Tuesday 25 October 2016

Teaching environment

I'm not counting but this is my 400th blog post. If I were counting, I'd write something special, but since I'm not, this is just a regular day in the life of a teacher trying to do something about the environment. 

The low energy building course has started up again, with more students this year, and several architects, engineers and materials scientists. In the first lesson I asked what language they wanted me to speak, and what language they wanted to speak to each other. They all seemed to be happy with me speaking English, and over half of them wanted to speak English to each other, with the rest wanting to speak Japanese. Speaking to each other is important as I need to give them time to process what I'm talking about, and it helps them to work together on exercises and calculations. Also it's an interdisciplinary, and an international class, and I want them to meet as many other people as possible, and build the kind of relationships that make universities worth going, because frankly sitting in classrooms listening to teachers is very last-millennium.

I use an instructional method that is borrowed from Management, the teaching industry's estranged sister. The original is called Management by Wandering Around, or MBWA, and I call my version Teaching by Wandering Around, or TBWA because language teachers are the only people who like acronyms as much as management consultants. MBWA is often called Management by Waving of Arms, and I find myself doing a fair bit of arm-waving in my lessons, although this one is very amicable so far. 
A completely irrelevant picture of an electricity-generating shoe

To accommodate everyone's language preferences, I have split the classroom in two, with the Japanese speakers on the right and the English speakers on the left. Hopefully this works for the students, as they will be able to communicate in their preferred language. It also makes it easier for me to know which language I should speak as I patrol the class, see how they are progressing, and offer advice and encouragement. 

There is a significant Malaysian contingent, all of whom want to speak English, although I hear a bit of Bahasa when they are sitting together. I'm encouraging students to sit with different people each week. I'd also like to leave the option open for people to cross the floor, so they are not stuck in the same language with the same people for the whole fifteen weeks. But if I do this too forcefully then I may get all the people from the Japanese side move to the English side, and everyone from the English side move to the Japanese side.

Friday 21 October 2016

Passive House open days in Japan November 11th to 13th

Look inside passive houses around Japan, and around the world, between November 11th and 13th. They will be warm inside, but probably won't have turned the heating on yet!


You can search internationally here: passivhausprojekte.de.

Wednesday 19 October 2016

LED innovations


Usually I opt out of the vendor's email lists when I buy stuff online, but for some reason I didn't for Beamtec, the shop I bought our house LEDs from.

I get really annoyed with advertisements for things I have already bought, or hotels in places I've just come back from, so it was a bit stupid to subscribe to the website where I bought LEDs for my house, most of which proudly announce that they will last for tens of thousands of hours. 

One advantage is that I have been aware of the prices of LEDs, and have a record of their downward trends over the past few years. 

I have replaced one light so far: a compact fluorescent built into the kitchen hood, which blew after a rather pathetic four years. 

there are other fluorescent lights I'd like to change if I can. I'd like to replace the strip light above the upstairs wash basin. We got the washbasin as a unit with cupboards and drawers below, mirrored cupboards above and a 20 watt fluorescent strip light along the top. 

I've been looking at the prices of LED replacement strip lights, wondering at what point it's worth switching from the fluorescent tube that still works. 

They were around
2,200 yen in December 2012
1,600 yen in May 2013
1000 yen in June 2015
700 yen in September 2016

Interestingly they boast a 300-degree radiation compared to the conventional LED strip light's paltry 180 degrees. In fact in most applications fluorescent tubes are mounted on walls or ceilings, so half of the light is going into the wall, and you only need 180 degrees, but looking at the picture, and with the knowledge that the LED inside the tube is mostly sending light out perpendicularly, the larger translucent area of the tube makes some kind of sense. 




Sending light in all directions is actually a weakness of fluorescent tubes, and not something they need to go out of their way to remedy. Anyway, here are some more ideas of retro-features that they may add to fluorescent tube replacements. 

  • Why not add a circuit to LED lights to make them flicker on and off a bit when you switch them on. After all, do we really want a light that comes straight on when we turn on the switch?  
  • How about adding a radiant heater to the LED bulb so that it will emit heat, just like an incandescent light. 
  • Or why not change the spectrum of the light to add frequencies that are invisible to us but that will attract more insects. 

Friday 14 October 2016

Thermodynamics of cooking sources

There is obviously a link between food and thermodynamics, and it's not hard to see eating as primarily a means of getting energy into the body. 

In What is Life (the 1944 book by Erwin Schrödinger, not the 1970 George Harrison song), the physicist and theoretical cat-tormentor turned his hand to deep biology. His view seems to have been that the meaning of life is basically beating the second law of thermodynamics by moving energy from the colder bits of the universe into hotter bodies, and beating entropy by promoting some kind of order out of the inevitably increasing chaos.

Schrödinger inspired Watson and Crick in their search for the double helix, and in turn he was standing on the shoulders of Darwin, who had brought the field of biology well into the realm of science from its previous home somewhere down the corridor from stamp collecting.

In terms of evolution, getting energy into the body has been an important part of our development, and the taming of fire was a big breakthrough. Once we applied that to food, we got a double benefit of increasing the number of things we were able to eat, and reducing their volume and the time it took us to eat them. 

Previously I suggested that Watt invented the positive feedback loop that led coal to be used to power pumps that would remove water out of mines and allow more coal to be removed. But perhaps this wasn't really an invention, but simply another application of something humans have been doing for a very long time. 

It's Interesting that calories are now more often seen as enemies, to be scanned on packages, counted, and where possible reduced. Personally I always look at the label when I'm choosing what food to buy, and usually get the food with the largest number of calories since that's what I'm paying for. While some people are desperately trying to reduce the calories in the food, we rarely look at how many calories of energy went into preparation, packaging and transport of the food.

Early attempts at cooking were not so efficient. Wood was most likely the fuel, and little of the heat will have gone into the cooking, so most of the energy was going up in smoke rather than into those hungry human stomachs. 

This discussion on Ask Historians looks at the effects of gas and electric stoves on lifestyle, with many suggesting a revolution in the twentieth century, when cooking stopped being a full time job, and kitchens were no longer dedicated to food preparation, but became integrated into dining rooms. 

Another big innovation has been the microwave oven. Although scorned by a lot of people concerned about health and nutrition, and pining for "real" cooking, microwaves may be more efficient. Of course microwaves do put out radiation, but so do all other cooking appliances. Instead of sending out a broad spectrum of radiation, microwaves focus on frequencies that will excite the water molecules, and however you wrap it up in culinary language, cooking is basically about removing water. Also, you don't need to heat up a heavy metal container to cook what is inside a microwave, so it should be more efficient, but any efficiency is likely to be marginal, and savings will be much less than the energy used to read this.

(Picture stolen from: Green Lifestyle Magazine