Explaining String Theory: A Beginner's Guide

[Alethia]

Okay I have to do a project on "the string theory." I've done some research on it using sources from the internet and some books--but I don't really understand what it exacly is. All of these things I have read explain it in such complex ways that make it difficult to grasp. I don't understand what it means by 'particles being excited,' or what a 'string' is. I know it is related to "Einstein's Dream." But, to put it blatantly, I do not understand its concepts. Anyone care to explain? ^.^

 

[Ambitwistor]

Originally posted by Alethia
Okay I have to do a project on "the string theory."

Read the introductory chapters of Brian Greene's book The Elegant Universe.

I don't understand what it means by 'particles being excited,'

What is the context?

Something being "excited" means increasing its energy.

If you're talking about a particle in, say, an atom, then "exciting" the particle means increasing its energy.

On the other hand, sometimes people say that particles are "excitations"; in string theory, particles correspond to different ways that a string can vibrate, so we can say that these particles (vibrational modes) are what you get when you "excite" a string.

or what a 'string' is.

A string is, well, a string...

Matter is usually thought of as made up of molecules, which are made up of atoms, which are made up of elementary particles like electrons ... which are not made up of anything else. Elementary particles are zero-dimensional, pointlike objects, which are not themselves made from anything smaller or simpler.

In string theory, electrons are not zero-dimensional points, they are one dimensional strings. These strings are "elementary" in the sense that we thought electrons were: they're not made up of out anything smaller or simpler; they are the simplest, most fundamental form of matter. Electrons are made up of them (or rather, electrons are strings that are vibrating in a certain way), and atoms are made up of electrons and other particles, etc.

 

[M98Ranger]

String theory is a complex and abstract concept in physics that attempts to unify the two major theories of modern physics, general relativity and quantum mechanics. It proposes that the fundamental building blocks of the universe are not particles, as we traditionally think of them, but infinitesimally small strings that vibrate at different frequencies.

These strings are believed to be the underlying structure of all matter and energy in the universe. Just as musical notes produce different sounds depending on their frequency, the vibrations of these strings give rise to the different particles and forces in our universe.

One of the key ideas of string theory is that these strings exist in multiple dimensions, beyond the four dimensions we experience in our daily lives. This is where the concept of "Einstein's dream" comes in, as it relates to his theory of general relativity which suggests the existence of extra dimensions.

So when we talk about particles being "excited," it means that the strings are vibrating at different frequencies, which in turn determines their properties and characteristics. And the term "string" refers to these tiny, one-dimensional objects that make up the fabric of our universe.

Overall, string theory is still a highly debated and complex topic, and there is much that we still don't fully understand about it. But it is a fascinating concept that has the potential to revolutionize our understanding of the universe and its fundamental workings. I hope this brief explanation has helped to clarify some of the basic concepts of string theory for you.