Wednesday, 17 December 2014

The Great Barrier Reef by Aditi Raju 6C


TABLE OF CONTENTS

1.   A New Perspective

2.Threats

3.Endangered Ecology

4.  Tourism – Having Fun J

5.Conclusion

6.  Glossary

7.  Bibliography


A New Perspective

The Great Barrier Reef , a natural wonder of the world is unique beyond imaginable. It is one of the most popular tourist spots and it has the most diverse marine ecology in the world.

However , as the world heats up like a giant preheating oven(Global Warming*)the reef’s luck is going down. Human activities are threatening the environment including the reef.

We now have a basic idea about the endangerment of The Great Barrier Reef. Do we know what to save the reef from?

 Threats

Climate change is the biggest threat to the Great Barrier Reef. It not only affects us but the whole reef ecosystem.

Climate change further affects…

·      Ocean temperature

·      Supply of nutrients

·      Food chains

·      Ocean currents (cyclones)

All of these again affect…


Many oil spills also damage and destroy the life underwater. The thick greasy oil makes the water very unsafe to live in.

 

Coral Bleaching

Coral Bleaching is the whitening of corals due to stress induced expulsion*.Once bleaching starts it does not stop for a very long period of time. This also reduces the biological diversity .

 

 
Acidic oceans

A lot of carbon dioxide* is being released by humans thus oceans becoming acidic and slightly dangerous.

Many other things such as

-Pollution     -Fishing boats  -Toxic runoff*

And many more affect The Great Barrier Reef.

The huge amount dangers the reef faces does not affect us. Who does it affect?

 

Endangered Ecology

The great barrier Reefs wildlife is diverse and like no other. It is such an inspiring community of creatures. It is hard to imagine the Great Barrier Reef without all its life.All the animals use the corals as a home. In return the creatures clean the coral of algae* and other fungi.

‘Coral reefs represent some of the world's most spectacular beauty spots, but they are also the foundation of marine life: without them many of the sea's most exquisite species will not survive.’

Sheherazade Goldsmith

 
Turtles, being an endangered species need to be protected. Out of 4000 eggs laid only about 3 survive.

Turtles are valued in the Great Barrier Reef  because they are endangered.6/7 of the world’s turtle species make their home in the reef for many reasons. The turtles that swim in the blue waters are the green sea turtles, leatherback sea turtle, flatback turtle, hawksbill turtle, the loggerhead sea turtle, and the olive ridley.

Another creature in danger is dugong. Not many people have heard of the dugong. The dugong is very special because it plays a huge role in the ecosystem.

Endangerment of the reef, is a very serious topic. However, most people visit The Great Barrier Reef.

Tourism – Having Fun J

The Great Barrier Reef  was made to be explored. The vast expanse of corals can be explored from inside the water or outside.

Here are a few activities that can be done.

 











PRIVATE HELICOPTER TOUR
 


SNORKELLING
 

PARASAILING
 
SNO


SAILING
 
SWIMMING
 
GLASS-BOTTOMED BOAT
 
 

 

 

 

 


In the reef, underwater we can see the inner beauty of the structure and the heart and soul of the reef lies beneath the water surface.

 

When we go underwater we can see the corals and wildlife. Even deeper in the water there are breathtaking caves and shipwrecks.

Even though the Great Barrier Reef from underwater is like entering a whole new world, the reef from above is quite beautiful too. Hangliding and Helicopter tours are ways to see the reef from an eagle’s eye view. The waters of the coral sea are warm all year round. This brings tourists at any time of the year.

 

Turtle Hatchings

People from all over the world come to see the baby turtles emerge from their eggs. Turtle hatchings happen in January.

Conclusion

The world has so many places to see. One of them being , the Great Barrier Reef. Mother Nature provides fun and surprises by giving us this reef.

What do we give in return? Nothing but harm.

We humans are quite selfish to our environment. The one thing destroying the reef, global warming is mostly our fault.

The message conveyed being…

WE NEED TO SAVE

THE GREAT BARRIER REEF

BY

CONSERVING ENERGY!

‘You must be the change you wish to see in the world.’

Mahatma Gandhi



Glossary

1.  Global Warming - an increase in the earth's average atmospheric temperature that causes corresponding changes in climate and that may

result from the greenhouse effect.

 

2.  Stress induced expulsion -  is a generalized stress response of corals 

 

3.  Carbon dioxide -  a colorless, odorless, incombustible gas, CO 2, present in theatmosphere and formed during respiration

 

4.  Toxic runoff - Toxic runoff can pollute surface waters, like rivers and lakes, as well as seep into underground groundwater supplies. It is caused by any source that empties directly into a waterway.

5.  Algae - any of numerous groups of chlorophyll-containing, mainly aquatic organisms

 

Bibliography

www.gbrmpa.gov.au

en.wikipedia.org

Round the Globe by Sumitra Ray

www.wwf.org.au

www.dictionary.reference.com

Google &

I THANK ALL THE WEBSITES AND BOOKS ABOVE FOR HELPING ME MAKE THE MOST PART OF SUCH AN INSPIRING FEATURE ARTICLE!
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Tuesday, 16 December 2014

Stars By Nikhil Niranjan 6C



Contents

INTRODUCTION: THE BIG BANG.. 2

WHAT ARE STARS. 3

LIFE OF A STAR.. 5

TYPES OF STARS. 8

CONCLUSION.. 10

GLOSSARY.. 11

BIBLIOGRAPHY.. 12
 
 

 
 
About 15 billion years ago, there was a huge explosion. Not any old and ordinary explosion. It was a gigantic explosion that formed the whole wide universe! This is known as the Big Bang.
Can you believe that all this began as the smallest single point in the vast expanse of space called a singularity? Soon, this point started expanding rapidly. This massive explosion was like a nuclear bomb. The explosion caused protons, neutrons, electrons, etc., to form. Several clumps of gas and dust came together and they were pulled and squeezed together by their own gravity. All these clumps slowly formed STARS!
The wondrous10 stars that we see, glow because of the nuclear fusion reaction which is Hydrogen turning into Helium. Without this, we wouldn’t be able to see the number of stars in the night sky!
I have always been amazed by the stars in the night sky. I would like to share my fascination with you. In this article, I will explain to you all about stars and introduce you to some mysteries of space.
 
Like we saw in the last chapter, stars are the objects twinkling and shining far away in the night sky. For us, stars seem very small, like dots in the sky. You won’t believe this, but most stars are many times bigger than the Sun! So, you can imagine how many times they are bigger than the whole Earth!
Stars are huge, fiery balls of extremely hot gas. They are constantly burning inside, which is what gives them their glow and shine. They are mostly composed of Hydrogen (about 90%) and Helium (about 10%) with slight amounts of other gases. The extremely hot temperatures helps it to have nuclear reactions6 between Hydrogen and Helium.
Stars vary in size. Our Sun is an average-sized star. Many stars are bigger than this, such as:
·         Red Giant Stars – 20 to 100 times bigger than the Sun
·         Supergiants such as Betelgeuse – 500 times as big as the Sun
Some of these stars are actually so massive that they have collapsed under own gravity4. There are also stars much smaller. For example, there are white dwarf stars that are only 9 miles across.
Can you guess what the brightest star that can be seen from Earth might be? It is SIRIUS, the Dog Star. This star is about 26 times brighter than the Sun!
One of the brightest stars is the Hypergiant Cygnus OB2 No. 12. It is 810,000 times brighter than the Sun! Since it is almost 6 billion light years5 away, it appears quite dim to us on Earth.
After our Sun, the nearest star is Proxima Centauri. It is just over 4 light years away. There is also a star named Alpha Centauri, which is over 4.35 light years away. This is the nearest star visible to the naked eye.
Something to Wonder About
Even today, the universe is still expanding. Its future depends on how much matter it contains. Some astronomers believe that there might be enough matter to slow down the expansion so that the universe eventually stabilizes. However, if the universe keeps expanding at this rate, galaxies3 will move further away, stars will slowly die, and all matter will eventually DISINTEGRATE1!
 
 
 
In the previous chapter, you learnt about what stars are. But, how are they formed? Well, a star’s life begins when clumps of gas and dust in space are pulled together by their own gravity. The middle of the whole clump is squeezed so hard by gravity that it begins to get immensely hot. This starts the nuclear reaction between Hydrogen and Helium, which makes these objects burn. It is now a Main Sequence Star.
After a long time, the star runs low on Hydrogen fuel. It swells into a huge Red Giant that starts pulsating9.
After another 3 billion years, the expansion and pulsation goes stronger and the vast bloated star sheds all its outer layers to form a gaseous shell around its core, which is known as a Planetary Nebula. In less than about 50000 years, the planetary nebula collapses. However, the core becomes a White Dwarf, a Neutron star or even a Black Hole. Are you wondering what Black Holes are?

However, if Red Giants swell up way too much, they can become massive Supergiants. The end of a supergiant star is the most important part. No one would believe this but a gigantic explosion, known as a Supernova, finishes off a supergiant. It is like a nuclear bomb. For just a brief moment, the supernova flashes out with such a brilliant light, it seems like it is coming from a billion suns! These supernovas are rare and very short-lived, but there is always one in the Universe.
FUN FACT
Supernovas can send out more energy in a few seconds than our Sun in 200 million years!
The Supernovas and Black Holes are two amazing mysteries of space. They are at the end of life of a Main Sequence Star. However, how a star dies, and whether it becomes a Supernova or a Blackhole, depends on the type of the star. In the next chapter, you will learn about some important types of stars such as, Red Giants, White Dwarfs, etc.
 
There are many types of stars in the Universe. There are three main stars that are part of a main sequence star’s life: White Dwarfs, Red Giants, and Neutron Stars.
 
White Dwarfs
 
White Dwarf stars are really unique.. They are formed when stars are very dense objects, and they have an unusual faintness2 compared to other stars. They are mostly composed of Carbon and Oxygen. They are really hot when formed, but over time, they cool down.
White Dwarfs have the densest matter and their material is made up of plasma8 of unbound nuclei7 and electrons. But enough of White Dwarf stars. Let us move on to the next type of star!
 
Red Giants
 
As you can guess from the name, Red Giants are massive, luminous stars. However, compared to their size, they have a very low mass. These stars appear a yellowish-orange to red colour, and are actually many times more luminous than the Sun. They are cooler than most stars, mainly because they have used up their supply of Hydrogen in their core.
Some well-known Red Giants are Arcturus, Aldebaran, and Gamma Crucis. Even our own Sun will become a Red Giant in 5-6 Billion Years. It will become so big that it will swallow the Earth!
Well, now, let us move on to our last (but not the least!) type of star.
 
Neutron Star
 
Neutron Stars are as interesting as Black Holes and very similar too.
These Neutron Stars are the densest and also the tiniest stars in the universe. Their radius is just about 10 km but their mass is still few times that of the sun! This is what makes these stars so unbelievable!
They are composed entirely of Neutrons, from where they get their name. Their whole surface is made of only Iron. Most importantly, they have the most intense gravitational force. Objects are 100 billion times heavier on a Neutron Star than they are on Earth!
 
Well, that's all I have in store for you in this edition for the topic STARS. But overall, that was a whole lot of fun! We learnt a lot, too. We learnt about the BIG BANG THEORY, stars in general, the whole life cycle of a star including SUPERNOVAS and BLACK HOLES and few important types of stars that were part of a Main Sequence Star's life!

However, this is just basics of Stars. There is a whole lot more you can learn about them. You should try STAR GAZING!

 1. Disintegrate - Break up into small parts as the result of an impact

2. Faintness - Lacking brightness or distinctness

3. Galaxies - Numerous large groups of stars, gas and dust that constitute the universe

4. Gravity - the natural force of attraction exerted by a celestial body, such as Earth, upon objects at or near its surface, tending to draw them towards the center of the body

5. Light year - The distance that light travels in a vacuum in one year - approximately 9.46 trillion (9.46x10*12) km

6. Nuclear reaction - A process in which the  structure and energy content of an atomic nucleus are changed by in interaction with another nucleus or particle

7. Nuclei - Plural of nucleus, which is central part about which other parts are grouped or gathered; core

8. Plasma - An electrically neutral, highly ionized gas composed of ions, electrons and neutral particles

9. Pulsating - To expand and contract rhythmically; vibrate

10. Wondrous - Remarkable or extraordinary; wonderful
 
1.      En.wikipedia.org/wiki/Star
2.      http://www.kidsastronomy.com/stars.htm
3.      Children’s Atlas of the Universe
4.      Magic Tree House – Space
5.      Fantastic Book of Q and A
6.      En.wikipedia.org/wiki/White_dwarf
7.      En.wikipedia.org/wiki/Red_Giant
8.      En.wikipedia.org/wiki/Neutron_Star
9.      En.wikipedia.org/wiki/Galaxy
10.  www.kidsastronomy.com/galaxys.htm
11.  En.wikipedia.org/wiki/Galaxy#Ellipticals
12.  En.wikipedia.org/wiki/Irregular_galaxy
13.  En.wikipedia.org/wiki/Small_Magellanic_Cloud
14.  En.wikipedia.org/wiki/Milky_way
 
 


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