jueves, 20 de octubre de 2016

About solar eclipses

In these days, we are learning about eclipses in our classes. In my opinion, all of you have understood the relative positions of the Sun, Earth and Moon, both in solar and moon eclipses. So, you should be able to explain what is an eclipse, the different types of eclipses and the differences between total and partial ones.
And as you have asked to me about next solar eclipses, here you have information about those visible from Granada in coming years:
Monday, 21st August  2017 (Partial, 6,3%).           
Thursday, 10th June 2021 (Partial, 1,4%).
Saturday, 29th March 2025 (Partial, 16,3%).
Wednesday, 12th August 2026 (Partial, 95,7%).
Saturday, 6th February 2027 (Partial, 0,5%).
Monday, 2nd August 2027 (Partial, 99,3%). 
Wednesday, 26th January 2028 (Annular, 82,6%).
And here you have a short documentary that we made about the solar eclipse we watched from this school two years ago.
I would like to know your opinion. Please write a comment in English.

jueves, 13 de octubre de 2016

What has happened with the horoscope?

In ancient times, people believed that the Earth was the center of the Universe and the Sun rotated around our planet. Today we know that the Sun is in the center of the Solar System and every planet orbits our star. They also observed the sky and connected the stars with lines drawing pictures known as constellations. They were convinced that those constellations were important symbols telling stories about their gods and myths and were very useful in order to know about people personality  and predict their future too.
The ecliptic. By Tauʻolunga - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=935439
As a result of the motion of the Earth around the Sun, our star appears to pass in front of different constellations. This apparent path of the Sun on the celestial sphere marks the ecliptic; the constellations through which the sun passes define the zodiac. Consequently, all the zodiac constellations lie along the ecliptic.
Babilonians, about 3.000 years ago, had a 12 month calendar, so they decided to divide the zodiac into twelve equal parts. For them, there were twelve zodiac constellations and this is the origin of the twelve signs listed in the horoscope that everybody knows. For example, if you were born under the sign of Leo, it means that the Sun was in this constellation in that moment and, of course, every year at your birthday.
But... is it true? Recently some newspapers said that NASA have changed the astrological signs for first time in 2000 years; consequently, lot of people now have a different zodiac sign. In my opinion, this is not a great problem for people who don't believe in horoscope, but what happens with the other people? Has their luck changed? 
I think that this is a very interesting matter that we can investigate. An to begin with, just some easy questions:
What do you know about zodiac? What is your zodiac sign? Can the stars really predict the future or describe what are people like based on their birth date? Please, write your answers as a comment.
(Spanish version)