Last Friday I was invited to deliver a lecture at Anula Vidyalaya, Nugegoda. (Nugegoda is a suburb of capital Colombo located 20-minute drive away from Colombo). Normally the Astronomical Association of Anula Vidyalaya holds their weekly lectures on Fridays. There are 2 basic lecture scenarios dedicated for both junior and senior students.
I think you guys are still aware of my fellow amateur astronomer Pulasthi Kanattage, who is also an astronomy lecturer. Usually it's him who lectures at Anula. However, as he had to go to Kandy for another astronomy project, I had to take care of his responsibility at Anula on that specific day (10th July 2009)
As lectures are usually started at 1.45 pm (In Sri Lanka schools open at 7.30 a.m. and close at 1.30 p.m.) I arrived at the school at 1.30 in the afternoon. Then I was accompanied to the lecture hall by a senior member of the Astronomical Association. I had earlier informed the board officials about the topic I would be lecturing. I hoped and had prepared to deliver a lecture on "Doppler Effect & Expansion of the Universe" as I had been told that I would get an audience where majority would be Advanced Level students (*Grades 12, 13). Unexpectedly I had to adjust to the situation as the audience was comprised of girls from Grade 8 onwards to Grade 12. Therefore I didn't go that advanced on the lectures explaining the analytical applications of Doppler Effect. Instead I showed them how to derive the Doppler Equations depending on the movements of the source and the observer. Also I explained how the expansion of the universe was proved true with the application of Doppler Effect resulting in a Red Shift. I also discussed the related topics including the introduction of Einstein's cosmological constant and Hubble's law which is
V= Apparent Velocity
H= Proportionality constant / Hubble constant
d=Distance to the galaxy from the Earth
I conducted the lecture till 2.50 p.m. and was glad in the end answering the random questions arisen, which proved that the girls have added something from the lecture to their knowledge.
I really enjoyed the lecture and an bit disappointed that I am unable to upload the pictures as I didn't have a camera at the time of lecturing. Don't worry, next time I surely will buy a new camera and let you guys witness the pictures and perhaps some videos too.