Ancients believed that the astras had to be invoked using special mantras or spells. Different astras had their own and unique mantra. And if that one specific mantra, in that specific frequency was not used, the astra would not activate. None but only a few selected ones possessed the knowledge and the mantra to invoke an astra. Once invoked, one had to be very careful in invoking it, since, once launched, most the astras could not be intercepted or stopped by any other power, however strong should it be. They were weapons of great destruction and devastation.
Examples of such astras are
- Brahmanda Astra
- Daivi Astra
- Agneya Astra
- Sudarshana Chakra
- Vaishnavastra etc.
PHENOMENON OF RESONANACE
First, we have to understand the scientific phenomena of resonance. It is the property of waves, by the virtue of which, if the frequency of an externally applied force exactly equals the natural frequency of a body, then it starts vibrating with a much larger amplitude.
You would probably be surprised to know that the astras used the mechanism of resonance. Each kind of astra had its own natural frequency, which was actually very low. At that particular frequency and amplitude, it remained inactive. In order to activate it, it needed a larger frequency and amplitude.
This was to be provided by an externally applied wave. This externally applied wave had to be of the exactly same frequency as the astra. And this externally applied frequency was provided by the mantra. As different astra had different natural frequencies, they had to be activated by mantras of different frequencies. As resonance happened, this astra was set to motion and became nearly unstoppable... unless there was any other astra of almost the same power to counteract it. Generally, these astras were electromagnetic (like the sudarshan chakra), radioactive (like the Brahmastra, Brahmashirsha, Brahmanda, pashupatastra) or piezoelectric (vajra).
Some aerial astras worked on the principles of anti-gravity and aerodynamics. The rules and directions of constructing aerial weapons were mentioned in details in the books Vaimanika Shastra, Sulabasutra etc.
The three broad types of Brahmastra – the simple Brahmastra, Brahmashirsha, and the most powerful nuclear weapon ever – the Brahmanda Astra.
The simple Brahmastra was very target specific. Once it was launched, other astra except another Brahmastra could counteract it. It was the third most powerful radioactive weapon of ancient India. It had a very complex mechanism. It worked in nuclear fission, similar to the one dropped in Hiroshima. It led to immense devastation where it was dropped and rendered the whole are barren and uncultivable and unsustainable of life for centuries. It even made the survivors of that area infertile and inflicted genetic mutation.
The Brahmashirsha was more precise and the second most powerful nuclear weapon. It inflicted permanent and irreversible biological damage to the targeted victim, by mutating and altering the genetic structure and inhibiting their bodies’ mitotic as well as meiotic cell division. Its specificity was such that when it was targeted on a specific victim, it would affect only him sparing the others around. Brahmashirsha was used on the womb of Uttara by Ashwathhama, which killed the unborn child in the womb. Thankfully, the uncontaminated stem cells were extracted from the embryo and cultured externally under the guidance and recommendation of Krishna. Parikshit was thus born successfully.
The Brahmanda astra was the most powerful of all radioactive weapons and it affected a much larger area, about that of modern India! They were hardly used and were not given in wrong hands. When used, they were kept under control to avoid immense devastation.
(Article contributed by Shri Arkajyoti Banerjee)