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!