Volcanic Glass

There are three types of rocks on earth. They are Igneous, Sedimentary and Metamorphic rocks. Igneous rocks are formed by the solidification of magma and are further divided into two types, Namely, Plutonic rocks(Intrusive igneous rocks) and Volcanic rocks(Extrusive igneous rocks). Plutonic rocks are the rocks that are solidified inside the earth and are usually crystalline in nature due to the slow cooling process Thus they have a coarse grained crystal structure. Volcanic rocks however solidify muck quicker and therefore often show a very fine grained crystal structure. If the cooling and solidification of the volcanic rocks happen even faster it leaves no time for crystal formation. This makes the volcanic rocks amorphous and therefore have properties of a supercooled liquid. That is, These rocks have a glassy texture and are brittle like glass. They also exhibit a conchoidal fracture just like glass. One such rock is Obsidian. Obisidian looks almost artificial and has a remarkable appearance. They are sometimes used to fashion precision cutting tools such as surgical knives. Obsidian has such an appearance that it is hard to believe that it actually is a rock and that it is formed naturally.. It looks artificial. It is a remarkable product of Earth's natural geology. Here's a picture of Obsidian.

Hard to believe..

Here's an interesting problem. Suppose you take an extremely long ribbon and wrap it tightly around the Earth-along the equator, the distance being about 40000km. Imagine that the earth is smooth and that there no space whatsoever beneath the ribbon. Now suppose you lengthen the ribbon by 1meter. This would cause the ribbon to slack and will leave a gap from the surface of the earth to the ribbon. (look at the diagram)

How big is this gap? (Indicated by the arrow on the diagram)
Any guesses?
Well its roughly 16 centimeters. This is an interesting result many people find hard to believe. But a simple calculation will show you that it's true.
Here's the math,

For the initial case ,
c=pi*d
where
c- circumference of the earth and thus the initial length of the ribbon.
d- diameter of the earth
c1=c+1
c1-new length of the ribbon(after lengthening by 1 meter)
c1=pi*(d+2*x)
x- gap between earth and the ribbon(indicated by the arrow)
therefore,
pi*d+1=pi*d+2*pi*x
x=1/2*pi=0.159m
which is approximately equal to 16 centimeters.

Environmental Engineering

Environmental Engineering was formerly known as Sanitation Engineering and was a subdivision of Civil Engineering. As many new engineering fields, it developed into main engineering stream as its demand and complexity increased. Today it is an vital and interdisciplinary field incorporating many areas such as, Chemistry, Fluid mechanics, Hydrology, Geology and Ecology. Environmental Engineering is mainly concerned with improving public health while protecting nature.
While traditional Engineering focuses on merely utilizing resources and improving living conditions of humans, environmental engineering incorporates the conservation of nature and promoting the well being of humans and other living species in the environment as well. This approach brings out sustainability and overall development.
The key areas of environmental engineering could be identified as,
1. Providing palatable and safe public water supplies in adequate amounts.
2. Control and implement procedures to minimize water soil atmospheric and noise pollution.
3. Recycling waste where possible and proper treatment and disposal of solid and liquid wastes.
4. Implementing procedures to minimize the overall footprint.
5. Incorporating cleaner production mechanisms to protect the environment and to increase sustainability and efficiency of industries.
Environmental engineering is still an emerging field in developing countries and needs to be given immediate consideration because the efficient use and management of the earth's resources will aid development and help to sustain it.

"With great power comes great responsibility"

Says Uncle Ben to Peter Parker in "Spider Man", and is one of the most frequently quoted and well remembered sayings from a comic book. The message it conveys is very simple-(that responsibility is directly proportional to power, being strictly scientific...  :D :D) No, but the message is very easily understood and does not require paraphrasing. But take a look around the society. Most of the cases you see will not hang together with the above quote. In fact it will be pretty much the opposite- "With great power comes even greater corruption".
From the small positions right up to the highest reigns of power, the positions of power are often occupied by selfish individuals whose only responsibility seems to be filling their own pockets. These people do not understand their responsibilities or the reason they are put into that position. They just keep wasting valuable time and resources while at times not even being aware of the duties and obligations that they are expected to fulfill. That being stated, it is necessary to note that not all individuals in positions of power are like that. Although very rare, few good souls do exist. There are people who fulfill their responsibilities properly and do justice to the position they hold. But the majority outweighs the minority.
It is a well known fact that government institutions are filled with corruption. Even the Police which is supposed to maintain and promote civil order, does not function lawfully. Also the quality of service provided by the government institutions including the Police is of very poor quality. For example the police has become a body that acknowledges crime instead of being the one that prevents it. Nowadays pizza is delivered to a home faster than the Police arriving at a crime scene. Examples like the above are often found in today's society. The main reason for this is, people in positions of power failing to realize what is expected from them or simply because they ignore their responsibilities. To change this situation the entire system needs to be changed and revolutionized, and that is not going to be easy...

(image from : wikipedia.org)

XRF

This post is about X Ray Fluorescence Spectroscopy. If the Name sounds too complicating or sounds uninteresting feel free to ignore this post. Stephen Hawking says in the preface to his book-"The Universe in a Nutshell", that his publisher advised him saying that the inclusion of an equation or technical details will cut down his readership by half. So he didn't do it. But I'm going to write about X Ray Fluorescence Spectroscopy in this blog, and I don't care about the readership. Besides, at the moment I'm writing this post, I don't have any readers! I 'm writing this as a way of remembering what I learned in preparing a presentation on XRF under the module Analytical Methods.
Back to the topic. When high energy electromagnetic radiation-usually in the form of X Rays, strikes a material, The atoms in the material may get ionized. If the energy is sufficient, an atom can lose an electron from one of its lower orbitals. This causes an instability in the atom and therefore an electron from a higher orbital fills in the gap created by the dismissed electron. This causes a release of energy again in the form of X rays but with lower energy than the primary, incident X rays. These secondary X rays are called Fluorescent X rays, and the phenomenon is named Fluorescence.
This released energy corresponds to the energy difference between the orbitals involved and is unique to the atoms of a particular element. This makes it possible, to identify the elements present in a sample by analyzing its fluorescent X rays. In fact, analyzing here means measuring the energy of the emitted radiation. This method of analysis is called X Ray Fluorescence Spectroscopy.
The XRF Spectrometer consists of the primary X ray Source, the sample, the detector and the computer. XRF Spectrometers are further classified into two types;
1. Energy Dispersive Spectrometers(EDS/EDX)
2. Wavelength Dispersive Spectrometers(WDS/WDX)
In the energy Dispersive type the fluorescent X rays are directly measured and is the faster and cheaper method. The Wavelength dispersive type uses an analyzer crystal to separate the different wavelengths before they are focused into the detector. This method the more sensitive method.
A variety of elements can be identified using XRF Spectroscopy and it is commonly used in Geo Chemical investigations and mineral analysis. Recent developments to this technique and emergence of handheld XRF Spectrometers has brought about its application in fields like forensics and archaeology as well. XRF Spectroscopy was recently used to analyze the painting techniques used by Leonardo Da Vinci in creating his world famous masterpiece-"Mona Lisa".

The Onion Earth

I knew the internal structure of the Earth and its layers- crust, mantle, outer core, and inner core since I was 9 years old. I also knew about plate tectonics and how continents change over time. But few days ago when I was thinking about the plate movements and volcanoes I came across a contradiction... If the crust lies on top of the mantle and if the upper part of the mantle is solid, how do the plates move about? where does the lava come from?
After reading about it I saw that I had not known the existence of a layer within the mantle until then..-The "Asthenosphere". Upon further reading I found that there are so many layers of the earth in addition to the above mentioned primary layers.. like an Onion.
So the Earths tectonic plates comprise of the crust and the uppermost, solid part of the mantle. This is called the "Lithosphere" below the lithosphere lies the asthenosphere which is also part of the mantle. The asthenosphere is of higher temperature and partly molten. It on this layer that the lithospheric plates lie and slowly move giving rise to the continental drift. Beneath the mantle lies the usual liquid outer core and the inner core.

Image taken from Wikipedia

 The onion like structure of the earth even extends beyond the surface of the earth into the atmosphere. The layers of the atmosphere starting from the bottommost layer are, Troposphere, Stratosphere, Mesosphere, Thermosphere and Exosphere.

Remembering Pi..

3.14159265358979..... Pi is arguably the most famous constant in mathematics. First introduced in primary school geometry, it continuously appears even in the most advanced areas of mathematics and physics. The digits of Pi are still being calculated and no pattern has been found in the occurrence of the digits.
In the past memorizing the digits of Pi has been an obsession, although today memorizing Pi would be of no use because any pocket calculator would give its value up to the 8th decimal place..Nevertheless I feel it is good to remember this important constant to at least its 6th decimal place (because we are capable of  memorizing several 10digit phone numbers! ). However, the purpose of this post is to give a an easy way of remembering the digits of Pi, which I found in a book that I read. It would be useful for those who don't want to memorize numbers..Use the sentence "How I wish I could recollect Pi" in which the number of letters in each word equals a digit, to remember Pi up to 6 decimal places. To remember up to 10 decimal places, use, "How I wish I could recollect Pi easily using one trick ". I found the above sentences in the book "Strength in Numbers" by Sherman K. Stein.