Tag: fatal

Sharks Are Not So Bad After All

By Anupum Pant

Sharks have been on earth for millions of years more than we have been here. Also, they haven’t changed much since a long time. The kind of sharks we see today, were the same sharks that existed 350 million years ago.

That means, modern sharks have lived happily for millions of years without eating humans. Even today, they aren’t very keen on killing us for food. They simply aren’t designed (or haven’t evolved) to do that. Humans were never a part of their normal diet. Instead, they normally feed on small fish. While a few other species of sharks may eat seals, sea lions and other mammals too. In fact, they can go on for months without food.

Funny as it may sound, sharks are scared of humans. When a shark sees a human in water, it gets confused and scared. It goes near to check,  and this usually results in an accidental bite. They don’t kill humans out of aggression. With 15 rows of razor sharp teeth on each jaw, even their gentle bites may kill a person. About only 20 out of 300 species of sharks are reported to have been involved in accidents with human beings.  About 100 such accidents occur every year.

Not being insensitive about human deaths: Can you estimate how many people do sharks kill every year? The answer is 10. Ten people, on an average are killed by shark bites every year. That is about 1/15 th of number of people killed by coconuts every year*
*Note: “150 people are killed by coconuts every year”, is a popular urban legend. The coconut death figure is a crude estimate or just a figure pulled out of thin air.

Nevertheless, the number of people killed by sharks every year is very very less (again, even a single human death isn’t really ‘less’). I’d rather not use statistics to prove my point. [image]

Why are sharks scared of us? … Why shouldn’t they be?
We kill about 100 million sharks every year. That is such a huge number when compared to number of people sharks kill every year. Again, statistics could be deceiving here. But we do get an idea. There is a massive difference in the number.
Why? Humans catch sharks for their meat, internal organs and skin,  to make products such as shark fin soup, lubricants, and leather etc. Some times, fins are cut and live sharks are thrown back into the sea, crippled. This eventually kills them due to excessive bleeding or other obvious reasons.

It is ironically that we move into their natural habitat and in turn blame sharks for destroying our boats, surf boards. Moreover, we are shocked to hear about reports of shark attacks on humans. Shouldn’t it be the other way round? We should stop looking at sharks as if they are the monsters; we are. At the same time, that doesn’t mean you should risk your life by going in shark waters to give it a high-five.

Random Science Fact:  

Only 14% of the Earth’s species are known to us. 75% of all the species on Earth will be gone within the next 300 years. Think about those species which will go extinct while we are here, and we’ll never know about them.

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]