Tuesday, June 28, 2005

Leading causes of mortality throughout the world

The question of "saving lives" comes first when someone gets serious about altruism.
However, before discussing what can be done to save lives, it's good to have some statistics on the leading causes of mortality throughout the world.

Source: WHO, 2002

2 causes of mortality tops the list:
1. "Ischemic heart disease"
2. "Cerebrovascular disease"

In summary, ischemic cardiomyopathy is a medical term that doctors use to describe patients who have congestive heart failure that is a result of coronary artery disease

Patients with this diagnosis may at one time have had a heart attack, angina or unstable angina.

High blood pressure, smoking, diabetes, high fat diet, high blood cholesterol, obesity and (rarely) stress can all precipitate ischemic heart disorders.


Cerebrovascular disease: A stroke is when the blood supply to any part of the brain is interupted, resulting in tissue death and loss of brain function.

The risk of stroke is increased by smoking, hypertension, diabetes, hyperlipidemia, and heart disease.


From these informations, a straight-forward way to save lives is to encourage people to exercise and eat healthy food. These changes in life-styles are the most efficient ways to quit smoking... stop drinking... avoid obesity and high cholesterol rates.

However, these diseases don't kill children, teenagers and young adults. What would be the leading causes of mortality for these age groups?

For children under the age of 5: Pneumonia accounts for 19 percent of all child deaths, diarrhea 17 percent . Undernutrition is an underlying cause in more than half of all deaths before age 5. In other words, these causes of mortality affect mainly the children living in the poorest countries of the world.


Worldwide statistics on the causes of teenagers mortality are harder to find! However from the existing statistics for all age groups, we can assume that HIV/AIDS is the most worrying one.

Here is what I found one HIV/AIDS preventions for teenagers (US website discussing the cases of US teens only)

"One common argument against HIV/STD education programs is that exposing teens to information about sex will encourage them to engage in sexual activity. But a comprehensive review of 23 school-based programs found quite the opposite was true: teens who received specific AIDS education were less likely to engage in sex, and those who did were more likely to have sex less often and have safer sex.

Schools alone can't do the job. There remain major obstacles to good HIV/STD education. Some schools lack properly trained personnel. Others refuse to discuss homosexuality. And many offer inadequate instruction on condom use. Although three-quarters of sex education curricula in the nation's schools mention condoms, only 9 percent include information about how to use them.(9) Significantly, studies show that for teens to wear condoms, they must not only believe that sex with a condom can be enjoyable, but trust their technical ability to use condoms in a confident way."


An overall conclusion is that health issues are fundamental for anyone who wishes to "save lives".


Tuesday, June 14, 2005

Found: Earth's Distant Cousin (About 15 Light-Years Away) - NYT

The detection of extrasolar planets is a great wonder of our times. It's a way to test the likelihood of other forms of life in the universe.



Found: Earth's Distant Cousin (About 15 Light-Years Away)

Published: June 14, 2005

In a discovery that they described as a milestone in the quest to find out if humans are alone in the universe, astronomers announced yesterday that they had found the smallest planet yet outside the solar system.

With a mass only seven times that of the Earth, the new planet is probably a ball of rock, its discoverers said. Orbiting closely to a dim red star in Aquarius known as Gliese 876, it is the third and innermost member of a shrunken version of our own solar system.

"This is by far the most Earth-like planet ever found," said Dr. Geoffrey Marcy of the University of California, Berkeley, a member of the team that made the discovery using one of the giant 10-meter diameter Keck telescopes in Hawaii.

To understand the importance of the discovery of Earth-like planets, it's good to mention what the "Drake Equation" is about:

1> There are more or less 250 billion galaxies in the universe.
2> In each galaxy, there are more or less 200 billion stars
3> More than 30% of these stars have planets
4> In each solar system, there are about 2 potential life-supporting planets
5> Among such planets, only one in a million actually supports life...

There would still be more than 30 billions of billions planets with some forms of life in the universe! (More than 100 millions in our galaxy alone)

The more Earth-like planets will be discovered, the more accurate will be the parameters in the Drake Equation!

Note than very few astronomers doubt that life is widespread in the universe these days...


Tuesday, June 07, 2005

What's the fuss with the evolution of species?

Following many debates about "intelligent design", I read an article in the Washington Post about the attempts of "creationists" to undermine the current knowledge of the origin of life on Earth. I'm asking the question: Should religion and science been mixed up? What about scientific truth?


The article:


THE INVITATION was straightforward enough: "The Director of the National Museum of Natural History and Discovery Institute are happy to announce the national premiere and private evening reception for The Privileged Planet: The Search for Purpose in the Universe," on June 23. But for the museum's directors, the decision to allow this film to be shown in one of their auditoriums turned out not to be straightforward at all. The Museum of Natural History is known, among other things, for its collection of fossils and its displays describing Darwin's theory of evolution. The Seattle-based Discovery Institute, by contrast, is known for its efforts to undermine the teaching of Darwinism in schools and to promote the theory of "intelligent design" -- life is so complicated it must have been designed by an intelligent creator.

For these reasons, the Smithsonian and its Museum of Natural History should have been wary of this project. But the film itself also should have given them pause. The museum's policy, according to its spokesman, is to allow private groups to use its auditorium for a fee -- in this case, $16,000 -- so long as the material shown is not religious or political in content. While "The Privileged Planet" is an extremely sophisticated religious film, it is a religious film nevertheless. It uses scientific information -- the apparently "perfect" position of Earth in its orbit and in its galaxy, the uniqueness of its atmosphere -- to answer, affirmatively, the philosophical question of whether life on Earth was part of a grand design, and not just the result of chance and chemistry. Neither God nor evolution is mentioned. Nevertheless, the film is consistent with the Discovery Institute's general aim, which is to drive a wedge into the scientific consensus about the origins of life and the universe and to give a patina of scientific credibility to the idea of an intelligent creator.

The museum was naive or negligent not to recognize this, and more naive not to anticipate the backlash. When news of the film showing recently began circulating, one Web site that supports intelligent design asked enthusiastically whether this meant the Smithsonian was "warming up" to the theory of an intelligent creator. In a newspaper interview, Bruce Chapman, president of the Discovery Institute, also said how delighted he was that the Museum of Natural History would "co-sponsor" the event despite the fact that the evening was intended to be a private affair. This is precisely how the intelligent design movement has gotten as far as it has: by advocating outwardly inoffensive ideas in ever-more prestigious places, thereby giving the movement scientific validity. This week, after protests from within and outside the museum, the directors returned the $16,000 auditorium rental fee and issued a statement declaring that "the content of the film is not consistent with the mission of the Smithsonian Institution's scientific research." It's an embarrassing about-face, but not as embarrassing as the original decision.

Thursday, June 02, 2005

Religion and the size of the universe

This is an interesting attempt to show how little significance the existence of mankind has on the universe. Just like many others, the author of this text concludes that organized religions have misled people in believing that they have a special relationship with a "creator" or an "omniscient" god. The awareness of our relative size compared with the size of the universe shows that we are not at the center of this universe, we are only a "grain of sand on the beach".
By the way, I'm not sure he's got the right data for the age of the universe...



"How old are you?
You probably think you've been around a while, that your 20/30/40/50 years on this planet is quite a long time, that you've seen a lot of changes?
On our time-scale, you're probably quite right.
On the time-scale of this planet, in geological time, you might as well have never existed.
I think one of the reasons that many people turn to religion is the human mind cannot easily comprehend the vast scales of time and space in the universe. To us, two-thousand years (since the birth of one J.Christ) is a huge amount of time. Look at what we've done since then - discovered America and Australia (although the Indians and Aborignes might dispute that claim); discovered how to refine crude oil, allowing us to build cars, planes, spacecraft; we've been to the moon and the bottom of the sea. What accomplishments!
The universe is estimated to be about 15 - 20 thousand million years old. This planet has existed for about four thousand million years. The last two thousand years are approximately 0.00001% of the planet's age.
Mount Everest, the highest point on the planet, is composed of marine limestone. It used to be under the sea, but slowly, millimetre by millimetre, it has been pushed upwards (and continues to do so, as India collides with Asia). You might think a year is a long time, but can you even begin to comprehend the lifespan of Everest?
Our planet is one tiny insignificant rock orbitting one average, ordinary star in the outskirts of the Milky Way, itself just one ordinary galaxy among billions. When you look up into the night sky on a clear night, you can hardly see any stars at all. If you could see all of them, if our eyes were better and there was less dirt in the universe, the sky would be completely white. There would not be the smallest gap between the stars that you see. (in theory, anyway, see the footnote for more details).
For every star that you can see, there are thousands of galaxies, each containing thousands of millions of stars.
The Milky Way itself is an insignificant speck. Our solar system is an insignificant speck within that. The image at the top of this page is from the NASA archives. It was taken with the Hubble Space Telescope, and the area of sky that is represents is approximately 1/30th the apparent diameter of the full moon. As you can see for yourself, it is packed with galaxies. Galaxies, not stars.
People think that we are somehow blessed or special, so of course the Creator Of The Universe must have set aside this little corner of the universe just for us.
Religion used to teach that the Earth was the centre of the universe, the single most important place that God created.
Now, we know better. If the Earth was destroyed tomorrow, the universe would neither miss us nor mourn our passing. Would you notice one grain of sand missing from the beach?
We think we are special, and that supremely powerful beings look after us.We are not special, we are simply the result of a (probably very common) chemical accident billions of years ago, in a place where the conditions are right for life to flourish.
The same thing probably happens all over the universe, and in many places there will be life. Some will be more advanced than us, others less advanced.
In many places, the conditions will not be right for life. There are probably entire galaxies or clusters of galaxies where life will never arise, because the conditions there are too extreme. Galaxies with supermassive black holes, areas of stellar genesis (such as the Orion Nebula), maybe regions close to quasars may never produce life due to intense radiation or gravitational disturbances.
We are certainly lucky, yes, but special? No.
(Gosh, that all got a bit heavy, didn't it?)"

More on the size of the universe:

a man/woman is 1.7 meters high on average (6.5 feets)
1,000 times bigger is a city-park (1 km wide)
1,000 times bigger is the size of France
1,000 times bigger is much more than the distance from the Earth to the moon.
1,000 times bigger is the distance from the Sun to Jupiter
1,000 times bigger is the distance from the Sun to a faraway comet.
1,000 times bigger is much more than the distance to the closest star.
1,000 times bigger is the size of our galaxy
1,000 times bigger is much more than the distance to the Virgo cluster of galaxies
1,000 times bigger is slightly less than the size of the universe.

The universe is thought to be 156,000,000,000 Light-Years wide.
That's about 1,475,760,000,000,000,000,000,000 km

More on time and human history:

If Jesus Christ was born 1 second ago,
Then the first hominids (early humans) appeared 35 minutes ago.
The universe was born about 2 months and half ago.

The universe is about 13,700,000,000 years old