Showing posts with label Science. Show all posts
Showing posts with label Science. Show all posts

Monday, August 27, 2007

Total Lunar Eclipse: August 28, 2007

Path of the Moon through Earth's umbral and penumbral shadows during the Total Lunar Eclipse of Aug. 28, 2007. (Pacific Daylight Time)


A total eclipse of the Moon occurs during the early morning of Tuesday, August 28, 2007. The event is widely visible from the United States and Canada as well as South America, the Pacific Ocean, western Asia and Australia. During a total lunar eclipse, the Moon's disk can take on a dramatically colorful appearance from bright orange to blood red to dark brown and (rarely) very dark gray.

An eclipse of the Moon can only take place at Full Moon, and only if the Moon passes through some portion of Earth's shadow. The shadow is actually composed of two cone-shaped parts, one nested inside the other. The outer shadow or penumbra is a zone where Earth blocks some (but not all) of the Sun's rays. In contrast, the inner shadow or umbra is a region where Earth blocks all direct sunlight from reaching the Moon.

If only part of the Moon passes through the umbra, a partial eclipse is seen. However, if the entire Moon passes through the umbral shadow, then a total eclipse of the Moon occurs.

Tuesday, July 31, 2007

Like Father, Like Son ?

For parent whose children have caused them great pain through rebellion and misbehaviour, recent years would have been a nightmare of conflict and disappointment for them.

Parents in that situation today have been much too quick to blame themselves for everything their sons and daughters have done wrong and that's only been true in this century.

A hundred years ago, if a child went bad, he was a bad child. Now, it's the fault of his parents. Admittedly, some mothers and fathers do warp and twist their offsping, and I'm not pleading their cases.

But there are others who did the best job they could, to raise their sons and daughters properly. Neverhteless, you know who will get the blame for the stupid blunders and bad choices in the next generation.

Genetic studies have been conducted at the University of Minnesota and the bottom line from decades of work with identical twins is that the basic temperament of a child is largely inherited.

This includes a tendency to test and challenge convention and authority. Some kids come into the world just looking for a fight and they usually find it.

For those paremts out there with rebellious teenagers. I suggest you take aother look at the guilt you've been carrying.

By Dr James Dobson

Monday, July 30, 2007

A slice of the same genes

Studies of identical twins tell us that at least 70 per cent of the human personality is inherited. It is just amazing how similar most of these children are, even when they have had very little contact with each other.

One set of twins that was raised in different countries from birth is now in their late 40s and they even share the same weird sense of humour. For example, both enjoy faking sneeze in elevators to see how strangers will react.

A person's genetic structrure is thought to even influence the stability of his or her marriage. If you have an identical twin who gets a divorce, your risk of getting a divorce is 45 per cent. But if your fraternal twin - who shares only half as many genes - gets divorced, your risk is ony 30 per cent.

What does all this mean ? Are we mere puppets on a string, playing out a pre-determined course without free will or personal choices ? Not at all.

Unlike birds ad mammals that act according to instinct, humans are capable of rational thought and independent action. We do not act on every sexual urge, for instance, despite its genetic underpinnings.

What I am saying is that even though heredity provides a nudge in a particular direction, that impulse can be brought under the control of our intellectual processes.

Dr James Dobson

Saturday, July 28, 2007

The first Sunshine

Billions of years after the Big Bang - about 5 billion years before our time - our solar system was born.

Right at the beginning, there was a huge fog cloud - a mass of gas and dust. This cloud turned into a series of rings, all circling around the sun and each ring eventually became one of the planets or another of the many things in the sky.

In our own solar system there are about 100 billion comets, 30 000 asteroids, 34 moons, nine planets (of which our Earth is one) as well as a lot of dust and gas and so many fireballs that it is impossible to count them.

But the largest amount of matter - more than all other planets and asteroids combined - makes up our sun.
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