DIY : A simple CD Spectroscope

This is a make it yourself guide to build your own CD Spectroscope with which you will be able to easily make out the Sodium D-lines with the help of a street light.


  This is what I got with a crude instrument that I made, I promise you’ll end up with a better one!

  Before we jump into the making of the spectroscope, let us take a look at the concepts and phenomena involved in the experiment! After all, a lil’ background does no harm! Although I’m no expert on this subject, I’ll do my best to be as lucid and factually perfect as possible! To skip to the procedure, please scroll down.

Diffraction : It is described as the apparent bending of waves around small obstacles and the spreading out of waves past small openings.
     Consider a plane wave front as shown in the figure. When it encounters an obstacle which is of the same order as its wavelength, it diffracts or spreads out. When the diffraction pattern of white light is observed, one can make out its constituent colours, as each constituent colour diffracts in a different way which is dependent on its wavelength.

   Optical instruments called diffraction gratings, have a periodic structure in the form of closely spaced parallel lines or divisions which splits and diffracts light into several beams travelling in different directions. For example, a particular grating can even have 6000 lines/cm!
Just like prisms, they split up a white light source as I have mentioned earlier.
Around us, we see lots of phenomena due to diffraction, and although it might sound pretty much theoretical, diffraction is the phenomena that has lots of real life applications. The surface of holograms that one sees are somewhat like a diffraction grating itself! Also, you must have come across these tiny floating grids or ‘maps’ in front of your eyes, that is itself a product of diffraction!!
   Compact Disks or CDs as we better know them, are just another example or it. Do you know a CD stores data? Well, it’s in the minute grooves on its surface that are etched with the data. These grooves which are densely packed, run in spirals. A blank CD makes for a real good diffraction grating!
  Now that we know the basics about the devices that we are going to use, let us take a jump into the very much ‘exciting’ atomic realm!
   To keep it simple for everyone, let’s start out with the fact that electrons are particles that orbit around the nucleus of an atom. These electrons, as Niels Bohr showed, orbit around the atomic nucleus in stable paths. Each of such path possible had a definite ‘energy’ value assigned to it, and only those paths were permitted wherein the energy value was a integral multiple of the energy related with the 1st energy level or orbit.

   According to him, electrons which travel around these defined paths do not loose energy over time (Due to the wave nature of particles, electron orbiting nuclei form standing waves wherein the transfer of energy is null). The only way in which a electron can ‘jump’ up or down a energy level is when it absorbs or emits energy. And as this energy is most commonly shared in the form that we all are familiar with. And that form of energy is nothing but light itself!
   So in short, light ‘excites’ an electron and makes it ‘jump’ to a higher energy level, or an electron emits light or energy and jumps down to a lower energy state. Remember that the lower the energy is, the more stable the electron is!
  Now, comes the application part! Most of the street lights that we see around us, at least the yellow ones, are Sodium vapour lamps. And the light that we see comes from the very same excitation of the electrons present in the Sodium in the lamp. As we know, the number of electrons present in Sodium is 11, and its electronic configuration can be represented in simple terms as (2,8,1). For those who indulge in higher studies it goes as 1s² 2s² 2p⁶ 3s¹. What is more of our concern is that the lone electron in the 3s subshell jumps up when exited to the 3p subshell. When it makes an effort to come down again, it releases energy in the form of light, the very same light that illuminates most of our streets!!!
   Also, one should make a note of the fact that every element has a unique energy absorption and emission spectrum by virtue of their unique electronic configuration! This fact helps us a lot in identifying elements due to their spectra and this technique is heavily employed in astrochemistry!
Given below is a continuous spectrum, and the absorption spectrum of Sodium.

   
   In the above spectrum, you can see two distinct yellow lines separated by a small distance. These lines are due to the light that is given out by the electrons when it jumps to a lower energy state. using the spectroscope, we will see the very same lines, we will get an insight into the ‘excited dances’ of the atomic world! Aren’t you excited too?? Well, hope not bored!
  Let’s Begin!

Things that you will need  :

• A blank Compact Disc
• A tape (preferably packing tape)
• A pair of scissors
• A smile on your face cause you are going to enter the quantum realm!

  The first step would be to scratch a line along the radius on that side of the CD where the silver coating is.

Once you do that, take a long strip of tape and paste it along the scratch. The wider the tape is, the better the quality of the stripped CD.

Now that you have done so, apply some pressure over the taped area so that when you try to peal it off, it comes out with ease and this also prevents a mess. Make it a point that you do not get a large amount of fingerprints on the CD.

In this photo, you can see how the CD will look after you repeat the procedure. While doing so, try to overlap the tape that you apply on a small portion that you have already peeled off.

Within no time, you will have the whole CD peeled off! And what you will end up is something like this. A transparent disc and a ball of tape.

    Once you do this, hunt for an Sodium or Mercury vapour lamp. The orange lamps out on the streets are of the Sodium variety and can make a good lighting source for this demo. Now, try to find a dark place from where you can look at the source of light. Once you are ready, hold the CD in front of one eye and close the other eye. Try to align your eye, the light and the hole in the CD in a straight line, this is the trick to get a perfect ring! I had found it out by trial and error and it was really interesting to do so! Once you have this alignment, hold the CD at your arm’s length and draw it near and more near to your eyes until you end up with the kind of pattern that you saw in the first image of the post! And there! You will have unlocked one of the most potent tools used for identifying  various elements!

Do leave me a message on Facebook or in the comments section below telling me about potential improvements and how your spectroscope ended up! I’ll be glad if you capture the image that you get ; do mail it to me at thebiggerbang(at)ymail(dot)com. I shall surely upload it here on my blog!
Promise

Mid@$Touch aka thebiggerbang
P.S. : A special mention to my cousin Suyesh Prabhugaonkar for clicking the photos and helping me make the CD spectroscope.

(Also posted on www.enli8en.com/rajkunkolienkar/DIY--Spectroscope-from-a-CD.php)

Me, Cats and Dogs…

     If you don’t have a clue about it, then let me tell you that I’m a fanatical animal lover. But, as the typical story goes, my mother cites various reasons to not allow me to pet any sort of creature that stands on four legs. There is a loophole to this, but being a late riser, I don’t want to pet a rooster and get woken up at the wee hours.

   Let’s take a little diversion.

    I had managed to pet a dog in 2005, it was pretty much of an adventure doing so! Within three days of getting him home, he was kidnapped or dognapped by a few kids from the neighbouring colony. As I am too bored to study, I shall go on and tell you what exactly happened. Although these events occurred 6 years ago, I pretty much remember the details as it is all about things that I love.

    I had got a dog on the 23rd of January 2005 from ‘PAWS’, which is a local animal welfare centre. He looked like a mixed breed Alsatian, was black in colour and after pondering over what to name him, the name ‘Roxy’ struck a chord with me. Little did I realise that it was feminine name and a short lived character of the same name would make her appearance in Mr. Bean’s Animated Series. It used to remind me of my dog all the time.

Mr Bean in Love with Roxy!

   As soon as I had got him, a little puppy that he was, he used to be huddled up inside my apartment on the ground floor. But on the first night itself,  I had taken him out for a walk and left him around in my colony parking lot and had gone inside to fetch him water. When I returned, he had already disappeared.  A frantic search followed under all the cars and around our colony. Sadly, I had to return back home late at night not knowing where he was. But the very next morning, when our maid went to the terrace to keep stuff to dry, she found him there tired of whining and sitting in a corner. Now who would have expected such a small pup to climb up two floors just out of curiosity? Thus, the place had gone unsearched! The problem he had with is was that he could climb up, but unfortunately couldn’t come down (maybe he was inexperienced and scared to do so). And that was not the end!

   Roxy, as adventurous as he was, he never escaped the eyes of the neighbouring kids who managed to lift the petty bag of muscles and bones up when he was let out to answer his nature’s call or calls in the evening. Although it was negligent on my part not to be with him, I was sure that it was they who took him. In the night, me and my friend roamed the neighbouring buildings in search of him, but it was in vain. But on the 26th, as luck would have it, another guy who was much younger than me managed to give me clue of where he was. For a day and a half, he was kept hostage on the terrace of an adjacent building (his fate was interlinked with terraces, I guess!). It took my dad to rescue him from there and give the kids who had done it a good scolding. Phew. Another day gone by!

    For the next few months, being with him was an amazing experience, and leaving him out in the open was a wilder one. Although he was very playful, people used to mistake it for aggression a lot of times. He grew tall and strong, and he used to drag me down the street in a few months. It looked as if I was under his leash and not the other way round. The wild guy once even managed to run after my dad’s bike to half the distance between my house and my shop! He was my life for a few months! I very well remember him nearly getting me down on the floor after he saw me returning from my vacation, I was just away for 5 days! That made realise that dogs are much more emotional that people think of them to be. They might not have brains to send sent a probe to dig up Mars, but they have a very large heart!

  Then comes the sad part. Not exactly sad but weird enough to raise your eyebrows. Me and my parents were away, so we decided to keep him at out experienced granny’s house for a few days. I say experienced as they once had five or six Pomeranians making their house their domain.  Now the dogs were gone, but there was my cousin brother, 5 years of age and as they say he had the same blood running in his veins.

    What he did was that he displayed a little too much affection to the dog. He fed the dog water and maybe as a sign of brotherhood, he drank from the same plate! Yeah, he was caught once while doing that. And that was the end of Roxy. Added to that was my mother’s opposition and a pretty bad time that we were facing that made granny pack the dog off to somebody. Now I don’t remember who he was, but he also passed on the dog to some-one else. When I tried to track him down, all my efforts were in vain. That was the end of it.

  Here is what my friend Pawan Garde had to say about the loss of his dog when he was young- “He was great friend!! I used to go on adventures investigating with him..we both were about the same height.. and he was an expert in fighting against snakes..his speciality were cobras..but alas it was a cobra who killed him…on a Sunday afternoon in mid April..Sandy was a real Baazigar!!” This makes me realise that I am not alone. Aniruddha & Anjali Sen Gupta, two of the most devoted dog lovers that I have ever come across recently lost their dog Hero and the post that Annie made about it was really heartening to read!

    But I guess Mother Nature always gives you a second chance. And it did just that. My not-so-far away neighbour adopted a dog that looked just the same! And it grew old under my nose. He was fun too! The photo that you see, is of the very same ditto-Roxy dog that we all loved. Unfortunately, he was found dead one day, suspected of being poisoned to death. Sick people around.

   Years have gone by, but my affections for them hasn’t died. I think I can still make most of the dogs wag their tails by whistling alone. My mother says that they can perhaps sense a person who is good to them. I know I’m being a little kiddish, but that statement does make me happy! After my Tenth Std. Board examinations, I decided to keep two dogs, Romeo and Juliet. It was rather unsuccessful. My mother couldn’t bare them after two days. Funny part is that she likes dogs very much, but not when they are in our house. Makes me go crazy! I searched for half an hour now, seems that the photo that I had clicked of theirs is lost. I leave you with some of the photos of cats and dogs that I have clicked over the years! Overdose of cats coming in your way! Enjoy!

        Chupke Chupke,  on my Granny’s roof            A few of the ferocious cat’s at Percival sir’s house

     A sleeping pup at Kala Academy                              My old neighbour’s dog, alive and kicking!

  

   Chuku, Percival Noronha’s old cat, royal!                   A monsoon shot, from my window

   

  One of my favourites, near Boca de Vaca!                    Recent capture, just outside my door!  

  

    Just opp Police Station, on the HDR trip                   Again, my old neighbour’s dog!

Me, in 2009 with the cat that shares her home with my uncle. They need not be invited to my grand-mother’s place, they just come along as if it is meant to be a Noah’s Ark! I leave you with a video below that is of the same cat as you see. I was at my granny's house to check on her cat and the kittens and LUCKILY I had my camera along with me. I could witness this happening as I had left the door of my aunt's room open by mistake. This is one of the best videos I have ever recorded. In the end, I was really stunned to see the way she carried the kittens on the bed!

My granny’s cat transporting her kittens!

I sign quoting a good friend of mine

"I always fought for a baby sister. Its too late now so now I’m fighting for a dog!"

Feed them and they will return,
love them and they will die for you....

Bow wow!  

Mid@$ Touch

Songs to listen to in the rains…

               As my favourite season is already on the way, I’d like to share with you my playlist-to-be so that you also can pick and choose songs. Songs that you can play on while sipping a hot cup of coffee, while you stare and revel in nature’s spectacle, stuff that we call the rains!

This collection includes many songs that you might have never come across or are classical favourites. So try to be open to each and every song. As one would not listen to Sheila ki Jawani or Eminem rapping in the rains (Definitely not ‘Friday’!), expect to find an overwhelming number of mellow songs in here! I’m still expanding the playlist so keep a lookout for new songs!
To listen to the songs, please click on the song title. To download the required song, just right click it and select ‘save link as…’ option.

                         Suggestions for inclusion in this playlist are welcome!

 

            

 

                                                                      English

Constellations -  Jack Johnson
Believe me, this has got nothing to do with it’s astronomical title that gets it on top of the list. I have literally danced on my terrace to this song a few nights ago (danced all alone, mind you!), walked innumerable distances listening to only one song and thus it makes it to the top of the list.  I have absolutely no words for this song, I say just give it a listen! Jack Johnson, Salaam to your surf rock!

The Call – Regina Spektor
To not love this song, you’d have to be really deaf. This would be the one song I’d choose to define this playlist. It’s a song of ultimate hope, the first track that people ever hear when it comes to Regina Spektor. No need to say goodbye to this song!

32 Flavors – Ani DiFranco
This is one song that can be heard anytime to lift up your mood. One of the best in my collection, I value it a lot as it was my window to the world of alternative music. It is rumoured that the song’s title is meant to be a parody of Baskin-Robbin’s, but do check out this gorgeous track!

Unwritten – Natasha Bedingfield
Feel the rain on your skin
No one else can feel it for you
Only you can let it in
No one else, no one else…

If you do not fin the chorus of this song really familiar, I bet you are not having your recommended dose of television watching! Soul-pumping and mind-blowing are the only the two phrases that can describe this song. I bet you’d get hooked onto the beats in no time at all! If you know where you have heard this song, do post it in the comments section!

Somewhere over the rainbow/What a wonderful world – Aselin Debison
As if the name didn’t indicate it to you, this song has got the feel of the rains written all over it! This melodious medley by Aselin Debison combines two of my most loved tracks. I am sure you must have heard the classic ‘What a wonderful world’ in the Aircel Wifi advert, but this is the same song with a unique ukulele twist! Go ahead, float in the air!

Let go – Cover by Boys like Girls
Yeah, It’s from the same band that gave us the romantic hit ‘Two is Better Than One’. Just that I prefer this one as it really helps you let go from everything that holds back form being yourself! It was just meant to be a cover song to get a contract which is now going to steal your heart! 

Across the universe – The Beatles
This song by the most rocking band in the history of music, is a marvellous piece of music which just flows and flows down the way to your heart. Check out if you can find out the very much Indian/Hindu influence in the song! One of the best pick to get lost in the gloomy atmosphere of the rains!

Hey there Delilah – Plain White Tee’s
Being a song that is one of the most popular amongst today’s college going youth, one can’t just avoid listening to this classic tale of struggle for love the ‘Maine Pyaar Kiya’ style! It soothes you, it gets you addicted to it. A more than perfect song to listen to during the monsoons! And mind you, this song is inspired by a real life girl named Delilah DeCrescenzo! Isn’t that great?

Annie’s song – John Denver
For those inclined towards Western music from the last few decades, this song will always linger in your ears. A must have song on every love song collection,  it really ends up filling up your senses like a walk in the rain, so much so that you'll hit the repeat button!

The Best Day – Taylor Swift
Being such a huge fan of TS, it might come as a pleasant shock that I have included only one song of hers. But the one that I have included is justified. An ode to her father, who she describes as very supportive in the song, this song perfectly fits in the progressive mood of the rains and will surely will make its way to your heart!

1,2,3,4 - Plain White T’s
Their second listing in this playlists comes with a magical song that is an ode to love. Written with one of the best lyrics possible in the recent times, it’s another song that you are unlikely to forget very soon! (Last minute inclusion, thanks to Shubhankar!)

In my heart – Moby
I was introduced to this song from the Nokia adverts a few years ago, and has been one of those songs that you listen to while walking alone in the streets at night! (unless you are Amitabh Bacchan in Shehenshah!). Besides Owl City’s Adam Young, Moby is one of the best in the Electronica genre!

Here I am – Bryan Adams
Here is a guy who has been known to deliver hits all the time, hits that make you want to live life at the edge! Here I am is another such track which perfectly suits the mood at the onset of the monsoons! It’s just magical.

Come away with me – Norah Jones
One can’t make a playlist for the rains by excluding jazz, one of my favourite genres. A song from the Grammy nominated singer, which trickles down your heart and makes you feel at ease like no other. Music runs in her blood, she being Pt. Ravi Shankar’s daughter and Anoushkar Shankar’s half sister! Come away with me does manage to take you away to dreamland!

Against the wind – Bob Seger
A song as old as I am doesn’t mean that it is out-dated. This song is from the OST of Forest Gump, a top rated movie. A classic number on the guitar, it is his recollection of the past gone by.

Sovay – Andrew Bird
A truly alternative track, with a pinch of much required salt. Have a go at it!

You're Beautiful – James Blunt
Blunt, who started off as a second lieutenant in the British Army delivered this hit song in 2005 and from then on, has never looked back. I remember me and a friend of mine requesting this song on the radio every weekend for quite a long time! Such is its appeal, that it deserves a listing in this playlist.

The Reason – Hoobastank
“I’m not a perfect person, there are many things I wish I didn’t do”. This song is dedicated to people who want to break open, at the end of a frustrated walk down the street in heavy rains! If you are the kind of person who is going through a roller coaster called life, you’d better give this a listen!

Rhythm of Love – Plain White T’s
This chartbuster has everything in it to get you swaying in a trance, a song so beautifully played out that you’ll be left humming it for days to come. It’s Plain White T’s third listing on the playlist, and they totally deserve it for the number of peaceful nights they have given me!

21 guns – Green Day
If you have got into a sad mood, or have reasons to make your mood sad and pay a tribute to yourself, give the lyrics a listen. Or, try to not focus on the lyrics and go, enjoy the pumping track! Slightly on the rocking side, but it helps to break the monotone!

Hindi
Iktara – Wake Up Sid (Album)
Simple. Think rains, think Iktara! When it comes to the recent hits in Bollywood, Iktara is one song that has already carved its niche in the hearts of millions, no questions asked! I doubt whether you’ll have any need to download it, as you must be already having it! It’s still the king!

Sham -  Aisha (Album)
Personally, I consider this to be the best bolly track of the year 2010 especially because I won a Bru mug supposedly signed by Sonam Kapoor herself, all thanks to this song! Nothing can match the serenity that this song brings to you, the crisp voice and guitar chords make you really want to enjoy a cozy night out with the best of your pals! 

Dil Mein Jaagi – Dev D (Album)
When I first listened to the intro of this song, I was blown off to listen to Hindi lyrics to such a marvellous piano background, a thing that is completely unheard of in Bollywood. If you think you have traversed the length and breadth of Bollywood soundtracks, wait till this song changes your notion! Three cheers to Anusha Mani and Amit Trivedi!

Zara Zara – Rehna Hai Tere Dil Mey (Album)
For the romantics, here is one of the most suiting songs that one can find to listen to with your loved one, during the rains!

Kya Karoon – Wake Up Sid (Album)
A perfect addition for predictably, a long drive or so. Consider yourself lucky if you get to do this thru a sun-roof!

Phir Dekhiye – Rock On!! (Album)
This is just another song from an already power-packed album which is truly rocking! The wonderful guitar and Caralisa Monteiro’s crisp voice make it even good to listen to. The most suitable song to play back while you get nostalgic about the way you spent your monsoons making paper boats! (Thanks again to Shubhnakar!)

O Meri Jaan – Life in a... Metro (Album)
You might call Pritam a chorr but you can’t deny him the right to one of the most amazing pieces of music that people still tend to carry around in our country (unless he has done it again, without my knowledge!). A pure feel-good song, give it a listen if you have not heard it as of now!

Dhoop Ke Makaan Sa (Acoustic) – Break Ke Baad (Album)
Although the title reads ‘Dhoop’, no need to take it so literally! There are a lot of ‘boonds’ and ‘tapkofying chhats’ that keep you tuned in to this song. For more beats, listen to the original version.

Still writing descriptions and getting links for ‘Kahi toh Hogi Woh’ – JTYJN , ‘Is this Love?’ – Kismat Konnection, ‘Roobaroo’ and ‘Lukka Chuppi’ – RDB. Blame it on my bad memory that I forget these songs and thank Shubhankar for reminding me back!

Others
Rylynn – Andy McKee
The only instrumental piece on the playlist, that too coming from the person touted to be one of the best living guitarists ever, this song is nothing less than magic. If you ever wished to visit heaven on Earth itself, this is the song to listen to!

Le Festin – Camille
It’s a French track that I fell into love with, and is picked right from the OST of Disney’s Ratatouille. As they say, music has no no borders, no language to bar the feelings! This song is a testimony of the very same fact!

On this note, I take your leave.
Mid@$ Touch