Author: Arjen

Lizard Moving From Eggs to Live Birth | National Geographic

A National Geographic news article from a few years ago, but awesomely interesting:

Along the warm coastal lowlands of New South Wales, the yellow-bellied three-toed skink lays eggs to reproduce. But individuals of the same species living in the state’s higher, colder mountains are almost all giving birth to live young.

Evolutionary records show that nearly a hundred reptile lineages have independently made the transition from egg-laying to live birth in the past, and today about 20 percent of all living snakes and lizards give birth to live young only.

So with this particular skink variety, we can see the transition as it’s happening. As the article explains, the transition causes a potential nutrient problem for the baby skinks (less calcium as there’s no egg), but the mother skink’s body solves this already:

“Now we can see that the uterus secretes calcium that becomes incorporated into the embryo—it’s basically the early stages of the evolution of a placenta in reptiles,” Stewart explained.

These observations also show how seemingly complicated transitions in life on earth turn out to in fact be relatively small changes that can be achieved with minor adaptations.

Sometimes, when you [have the opportunity to] look closer, things are actually simpler.

Finland scraps cursive writing lessons in schools | ABC

http://www.abc.net.au/news/2015-02-03/finland-scraps-cursive-writing-lessons-in-schools/6066826

Finland is scrapping cursive writing lessons in schools from next year and will instead teach children how to type.

On consideration, I think it’s good to have this discussion. Of course students need to be able to write legibly, and at a fair speed. But cursive writing is not the only way to achieve that.

Keyboard and mouse skills are very important as well – the awesome GCompris suite (approx age range 2-10) has games for even very young kids, getting to grips with the mouse and learning their way around the keyboard. Kids love it.

E.A.K. | Erase All Kittens

E.A.K. (Erase All Kittens) is an online platform game that teaches kids (yes that’s you!) to code and create on the web. It does this in a unique way – by encouraging hacking into levels, written in HTML and CSS (the languages of websites) – in order to complete the game.

Now go forth and save some kittens!

Thinking Outside the Quadrilateral

Insightful: http://www.buzzfeed.com/jobarrow/think-outside-the-quadrilateral

The common answer would be that the the student who wrote the answer below is “clearly wrong”. But are they? Different people think in different ways. For instance, some think in a very literal way. Simply declaring this wrong would be missing the very important point of what’s actually going on.

Students would likely contest that they did exactly what they were asked to do – now unless you choose to think that the kid purely wanted to be a smarty-pants and specifically went out of their way to annoy the teacher (a definite possibility, but not necessarily the case here), this reasoning is entirely valid. I’ll grant you it’s not what the teacher (or the person preparing the sheet) intended, but that’s really not the student’s problem. By making it the student’s problem, you’d just create confusion as they are likely to genuinely not see how what they did was invalid as they literally did what was requested.

The phrasing of questions is often dreadful. In this case it is also ambiguous. To you and I it may be obvious what is intended as the consequences of the alternatives end up being silly, but if you actually stop and think about it, that’s purely by analysis of the options, knowing about conventions, and thus actually using a lot of acquired skill built over the years – which kids don’t yet have fully developed. Even if most kids were to pick the “intended” way, that doesn’t mean that kids who read it differently are wrong.

It’s definitely helpful to assist the student to look at the questions and see which of the possible meanings would make the most sense from the context of the teacher – it’ll help them later in life. But depending on the age of the student, that’s actually a fairly tall ask that will still see many funny “mishaps” along the way. In any case, failing or punishing the child is I think a faulty approach. What do you think? Perhaps you were you one of “those” children yourself? Tell us about it, please!

Space Travel on Impulse Engines

A piece of Star Trek type technology appears to be closer to becoming reality, with the EMdrive mechanism now proven independently: Nasa validates ‘impossible’ space drive (wired.co.uk, July 2014)

British scientist Roger Shawyer has been trying to interest people in his EmDrive for some years through his company SPR Ltd. Shawyer claims the EmDrive converts electric power into thrust, without the need for any propellant by bouncing microwaves around in a closed container. He has built a number of demonstration systems, but critics reject his relativity-based theory and insist that, according to the law of conservation of momentum, it cannot work.

The NASA paper (PDF) Anomalous Thrust Production from an RF Test Device Measured on a Low-Thrust Torsion Pendulum avoids conjecturing on how the system works, instead focusing on the test methodology that validates the observations.

So while the “why it works” is not clear yet, scientists are becoming more interested as there really appears to be something going on – a paper (PDF) on the possible workings of it behind it Can the Emdrive Be Explained by Quantised Inertia? (Michael E. McCulloch, University of Plymouth) was published in Progress in Physics, January 2015:

It has been shown that cone-shaped cavities with microwaves resonating within them move slightly towards their narrow ends (the emdrive). There is no accepted explanation for this. Here it is shown that this effect can be predicted by assuming that the inertial mass of the photons in the cavity is caused by Unruh radiation whose wavelengths must fit exactly within the cavity, using a theory already applied with some success to astrophysical anomalies where the cavity is the Hubble volume. For the emdrive this means that more Unruh waves are “allowed” at the wide end, leading to a greater inertial mass for the photons there. The gain of inertia of the photons when they move from the narrow to the wide end, and the conservation of momentum, predicts that the cavity must then move towards the narrow end, as observed. This mode l predicts the available observations quite well, although the observational uncertainties are not well known.

See also Mike McCullogh’s blog post MiHsC vs EmDrive: paper link.

Wikipedia’s entry on the EMdrive contains another overview of the differing thoughts on this topic, and numerous references.