I am regularly doing agnihotra. Agnihotra appealed to me as an ancient practice of synchronizing circadian rhythms of humans, plants to planetary rhythms to improve health of living things. . While performing Agnihotra the body is stimulated with light, heat, chemical [smoke] and sound [the chanting] energies. There are people advocating agnihotra but none of them studied it as a method of fine tuning of the synchronization of biorhythms with planetary rhythms a possibility which can't be ruled out.
Circadian rhythms are the periodic changes that happen around a day. For example the sleep and wake cycle. suprachiasmatic nucleus SCN acts as biological clock which actually is a pair of pinhead sized brain structures both of which contain around 20000 neurons located in the hypothalamus above the point where the optic nerve cross. The signals from the photoreceptors in the eye [ rods and cones on the retina] are transmitted to SCN through optic nerve. SCN in turn sends signals to various brain regions including pineal gland which switches off the production of the hormone melatonin on receiving light signal. The melatonin level in the body increases during darkness. Apart from this SCN is also known to govern other functions that are synchronized with the sleep / wake cycle such as body temperature, hormone secretion, urine production and blood pressure. Biological clocks are said to follow an innate cycle of 25 hours rather than 24 hour cycle. Circadian rhythms can be affected / reset to an extent by external stimuli / time cue such as beeping of the alarm clock, timing of meals etc. The external time cues are called zeitgebers a German word meaning" time givers"
Circadian rhythms are important to humans, animals, plants and even fungus and cyanobacteria etc in controlling / activating several physiological / genetic functions.
Agnihotra is homa or yajnya an ancient Rig vedic practice performed at the exact timings of Sun rise and Sun set. It is said that human health and agricultural production improves if Agnihotra is performed. The five aspects of this homa are that
[1] it is performed exactly at the local timings of Sun rise and Sun set
[2] an inverted semi-pyramid shaped pot of copper is used. The size is specified as 14.5cmx14.5cm at the top and 5.25cmx5.25cm at the bottom with a height of 6.5 cm
[3] the fire is in the pyramid using dried cow dung cakes, cow's ghee. The cow dung cakes are ignited using camphor or cotton soaked in ghee ten minutes before the local Sun rise / set time.
[4] a pinch full of uncooked full grains of rice smeared with ghee are offered as oblations to the fire at the precise time while chanting the mantras.
[5] the mantras are as follows.
[a] At Sun rise:
Suryaye swaha, Suryaye idam na mama
(1st oblation released into the fire)
Prajapataye swaha, Prajapataye idam na mama
(2nd oblation released into the fire)
[b] At Sun set:
Agnaye swaha, Agnaye idam na mama
(1st oblation released into the fire)
Prajapataye swaha, Prajapataye idam na mama
(2nd oblation released into the fire)
