Sunday, April 29, 2012
Sunday, April 22, 2012
Sunday, April 15, 2012
Sunday, April 8, 2012
It all started with a free spirited, middle-aged back packer, who used to knock around Europe staying at Youth Hostels. When he was traveling in Scandinavia he was struck by how active older people were there, 60, 70 and even 80 year olds. When he got back to the U.S.he enthused about his experiences to a friend, a university administrator, and between them they came up with the idea of creating Elder Hostels, using inexpensive university student accommodation during the long summer break when they were free. They also involved faculty members to give in-depth lectures about the history and special feature of an area in the mornings and arranged for guided course-related excursions to sites of interest in the afternoons.
The program took off and within 5 years it started to expand to include year-round trips that are now offered in 150 countries. Accommodation changed to staying in good hotels but the agenda still included morning lectures, often at the University, and afternoon field trips. The name Elderhostel was no longer fitting and, though it took a while, the program is now appropriately called ‘Road Scholars’.
We have joined several Elderhostel overseas programs but the first lecture on our schedule in Egypt was particularly memorable. I cite it because although I had visited Egypt before, it gave me a new perspective on why Egyptian civilization was so different and seemed to be so unaffected by other cultures in the region. The lecturer immediately made it clear when she drew our attention to how isolated the Egyptians were in its earliest millennia. The country is surrounded on three sides by deserts, the harshest and most dangerous in the world, and their northern coast had shallow water and sandy beaches with no natural ports. The lighthouse at Alexandria, only completed in 247 BC was built to light the way for sailing ships navigating the tricky harbour there and was one of the seven wonders of the ancient world.
Because of the natural barriers that isolated them, it was virtually impossible to invade Egypt so, except for internal struggles, it had a peaceful history for the most part and, as is clear when you look at the map on the right, the fertile Nile river valley not only made it easy to unify its people but provided the water for a plentiful and stable food supply. The result was that Egyptians developed their own unique hieroglyphic script, complex religious beliefs and colossal monuments. It is a truly fascinating country to visit especially with the guidance of road scholar lecturers! Rie
Sunday, April 1, 2012
When we visited Iceland in 1997, we rented a car and did some exploring of the area around its capital, Reykjavik. The picture shows the kind of thermal activity we encountered and it made me aware once more that underneath the Earth’s crust is a layer of molten rock that is about 9000 Celsius. Usually that crust is from 30 km (20 mi) to 50 km (30 mi) thick but under western Iceland it is much thinner and responsible for the thermal pools and steaming cracks. The people of Iceland take full advantage of the available heat by extracting the geothermal energy for warming greenhouses, producing electricity and heating their homes.
Even with the thick crust we have under us, there is plenty of geothermal energy available because the deeper you go in the ground, the warmer the temperature gets. Where we live, if you only go down 6 feet the ground temperature is a constant 70 C [44.60 F] summer or winter.
In the summertime when the air is 320 C [900 F] or warmer, the relatively cool ground water can be circulated in coils and air blown over them to cool a house. Fans use little electricity and this system is much more efficient than any air conditioner.
If you live in the country and get water from a well, you can just circulate well water through a refrigeration unit to extract heat but on a serviced city lot, coils of plastic pipe must be laid in trenches as shown on the right. The initial expense of laying the pipe is amply paid back in energy saved. Compared to other alternate forms of ‘green energy’, a geothermal (ground source) heat pump is the most popular because it is so predictable and cost effective.
There is enough energy stored under your house to more than supply its heating and cooling needs. When compared to an electrically heated or cooled home, geothermal heat pumps use less than 1/3 the amount of electrical energy needed to heat your home and savings are much greater than that to cool it. Well worth considering especially if you're building a new house. Rie