Plasma Speakers

by Anupum Pant

Not many would have heard of speakers other than those which use magnetic materials to produce sound. But if you still haven’t heard about Plasma speakers or ionic plasma tweeters, you are really missing something great. Read on for more.

About Plasma Speakers

I talked about sound a few days back and mentioned that it is something that propagates through a medium due to pressure changes. Normally, magnetic speakers create these pressure waves by moving a diaphragm with the help of a varying magnetic field. But, plasma speakers do this by varying the air pressure through a high energy electric arc. This arc is produced by ionizing the gas present in between two terminals (ionizing reduces the electrical resistance of air which creates a visible arc).

These speakers use an extremely high energy arc which also increases the temperature of surrounding volume of gas to very high levels. So, before learning anything about them, the first thing you have to know is that these seemingly harmless things can kill you.

The Dangers

Plasma speakers are not toys. Old men, people with heart problems, kids etc should stay away from them. Even if an adult is handling them, they need to be informed about what they are doing first. It is better to have someone close who knows well, how these things work. Although the commercially available speakers are fairly safe, DIY kits can prove to be fatal. The kind of dangers involved with these devices:

1. The electric discharge – Think of it as a lightning. The dangerous high voltage device has the potential to kill you, if any of your body part comes close. Keep all bodily parts away.

2. Gas danger – The constant supply of ozone used for this project can actually be much more dangerous than the electric arc. Ozone used in this project, silently increases in concentration which can be fatal. It is important to keep the room well ventilated.

A few more things about them

Invented by WIlliam Duddells in the year 1900 these are not speakers, but tweeters. That means, that there will be no window cracking bass that is going to come out of them. Unlike magnetic diaphragms, the arcs have no weight and are able to produce a very crystal clear sound by moving back and forth very quickly. See the video below.

They work by changing temperature inside the gas chamber which makes them go red to purple as the frequencies of a song change. However, an un-modulated arc will just produce noise, something like you hear at first in the video. Also, they need a constant supply of Helium and Ozone coming into the chamber. These gases get ionized inside to produce the arc.

[Read this for more history]

Where can I get them?

In 1970 Magnat used to produce them, but they no longer produce plasma speakers now. The point is, they were the pioneers in bringing this to the masses.
Acapella sells them for an eye-popping price of 23000$. These costly ones are revered for their sound quality.
Other DIY kit can be bought for as low as 100$ [here]
Build one on your own for cheaper. (if you are willing to risk your life) [tutorial here]

 

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.

Latest Stories

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!

A Few Things About Sloths Everybody Should Know

by Anupum Pant

A few days back, on 20th October, Sloth Day was celebrated all around the world. You’d be thinking, what is so good about these strange animals, that makes people have a special day around them. Well, in that case, you need to read this.

What are these creatures?

Sloths are slow animals that make even cows look extremely active. They are so slow that they are almost stationary and algae grows on their hair. Most of their life is spent on trees hanging upside down. They hang on trees to protect themselves from the predators on the ground. Their bodies are so well engineered to stay inverted that the hair on their bodies, is oriented in the opposite direction – growing from stomach to back (This helps them to stay dry by draining water easily). Even dead sloths have been know to retain their grip and remain suspended after death. They come down only around once a week to excrete. They eat, sleep, travel, find partners, mate, give birth and even raise young ones in the canopies.

Although sloths might seem gross, creepy and unseemly, they really aren’t that bad. Sloths are sweet looking [1] [2] [3] animals (especially their babies, they are adorable) who can also swim efficiently and move wisely. We can definitely learn a lot from them.

Their diet is unbelievable

Sloths eat only leaves throughout their lives. They chew leaves slowly like cows to extract whatever nutrients they can. Sloth intestines are also adapted to extract the maximum out of their poor quality food, they are unusually long. They often like to shift to a different kind of leaf after a day or two. This balances their nutrient intake. Humans couldn’t possibly survive on a leafy salad diet for a very long time.

To save energy, sloths drop the temperature of their bodies at night. Even their bodies have more bones than muscles to prevent wastage of energy through muscular movement. After the Orangutan they are the most energy efficient animals.

Other facts about them

Sloths have blunt teeth to chew leaves properly, have large claws to hang on to branches and inverted fur orientation (as also mentioned before). Another interesting thing about them is that they have remained physically un-evolved for a long time because they don’t really have to compete with anyone else for their diet.

Mutualisms

This is where the awesomeness of Sloths come in. Sloths are home to a several kinds of other organism (tiny ones living in their fur). These organism depend on sloths (hosts) for various things and in turn provide an advantage to their hosts. This is called mutualism.

  1. Algae + Sloth – Algae, for instance, uses the long grooves on sloth hair to grow with a secure footing. As a rent for this safe apartment, the algae gives them [sloths] a nice shade of green color to camouflage on trees. This and their still bodies make them virtually impossible to spot with the naked eye. The camouflage protects them from eagles.
  2. Bacteria + Sloth – Apart from the several other bacteria which live inside a sloth to digest the leafy diet, two kinds of Cyanobacteria live on sloth furs too. These bacteria also give sloths a nice gray hue which helps them in the same ways as above.
  3. The Sloth Moth – The Pyralidae Moth also live on Sloths. These feed on the algae which grows on the fur. In return for the good food, moths give them nothing. Yes, nothing. This is called Commensalism.
  4. Others – Similarly, various other organisms like flies, mites and three types of beetles are often found living in a Sloth. Up to 900 beetles have been found on a single Sloth!

There is so much more to write about these amazing little creatures who provide for so many other creatures too. I’ll keep it for the second part that I’ll write some other day. So the next time you see a Sloth crossing the road, carefully pick it up by holding its mid body and gently place it on a tree. Remember to use a glove/cloth.