Daily Archives: August 29, 2011

A Peek Into the Sky


The quest for mans’ knowledge about the universe started since he became a rational animal.Ancient civilisations made use of astronomical observations in prediciting seasons, The first observatory perhaps might be the stonehenge situated in UK. It is believed to have been used for marking sunrise and sunset and also the moonrise and moon set.

MYTHS ABOUT THE EARTH AND SUN
In the ancient time people believed that the sun was carried from the eastern horizon to the western horizon on a chariot pulled by seven horses, and that the earth was a large island surrounded by seas on all sides and carried on the back of a turtle.

CONSTELLATIONS AND THE ZODIAC
A group of stars is called a constellation.Ancient people used the constellations for navigation, to know the seasons etc. The stars in the sky are grouped into 88 constellations. Among the 88 there are 12 that stradle the sky along the apparent yearly path of the sun called ecliptic. These 12 are known as the zodiacal constellations and the band of 12 constellations is known as zodiac.
These are:

Name Image Mythology
Aquarius Water CarrierBabylonian Name.In Greek mythology, Aquarius (also known as Ganymede in Roman myth) was a beautiful young boy whom Zeus brought to Olympus to be the cup bearer of the Gods. It is suggested that Zeus fell in love with Aquarius.
Aries Ram or Golden Fleece.In Greek mythology, the ram carried Athamas’s son Phrixux and daughter Helle to Colchis to escape Ino. When the ram reached Colchis, Phrixux sacrificed the ram and hung its fleece in the Grove or Ares. This fleece turned to gold and later was the quest of Jason and the Argonauts.The constellation name was common in Greek, Babylonian and Egyptian cultures.
Cancer CrabJuno sent a crab to defeat Hercules while fighting Hydra. The crab was crushed by Hercules.
Capricorn Sea GoatAlso known as Amalthea who provided for baby Zeus after Rhea saved him from Cronos.The word “cornucopia” comes from the broken horn of Capricorn – or the “horn of plenty.”
Gemini Twin BrothersThe two bright stars– Castor and Pollux – are also the brothers’ names. They were the brothers of Helen of Troy.They are also the protectors of ships and sailors.
Leo LionPrehistoric constellation associated with royalty. In Egyptian mythology, it represents the life giving floods since the Sunwas in this constellation during the heavy rains.In Greek mythology, Leo represents the Nemean Lion which was killed by Hercules.
Libra ScalesThe only “non-living” object in the Zodiac.Romans chopped claws from Scorpio during Autumn Equinox to make Libra.

In Greek mythology, Libra is the scaled held by Astraea that represents justice.

Ophiuchus Serpent HolderWhile not an Astrological sign, Sunspends longer time here than in Scorpio.In Greek mythology, Ophiuchus is a legendary physician who tried to become immortal to avoid death. Zeus killed him with a bolt of lightening, but honored him because of good works.
Pisces Two FishVenus and her son Cupid escaped Typhon as two fish tied together.In Greek mythology, they are Aphrodite and Eros.
Sagittarius The ArcherA Chiron, half-man half-horse, sent to kill the scorpion (Scorpio).In Babylonian mythology, this represents the demon Pabilsaq.
Scorpio The ScorpionSent by Gaia to kill Orion when he said he would kill all animals.It is also said that Apollo sent the scorpion to kill Orion.

Orion and Scorpio are on opposite sides of the sky.

Taurus The BullBabylonian constellation.Jupiter turns into bull to carry off Europa – daughter of King of Crete.

It is also said that Zeus brought the ram to try and win the heart of Europa.

Virgo The VirginGoddess of farms and harvest. Virgo could also represent Ishtar, Isis, Demeter, Cybele, and Athena.Also thought to represent Astraea, the daughter of Zeus representing justice.

It is also suggested that Virgo represents Persephone, queen of the underworld.

The Following Link gives details about the 88 constellations

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An alarm to remind you to water Plants


This is a circuit that will remind you to water plants when the pot is dry, this circuit is mainly meant for the indoor plants that are the unfortunate ones that don’t even receive rainfall.

The Circuit consist of two probes( You can use nails or just strips of uninsulated wires) When the probes are shorted the LED will be turned off. When the soil is wet the resistivity of soil is so low that the LED is turned off, when the soil is dry the resistivity of soil is high and it does not conduct.

Plant watering reminder

 

In this circuit Q1 and T1 form an astable oscillator and T2 acts as a switch that turns on and off the astable oscillator. A buzzer can be used instead of the LED. The pot can be used to adjust the sensitivity of the device.

 

 

 

 

wateralarm

Parts List

Part     Value
C1       100nf
R1       100k
R2       470k(Pot or Preset)
R3       1M
Q1       BC328
T1       BC107
T2       BC107
LED      (Or buzzer)
Battery  9V
Battery clip
Wires, solder,pcb etc

 

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