By Maria Papanikolaou (B class)

Einstein’s general Theory of Relativity predicted that space-time began at the big bang singularity and would come to an end. At the beginning, the universe is thought to have had zero size, and so to have been infinitely hot. However, as the universe expanded, the temperature of the radiation decreased. One second after the big bang, it fell to about ten thousand million degrees. At that time, the universe contained mostly photons, electrons, and neutrinos and their antiparticles, together with some protons and neutrons. As the universe continued to expand and the temperature to drop, most of the electrons and antielectrons annihilated with each other to produce more photons, leaving only a few electrons. About one hundred seconds after the big bang, the temperature fell to one thousand million degrees. At this temperature, protons and neutrons started to combine to produce the nuclei of atoms of deuterium, which contain one proton and one neutron. The deuterium nuclei then combined with more protons and neutrons to make helium nuclei, and small amounts of a couple of heavier elements. Protons and neutrons converted into helium nuclei, along with a small amount of heavy hydrogen and other elements. The remaining neutrons decayed into protons, which are the nuclei of ordinary hydrogen atoms.

After millions of years, electrons and nuclei started combining to form atoms. The universe as a whole continued expanding and cooling, but the expansion slowed down by the extra gravitational attraction. This eventually stopped expansion in some regions and caused them to start to re-collapse. Eventually, when the region got small enough, it was spinning fast enough to balance the attraction of gravity, and in this way, disk-like rotating galaxies were born.

As time went on, the hydrogen and helium gases in the galaxies broke up into smaller clouds that collapsed under their own gravity. As these contracted, and the atoms within them collided with one another, the temperature of the gas increased. These converted the hydrogen into more helium, and the heat given off raised the pressure, and so stopped the clouds from contracting any further. They remained stable in this state for a long time as stars. The earth was initially very hot and without an atmosphere. In the course of time, it cooled and acquired an atmosphere from the emission of gases from the rocks. This early atmosphere was not one in which we could have survived. There are, however, other primitive forms of life. It is thought that they developed in the oceans, possibly because of chance combinations of atoms into large structures, which were capable of assembling other atoms in the ocean into similar structures. They thus reproduced themselves and multiplied. In some cases, there were errors in the reproduction. Mostly these errors were such, that the new macromolecule could not reproduce itself and eventually was destroyed. However, a few of the errors produced new macromolecules that were even better at reproducing themselves. They therefore had an advantage and tended to replace the original macromolecules. This way a process of evolution started that led to the development of more and more complicated, self-reproducing organisms. The first primitive forms of life consumed various materials, including hydrogen sulfide, and released oxygen. This gradually changed the atmosphere to the composition that it has today, and allowed the development of higher forms of life.

In an expanding universe in which the density of matter varied slightly from place to place, gravity caused the denser regions to slow down their expansion and start contracting. This led to the formation of galaxies, stars, and eventually even insignificant creatures like us. Thus, all the complicated structures that we see in the universe can be explained by the no-boundary condition of the universe together with the uncertainty principle of quantum mechanics. So, what if the universe is really completely self-contained, having no boundary or edge, it would have neither beginning nor end: would it simply be?

 Sources:

A Brief History of Time, by Stephen Hawking

image: http://www.wallpapersbyte.com/space/download-hd-space-universe-stars-nebula-in-red-yellow-and-blue-color-wallpaper/

By Maria Athanasopoulou (A Class)

        What is infinity? Is it a number? It is nowhere on the number line. But we often say things like an infinite number of something. As far as we know, infinity could be real. The universe may be infinite in size and flat extending out forever and ever without end, beyond even the part we can observe or ever hope to observe. That’s exactly what infinity is; not a number per se, but a size; the size of something that doesn’t end.

Infinity is not the biggest number; on the contrary, it is the total of numbers that exist. But we have divided infinity in different kinds. The smallest kind is called countable infinity: for instance, the number of hours in forever or the total of whole/natural numbers that exist. Sets like these are unending but they are countable. It means that you can count them from one element to the other in a finite amount of time. Even if that time is longer than you will ever live or the universe will exist, it is still finite. Uncountable infinity on the other hand, is literally bigger; too big to even count. For example, the set of real numbers, not just whole numbers, is called uncountably infinite. You literally cannot count even from zero to one in a finite amount of time by naming every real number in between. Think about it, you start with zero but what comes next? 0,0000000…. eventually we would imagine a 1 going somewhere at the end, but  there is no end, we can always add another zero. Uncountability makes this set so much bigger than the set of whole numbers that between one and zero there are more numbers than whole numbers on the entire endless number line.

       The mathematical proof of this is called the Diagonal Argument and is fairly simple. First of all, you need to understand that when it comes to infinity two sets are even when there is a one-to-one correspondence. Which brings us to this: imagine listing every number between zero and one. Since they are uncountable and can’t be listed in order, let’s imagine randomly generating them forever with no repeats. Each number we generate can be paired with a whole number. If there is a one-to-one correspondence between the two that would mean that countable and uncountable sets are the same size. But we can’t do that. Even if the list of real numbers goes on forever, forever isn’t enough. If we go diagonally down our endless list of real numbers and take the first dismal of the first number, the second of the second number, the third of the third and so on, and add one to each subtracting one if it happens to be a nine we can generate a new real number, that is obviously between zero and one, but since we have defined it to be different from every number on our endless list, on at least one place it’s clearly not contained in the list. In other words, every single whole number in the entire infinity of them is matched up and we can still come up with more real numbers.

            Here is something else that is true but counterintuitive. There is the same number of even numbers as there are even and odd numbers. At first that sounds ridiculous; clearly there are half as many even numbers as there are whole numbers. But that intuition is wrong. The set of whole numbers is denser but every even number can be matched with a whole number. You will never run out of numbers of either set so this one to one correspondence shows that both sets are the same size. So as its turns out infinity divided by two is still infinity ( ∞/2 = ∞). Infinity plus one is also infinity (∞ +1 = ∞). A good illustration of this is Hilbert’s Paradox of the grand hotel.

      In the 1920’s the German mathematician David Hilbert conducted a famous thought experiment. Imagine a hotel with a countably infinite number of rooms and a very hardworking night manager. One night the infinite hotel is completely full. Totally booked up with an infinite number of guests. A man walks into the hotel and asks for a room. Rather than turning him away the night manager decides to make room for him. He asks the guest in room number 1 to move to room 2, the guest in room number 2 to move to room 3 and so on. Every guest moves from room n to room n+1. Since there are infinite rooms there is a new room for each existing guest. This leaves room 1 open for the new customer. The process can be repeated for any finite number of new guests. If, say, a tour bus unloads 40 new people looking for rooms then every existing guest just moves from room number n to room number n+40; thus opening the first 40 rooms. But now an infinitely large bus with a countably infinite number of passengers pulls up to rent rooms. Countably infinite is the key. The infinite bus of infinite passengers perplexes the manager at first but he realizes there is a way to place each new person. He asks the guest in room 1 to move to room 2, the guest in room 2 to move to room 4, the guest in room 3 to room 6 and so on. Each current guest moves from room number n to room 2n, filling up only the infinite even numbered rooms. By doing this he has now emptied all of the infinitely many odd numbered rooms, which are then taken by the people filing off the infinite bus.

We, humans, are finite creatures. Our lives are small and can only scientifically consider a small part of reality. What’s common for us is only a sliver of what is available; we can only see so much of the electromagnetic spectrum, we can only delve so deep into extensions of space. Common sense applies to that which we can access. But common sense is just that: common. If total sense is what we want, we should be prepared to accept that we shouldn’t call infinity weird or strange. The results we have arrived at by accepting it are valid; true within the system we use to understand, measure, predict and order the universe. Perhaps the system still needs perfecting, but at the end of the day history continues to show us that the universe isn’t strange; we are.

Sources:

http://www.mathpages.com/home/kmath371.htm
https://simple.wikipedia.org/wiki/Hilbert’s_paradox_of_the_Grand_Hotel

By Marilena Vdokaki and Sophia Koutra (B class)

A black hole is a region in space where the pulling force of gravity is so strong that light is not able to escape. The strong gravity occurs because matter has been pressed into a tiny space. This compression can take place at the end of a star’s life. Some black holes are a result of dying stars. Black holes can come in a range of sizes, but there are three main types of black holes. The black hole’s mass and size determine what kind it is.

Stellar black holes form when the canter of a very massive star collapses in upon itself. This collapse also causes a supernova, or an exploding star, that blasts part of the star into space. Black holes do not wander around the universe, randomly swallowing worlds. They follow the laws of gravity just like other objects in space. The orbit of a black hole would have to be very close to the solar system to affect Earth, which is not likely.

Will the Sun Ever Turn Into a Black Hole? If a black hole with the same mass as the sun were to replace the sun, Earth would not fall in. The black hole with the same mass as the sun would keep the same gravity as the sun. The planets would still orbit the black hole as they orbit the sun now. The sun does not have enough mass to collapse into a black hole. In billions of years, when the sun is at the end of its life, it will become a red giant star. Then, when it has used the last of its fuel, it will throw off its outer layers and turn into a glowing ring of gas called a planetary nebula. Finally, all that will be left of the sun is a cooling white dwarf star.

ΠΗΓΕΣ

• http://www.nasa.gov/audience/forstudents/5-8/features/nasa-knows/what-is-a-black-hole-58.html
• www.ultrahdwallpaper.in

By Gerasimos Gerogiannis (B Class)

1.  On average we spend more than 6 years of our lives dreaming.
2. Negative feelings such as anger and fear are the most common whilst dreaming.
3.  Most people have on average 4 to 7 dreams every night.
4.  All animals dream too.
5. If you are snoring you can’t be dreaming.
6. You forget 90% of your dreams within 10 minutes of waking up.
7. We only dream of what we know. Faces we see in our sleep are based on people we have seen before.
8. Research indicates that scientists may soon be able to record our dreams!

By Tsorbadgoglou Vasilis (A Class)

Human beings are unusual in that our mouths are surrounded by hypersensitive easily – hurt pink tissue.

The flap around on the front of your face get dried out during winter and sometimes get caught up between your teeth and mistaken for food. Seriously what good are lips! Birds get on just fine without them and turtles have them hardened. However, it seems that there is some kind of importance of their existence

Using our lips to suck is one of the very first skills we have after we’re born. In fact it’s crucial to our survival that it’s known as a private reflex (we are born knowing how to suck and no learning is necessary).  That’s true for nearly all mammals.
The lips are of course also important in the act of eating foods and in speech in linguistics, the lips are two of many spots in our mouth and throat that helps dockage of air moving out from the lungs.

To sum up, it turns out are quite important, so important, even that it seems worth the risk of having your bottom limp caught in between your chomper. Even though that can really hurt

By Manenti Chrisanthi, Papanikolaou Maria, Rodopoulou Vasiliki and Sergiou Anna(A Class)

Water has a significant impact on our lives. People can’t live without it. But nowadays, even though humanity has made enormous progress in sciences and in other domains, nearly a billion people worldwide don’t have access in clean drinking water.

To start with, people in areas like Africa, South Asia and Latin America live without potable water. People are forced to walk for hours in order to find a lake or a river. But even then, the water they collect isn’t clean as it has been exposed to any kind of germs. The contaminated water might cause dehydration and sometimes death. Waterborne diseases and the lack of sanitary water is among the leading causes of death all over the world. Apart from that, water crisis leads to regional conflicts over scarce water resources.

But this problem is solvable. Water filtration, which is an innovated solution and hand-up wells can contribute to face effectively this situation. This would have a significant impact on other domains. That would improve people’s education as children would not have to walk in order to find water and would be able to attend school. Moreover, the money that is spent to face diseases related with water could be spent on education or to improve their quality of life.

Finally, let’s not forget that there’s a human right to water that entitles everyone to safe, physically accessible, sufficient and affordable water and none should be deprived of this right.

Sources:

wikipedia

youtube

www.huffingtonpost.com (image)

By: Catherine Paisiou (A Class)

Nowadays there are many demonstrations for the protection of our environment, for the preservation of our planet. But unfortunately we will rarely see people who really care about it!

The truth is that we are not used to thinking about the destruction of our environment because we think that this is a problem of the governments. And this thought is our biggest fault! We all have to care about it if we want to keep living in Earth.

We are all responsible for the problems that we face today. For example, the excessive use of cars and machines has led to the climate change. The climate change has led to the death of many animals and plants that lost their natural habitat. The list is very long…

From this we can easily understand that we have to preserve our planet for the generations coming. There are many things that we can do to accomplish this. These things are simple and ordinary actions that are not going to need a lot of time. They are only going to make our time special and help us profit from it. The only thing needed is some willingness!

So let’s see now some things we can do every day to improve our life in Earth:

• First of all something very common is recycling. Keep the recyclable objects, like glass, paper, plastic and metal, in another bag and try to use reusable   and biodegradable products as often as you can.  We must not throw them away because for example the glass needs one million years to decompose! After all, it is not that difficult to have two bags of rubbish instead of one!

• Secondly we must realize that water is not unlimited. A damaged faucet spends 10-15 liters of water per minute. If we close the faucet when we brush our teeth we save 10 liters of water every time. Imagine how much it is when we wash the dishes! Also it’s more preferable to take a shower than filling the bath with water because this way we use 3 times more water. And finally it is important to prefer to wash your car with a bucket and a sponge than with a hose.

• Moreover we have to reduce the use of the electricity. When we stop using an electric device we should disable it as by doing this we save energy and… money from our pockets! We should also replace the ordinary lamps with energy saving lamps because they last 10 times more and use 75% less electricity and start turning off our computers and the monitors when we don’t use them.
• A good idea is to have plants! Trees are sources of oxygen and we cut them! So isn’t it better to plant some? Plants make our lives more beautiful and help the environment. So if each one of us planted a tree, we would have cleaner air and an interesting occupation. And of course we could reduce some problems like pollution, global warming and the greenhouse effect.

• Furthermore it would be helpful to limit our transportations. We have to use our car as less as we can so as to reduce the exhaust gases. Also it would be a good idea to use vehicles of public transport or share our cars with people who do the same route with us. This way we help the environment as we contribute to the reduction of pollution and we become more social by meeting new people!

To sum up, these tips are only indicative! There are millions of actions we can do to help our planet. We just need to care about these problems and try to apply some simple rules in our everyday life!

And don’t forget to share these ideas with your friends and talk about them so that everyone will know them!!

Save the Earth!

Sources:

• http://imbluedabadiedabadye.pblogs.gr/prostasia-toy-periballontos-symboyles.html
• http://aksioperierga.blogspot.gr/2011/07/10.html

Pictures:

• http://ec.europa.eu/digital-agenda/sites/digital-agenda/files/environment%20(1).jpg
• http://www.kafkas.gr/d/perivallon-449.htm?lang=el&path=591798377
• http://foodenthusiastmag.com/luxury-water-thats-right-luxury-water/
• http://www.econews.gr/2011/09/21/anakyklosi-symboules/
• http://www.tlife.gr/Article/news-apergia/0-9-10545.html
• https://www.asdreports.com/news.asp?pr_id=444
• http://roadtovictory.deviantart.com/art/Planet-Earth-287805909

By Aggeliki Chala (A Class)

   The latest years we’ve all heard and read about keeping the seas and coasts clean. We all know that if we throw rubbishes, in a few years that ordinary habit of ours that’s called swimming will not be feasible any more. You might think it’s a cliche topic but if we remind ourselves it might pay off. We might avert beaches from becoming a restricted area. So it’s our debt and responsibility to keep our seas and coasts clean.

Do you know how many years, months or weeks it takes for something to decompose in the sea?

-A bottle made of glass takes 1.000.000 years to decompose.

-The fishing line takes 600 years.

-A plastic bottle takes 450 years.

-An aluminum can takes 80-200 years.

-A rubber sole takes 50-80 years.

-A plastic cup takes 50 years.

-A can (tin) takes 50 years.

-Nylon fabric takes 30-40 years.

-A plastic bag takes 10-20 years.

-A cigarette filter takes 1-5 years.

-Woolen clothes take 1-5 years.

-Plywood takes 1-3 years.

-A carton of milk takes 3 months.

-An apple core takes 2 months.

-A newspaper takes 6 weeks.

-Orange peels takes 2-5 weeks.

-A napkin takes 2-4 weeks.

Which beach would you prefer?

                                                                                                                                        This one       …or…            this one…?

Source: http://www.piperies.gr/posts/posa-xronia-xreiazontai-gia-na-dialythoyn-sti-thalassa

By GEORGE THANOPOULOS – GEORGE KARAGIANNIS – GEORGE GALANOPOULOS (A Class)

In Scotland, many stories are told about mysterious creatures. Many of them are described as long dragon-like lizards. However, the most famous and well-known monster, as I suppose you have heard, is the story of the monster of loch ness.

Loch Ness is a large, deep, freshwater lake in the Scottish Highlands extending for 37 km southwest of Inverness. Its surface is 16 m above sea level. Loch Ness is best known for alleged sightings of a serpent known as «Nessie». It is connected at the southern end by the River Oich and a section of the Caledonian Canal to Loch Oich. At the northern end, there is the Bona Narrows which opens out into Loch Dochfour, which feeds the River Ness and a further section of canal to Inverness. It is one of a series of interconnected, murky bodies of water in Scotland; its water visibility is exceptionally low due to high peat content in the surrounding soil.

But how did the myth spread? Many of the local inhabitants claim that an enormously large snake was kidnapping their children. Others said that a lizard was sinking the boats that were trying to cross the river and reach the Cherry Island. However, the most possible version is the less known one.  It was said that passengers heard screams from the island and though that some mysterious creature attacked the lonely hut that was built there. Cherry Island (: Eilean Muireach, meaning Murdoch’s Island) is the only island, and also an example of a crannog. The island is about 150 yards (140 m) from the shore near the southern end of the loch. The island was originally 160 feet (49 m) by 168 feet (51 m) across, but is now smaller as the level of the loch was raised when it became part of the Caledonian Canal. The increase in the level of the loch caused a smaller natural island nearby Eilean Nan Con.

A castle stood on the island during the 15th century; this was constructed of stone and oak wood and was probably used as a fortified refuge. Many scribes that were found there wrote that one day, some soldiers from a southern region (someplace near Walle), decided to attack the local villages. Having no other solution the villagers run into that castle. When the soldiers attempted to forge it, a weird looking creature stroke their boat and sunk it. As far as the significance of the monster in civilizations, many of them used to scratch a snake on their shields, to symbolize the power that they gained from the monster. Moreover, they used it with the view to have luck and succeed in war. Once a fight took place between Scotland and Wales. The Scottish were on the verge of defeat when suddenly local people advocate that a large lizard appeared which caused fear to people from Whales and made them run away!

But myths remain myths! Jeremy Wade, a biologist who studies fish and tries to catch rare ones, once, presented a programme about the loch ness monster. After days of research, what he discovered and revealed was that the loch ness monster does not actually exist. It exists just in people’s imagination. What the monster of loch ness actually is, is a type of shark living in the deep freezing waters of the lake: Somniosus microcephalus. This is one of the largest living species of shark, of dimension. Greenland sharks grow to 6.4 m.  and 1,000 kg,^] and possibly up to 7.3 m and more than 1,400 kg. However, most Greenland sharks observed have been around 2.44–4.8 m long and weigh up to 400 kg. Males are typically smaller than females. It rivals the Pacific sleeper as the largest species in the family Somniosidae. The Greenland shark is a thickset species with a short, rounded snout, small eyes, and very small dorsal and pectoral fins. The gill openings are very small for the species” great size. Coloration can range from pale creamy-gray to blackish-brown and the body is typically uniform in color, though whitish spots or faint dark streaks are occasionally seen on the back.

As far as the fight between Scotland and Wales, Wales did not count the power of the archers hidden in the forest and as a result they were not efficient in highground making them lose.

So as we can all conclude, the monster of loch ness was just an illusion. What it actually was, is a type of shark looking like a lizard from above…

By Katsidima Georgia (A Class)

           Pollution is presence of matter (gas, liquid, solid) or energy (heat, noise, radiation) whose nature, location or quantity, directly or indirectly, alters characteristics or processes of any part of environment, and causes (or has the potential to cause) damage to the condition, health, safety or welfare of animals, humans, plants, or property.

          More specifically, land pollution is the degradation of earth’s land surfaces caused by human activities and their misuse of land resources. There are many factors that contribute to the existence of the problem mentioned above. The main causes and types of land pollution are:

• Waste disposal Humans produce vast quantities of waste in their homes, in factories and offices, in schools or in hospitals. What’s more, nuclear plants produce toxic waste that can remain dangerously radioactive for thousands of years and, what’s worse, will contaminate anything or anyone that comes into contact with it.

• Agricultural chemicals It is widely known that farmers who want to make their plants grow faster use all sources of chemicals which are absorbed by the ground.

•  Urbanization One of the most important problems that urbanization causes is that by concentrating people, their wastes products concentrate at the same time.

• Mining People exploit the earth’s sources and produce pollution.

The main negative effects are:

• Soil erosion The chemicals produced from human activities are often toxic and they have hazardous results.

• Effect on human health Nowadays, because of that pollution there are way more bacteria in the atmosphere and as a result people tend to get sick more often. The toxic chemicals can reach our body through foods and vegetables that we eat as they are grown in polluted soil.

• Environmental impact

• Distraction for tourists The city loses its attraction as tourist destination as landfills do not look good when you move around the city.

• Effect on wildlife It causes extinction of some animal species. Also it forces these species to move further away and adapt to new regions.

•  Air pollution All the trash produced by people smell really bad and this affects all the residents of the city.