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Sunday, November 27, 2011

Kite surfing

To the uninitiated, kite surfing is the sport of riding on a small surfboard propelled across water by a large kite to which the rider is harnessed. I was introduced to it when we wintered in Caberete, on the north shore of the Dominican Republic. The bay there is touted as being one of the world-class sites for kite surfing.

That is because on every sunny day, the air over the land is warmed and, as it rises, air is drawn off the water to take its place. This causes the consistent, steady onshore breezes that sweep in over the large open bay - perfect conditions for kite surfers. They begin appearing around 2 pm ready for hours of extreme sport. Besides jumping and stunts in the air, some kite boarders with the latest equipment and a good wind, can reach speeds of 80 to 90 km/hour and they can travel very long distances in a downwind.

With this background, I was intrigued to hear the following story, the truth of which I cannot verify but it does make for a good tale. It is about an entrepreneur from Marseille who used to windsurf for fun and exercise in the large bay there, The story goes that he was very happy with the sport until one day a couple of kite surfers showed up. Seeing their amazing speed and comparative lack of effort - a harness strapped around their waist is directly connected to the kite - he decided he had to try it for himself. It would not be inexpensive to take lessons and to rent or buy equipment but apparently it paid off for him. As he directly experienced through his body harness the powerful force of the wind in the kite, it suddenly dawned on him that that same power could be used to pull along the ships in his merchant fleet.

And so it came to be - huge new towing kite systems that capture the energy of the wind are now a reality and one kite can cut down on a ship’s fuel costs up to 20%. Considering that the cruise liner Queen Elizabeth II moves only six inches for each gallon of diesel it burns, the saving are worth a lot of investment.

Using sails to harness the power of the wind is an old story but it turns out that kites have several major advantages over sails. First the wind's speed near the surface is slowed down by friction with the water and there are much stronger winds higher up where a kite flies. The kite above a ship are in an unhindered position to capture the much greater energy accessible up there. Then important too, the kite is controlled by a computer that maintains the shape and position of the kite so that most of wind’s available energy is captured and is concentrated in pulling the ship straight ahead with an ‘even keel’ so it to slips through the water with least resistance.

Ship’s ‘sky kites’ are good news and hopefully we'll increasingly hear of more green ideas like this to help stop the pollution of our planet in time. Rie

Sunday, November 20, 2011


Antioxidants are all about the problems that happen when oxygen we are constantly breathing in, ‘burns’ the food we eat to give us the energy we need to stay alive.
It works like this: single oxygen atoms need extra electrons [they need 8 to be stable] so two of them pair up to form a weak bond and they go around as a molecule [see picture]. But when molecules encounter food that’s ready to be oxidized, they easily split apart and while one atom oxidises food the other – it’s called a free radical - is compelled to attack anything to grab a couple of electrons to satisfy it’s chemical need. Cell tissues are most often attacked and disrupted but it doesn’t stop there – the attacked cellular molecules split apart themselves each creating two free radicals and they in turn attack more cellular components forming more and more radicals needing electrons and a chain reaction starts that only ends its destructive deeds when enough antioxidants are present to donate electrons and not become free radicals themselves. If you click on video the whole process is nicely illustrated and makes it plain that antioxidants mop up free radicals helping prevent damage to cells and tissues.
The damage caused when antioxidants are not present can trigger all sorts of nasty things like a variety of cancers, arthritis, cataracts, heart disease, atherosclerosis, and premature aging to name a few. So it’s obvious we should make every effort to see that our bodies have an ample supply of antioxidants to stop damage as quickly as possible!
We do naturally produce some antioxidants but since most are found in foods we eat. It’s important to know that antioxidant rich foods are fruits and vegetables [especially the coloured ones], cereals, beans, nuts and seeds. Apparently the best way to make sure you are getting enough antioxidants is to eat 5 to 8 servings of fruits and vegetables a day. That’s a bit much for me so I take vitamin supplements like vitamins A, C and E that are concentrated antioxidants.
If you want to have the best information possible about antioxidants for optimal health and foods high in antioxidants, I suggest you click on the link provided here. Knowledge is power - fight back - live long. Rie

Sunday, November 13, 2011

Microwave Ovens

All sorts of rumors abound about the dangers of microwave ovens leaking and microwaved food being harmful. I think it must be that some people are disturbed because they don’t know what’s going on in the oven and how it works. I hope then that my attempt at explanation is understandable and allays any concerns.
First of all you must know that microwaves are part of the electromagnetic radiation [EMR] spectrum just like radio waves and visible light and x-rays - they are rays of energy that pulse positive, negative, positive, negative, etc. through space and travel at the speed of light.
If the frequency at which the EMR changes from positive to negative is in the visible light region it affects our eyes so we can ‘see’ it as light. When the EMR comes from the sun, the part of it in the microwave region we feel as heat on our skin and think nothing of it. The remote control to turn a TV on and off is in the radio frequency region. X rays are pulses that change positive negative with such high frequency that mostly they pass through the body but the waves are partly absorbed by flesh and bones so give us an ‘x-image' of them.
To understand then how microwaves heat food, you have to know four things:
- 1. Positive is attracted to negative and repulsed by positive – something like the poles of a magnet. - 2. Lots of molecules have charges on them and we’re interested especially in charged water molecules here. - 3. Microwave pulses are slow enough to push and pull charged molecules, like water, around by attractive and repulsive forces as the waves, go past them, just like stick in the water bobs up and down as a wave goes by. - 4. We feel faster moving molecules as heat - the faster they go, the hotter they feel.
So essentially, all microwaves are doing is making charged molecules move faster. Since most plastics and pottery and glass have no charged molecules, they don’t react and stay cool in a microwave oven. Food, on the other hand, mostly has charged water molecules in it and heats up. Actually, microwaving has benefits because, by not heating food too long or too hot, many of the nutrients are preserved!
As far as microwaves leaking out of the oven, unless there is poor seal on the door - as an old, much used oven might have - no microwaves can escape. It’s like a box with a light in it in a dark room, if there are no cracks in the box, no light can escape.
So rest easy – microwave ovens have been around commercially since 1967 and when you look up the hazards, examples have to do with whole eggs in their shells and potatoes with skins intact which tend to explode and splatter because off the pressure of steam formed inside. You can’t heat water to more than 100 degrees C because it then just uses extra heat to form steam - but fats can be heated easily to very high temperatures and splatter so take care in heating them. Otherwise, rest easy – nothing unusual is going on in your microwave oven so just enjoy its wonderful convenience! Rie

Sunday, November 6, 2011

Alone in the Universe?

As usual my tendency is to look at things with a long perspective and scientific bent. However, it’s evident I’m not alone in wondering about the chances we’ll ever reach any form of life out there in the Universe. As is common knowledge, a radio call is being sent out through SETI – the global Institute whose purpose is to explore the ‘nature and prevalence of life in the universe’.

To answer that message, the life form on another planet would have to be advanced enough to understand it. Certainly we are unique on Earth in that we are intelligent enough to be logical and to communicate but it has taken most of the time since our planet was formed for us to have reached this level of complexity.

The fossil records are our main source of information on just what has happened during the evolutionary process. These scientific records tell us that:

- 4.6 billion years ago our planet was formed

- 3.8 billion years ago, life evolved in the form of single celled bacteria or microbes

- 0.53 billion [or 530 million] years ago bacteria got together to form multi-celled life forms and in a remarkably short period, many different species came into being in the so-called Cambrian Explosion

- 0.050 billion [or 50 thousand years ago] homo sapiens reached the modern form that could be recognized as us.

- 0.000,000,050 [or about 50 years] since radio became advanced enough to send messages out to the Universe. That has happened in the last very small fraction of time since the planet has existed.

If you consider that from our point of view on Earth, the sun has risen and set and the seasons have existed all those billions of years – in comparison to other planets, that makes ours a very rare and remarkably stable one. For this stability to occur we have had to:

- Be orbiting around a medium-sized, single sun in the outer reaches of our galaxy so as not to have been disturbed by other nearby suns.

- Be a planet that makes a circular orbit around the sun at just the right distance away to be in a good temperature range where most water was liquid.

- Be a planet spinning on its axis frequently enough (24 hours for us) so all parts were warmed in the day and cooled off at night. The axis had to be tilted so over a period of a year it wobbled and gave both hemispheres summer and winter seasons.

- Be fortunate enough to have a large moon that caught much of the debris during our planet’s early formative years.- There is much more about how rare our stable Earth has been if you click on the highlighted text.

Let’s try to always be aware how special and precious our planet is and do everything possible to prevent environmental deterioration so future generations can enjoy its beauty and bounty. Rie