Saturday, April 18, 2009

Ideas Worth Spreading

TED is a short for “Technology, Entertainment, Design”, an annual conference held on Monterey, California. The lectures cover topics on areas such as culture, science, technology, education and politics. The list of speakers is impressive. It includes Nobel Laureates like James D. Watson and entrepreneurs like Bill Gates and Google co-founders, for example.

The TED motto is “Ideas Worth Spreading”. Well, they really are! More than 400 TED talks are available on their You Tube channel. Take a look.

Friday, April 17, 2009

Astrology: What does Science have to say about it?

by Alexandre Couto de Andrade
(This text was originally posted on my discontinued blog "HOMO SAPIENS")
There are various theories (physical, spiritual, magical, psychic and informational) that try to explain how astrology is supposed to work. All these theories have something in common: they offer explanations that are incompatible with existing knowledge. The aim of this article is to expose some of the main flaws of astrology. The arguments presented here are not exhaustive, i.e., they do not comprehend all that is wrong with astrology. If you are interested in having a deep understanding of the scientific evidences against astrology, I suggest that you visit the following web site: It offers an impressive quantity of detailed information on this subject.
The main problem of the physical theories resides on the fact that long range forces, like gravity, get weaker with distance. Astrology does not take this fact into consideration. Concerning gravity, for example, astrology not only disregards the influence of the distances and masses of the celestial bodies, but also ignores the fact that it is an extremely weak force. The influence that a planet like Mars exerts upon us, for instance, is much smaller than the influence from the objects and people around us. Gravity force is so weak that, when you pick up an object from the floor, you are opposing the force that the entire planet Earth exerts upon that object. Besides, if the distances and the masses of the celestial bodies and matter are not relevant, shouldn’t astrology take into consideration all the innumerable billions of celestial bodies? What about black matter and black holes? Shouldn’t they be taken into account as well?
Astrology techniques are very inaccurate and its criteria are arbitrary. Astrologers disregard the existence of a 13th constellation of the zodiac (Ophiuchus). Furthermore, they do not take into account the fact that the constellations do not fit well into the 12 equal segments of the sky that astrology assigns them to. They overlap and are irregularly distributed in space. Thus, the Sun path across them is not equally divided along the 12 months of the year (a person’s sign is determined by the position of the Sun in relation to the constellations of the zodiac on the date of birth), and it can cross more than one constellation at the same time. Astrologers also ignore the precession movement of the planet. Due to the precession movement, Earth constantly changes the inclination of its axis of rotation. The complete cycle takes thousands of years. The result is that the sky that we see today is not the same that people saw centuries ago.
Astrology charts are based on the moment of birth (birth charts). This choice is arbitrary. Isn’t the moment of conception much more significant? Besides, if the time of birth is so important, how do astrologers explain the fact that twins (as well as any other people who are born in the same place, at the same time) are able to lead lives completely different from each other? They simply cannot explain it.
Many people who believe in astrology affirm that it effectively describes their personality and successfully predicts events of their lives. How can science explain that? First of all, horoscopes are so vague that their statements can be applied to almost anyone. In addition to that, mere chance and psychological biases are the most reasonable explanations for most of these apparent successful descriptions and predictions. As a matter of fact, in innumerable well conducted scientific experiments, astrologers failed to show that the accuracy of their predictions was any greater than what is expected by chance.