Shri Arun,
The two names Bheema and Rathi, I believe, originate from some less-known astrological sources; the words denote the numbers 54 and 72 respectively, according to the kaTapayAdi rules. It is still believed that at age 54 there may be a MadhyAyur KhaNDam in some horoscopes and so death may befall the native. Similarly, age 72 is considered as the 'maximum' MadhyAyus and in many horoscopes death may be indicated at this age.
Among tabras both these were not recognized much till about 15 or 20 years back, i.e., till our youngsters started earning fabulously through the IT/BPO routes. When the tabras' financial position improved suddenly and drastically, their old values of detachment evaporated, there was a new wave of "enjoy every moment" of your life set in and so also, a fear of untimely death snatching away the newly acquired lollipop. Then started the celebrations of 54/55, 70/72 etc., birthdays and priests (Vadhyars) and some temples like Tirukkadavoor capitalized on this frenzy.
Though my experience in astrology is nothing as compared to Shri yesmohan's, my humble feeling is that the KhaNDam at age 54/55 is usually more effective in bringing death to a person than the one at 70/72.
In Kerala, and amongst the Nair Tarvads, the Saptati has been celebrated with pomp and feasts for a long, long time. Very few observe their 60th. birthday on an equal footing.
