Monday 14 September 2009

String Theory There are two areas of research that we don't know much about and where research over the next twenty years: Quantum Mechanics and String Theory. In this article I'm going to discuss String Theory why we think all things are made up of strings. String Theory is a contender for The Theory of Everything and is based on the principle that all things are made up of tiny 1-dimensional superstrings. The first ever String Theory was formulated in the late 1960s and was called Bosonic String theory. However, soon afterwards it was abandoned as it predicted the existence of a particle that we don't believe to exist and it predict only the position of boson whereas most physical particles are fermions. Then along came the Superstring Theory which predicted a 10-dimensional universe. This was then split in to five versions of this theory. However, all these versions seemed to be right but this wasn't possible. Here, we introduce Edward Witten who has been hailed as the next Einstein. He looked at all these theories and decided that they were all different ways of saying the same thing. He then went on to unite these theories in what we call M-Theory which is based on a 11-dimensional universe. This is just basic theory behind string theory but for more advanced reading go to Wikipedia.

Monday 24 August 2009

Accessible Science Has Moved! Hi, this is just to tell you that Accessible Science has moved to a more updated website, one of the reasons why we decided to move was because we could put in a forum were you can sign up and post threads related to science! we will still keep this website going but our new website will be our main one, the new website is called http://www.accessiblescience.webs.com thanks, Cameron and Saul

Wednesday 22 July 2009

HAPPY 40TH ANNIVERSARY APOLLO 11

Saturday 11 July 2009

How does an Airplane fly? Every day of our lives, we hear or see at least one type of aircraft sore above our heads. Most of us travel on one once a year to make a journey of over a hundred miles to another country in an hour or two on an airplane. But how can a standard 737 (which weighs roughly 50 kg per square meter) resist the force of gravity. How can it soar at 35,000 feet at a speed of 500 miles per hour. In this article I will talk about the science behind flying in heavier than air machines. There are two factors that prevent an airplane from flying. These are weight (preventing a plane from rising) and drag (preventing it from moving forward. For an airplane to fly, these factors must be equalled out be another two which are produced by the airplane. These are lift (created by the wings and other parts) and thrust (created by the engines. The following equations below must be obeyed to take off from the ground. - Drag < Thrust (to move forward) - Weight < Lift (to rise) Now let's look at each component individually. Drag is caused by friction with the air. As an airplane flies, its body brushes against the different air molecules creating friction. This slows the plane down. Thrust is the opposite of drag as it is used to propel a body forward. It is created using Newton's third law of motion. It states that when one force goes one way, a force of equal strength must go the other way. Hence thrust is created by huge engines pulling and pushing huge amounts of air out the back. Therefore, an equal force must go the other way. Weight is caused by gravity. The mass of an object depends upon what it is made up of and the weight of an object is this number in kilograms multiplied by the gravitational field strength of the Earth which is roughly 9.8 N/kg. Einstein proposed General Relatity in 1915 which states that a body curves Sapce-Time and this curvature pulls bodies into the object. This is known as gravity. We counter gravity by using lift. We generate lift by angling the the wings so that it pushes air down. Newton's third law comes in to play again here as the air is pushed down, another force must go up. IN other words, the plane rises. Of course, Lift doesn't have to be more than weight when its cruising as the pilot will want to remain level so the the lift will be equal the weight. So next time you are watching a plane cruise in to the sky, remember the physics behind this way of travelling that has been attempted many times for centuries that has now become a reality.

Wednesday 1 July 2009

Time Travel: Possible or a sci-fi myth? by Cameron Webb Time Travel, it is very easy, infact we do every single day but only in one direction! For thousands of years scientists and philosophers have refered to time as a river that flows steadly forward year after year, but the big question on their mind was if there was a way to swim against the flow of the river, like a salmon returning to their breeding ground or maybe a way to run down the bank ahead of the the river? Could we be able to journey back and forth in time? The funny thing is that the idea of "Time Travel" is not as absoured as it might sounds! If time machines are possilbe, it would be likely that someone in the future would have already consturcted one and might of already visted us in 2009! But like in Back to the Future, But happens if some one in the future invents a time machine and ventres through the river of time and mets his teenage mother and falls in love with her and as Dr Michio Kaku said "You're in deep do-do" but Dr Kaku and many other scienctists say that the river of time forks into two rivers and so you jump stream. This rules out the possiblity of you never being born in the future, as the woman that you have just met when you went back in time is genecticully the same as his mother, talks like his mother but it is NOT HIS MOTHER, as his mother fell in love with his father. So your "fake" mother is your mother in a pararell univeres. So you saved Steve Irwin from being stung from a Sting-Ray but this is not our Steve, history is our own history, you cannot change the past, but what you have done is changed some else's past in the Parallel Univeres. (phew) If humans do not step up to the task, then maybe creatures from other intelligent lifeforms may take a stab at it, like the Goulds in Star-Gate. They created a rotating Cylinder through time which enabled them to concour other planets and taking woman as hosts for thier creature in side of them called the Gould (very good series, I would advise you to watch it) This is what it looks inside the Stargate when all your matter is torn up and then put back together when you reach the other stargate (pretty awesome) So Far we have managed to avoid being visted from time travelling jockies for a very good reason, Time tourism is unlickly the poblem,: Theoretically time machines have a very limited capacity! End of Part 1, in part 2 I will continue this atricle and I my touch upon the three possible ways of time travel!

Friday 26 June 2009

Time Time has been the study of many physicists over the past two centuries. Einstein was the first to really understand it by saying that it was a 4 dimensional object. In this post I will write about Time Dilation and what this has to do with a theory of time travel. As in the Google Video in the last post, up until Einstein people thought that time was the same everywhere in the universe and that everything else varied according to a velocity. Then Einstein came along and said the speed of light was always constant and that time was variable. This formed Einstein’s special theory of relativity and also explains time dilation. Let’s assume that there is a man who travelled at the speed of light for eternity. Let’s also assume that you have a twin brother who goes about living his ordinary life. Your brother lives for 80 years but you live on for eternity. The obvious question to ask is why? This is where time dilation comes in. Time dilation is based around Special and General Relativity. General Relativity explains gravity. A body of some sort, in Einstein’s view, curves the Space-Time Continuum. This curvature creates the affect that we know as Gravity. Time Dilation occurs in two ways. The first is to do with General Relativity. The less affect that gravity has on you, the slower time goes by. It varies in minute amounts but it still slows down. The second explains the brother example that I gave earlier on. It states that the faster you go, the slower time goes by. However, if an object were to travel faster than the speed of light, it would travel back in time. In the brother principle, the speed of light is in the middle where time stops. Hence, the first man never ages. This is one of the many time travel theories. If man could create a machine that could travel faster than light, we could time travel. However, this is currently an impossibility as the laws of physics don't allow us to do this. According to Einstein Special relativity theory, when an object gains a certain amount of energy, this energy converts into mass as explained by E=mc2. Another way to possibly time travel would be to use wormholes. Wormholes are like a shortcut through space-time. As in the diagram on the left, space-time sort of folds in half allowing two point that would usually be very far apart to come together. It may also help you travel in time. Look on Wikipedia for more advanced reading. `

Wednesday 10 June 2009

Here's a documentary that the BBC did on Albert Einstein

Saturday 6 June 2009

Darwin, Natural Selection and Evolution By Cameron Webb Have you ever wondered where we came from? How did we arrive on earth, was it because of god creating Adam and Eve and is this the reason why we are all here. Or did this all happen through evolution, evolving and adapting from our descendants? I am going to try and explain what scientists think and what the church thinks, and if this wasn't enough I am going to talk about the god of biology, our friend Charles Darwin and how he put forward his ground breaking theory called Natural Selection and how this single theory changed the way that we think about our past. It is thought that we all all other living organisms i.e., animals and plants, once lived in the sea and that we all descended from an organism called a Eukaryotes, This is one of the smallest living things that the earth has held and it is quite a thought to think that every living thing that we know of descended from this tiny organism which is smaller than a red blood cell(this organism cells are organized into complex structures enclosed within membranes). And from there on in we started evolving from algae to vertebrates. The first vertebrates that we think lived in our sea's was a eel shaped creature that sucked on algae for food, in the picture shown it is a lamprey sucking on to a fish, and sort of cleaning the fish but it is really searching for small organisms to eat. But the amazing thing so that this picture is really good proof that evolution has taken place as I previously said the Lamprey was the first vertebrate to swim in our sea's so there could not of possibly be any fish, so the lamprey has had to evolve and develop to change the technique for eating. And so from an eel shaped creature we then start to see the fish shaped creatures starting to develop. But it was the species called the Tetra pods that we have to thank, for they made the huge leap and started to take on off the biggest leaps that the animal kingdom has ever seen, they stepped on land, even though they could not survive on land for more than two minutes they had eventually made it onto land. So from these Tetra pods came the Amphibians Newts and Frogs, then came along the reptiles and birds and from that came the marsupials Kola's and Kangaroos and then came along the entrains and finally came along the Primates Humans and apes. At last we have arrived at the Primates but I have missed out a lot of other organism for example the insects, the fungi. This is the fascinating about eve lotion how have changed so much from an very small organism to over six foot tall, how has eve lotion mate so many other types of species? This very question is what fascinates so many people to do evolutionary science. Part two of this article will be out soon where I will talk about Darwin and the battle between science and the church!

Saturday 23 May 2009

Particle Physics Part 2 This article follows up from my previous introductory article on Particle Physics. In this, I will write about Fermions and Bosons, expand on the information that I gave in An introduction to Particle Physics about Quarks and Leptons and I will also touch upon how Albert Einstein made significant contributions to Physics. To begin with however, I will write about Fermions and Bosons. Physicists believe that all things are either a Fermion or a Boson. Fermions are particles that can't occupy the same space at one time which is why we can't walk through walls as we're made up of fermions. Bosons how ever, are forces (gravity, electromagnetism etc. etc.) which can occupy the same space at one time. For instance, gravity affects everything on Earth and electromagnetism is still present in on Earth as well. But now back to the fundamental particles. As far as we know, there are 12 fundamental particles (24 if you include anti-particles.)But it is at CERN where the Large Hadron Collider (the largest particle accelerator in the world) is trying to find some more particles. By smashing the quarks together, they may brake down into smaller particles. This is an example of an accelerator. However, there is no point in doing this if you can't see the particles which are created. Detectors do this. Although we can't actually see a particle, these detectors pick up on the tracks they leave behind after the collision and where they have travelled. Tiny details like these can piece together what happened during the collision. Finally, I will end with Albert Einstein - the greatest scientist in the history of mankind. To begin with, you must know that Einstein was very religious. He believed that God had created a universe where everything had an answer. With his General Theory of Relativity, Einstein had (accidentally) created a new field of Physics, Quantum Mechanics. However, Einstein hated the Quantum Theory as it was based on probability which Einstein didn't believe in. This led to a debate which lasted for years with Niels Bohr - another brilliant scientist who led Quantum Mechanics of that time. Einstein's achievements include: - Special Relativity (which states that the speed of light is always constant and that everything else depends on the speed that you are travelling.) - General Relativity (his theory on gravity which made him a celebrity) - The Theory of Everything (which he never completed. He was trying to discover an equation which would prove that everything was predictable (as goes with his religious belief that everything had an answer) and that Quantum Mechanics was wrong.) - His nobel prize for his contributions to Physics and for his photoelectric effect (the idea that photons(light) could also be particles as well as waves.)

Saturday 11 April 2009

Introduction to Particle Physics Particle Physics is a branch of physics that studies the fundamental constitutes of matter and energy. The fundamental constitutes of our universe (as far as we know) are 12 particles that can't be broken down any further. These particles and the four fundamental forces, come together to create what we call "The Standard Model." Before we look at the Standard Model however, I should explain in greater depth what the fundamental particles are. They consist of 6 so-called leptons and 6 so-called quarks. But to explain these, I must explain how the atom is structured. An atom consists of a nucleus which in it has electrically charged protons and neutral neutrons. Both these sub-atomic particles are made of up and down quarks.Then there are electrons that orbit the nucleus. These leptons are tiny compared with quarks. Then there are the four fundamental forces. These are Gravity (one you probably already know about), Electromagnetism (which affects the electrically charged subatomic particles), Strong Force (which acts like an elastic band upon the protons and the neutrons), and Weak Force (which is responsible for radioactivity.) The Standard Model shows the fundamental particles and which forces affect them (Look Right) As you can see, the Weak Force affects all the particles, the Strong Force affects all the quarks and Electromagnetism affects half of the Leptons (including the Electron) and all the quarks. It is because of the strong force affecting the quarks that we have a nucleus in our atoms. So this concludes my introduction to Particle Physics. Soon, I will be following this up with a "Particle Physics continued" post.