Knowledge can be of an individual. For example AryabhaTa: knew the earth was a sphere and that it revolved around the sun.
But some of his own students disagreed with him. Scientists and Thinkers always disagree. But the majority view is accepted as the science of that period.
Even though the astronomical siddhāntā: gave accurate methods for computing eclipses, and this was known to the scientists and the educated people, it was not known to the uneducated people who may well have believed that the sun was being swallowed.
So it is possible that some individual RSis like bharadwāja: did have some distance magnifying devices.
However, the vast body of the astronomical siddhāntā: that are available to us today, do not mention Uranus and Neptune. So the ancient astronomers may not have seen them. Of course much was kept secret and out of the texts and taught only to specially gifted children or students. So we can’t be certain.
Some amateur individual of the past might have learned about at-a-distance magnification.
Today, the knowledge of telescopes is in the public domain. Anyone with the interest and means can make or acquire one.
One does not hear of telescopes in ordinary homes of Ancient India.
One does not hear of Uranus and Neptune in the astro texts.
So at this point of writing, I’m thinking most folks in the astro and lay community did not have telescopes.
This book has a small chapter on telescopes in Ancient India also… which is interesting and useful. The images show the history and archaeological excavations of glass objects in India with dates.
Some caution is advised while reading.
- For eg “the word kancha” is mentioned in the yajur veda : fact.
- “Yajur Veda is of 1200 BCE” : an assumption based on many other assumptions about the date of the Yajur Veda
- “Kanch means glass” : We have to consult Kasysapa’s Nighantu plus Veda Mantras to find out in what sense that word was used in that mantra at that time.
I think this book is a worth a look-see .. It is available in IISc library.