The Diurnals

Contributed by Pat Larkin

The DIURNALS is a friendly group which meets during the daytime on the third Tuesday of the month February - December.

Objectives

To provide an opportunity for meetings during the DAYTIME.

To disseminate knowledge on various facets of astronomy and related fields, together with Space Exploration, in an informal environment.

To foster enjoyment of the subject matter with kindred spirits, and to encourage newer members who may show an interest in a particular area.

There are no pre-requisites and you don't have to be a mathematics or physics genius! Just come with a desire to learn.  Most months, we have a guest speaker, and talks given cover a wide range of astronomical fields and space exploration. Occasionally, a film is shown followed by discussion if desired.   Two or three times a year, we will have an excursion to another facility, e.g., Swinburne University, Melbourne Planetarium or a Science facility.

Next Meeting:           16th October  2018.

TIME:                        10.30 start  -  approx. 12-15 p.m.

VENUE:                     The Lodge, Burwood       

 TOPIC:                     TWO FILMS from the GREAT COURSES - Astronomy  - will be shown:

                                         Film 1:   "THE RAINBOW CONNECTION' 

                                         Film 2:    "SUNRISE, SUNSET"  

                                                           To be followed by discussion of each if desired.

PRESENTED by:      PROFESSOR  ALEX FILIPPENKO - UNIVERSITY OF CALIFORNIA (Berkeley) 

 

Have you ever thought that the phenomena of rainbows, sunrise and sunset are common, ordinary events?  Think again, as there is more to these events than meets the eye!   Reflection, refraction, perception, optical illusions, and more.

Film 1:    'The Rainbow Connection' - Professor Filippenko explains the properties of light caused by the different wavelengths and the complex effects of the sun entering and exiting raindrops.  Reflected light is studied in detail.  The mechanics of the more unusual Secondary Bow revealing a reversal of colours is also explained, along with the Moon Bow, the Glory, Sundogs and Sun Pillar.

 

Film 2:   'Sunrise, Sunset' - Professor Filippenko looks at the bending of light causing us to see the setting sun after it has actually set.  (Crepuscular rays during twilight appearing to fan out but are in fact, parallel also creates an optical illusion.)  Excellent animations explain the 'green flash' - and the rarer 'blue flash' - at the end of sunset and reversed at the beginning of sunrise.  The incidence of clouds reflecting the colours, red and orange after sunset is studied. This film concludes with the fascinating Mirage.

 

 Following the presentation, Members might like to bring a cut lunch and stay to chat further -   a nice time to mix with kindred spirits. 

   For enquiries:  Phone Pat Larkin on 0400 457 342