Sankranthi Festival – Astronomical Deviations Perspective

                  Sankranthi (Pongal) is one of the biggest festivals in India. Hindus celebrate this festival day as the dawn of auspicious days based on the movement of the Sun. The earth rotates around its own axis tilted 23.5 Degrees with respect to ecliptic plane (the Sun’s path across the sky). We all know, that Earth’s rotation causes day and night and its revolution around the Sun causes seasons. The seasons are not created merely by the revolution of the Earth but because of the Earth’s axial tilt due to which angular direction of Sun rays differ on the globe across different latitudes, causing different seasons across Northern and Southern hemispheres. As the Earth revolves round the Sun, it appears to the observer on the Earth that the Sun is moving on the celestial sphere. The points of intersection of celestial equator and ecliptic plane are called equinoxes (Day light and Night will have same length on the day). Solstice is an event occurring when the Sun appears to reach its  most northerly or southerly excursion relative to the celestial equator on the celestial plane. Two solstices occur annually, on about 21 June and 21 December. The seasons of the year are directly connected to both the solstices and the equinoxes. The concepts of celestial sphere, Celestial equator, Ecliptic plane, positions of equinoxes and solstices on the celestial plane can be better understood in the pictures shown below.

           Pics obtained from the internet for better understanding of the readers only.

                   Apart from rotation and revolution of the Earth, there is one subtle and important movement of earth, it is called precession. The detailed explanation about this subtle movement was dealt in my previous post The Precession of the Earth . The gravitational pull of the Sun and the Moon on the gyroscopic Earth bulge produces torque on its rotational axis causing it to drift periodically from East to West completing a turn in 25,800 years. This woobling movement of Earth’s rotational axis is called the Precession. Shifting of Equinoxes and Solstices is one of the important phenomenon, apart from shift of pole star, that is caused by the Earth’s precession. As the Earth revolves round the Sun, the position of occurrence of Equinoxes and Solstices will not be same every year because of the precession of the rotational axis. By the time, the Earth reaches the same point around the Sun in its orbit, the rotational axis orientation would be slightly shifted due to precession. The equinoxes are nothing but the intersection points of ecliptic plane and celestial equator on the celestial sphere, as the Earth precession goes on, the intersection points are also shifted and hence the Equinoxes and Solstices. The shift in Equinoxes and Solstices changes the occurrence of seasons for the given position of the Earth in its orbit. Approximately, the Equinoxes and Solstices will be shifted by 1 day for every 70.6 years. The seasonal cycle is exactly repeated after 25,800 years again. This cycle is also called the Great Year in Astronomy.

The ages in which spring equinox occurs in different zodiacs mentioned in this table

Zodiac ( Raasi) Spring Equinox period in Zodiac ( Raasi)

Gemini (Midhunam)

BC 6350 – BC 4200
Taurus (Vrushabham) BC 4200 – BC 2050
Aries (Mesham) BC 2050 – AD 100
Pisces (Meenam) AD 100 – AD 2250
Aquarius (Kumbham)

AD 2250 – AD 4400

              Note : The western zodiac and Indian Raasi system have many similarities, still, both are not exactly same. Western zodiac system follows position of the Sun and Indian Raasi system follows position of the moon. Both terminologies are mentioned here only to indicate the corresponding terms for the convenience of readers.

            Astronomically, Sankranthi festival is celebrated on the starting day of the year, when the Sun enters Capricorn zodiac. It is traditionally believed that on the same day, auspicious Winter Solstice (Sanskrit:Uttarayana Punayakalam) begin. On the day of winter solstice, the Sun ends its southward journey (Sanskrit:Dakshinaayan) touching tropic of Capricorn (Sanskrit:Makar Sankramanam) and begins northward journey (Sanskrit:Uttaraayan) towards tropic of Cancer (Sanskrit:Karkata Rekha). Traditionally, this day is celebrated as Sankranthi festival from the early ages in India at which time the Sun entering in Capricorn and Winter Solstice coincided i.e at the age where spring equinox occurred Aries (Mesha) constellation in BC 2050 – AD 100. But, due to earth’s precession, equinoxes and solstices shifted and now Winter Solstice happens on Dec 22 (in northeren hemisphere) when spring equinox occurs in Sagittarius (Dhanu Raasi). That means, Makar Sankranthi celebrated on January 14th or 15th of the year is about 23 days after Winter Solstice (Sanskrit:Uttarayana Punayakalam) happened. It is true that on Jan 14th, the Sun enters Makar Raasi (Italian:Capricorn) but Winter Solstice will not happen on Jan 14th every year. This discrepancy is because in Panchangams the Earth’s precession movement affect is not considered, which is very subtle, about 1 degree in 72 years !!!

              Astonishingly, there is a reference about this subtle movement in ancient Hindu texts. In one of the interesting story in Hindu mythology, Lord Vishnu appears and blesses his devotee, Dhruva, who he will be remained as constant star in the space and all the stars (Saptha Rishis) will revolve around him for 26,000 years! Hindu astronomers called the ,pole star’ as ‘Dhruva Tara’. Do they really know about the periodicity and the Precession of the Earth axis? If not, how Hindus referred this period exactly in their age old mythological story is a mystery! Probably, some texts were lost and later pundits who prepared Panchangams missed this subtle concept. Whatever may be the Astronomical dates accuracy, the basic recognition that Sun and Earth movements are critical for existence of life and observing it as festival in practical life, decorating animals in villages, observing as farmers festival, all together shows Hindus way of living is intertwined harmoniously with Nature.

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#MeToo

metoo          

             #MeToo is one of the most popular hashtag now a day in social networking, many women express their views on sexual abusing based on their personal experiences or their close friends’ experiences. It is true that women are being abused sexually ages together throughout the world, but, whatever may be the reason any abuse is not a welcoming scenario in the society. No sensible man ever encourages or support any kind of sexual abuse on women. 

           What is alarming in #MeToo campaign is, it is fashioned in a manner as though all men are of perverts and crave for women. In fact, such kind of generalised descriptions based on one personal abuse finally contributes for widening gender gap rather than cooperative living. Men are different creatures biologically than women, and men are hard wired and designed in evolution with different motives and approach towards women. In general men are more expressive, playful and extroverts than women. It may be a bitter truth, but it is a known fact that many abuses happen by known persons to which women has given liberty to do so. Many #MeToo stories come up after breakup that involve selfish motives of women. It is true that every #MeToo campaign story has a pathetic content which is to be addressed in the society. But the way it is expressed has taken different colors. Now a day, expressing personal content boldly has become fashion, used to become popular and some are even making it as a symbolism for women empowerment. The male perspective of women empowerment is entirely different. Men identify women empowerment with successful and hardworking role model women in the society but not with the women who express every personal sensible content boldly in the public domain in every context. There is a lot of difference in these approaches and men see these approaches in women’s life very differently.

          Many say that #MeToo campaign create awareness among women and even may change some perverted men. But, in my view the affect will be very less. In fact, by simply expressing every small abuse by everyone in the public platform, it creates an opinion that such things are common to everyone and not a big issue to be addressed. It also inculcates in women that a feeling of adjustment is a must in the society towards such abuses because many #MeToo stories finally ends in some sort of inconvenience adjustment or compromise even in celebrity lives. To be honest, many men enjoy reading other women personal issues much more keenly in sexual personal matters and enjoy with little bit admissible perversion. Unfortunately, though #MeToo is a serious concerning campaign, it finally turned into a good time pass reading topic. Instead, it is to be addressed seriously, in limited manner, case wise based on the facts but not based on the opinions. When men are really punished for their abusive behaviour in true sense, when youth are counselled, when children are exposed to moral behaviour, when humans are made close to spirituality, it definitely brings change in the society and #MeToo stories tend to reduce in the society.

             Whatever it may be, in the history of human race, men harass women and women seduce men. This is a never ending story because as some women say Men will be Men !!!

Maha Ganapathim – Nata Raagam

Tinned Copper Fuse Wire

             Tinned Copper fuse wire is one of the common and simple fuse element used in semi enclosed fuses for maintaining the safety of electric equipment. The material used is Tin plated Copper. Copper is a good conductor, has good tensile strength and corrosion resistance. Hence bare copper wire is not a bad choice to use as a fuse. But, Tin plated copper fuse wires are much popular and widely used. Why ?

Tin Plating

             When Tin plating is applied over bare copper wire, it improves the strength and longevity of the copper beneath it. The corrosion resistive power of bare copper wire to humid and wet atmospheres gradually decreases when temperatures exceed especially above 100 degrees Celsius when carrying currents. In such circumstances, Tin plating on the bare Copper wire protects Copper beneath it and improves longevity and strength of the fuse wire. Tin coating does not allow oxidation easily. Tin coating on the fuse wire also makes it convenient for soldering. Even though Tin plated Copper wire is expensive than bare Copper wire, the expenditure will be prudent in the long run usage. Hence, TC fuse wires are widely used in electrical maintenance.

Advantages of TC fuse wire

  1. It is cheapest.
  2. It requires no maintenance.
  3. It requires minimum time to replace.

Disadvantages of TC fuse wire

  1. Due to prolonged exposure to atmosphere, oxidation makes the wire thin and fails.
  2. Operation is unreliable and hence cannot be used for large fault currents.
  3. There is a chance of misuse by using inappropriate rated fuse wire.
  4. Loose connections causes local heating.

 

Specification & Ratings

The common specification of TC fuse wire is Standard Wire Gauge (SWG) in the market based on the diameter of the wire which is the main parameter to decide the current carrying capacity of the fuse wire. The current carrying capacity of a TC fuse wire is usually mentioned as ‘Rated Current‘ of the wire which indicates the maximum current that the fuse can continuously conduct without interrupting the circuit and ‘Fusing Current‘ which indicates the current at which the fuse blows isolating the equipment from the circuit.

The ratings of TC fuse wires as per IEE regulations are mentioned below for reference and practise of using correct rated TC fuse wires for the electrical equipment under protection.

TINNED COPPER FUSE WIRES

I.E.E Regulation 14th edition Table A1

Approximated size of Fuse Elements Composed to Tinned Copper wire for use in semi-enclosed Fuses.

S.W.G

Diameter in inches Rated Current‘ of fuse in amperes

Approximate ‘fusing current’ in amperes

40

0.0048 1.5 3
39 1.0052 2.5

4

38

0.0060 3.0 5

37

0.0068 3.5 6

36

0.0076 4.5 7

35

0.0084 5.0

8

34 0.0092 5.5

9

33

0.0101 6.0

10

32

0.0108 7.0

11

31

0.0116 8.0

12

30

0.0124 8.5

13

29

0.0136 10.0

16

28

0.0148 12.0

18

27

0.0164 13.0

23

26

0.0180 14.0

28

25

 0.020 15.0

30

24

0.022 17.0

33

23

0.024 20.0

38

22

0.028 24.0

48

21

0.032 29.0

58

20

0.036 34.0

70

19

0.040 38.0 81
18 0.048 45.0

106

17

0.056 65.0 135

16

0.064 73.0

166

15 0.072 78.0

197

14 0.080 102.0

230

13 0.092 130.0

295

Sample look

bfw-01

 

Bhajan Tune

JanaGanaMana

Raag – Bowli (Morning Raga)

Varaveena

Sri Gananatha

Naarayanathe