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.

Beagle 2: Interplanetary Lost & Found

http://arstechnica.com/science/2015/01/lost-beagle-2-mars-lander-found-11-years-after-launch/

Beagle 2The UK-made  Beagle 2 lander has been found on the surface of Mars more than a decade after it was thought to be lost forever.

The 2003 launch was the result of a collaboration of UK academics, whose nifty lander rode to the Red Planet aboard the European Space Agency’s (ESA) Mars Express spacecraft. By December 19 it had reached its destination and was released from the spacecraft.

“It was due to enter the atmosphere at about 02.51 on the 25th December,” said Mark Sims, professor of astrobiology and space instrumentation at the University of Leicester. But nobody heard from Beagle 2 following its ejection from the Mars Express and it was presumed lost. Sims said he had “given up hope” of ever knowing what happened to the lander.

Now, thanks to images taken by Nasa’s High Resolution Imaging Science Experiment (HiRISE), we have at last found the Beagle 2’s final resting place. Images show that it did indeed make it to the surface of Mars and even landed where it was expected to, at the Isidis Planitia basin. For 11 long years, the Beagle 2’s remaining team members have been scouring images captured by HiRISE for signs of their design. That work—and unbelievable patience—has paid off, because the images tell a story of how exactly the lander got to where it is today.

Kano – make a computer

Interesting recent Kickstarter project: Kano.

Kano box and contents

Uses Raspberry Pi as a basis, with a tweaked Linux that contains specific apps, on which various user challenges are based.

There are a few recent projects that do similar things, we’ll have to see which catch on (perhaps all!)