October 8, 2017 ALP Monthly Meeting Report
by James Kevin Ty

Last October 8, Astronomical League of the Philippines held its monthly meeting at Alice Villa-Real's residence in Quezon City. Members who were present were ALP President James Kevin Ty  and son Kendrick Cole KC Ty; Secretary Christopher Louie Lu,  director John Ray Cabrera ,  Robert Gascon , Alice Villa-Real and Singaporean guest Remus CJ.

Meeting started at around 3:30pm with Christopher Louie Lu sharing the current astro events calendar for the month of October. This month of October, our planet will be moving through a debris field of dust that is left by Halley's Comet (1/P Halley). In so doing it brings one of several spectacular celestial events on Earth called the Orionid Meteor Shower. Peaking around October 20 - 22, this meteor shower will have an average of 20 - 30 meteors an hour. Halley's Comet makes its way towards the Sun every 75 years, the last time was on June of 1986.

Along the way comet Halley leaves behind a trail of ice & dust that crosses the orbit of the Earth. When the Earth does cross this debris field, the small particles of dust & ice burn up in the upper atmosphere of our planet creating what we call meteors. Meteors are any of the small particles of matter in the solar system that are directly observable only by their incandescence from frictional heating on entry into the atmosphere.

Tips for viewing Orionid meteor shower:
1. Choose a spot that is far away from bright lights; open country is preferred.
2. Naked eye observation is best.
3. A reclining lawn chair is a good piece of equipment to have, as it prevents neck strain caused by constantly peering skyward.
4. Check the weather forecast and be prepared for chilly weather with proper clothing or a blanket. Hot chocolate can add to the enjoyment.
5. Before the big night, observers should have studied a star chart and perhaps located the constellation Lyra in the real sky so that time is not wasted getting oriented when the big night comes.

It was followed by ALPer John Ray Cabrera who discussed on gravitational waves and how the GW observatory works, particularly LIGO. 
Gravitational waves are ripples in the space time fabric, and the detectable waves are caused by some of the most violent energetic activities in the universe. Einstein once predicted it, but regarded it as one that can’t be practically observed due to its weakening waveform as it passes through greater distances. 
When you change the entropy, by changing its direction or adding more energy, the object accelerates and thus ripples are formed. Scientists framed the observatories with a characteristic vibrational signature defined in the parameters of the interferometer. Cataclysmic events compact binary such as merging or spiraling Black Holes or Neutron Stars, Gamma Ray Burst, Supernovae, and other hugely energetic processes (e.g.,Inflation) in the universe are the major causes of detectable waves. 

Detecting the wave makes use of a simpler yet extremely sensitive detection technology. A laser beam passes though a beam splitter (mirror) which splits the beam into two identical beams signified as the X and Y arm  derived from a Cartesian coordinate system. At the end of each arm, the mirror reflects back the beam to the beam splitter, where the two beams co-mingled and cancel each other out. In some cases though, under the gravitational wave detected, the beam doesn’t arrive at the same time as a direct result of the change in length in the mirror, causes by the slight squishing of the Earth as gravitational wave passes though it. As a result, interference patterns is observed from the intensity of light. The delta is then measured to indicate change in length of each ams. 
In the pursuant to further advance the study of gradational wave, scientists are expecting the unfolding of some data that will help us dispel puzzles that we come across in the understanding of our universe— the acceleration of the expanding universe, how much more Dark Energy is present, or what is inside the Supernovae, or perhaps the existence of the cosmic string as a component of the universe.

The meeting ended at around 7:00pm .




You are our   Free Counter  th visitor since August 2003