Question: whats string theory??
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well i never knew that well you learn something new everyday
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Hi H-zone students and scientists,
I’m Edward from Food Zone and an ex-physicist.
Kieran and Matt have got this question pretty much covered, and I just wanted to say that there’s plenty going on in particle physics (the study of the smallest particles/things in the universe) that is NOT string theory (or not directly string theory, anyway) and that CAN be tested.
A newer name for string theory is M-theory, M being for ‘membrane’, which is a 2-dimensional sheet rather than a 1-dimensional string. But all this string/M stuff is supposed to happen in 11 dimensions (whatever that means)!
lshar76
Edward
This is an area of physics that deals with the underlying nature of the universe. I don’t really know what “strings” or string theory is, but think it comes from the mathematical equations which deals with the underlying nature of the universe.
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This is a theory in physics. If you think about atoms, most people would say that they are little particles – like little tiny balls that collide and combine.
When you study some physics you’ll learn that there are times when atoms behave like that, and there are other times when they don’t. Sometimes they behave like waves – like the waves on water. So they kind of wash over things and behave weirdly. This is deeply cool. In physics it’s called “wave-particle duality” and is something I did in school when I was 17, but studied it properly at uni.
The message is that stuff behaves very differently on the atomic scale than it does on the scale of everyday objects. So we don’t normally see all this stuff, but can do experiments that shows it.
Now there are some people, more recently (last few decades), who point out a few problems with the basic theory of atoms. They say that what we’re seeing is not just this idea that atoms can behave as particles or waves. They say that actually what you’re seeing are a bunch of strings vibrating. That’s weird, and the word “string” is a little misleading. It’s not a string in a real sense, but some energy that connects two points, vibrating. The theory goes that things like electrons and things inside atoms can be explained by thinking about strings.
This is one of these things that’s easier to see with Maths rather than English!
Problem is that the theory doesn’t really have any experiments that can be used to test it. No experiments means no checking that it’s real. So there’s been criticism of the whole thing because nobody can properly test it.
This is an area of physics that describes stuff that’s very small, though. Your hand will still feel a table as hard, and the air as air. String theory is trying to understand the structure of the atoms, is all. If it’s right, there are some pretty weird conclusions you can draw about the nature of reality, but at the moment people don’t know whether it’s right or not.
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This is not my expertise, but I’ve tried to understand string theory before. I’ve seen scientists talk about it in a lot of documentaries on TV.
My simplistic idea of string theory is that people who study physics are always looking for a single super theory to explain how the whole world works. The latest theory is string theory, which, like Mat said, proposes that all stuff is made up of little vibrating “strings”.
But these “strings” are so small that we can’t see them, even with the highest powered microscopes we have. Like Mat said, at the moment no one has thought up a way to test if this theory is true or not. If you can, you will make yourself very famous one day!
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I don’t know much about string theory. This is about where I stopped studying physics.
It is an area of physics that tries to bring several areas of physics, quantum mechanics, particle physics and general relativity, into one bundled up theory. Well actually, into one mathematical formula.
Now for some of the detail in English, (I’ll do my best).
Everything we know in the world is made of matter. Regular every day matter is made up of atoms and these are often described as the smallest particle of substances. These atoms are made up of even smaller particles, negatively charged electrons, neutrons, (particles with no charge), and positively charged protons. It’s agreed that electrons can’t get any smaller.
Now when it comes to neutrons and protons, they’re made up of smaller particles known as quarks. There are six types of quarks with weird names, up, down, charm, strange, top, and bottom. And there are a few other smaller particles as well.
String theory deals with these smallest of particles that cannot get any smaller so atoms are too big. Protons and neutrons are too big as well but the smaller particles like electrons, quarks and a few other particles aren’t. These particles which are at the moment known as the smallest behave differently and this is where things get strange. Well I think they get strange.
String theory treats all these small particles as one piece of string. So how can an electron be a string?We normally think of electrons as a negatively charged particle moving about but with string theory, it’s thought that with the right equipment looking very close at the electron, we would see that it’s not a particle but a loop of string.
And what we see as an electron is because of the way the string vibrates. It the vibration was to change, we could end up seeing something completely different like a quark. It’s like how one guitar string can produce different notes. If string theory is correct, it would mean that everything is ultimately made up of little strings.
If my rambling hasn’t made any sense at all, this comic should help, http://xkcd.com/171/.
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