Tag: accuracy

The Coastline Paradox

By Anupum Pant

The length of Australia’s coastline according to two different sources is as follows:

  1. Year Book of Australia (1978) – 36,735 km
  2. Australian Handbook – 19,320 km

There is a significant difference in the numbers. In fact, one is almost double the other. So, what is really happening here? Which one is the correct data?
Actually, it depends. The correct data can be anyone of them or none of them. It completely depends on the kind of precision you decide to use while measuring the coastline. This is the coastline paradox.

The coastline paradox

The coastline paradox is the counter-intuitive observation that the coastline of a landmass does not have a well-defined length. – Wikipedia

The length of the coastline depends, in simple terms, on the length of scale you use to measure. For example, if you use a scale that is several kilometers long, you will get a total length which is much less than what you’d get when you would use a smaller scale. The longer scale, as explained neatly in this picture, will skip the details of the coastline.

This is exactly what happened when the two different sources measured the coastline of Australia. The first, Year Book of Ausralia, used a much longer scale than the one, Australian Handbook used. Ultimately, the great disparity in the result had to do with the precision of measurement. Had they used a scale just 1 mm in length, the result would have been a whooping 132,000 km.

This effect is similar to the mathematical fractal, Koch’s flake. Koch’s snowflake is a figure with finite area but infinite perimeter. Veritasium explains it better in this video:

Another factor is to take into account the estuaries to measure the length. Then,what about those little islands near the coast? and the little rocks that protrude out of the water surface? Which ones do you include to come out with the data?  And the majestic Bunda cliffs? Probably this article from the 1970’s clarifies what was included and what was not during the time the results were published.

So, the next time someone decides to test your general knowledge and asks you the length of certain country’s coastline, your answer should be – “It depends.”

Harnessing The Power of Nature – Biological Data Storage

by Anupum Pant

The present storage technology

Storage technology has come long way from the year 1956 when IBM, the massive corporation started pushing this technology. Its journey started with data storage densities of orders as low as 40 bits per square inch in 1956 (RAMAC 350). This effort from their side indeed brought in great results and IBM could set a record of density record of 14.3 billion bits per inch, by the year 2000.

Today, in the year 2013, most HDDs (Hard Disks Drives) are able to store with densities of around 500 Billion bits per square inch; technology at this level has brought Terabyte sized HDDs to our computers. The research being done on increasing density of data is still a bustling area. As a result, we often see news breaking in with breath-taking new storage technologies almost every month.

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Just a few months back, using a technique called nanopatterning a team from Singapore was able to show 3300 billion bits per square inch. That is almost 6 times the density of a normal HDD. It means that a 1TB HDD of present size could hold 6TB if this could come to manufacturing units.

Seagate, in another story, promised data densities of the order 1TB per square inch (8000 billion bits per square inch) within the next decade. Which would enable hard drives of up to 60 TB in capacity.

A similar thing has happened to compact disks. From CDs to DVDs to Dual Layer DVDs to BluRays and several other storages that didn’t last – from zip drives to holographic storage. The data storage densities have improved dramatically.

Is it enough?

Although, our present ability to store a lot of data in small physical spaces is enough for now, to meet the future demands we will need to keep progressing with an unbelievable rate. The fact – physical storage is reaching its limit gradually, could bottleneck our progress in the future.

Biological Storage Devices

The exact storage concept used in amazing natural systems like the human brain and DNA has remained elusive for decades now. To keep up with the rapid pace of development it is important that we step up our work in this area. I think, the answer to our demands lies with the nature.

A brain, for instance, is estimated to be able to store something closer to 2.5 petabytes (or a million gigabytes). The sad part, we don’t exactly know how it stores. Moreover, we don’t even know how we could precisely calculate their storage limits. These estimates are just a theoretical calculation. We still have a long way to go.

The greatest storage device

Recent successful experiments with storage and retrieval of data in the human DNA has come with a new hope for the future. Teams at the EU Bioinformatics Institute and Harvard University have successfully stored famous speeches, photos, and entire books, and then retrieved them with 99.99% accuracy.

Being able to store data in the DNA will confer upon us three advantages. Firstly, it will be fast (very), yes, faster than the flash drive. Secondly, it won’t age with repeated storage cycles (around 10,000 years), at least not like HDDs which have moving parts. Finally, DNA will enable us to reach data densities of unimaginable levels. Imagine being able to store of half a million DVD disks in a single gram of DNA!  Technically that would amount to 700 terabits per gram (measuring in area is difficult for an entity like this). Others have reached to densities as much as 2.2 petabytes per gram.

Bring DNA drives to our PCs I say!