Of trailing stars and thoughts…

     Of late, I have developed a habit of taking the liberty to create my own words and portmanteaus. The most recent one was ‘sparty=star+party’. ’Yeah, language was created by the living beings not only to survive this cruel world but also to communicate all about its beautiful facets. And it is the latter that I’m concerned with.

      Languages. On a random note, do you know of any language that helps you predict the future? A language so revolutionary yet so intuitive that even chimps and pigs learn to use? Poetry in this language assumes a different form. Creativity takes on a different meaning. But unlike all other ‘beautiful’ languages that exist, this language does not believe in breaking rules and creating exceptions. Yet, it is a language that has haters galore and romantics a few. If you still have no clue about the great invention of mankind, maybe it is time to learn how to do it from a dog.

    Well, that was no insult to your intelligence. It is a fact to be appreciated! The very fact that a dog can perform such mental tricks throws some light on the fact that nature around us is beautiful. That, we tend to take things (sometimes people too!) for granted. But I shall spare a few words about this some other time. For now, take a look at what a dog perhaps will never be able to do. It is the same language again!

    Quite dazzled, aren’t you? Well this for sure was no dog’s play. And hearty congratulations if you still have the willpower and the zeal to read ahead despite being freaked out.

    Life has never been oh so much impromptu and intuitive than what it is with me these days. On the 24^th and the 25^th December of 2011, I went on to attend the 4th star party of my life. It gives me great pleasure to say that we at the observatory believe in partying with the real stars. The immortal ones. Well, not exactly immortal but as compared to us they are. I always pity my best friend Anmol Naik who always dreams to watch the star Betelgeuse (pronounced Betel-jooze) explode into a supernova. Now even if this ripe old supergiant rips itself apart this very moment, it will take about 450 years for the news to reach us. And unless my friend here is not cryogenically preserved for those many years, he shall miss it. Unless, the explosion has already occurred 450 years ago. So what does it mean?

    It very simply means that we go to these star parties not only to create and gobble down our versions of Maggi noodles, but primarily to have a look at the past in the present. If this fact fails to blow your mind off, I think your senses have all gone dry. Knowing the fact is not enough. Feeling it and living it is what matters. There is nowhere else that one can do this, look into the past just by turning your head up.

    With the sky, we can feel the past. With the math, we can get a grasp of the future. And with our being, we journey through the present. We are all familiar with time but no one bothers to interpret it. And as they say, it is not going to wait for you to make sense out of itself. Aha!

    Sometimes my detours make me feel like changing the title and the whole purpose of making a particular post. I go away, drifting in a sea of ideas only to be awakened by a change in the mood of the songs that come on shuffle. Ah, that reminds me of probability. And also of music. Some other day, I tell myself.

    For this star-party, we headed to the dangerous Tillari Ghat, in Maharashtra. Dangerous enough for my relatives to scare the hell out of my mother and make her loose a night’s sleep.

                                      
   Doesn’t look dangerous from here, but when you undertake that tummy rumbling journey you know that the trip be better worth it. And it turned out that I wouldn’t mind making another hundred trips to get the view of that particular sky again. I usually narrate a particular incident to highlight the ignorance that people have right since the post-industrial revolution period.

“A strange giant, silvery cloud -- The above statement is not at all overly dramatic. It is a real trend. The National Institute of Health's issue of the January 2009 Environmental Health Perspectives Journal included a story from the 1994 Northridge earthquake that knocked out the power in Los Angeles. Apparently local emergency centres then received numerous calls from anxious residents reporting a strange giant, silvery cloud in the dark sky. What they were really seeing — for their first time — was the Milky Way, so obliterated by the urban sky glow that it was quickly forgotten and had practically become an urban legend.”

   I had read the story about 6 years ago. But I shall never forget it due to the repeated validation of this ignorance. In fact, the richest skies are found in the places that we think are ‘poor’. Have a look!

    I would seriously be in a fix if someone promises to set up an amazing observatory in remote Africa and tells me to shift my base there, forever. No kidding.

    In all, 7 people had a rendezvous with the stars. Two telescopes (a 6” and another 5”) and a camera (Canon 500D) is all they had. And boy oh boy, they rocked the night. Not to forget, our driver who was than curious!

    I will not be wrong to say that over the night, we exploited the sky that was exposed to us. 94 Messier, NGC and IC objects along with 40+ meteor sightings is not a joke. And yes, we were exploited back with the chilly winds in the valley. So much so that even if you managed to lock yourself up in the car, you could hear the winds howling outside. Photography being my forte, was running on my mind. After two hours of dedication behind only two images, I decided not to expect much when I come home and process them. The results were one better than the other. And this time, I managed to pleasantly shock my own self. Hah!

   Two hours of cumulative work had paid off! And my mom finally understood why I took up the ‘risk’ of going to such a ‘dangerous’ place. Phew.

    But what are these lines that you see?

I bet you that you have never seen such lines drawn across the sky! In fact, no one has. What you see, is a trick played by the camera. As you must be knowing, over a period of time the stars move. Well, they appear to move. The simple reason being that just like when we sit in a car and the trees appear to move past us while we are stationary, the Earth is what actually rotates and this rotation is perceived as the motion of the stars across the sky.

  But why is that star in the second photo stationary?

Imagine a globe that covers the entire Earth. Say, the stars are all stuck on the interior of the globe. This is precisely what the celestial sphere is. 

All of us know that the Earth rotates around its axis and that this axis passes through the Earth’s North and South poles.

In our construction, when the Earth rotates, we see that the celestial sphere rotates around this same axis. And co-incidentally, the very same axis points in the direction of the star that does not move!

Thus, we call it the ‘Pole Star’ or the never moving star. The current pole star Polaris is the brightest in the constellation of Ursa Minor. I have seen many people think that the Pole Star is the brightest star in the night sky which is a sad misconception. The brightest star in the night sky is Sirius whereas Polaris is hardly visible from city skies!

If you stand on the equator of the Earth and observe, the pole star will appear to be at the horizon and if you observe the pole star from the north pole itself, it will always remain exactly overhead. Thus, one can infer that the latitude a particular place is at, is equal to the angle the line between you and the pole star makes with the ground!

What the camera does is that it keeps its sensor or film exposed for hours at a stretch and thus picks up the motion of the stars as they chart their path across the sky. The very same thing that the human eye naturally fails to pick up!

Continue reading only if you have a clue about trigonometric functions.

Have you observed that as you move away from the pole star, the trails keep on increasing in length? While I was passing my time under the sky, I wondered if I could find out a way to relatively measure this difference in lengths.

All I knew was that the pole star never covered any distance on the celestial sphere and that the stars on the horizon covered the maximum distance. And what hit my mind immediately was something like this

     This pretty much seemed like common sense to me. But then, one can’t just go around and fit in formulae which work without a formal proof! So I pondered, thought I was wrong and so on. Well, I didn’t expect myself to unearth this!! But what happened is as follows.

[Consider theta to be angle made by the star to the ground; phi to be the latitude of the place. So phi subtracted from theta will be the angle made by the star to the pole star]

   It is pretty easy, this one. But I was overjoyed because I predicted the formula even before getting it. Frankly, it is really simple. But such small things bring joy. This is called poetry using mathematics and of course, common sense gained out of day to day experience. And you get overjoyed especially when you have been bored by studying chemistry for days at a stretch! Do note that the celestial sphere being an imaginary sphere, the radius is not defined. So one can use this only to compare the lengths of arc.

   One thing exciting about the formula is that it if you have stars in a line (along the celestial equator), and let them trail for some time, you shall get trails in the form of a sine wave. Given good enough wide lens and the right perspective, one shall obtain at least 1/4th of the wave.

   So here I am. Exams are approaching and I’m doing science. Identifying problems and finding solutions. This is life! Yes, this is it.

If you did not understand some part of the derivation or any assumption, please send me a mail or leave a comment as I have derived it in hurry after working for 6 hours to make this blog post. Phew. I leave you with some images, do scroll over them for the captions.

Wohoooo!

Thebiggerabang