Monday 26 October 2015

Wonders of the Sky!

The night sky is truly mesmerizing. I look at this quite often. Having seen the moon's craters, I now crave for a telescope strong enough to show Saturn's ring. And then I start wondering, science and technology has made observing the universe quite fun and easy (as compared to the days of  naked eye astronomy i.e. days of the ancient Greek astronomers).
 
Around 3rd century to 1st century BC (part of the Hellenistic period), a number of ancient Greek astronomers contributed to 'Astronomy', laying the initial foundations (if I may). During this very period, you do be amazed to know that 'Aristarchus of Samos' was the first Greek astronomer to propose a Heliocentric sun-earth model (i.e. in which the earth revolves around the sun)! Alas, this knowledge was lost and the Geocentric sun-earth model (i.e. in which the sun revolves around a fixed earth) prevailed for approximately the next 1800 years. 'Hipparchus', another great Greek Astronomer cum Mathematician, is credited with preparing the first star catalog during this period too. This genius used his eyes only (as there were no scientific tools then) and tried to capture all the movements in the night sky. What a feat! These men believed in the Heliocentric model, when the entire world was fixed with the Geocentric model.
 
In 2nd century AD, Claudius Ptolemy wrote many scientific treatises. One of the most famous is 'Almagest' - treatise on Mathematics and Astronomy (For more details, check out http://bertie.ccsu.edu/naturesci/Cosmology/Ptolemy.html). This is one of the most influential scientific texts of all times. Ptolemy further developed star catalogue (i.e. a version), originally created by Hipparcus.  And he advocated the Geocentric model.
 
It took nearly 1500 years for the Heliocentric model to be revived. And Nicolaus Copernicus did this in the 16th century AD. Tyco Brahe, Johannes Kelper and Galileo Galilei contributed immensely to the science of astronomy, in this century. They came up with planetary motions and accurate astronomical observations.
 
Telescope was invented in the 17th century AD and Galileo was the first to use one for celestial observations. He was kept  under house arrest for life, as he advocated the Heliocentric model. Think about this for a moment. Today, a 7-8 year kid is also taught about the planets revolving the sun. And just 2-3 centuries ago, supporting this very fact was considered a crime! We really have come a long long way since then. I believe that the advancement made by mankind in the last 200-300 years is equivalent to (or surpasses) around 2000  years' worth of advancement (prior to the 200-300 years period).
 
Today, there are excellent telescope systems that monitor the solar system and beyond. I am sure you have heard about NASA's Hubble Space Telescope (in honor of Edwin Hubble). Check out http://www.spacetelescope.org/images/archive/top100/, list of superb Hubble photos. NASA's Chandra X-Ray Observatory is another marvel. Check out http://chandra.harvard.edu/ for more information. This observatory (floating high above the earth's atmosphere) is designed to detect X-rays. These rays get absorbed by earth's atmosphere. And that is why we need an observatory floating above the earth's atmosphere, to detect them. Check out https://en.wikipedia.org/wiki/List_of_space_telescopes for a list of major telescopes put into Earth's orbit.
 
You have many options when it comes to buying a household telescope. Check out http://www.skyandtelescope.com/astronomy-equipment/choosing-astronomy-equipment/telescopes/ and http://www.skyandtelescope.com/astronomy-equipment/types-of-telescopes/ for more details. There are telescopes that can point and track the night sky objects automatically! Cool indeed. To start with, observe the moon. Do you know that we always see 1 face of the moon? We never get to see the other side of the moon. Why? Because the moon's rotation around it's own axis and it's revolution around the earth are the same. The other side of the moon (that we never see) is very different from the face that we see. Try some google searching to find out why.
 
Now, how do you decipher your local night sky? Easy! I frequently use this beautiful web resource to view the night sky at my latitude and longitude -  http://www.fourmilab.ch/yoursky/. Try it out. Know your local night sky and follow planets. Get hooked to the beautiful night sky.
 
If you are game to more than the local night sky, then check out http://live.slooh.com/. This website streams live celestial events (with scientific discussions) - meteor showers, eclipses, sun flares, comets and more. Sign up and you will get notifications before the start of such events. By the way, Sun flares (i.e. magnetic storms) create the phenomenon of the 'Northern Lights' aka 'Aurora' - on my To-Do list.
 
And if you need more, then plan a trip to the Australian outback! Pack your bags and a good DSLR camera. Learn a few photography tricks such as taking a long exposure shot. And you sure will be rewarded :) Another item for my To-Do list. They say that this part of Australia does not have light pollution i.e. light coming from manmade sources. Hence, you get a perfect clear night sky where you can watch, in awe, the milky way. Check out http://www.bing.com/images/search?q=australian+outback+night+sky&FORM=HDRSC2  and be humbled by the magnificent universe.

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