The Dobsonian Telescope

April 10, 2014 by kris de decker Filed Under: DIY, Telescopes

the dobsonian telescope“The design of this telescope is called a Dobsonian, after its inventor John Dobson, who passed away earlier this year. Dobson’s life took an unusual trajectory. He went from being a self described “belligerent atheist” to a monk in the Vendanta society to co-founding the San Francisco Sidewalk Astronomers.  Most of his life was spent bringing the night sky to people around the world and teaching people how to make their own low-cost telescopes.

As a monk, Dobson could not afford expensive materials. He kept the design inexpensive by using a simple mount and cheap materials: wood and cardboard. My Dobsonian was made by the now defunct Coulter Optical Company out of particle board and a cardboard concrete form. Its large 13.1 inch mirror makes it perfect for looking at nebulas, galaxies and star clusters even in light polluted urban areas.”

Find out more. Illustration.

Furoshiki: Zero-Waste Shopping in Japan

April 4, 2014 by kris de decker Filed Under: Cargo, Clothes, Low-tech solutions, Random, Shopping, Trash

In a time when cloth-making was one of the most advanced technologies, a piece of square cloth was all that a man needed to carry goods around. Japanese call it ‘Furoshiki’, a square cloth that with different wrapping techniques can basically transport anything. With its name meaning ‘bath spread’, Furoshiki is a traditional kind of wrapping cloth made of natural materials like silk and cotton. It is believed to date back to the 8th century. What was at first used to wrap up noblemen’s clothes in bathhouses gradually transported goods and gifts.

Furoshiki zero waste shopping in japan

Click to enlarge. More pictures here.

Modern bags might have outshone Furoshiki, but recent years have seen its comeback as a green alternative to shopping bags, thanks to the ‘Mottainai Furoshiki’ initiative by Yuriko Koike, Japan’s Minister of the Environment, in 2006. “It’s a shame for something to go to waste without having made use of its potential in full,” said Koike. Like what beauty label LUSH has followed to produce, the modern Furoshiki Koike upheld was made of recycled PET bottles that, as the Minister put it, “can wrap almost anything in it regardless of size or shape with a little ingenuity by simply folding it in a right way.”

The above graph demonstrating different wrapping techniques went viral on the internet. A wave of shops emerged to sell fancy furoshiki. The Minister’s statement holds some truism because a furoshiki does wrap up almost anything of all shapes and fragility – from vegetables to bottles, from wine glasses to eggs, from a baby to a dog. Besides its diversity, Furoshiki is a great alternative to adopt also because of its portability, leaving almost no room for excuses like ‘I forgot to bring my own bag’. Most of the time very decorative because Japanese treat it as an artistic craft, a furoshiki makes a great scarf, headband or pocket square.

ren wanLight and small, it comfortably fits in your pocket or day bag, whilst some furoshiki clothes are big enough to a bag whose form you can change every other day. A personal experiment proves that it helps encourage shoppers to opt for less- or un-packaged options. To avoid unnecessary packaging I visit local grocery stores for unpackaged tomatoes and to the plastic bag addicts’ surprise, it is very easy and light to transport. Just think about how one piece of cloth has the potential to replace all shopping bags. Does it not make it one of the smartest solution to shopping bags and excessive packaging?

This is a guest post by Ren Wan, a writer and sustainability advocate who is based in Hong Kong. She runs JupYeah, an online swapping platform, is a managing editor for WestEast Magazine, and blogs at Loccomama.

Solar Powered Grain Mill

April 3, 2014 by kris de decker Filed Under: Energy, Energy storage, Farming, Random, Solar

solar milling

“Graining cereal crops is a basic, century old business and it will continue to be as important as ever before for centuries to come. Before the age of oil grain milling was entirely based on renewable energy. It was either done by wind energy, hydropower, animals or manpower. For the last century the traditional grain milling has been mainly replaced by electricity and fuel driven milling.”

“The Solar PV Grain Mill works to the same principle like any conventional, electrically driven mill. The mill has a very efficient 3-phase AC motor which is directly coupled to the graining system. The main invention of the system is, and that makes it unique among PV systems, that it is a “direct drive system” without the need of batteries. The Solar PV generator converts solar radiation into electricity, and the generated electricity is directly feeding the motor drive. There are no additional conversion losses, such as energy storage losses in batteries, battery maintenance or replacement costs, which are a common problem in conventional Solar PV off-grid systems.”

Read More: Solar Milling. Via Engineering for Change.

I would like to add that the direct drive system also eliminates the high energy use caused by the production of the batteries, which can make solar PV off-grid systems everything but sustainable. Therefore, storing work instead of energy — the solar mill only operates when the sun shines — is a very interesting strategy in sunny regions.

Related:

The Atlas of Environmental Justice

March 19, 2014 by kris de decker Filed Under: Maps, Random

atlas of environmental justice

“Across the world communities are struggling to defend their livelihoods from damaging environmental impacts. Mining projects, mega dams, tree plantations, fracking, gas flaring, incinerators, etc … As resources needed to fuel our economy move through the commodity chain from extraction, processing and disposal, environmental impacts are externalized onto the most marginalized populations. But all this takes place far from the eyes of the consumers of the end-products. The Environmental Justic atlas aims to make these impacts more visible and to make the case for true corporate and state accountability for the injustices inflicted through their activities.”

“The map tells a story of environmental devastation and despoliation, of ecocide and eco-apartheid, but also a story of resistance, and communities mobilizing to fight against the odds. Of the cases currently in the map, 17% are successes for environmental justice. Court cases were won, communities were strengthened, and access to the commons was reclaimed. These victories are a testament to the power of protest and the ability to impact the political process. We don’t aim to “solve” the conflicts but to reveal the actors and drivers and structural patterns behind them. The defense of territory, the defense of livelihood and the defense of the resources that communities depend on are the best weapon against endless capitalist exploitation of the ecological system we depend on.”

The Atlas of Environmental Justice.

Adapting to Climate by Being a Nomad within your own House

March 18, 2014 by kris de decker Filed Under: Air conditioning, Architecture, Low-tech living, Low-tech solutions, Random

While some people seasonally move between dwellings, others are nomads within their own houses. In such diverse places as Iraq, Algeria, and India, climates and cultures may vary, as do the directions and rhythms of movement. But all share migration within the dwelling as a primary mode of adaption to climate.

Families living in traditional courtyard houses of Baghdad, without mechanical ventilation or heating, migrate by day and season for comfort. In September or October, they move around the courtyard to rooms facing south. In April or May they shift to the north-facing rooms. In summer there is a daily vertical migration, the afternoon siesta being spent at the lowest levels and the nighttime sleep traditionally being taken on the roof under the stars.

old baghdad house

Picture: muhammadshnait91.tumblr.com

Such migrations mean that space is used with a freedom unusual in modern life and in the West. Recent correspondence from Mounjia Abdeltif-Benchaabane, a professor of architecture in Algiers, describes how rooms there have not traditionally been organized with regard to individual use or established purpose:

A living room becomes a sleeping room at night. Closets are full of mobile furnishings. In the morning everything is hung near windows to air out under the sun before being reused, perhaps in a different room. The kitchen is a multifunctional space. They cook on the floor even if they have modern tools.

A long-established Arab concern with privacy, in conjunction with the custom of migrating through the house, established the texture of some old cities like Baghdad. Since the roof is used for sleeping during nearly half of the year and the privacy of the family at night is fundamental, no house could look down upon its neighbor nor could one house look into the courtyard of another. The result was an effective building height control with advantages for solar access: no house could overshadow another, thus assuring wintertime light and heat to upper living spaces.

Quoted from “Ritual House: Drawing on Nature’s Rhythms for Architecture and Urban Design“, Ralph L. Knowles, 2006.

Crimean Ovens

March 4, 2014 by kris de decker Filed Under: Heating appliances, History, Random, War

“Starting in 1861, the wintertime Union field tent hospitals of the U.S. Civil War often used subterranean heating systems known as Crimean Ovens. The system under discussion was basically a firebox, or oven, on the outside of the tent, with a shallow, brick-lined, sheet-metal-covered trough running down the center of the tent’s interior, and ending in a chimney on the opposite exterior side of the tent. The tents were placed on ground with slight inclines, allowing the hot air to naturally rise and escape out the flue.”

crimean oven

“Dr. Charles Tripler, Surgeon and Medical Director of the Army of the Potomac, writes in a letter of November 1861 the following description of “a modification of the Crimean Oven”, devised and put into operation by Surgeon McRuer, the surgeon of General Sedgewick’s Eighth Brigade:

A trench 1 foot wide and 20 inches deep to be dug through the center and length of each tent, to be continued for 3 or 4 feet farther, terminating at one end in a covered oven fire-place and at the other in a chimney. By this arrangement the fire-place and chimney are both on the outside of the tent; the fire-place is made about 2 feet wide and arching; its area gradually lessening until it terminates in a throat at the commencement of the straight trench. This part is covered with brick or stone, laid in mortar or cement; the long trench to be covered with sheet-iron in the same manner. The opposite end to the fire-place terminates in a chimney 6 or 8 feet high; the front of the fire-place to be fitted with a tight movable sheet-iron cover, in which an opening is to be made, with a sliding cover to act as a blower.

crimean oven 2By this contrivance a perfect draught may be obtained, and use more cold air admitted within the furnace than just sufficient to consume the wood and generate the amount of heat required, which not only radiates from the exposed surface of the iron plates, but is conducted throughout the ground floor of the tent so as to keep it both warm and dry, making a board floor entirely unnecessary, thereby avoiding the dampness and filth, which unavoidably accumulates in such places.

All noise, smoke, and dust, attendant upon building the fires within the tent are avoided; there are no currents of cold air, and the heat is so equally diffused, that no difference can be perceived between the temperature of each end or side of the tent.”

Read more: 1 / 2 / 3.