while letting it through in the winter. It relies on the simple fact that sunlight in summer and winter have different incidence angles and the invention consists of nothing more sophisticated that joining two sheets of glass together. This alters the refractive qualities of the joined sheet of glass and the researchers tuned this precisely to have the desired effects. What I don’t quite understand is whether or not the glass needs to be precisely tuned to the latitude of the place where it will be installed because presumably the incidence angle of sunlight depends on the latitude of the location.
• The next piece is not a science article but an extensive feature published in the New York Times about research on the outcomes to women and their babies who wanted abortions but were denied them. The key point is that the study manages to compare these women against similar women who wanted abortions and did get them. Not very surprisingly, the study found that these women have much poorer outcomes, with higher anxiety and depression levels, more likely to end up being poor and have poorer health. What is surprising is that despite these objectively poorer outcomes, most of these women still insisted that having that originally unwanted child was still the best thing that happened to them and significant numbers claimed years after the fact that they have never sought an abortion in the first place.
• Then here’s an article from The Conversation about how cheetahs actually use their fabled speed. One uneducated guess about cheetahs might be that because of their reputation as the fastest land speed animal on Earth, you might expect them to hunt best of all on flat ground where they can show off their top speed. This turns out not to be true because cheetahs hunt more successfully in dense forested cover than on open ground. This is because the true advantage cheetahs have is not absolute top speed but fantastic acceleration rates and even better deceleration rates. This allows them to manoeuvre much more effectively than the prey they chase.
• Bloomberg BusinessWeek has a very cool article about concrete, particularly the kind that the ancient Romans used. As we know from the copious amount of architectural works the ancient Romans left behind, they built a lot and a lot of it has lasted quite a long time. It turns out that ancient Roman concrete is significantly stronger than the modern variety we use today, commonly known as Portland cement. The precise formula for the kind the ancient Romans used was lost but researchers claim to have rediscovered by analysing their mineral content. By incorporating lyme and volcanic ash into their mixture, the Romans made more durable concrete than modern builders.