How is it possible for the earth’s equator to line up with the celestial equator when the earth is actually tilted by 23.4 degrees?
The earth is tilted with respect to the ecliptic. The ecliptic is the plane on which the Sun appears to travel. The celestial equator is 23.4 degrees inclined to the ecliptic. It is the Earth’s equator, but projected into the sky.
The celestial sphere comprises of 88 constellations. The path of the ecliptic has 12 constellations. In the realm of astrology, do the remaining 76 constellations have an impact on living beings (more specifically us human beings)?
There are as many constellations as you like. Each culture has different numbers. Vedic culture has 27, not 12 constellations on the ecliptic. Babylonians used to have 18, but when they started using the 12-fold solar system, they mapped it to particular stars, and approximated the divisions to 12 constellations.
The constellations outside the ecliptic are not visited by the planets, so there is no interaction with the symbolic elements. Therefore they are not part of astrology.
Who is the elder sibling: Ganesha or Subramanya?
Subramanya (Kārtikeya) is the elder, but has a very complex birth story (see the chapter of Kṛttikā in my book, 27 Stars 27 Gods) so he is not exactly Pārvatī’s child. Ganesha is truly Pārvatī’s child, but is younger. Yet he is truly the first child of Pārvatī.
Also, since Ganesha won the right to be Nārada’s student, he became wiser than Kārtikeya, and thus in that sense he is also considered elder.
Vigna means “obstruction”. Nirvigna means “removal of obstruction”. If this is so, shouldn’t Lord Ganesha be referred to as Nirvigneshwara instead of being called as Vigneshwara?
Either name is good. Only the master of obstruction (vigneshwara) can control them, and by controlling them, remove them.
Vigneshwara (another name for Ganesha) means one who causes obstruction. Was Ganapati (a spirit) a leader of bad spirits who caused immense fear and obstruction to humans? Is this the reason he is referred to as Vigneshwara? Do humans worship him only to appease him to get rid of obstacles before starting any new activity?
Vigneshwara does not mean “Causer of Obstruction” it means “Master of Obstructions.”
He causes huge obstructions for his enemies, and removes obstructions for his friends.
Yes, Gaṇapati is the son of Rudra, who is Bhūteśvara, the Lord of Monsters. His son is the general in the army of Bhūtas (monsters), thus he is called Gaṇapati. As such he has full control over them.
Yes, humans worship Ganesha so that he will remove obstacles.
In this image, why is the consort to the right of Subramanya/Murugan often depicted to be green in complexion?
Valli, the goddess on his right has a dark complexion. Devayani, the goddess on his left, has a fair complexion. Devayani is Indra’s daughter, from a high caste. Valli is an aborigine’s daughter, from a low caste. This is why the complexions are different.
This shows that intercaste marriage was not always considered abnormal or undesirable.
In paintings and images, a male deity (with just one consort) is often depicted on the right side of a female deity. For example, Vishnu-Lakshmi, Shiva-Parvati, Krishna-Radha, etc. Why is it like this? Like you said, is it because the right side of a revered person symbolizes respect?
As you can see above, it is not always as you depict it. But in polygamy there is always a queen-wife who is the leader of the others. Devayani being that wife has the position of respect, on the left (female side) of her husband.
The right side is masculine because males are much more muscular, and for the vast majority of people, the right hand is much stronger than the left.
The male respects the female by keeping her at his left, the female side. The female respects the male by keeping him at her right, the male side.
While circumambulating (parikrama) to show respect, we take a feminine persona and therefore put the circumambulated object/entity on our right and move clockwise.