Category Archives: Learning

A Natural 360 Degrees Astronomy Dome In Dholavira, Gujarat, India

There is a place, somewhere in the western extremities of India, which offers a perfect 360 degrees dome perfect for astronomy observations, star gazing and astro photography.

Let me highlight the elephant in the room first. There are many challenges of finding such a place. For many years, I have been on the lookout for “The Perfect Dome” – An unabated 360 degrees view of the night sky without any terrestrial features blocking the view. And more importantly, without any light pollution. It is very tough to find such a place these days with light pollution from cities, towns, villages and vehicles. You might say that there are many stretches in India where there are no towns,villages or cities. This does not really apply for long exposures, since having a bunch of light sources as far as 60 kms away can ruin your 3 hour night sky exposure!  And if light pollutants were not enough, there are hills, mountains, trees blocking your view.

To illustrate my point, check this picture that I had taken almost 4 years back. I drove about 130kms from Bangalore on NH-7 and then a further 15 kilometers on an untarred road to find an absolutely pitch dark place( to the naked eye). Once I setup the shot and clicked, the illusion of having found a dark place went through the roof. Take a look at the shot and look at the light pollution!

Starry Night

Considering all the above issues, finding the perfect dome was quite a revelation. On the way to a place called Dholavira in Great Rann of Kutch in the western most state of Gujarat in India, you come across a stretch of road that is dead straight for 50 kilometers and surrounded by salt pans in all directions. This is what it looks like during daytime:

Image

Image

Image

Image

Come nightfall, this place transforms into a star gazers and astro-photographers paradise. The milky way is clearly visible to the naked eye. Millions of stars light up the night sky. What you had seen in a planetarium when you were little kids suddenly seems like reality. (Wait, what?! counter-intuitive right?).  A friend brings out a light saber and we study the night sky. The light  saber in question is an astronomy laser used for pointing stars in the night sky. It is a green laser beam (wavelength of 532nm) and <5mW power rating so as not to be strong enough to bring down airplanes with it. (In fact you can see a glimpse of the laser in the picture below.)

After identifying the pole star , a few star trail shots were taken with a 11-16mm Ultra-wide lens. Since there was no foreground( and we wanted it that way!) there is no scale of reference except the little laser beam.

Star trailsThe best part about this road is that there is absolutely no traffic on it. I was on this road at this spot for about 5-6 hours and just 1 vehicle passed by. The irony is that the vehicle took about 20-25 mins to reach this point from the time we could first see it( from about 15-20kms away). Imagine shielding your camera for that long to avoid flooding your long exposure shot with the vehicle headlights. You will also have to pardon the high noise in the shot. My humble  Canon 450D just does not cut the chase for astro-photography. The shot was a 40 minute exposure. I wish I could have gotten a longer exposure of a couple of hours atleast. In case you are wondering which laser was used, THIS is the one.

So that wraps up this post. The verdict is out: In case you want to get some clear views of the night sky, head to Dholavira, Gujarat  and setup camp!

Advertisements

Bitcoins And Why You Should Watch This Video First

The world has been swept by a new currency- Bitcoin. It is a very interesting concept which has seen increased acceptance globally due to lack of trust in current currency systems and government policies, especially in Europe. 

 

But before you start exploring the nuances of the bitcoin currency, here is a must watch documentary on the very concept of money.. What is the note or coin that you hold in your hand? What does it mean? How inflation and deflation works? It is answered very effectively in this video. 

 

Tagged

Let’s Get Knotty (….With A Theatrical Encore)

I never went to any NSS camp. I never went to any Army school. I never really learnt any knots.

There have been numerous occasions when I have been stuck with two ropes that I had to tie together or tie a rope securely to a tree or a pole. I would have made numerous attempts to tie the ropes, only to realize 5 minutes later that the knots have slipped. I always resorted to the “Granny knot” ( I just came to know that’s what it’s called!) or a double overhand knot. It’s called a granny knot because even grandmothers can tie knots better than that(apparently). Turns out that this knot is the worst possible knot that you can tie and is mostly ill-suited for most occasions for two reasons a) gets extremely tough to untie once it has been bearing load and b) its tough to untie when wet c) its not a stable/efficient knot.

On most occasions, I thought to myself- ” If only I knew these damned knots”. My lifelong predicaments with ropes instigated with my new found interest in mountaineering inspired me to learn the ropes(get the pun?). So here I am after a week of learning the most important knots that everyone and anyone should know. Even if you are not into mountaineering/climbing/sailing, trust me, these knots are *very* useful for everyday use-cases. Often, once I have tied ropes, it had been very difficult to untie it. The main advantage of using standard knots is that they are easy to tie and easy to untie(even when the rope is wet)

I armed myself with four lengths of rope ( 2 rope lengths each of varying diameter), an internet browser with Youtube and set off into the seemingly unknown and infinite world of knots. Let’s not kid ourselves, but there are literally hundred’s of knots, if not thousands, to learn. I settled for 11. Here is a quick rundown of 11 very useful knots( +1 bonus knot for a theatrical encore)

A knot’s charecteristics are evaluated by multiple factors:

1. Strength

2. Security

3. Releasibility. 

Here are the knots along with their use cases.

1. Figure of Eight. 

Use-cases: -> To prevent a rope from running through a pulley or a loop or a retaining device. -> Used in climbing and sailing.

Image

2. Follow Through Figure of Eight

Use-caes: -> Tying into a rope using a climbing harness. -> Tying a rope around static pole.

Image

3. Double Fisherman’ s knot

Use-cases: -> Tying two ropes of same dia together.

Image

4. Sheet Bend

Use-cases: -> Tying ropes of different dia together where stress is in opposite direction. Eg towing a boat.

Image

5. Bowline

Use-cases: -> Single most important knot to tie a loop. Easy to untie even when subjected to very heavy loads.

Image

6. Bowline on a bight ( Double Bowline) 

Use-cases: For getting two loops out of a single bowline knot.

Image

7. Clove hitch

Use-case: loosely tying a rope to a pipe/pole .

Image

8. Prussik Knot

Use-cases: Arresting ascent or descent.

Image

9. Slipknot( No, not the band!) 

Use-cases: To tie a rope very loosely to a boat and as a stopper knot.

Image

10. Noose Knot 

Use-cases: -> Snares , Lasso.  ( Rodeo style lasso anyone ? )

Image

11. Handcuff Knot

Use-case: Go figure!

Image

And for a theatrical finish and for the encore, presenting the……

12. Hangman Noose. 

Image

I have managed to learn all these knotty and I can tie them even when half asleep. I strongly urge you to learn them too! You never know when they will come in handy. Here’s to knotty times ahead!

Useful resource: http://www.animatedknots.com

Please Note: All illustrations in this post are courtesy of http://www.animatedknots.com.

Tagged , , , , , , , , , , , , ,