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About LinkBackscould somebody please explain to me what string theory is.
it was brought up in the time theory or M-theory post and i need to understand what string theory is to understand the conversations...
...thank you
March 26th, 2008, 05:49 PM
could somebody please explain to me what string theory is.
it was brought up in the time theory or M-theory post and i need to understand what string theory is to understand the conversations...
...thank you
M-theory is the most recent version of string theory. String theory is a TOE (theory of everything) -- a theory encompassing all four fundamental forces: gravity, electromagnetism, weak nuclear force, and strong nucelar force, and thus uniting the two pillars of modern physics, General Relativity and Quantum Field theory, by quantizing gravity. There were several versions of string theory in different numbers of dimensions but the main idea was that instead of point particles what we had were tiny strings (either openended or loops) and the interesting thing was that calculations of what the vibrational modes of these strings would be, matched up with types of fundamental particles we see in the world. Thus the suggestion was that the different fundamental particles were just these different types of vibrations of these tiny strings (usually in a 10 dimensional space-time).
It is important to understand that all these ideas are just side issues, for the driving force in the development of string theory is the effort to make mathematics of quantizing gravity work out.
M-theory not only united all the different string theories into a single theory but has also explained that the strings themselves are a mathematical artifact of a higher dimensional theory - an 11 dimensional supergravity (General Relativity+Supersymmetry in 11 dimensions).
Imagining string theory:
http://www.tenthdimension.com/medialinks.php
my own thoughts:
impressed but i need to see proof :P
Originally Posted by Cynapse
This link is to something that is at most 50% science while the rest is at best philosophy or science fiction and at worst pseudo-science.
If this has value, it is for entertainment. M-theory being 11 dimensional clearly punches a gaping hole in the argument at the end that there can be nothing higher than 10 dimensions.
But as philosophy rather than science anyway, I can at least say that the person who came up with this had the courage to speculate what all these dimensions might mean.
I'm curious as to what aspect of M-theory is testable or falsifiable, so as to justify its status as a theory.
At this point just being able to succeed at the mathematical process of quantizing gravity might be considered a rather substantial test. But like all the string theories testability lies in verifying the existence of the particles it predicts to exist.
Besides I am not sure that testability is primary criterion of what makes something a theory, which is actually "utility" of which testability is only one important example. GR and QFT have more worth as theoretical frameworks in their utility to mathematically describe things. For example, some of the things that they can describe like wormholes and tachyons probably do NOT exist.
Science quite often does not have well defined criterion for the terms it uses. Consider the term "planet". Sometimes it uses these terms instinctually only later to discover inconsistencies in how it has been used. Quite a number of unified field theories have been considered and discarded. Thus maybe the word "theory" has more to do with how much time scientists have devoted to studying it and thus how much it is worth considering. Some of these theories have been discarded and then later revived (11 dimensional supergravity for example).
thank you very much i now have a greater understanding of string theory and the meaning of theory
This explains conventional string theory of 10d. M-Theory has 11d and this explanation is altered. However according to string theory of 10d this explanation is correct.
This link is to something that is at most 50% science while the rest is at best philosophy or science fiction and at worst pseudo-science.
If this has value, it is for entertainment. M-theory being 11 dimensional clearly punches a gaping hole in the argument at the end that there can be nothing higher than 10 dimensions.
But as philosophy rather than science anyway, I can at least say that the person who came up with this had the courage to speculate what all these dimensions might mean.
Does mathematically describing a thing necessarily mean we know the fundamental nature of the thing? I believe the mathematics of epicycles correctly describes the motion of planets but planets do not move in epicycles.
Planets do move in epicycles relative to Earth, though I do back your point that having accurate observations/predictions does not denote that one understands the underlying processes.
Exactly! Physics is about looking at the world through the eyes of mathematics. Questions about what really is the nature of things is a topic of philosophy (metaphysics) not physics. One can study either or both as one chooses. If one studies both then the discoveries of physics can certainly inform your philosophical studies.
Correct? Correct what? As I said this is 50% fanciful thinking that has nothing to do with any science or with string theory. Your calling the fanciful part correct, is a statement of personal philosophy and aesthetics, and certainly has nothing to do with physics.
We opened our interaction many moons ago with my disappointment in your rejection of Kuhn. Surely you cannot also be rejecting Popper?
I thought we settled my rejection of Kuhn by realizing that this was the typical reaction of the hard scientist, for his ideas are indeed applicable to the softer sciences. I still conclude that what he describes is therefore not characteristic of modern science but rather the non-scientific aspects of the softer sciences. Therefore I still claim that Kuhn is misleading.We opened our interaction many moons ago with my disappointment in your rejection of Kuhn. Surely you cannot also be rejecting Popper?
I certainly make no such claim regarding Popper. However this does not put his work above criticism or modification, besides even though it has been some time since I have read Popper, I don't think he made things quite so absolute. Furthermore, in contrast to my comments on Kuhn's paradigms and revolutions, I would NOT say that testibility is not characteristic of modern science. It most certainly is characteristic, but perhaps not entirely definative. In the most recent developments of science it has reached a little bit beyond the realm of testability requiring some adaptation to see why scientists nevertheless consider this work they are doing, science.
My comment is also intended to give a better account of the identification of evolution as a scientific theory, where I think its limited testability is only part of it. What seems rather clear to me, is that the critics of evolution fail to understand that scientists will never abandon evolution no matter what holes they think they are poking in it, simply because a scientist does not abandon his tools until better tools are available. In this ID and Creationism offers no alternative because they have absolutely no utility whatsoever.
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