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Asked by hollisterchicken to Allan, Angela, Diva, Harriet, Nathan on 29 Jun 2012. This question was also asked by zmzmzm.
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Allan Pang answered on 29 Jun 2012:
The String Theory comes about because of the disagreement between Theory of Quantum Mechanics and Theory of Relativity. It offers to explain the Quantum Gravity, which is useful in understanding Black Holes.
So basically, what the string theory suggests is that every single particle (atom) is made up of a string. And each string, if you think about it has different properties or flavors (ie oscillates different, sounds differently, length and width different, etc) – just like how a strings in the guitar are.
The problem with String Theory is that it cannot be proven yet. But physicists are working towards that.
That is as far as I know about String Theory. I am not really a physicist, so I’m not a perfect candidate to answer this.
String Theory is also popular in science fiction, especially in fictional world that deals with multiverse…. may have to check what is M Theory.
PS Nathan might offer a better answer because he knows more about “quantum stuff” (and sadly, we are not quantumly entangled for me to have that physics knowledge!)
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Nathan Langford answered on 2 Jul 2012:
I should say first that this is most definitely NOT my field of expertise, so I will just try and give a flavour of a couple of related ideas – and hope I don’t get anything majorly wrong! 😉
What’s wrong with quantum mechanics? Well, we know that “stuff” can be broken down into molecules and atoms, and that atoms are made up of electrons, protons and neutrons, and that protons and neutrons are in turn made up of quarks. At the moment, electrons and quarks seem to be as small as it gets and are called “elementary particles”. In quantum theory, these particles are described as “point” particles (particles with no finite size and which occupy a single point in space) and they can interact or exert force on each other by exchanging other elementary particles, such as photons or gluons. (Incidentally, the Higgs boson is another elementary particles, which was introduced to explain why particles have mass.)
So far, quantum field theory (the theory behind particle physics) has been successfully able to explain three of the four fundamental forces: electromagnetic, and weak and strong nuclear interactions. But it hasn’t yet been able to explain gravity in a consistent way. It’s possible to define a quantum theory that satisfies the Special Theory of Relativity, but not the General Theory of Relativity, which explains where gravity comes from.
As Allan mentioned, the main idea of String Theory is that elementary particles should be represented as “strings” (extended one-dimensional objects) rather than points in space. The extra properties of these fundamental “strings” (length, tension, etc) give rise to extra complexity in the theories which describe their behaviour – string theories – and in certain circumstances, it seems that these theories can as a result describe both quantum physics and gravity in a consistent way.
But there is one big thing that makes it difficult to work out whether String Theory is correct or not. Firstly, in science, it is a critical part of the scientific process to be able to test the theory with measurements to determine if the theory first the experimental observations. Unfortunately, however, it seems like most of the predictions of string theory involve such high energies or small length scales, that making experimental tests will be very difficult and we’ll need to search for very indirect evidence that String Theory might be correct…
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