[I put this in GD because it will probably develop into a debate.]
OK, my title may be just a little antagonistic, but I couldn’t think of any other way to title the thread, off the top of my head.
I freely admit to not knowing anything about ST, apart from what is contained within The Elegant Universe", its sequel, and some other snippets elsewhere. However, from what little I do know, ST basically posits the existence of multiple (9?) hidden dimensions, furled up, so as to be imperceptible, and posits that everything is made up of tiny strings" of matter, with differing vibrations of the strings corresponding to different behaviours. I also believe, that as of yet, there isn’t much in the way of real evidence for the existence of strings and/or multiple hidden dimensions, despite decades of search.
But doesn’t this seem a bit ridiculous? Why should there be so many hidden dimensions, and why is seemingly nigh on everyone in the theoretical physics community in love with string theory? Shouldn’t a theory that proposes so many extra dimensions be treated with a lot of suspicion (Ockham, and all that)?
Is there much opposition from within the theoretical physics community to string theory? Just what is it about ST that makes it so appealling and what is the evidence?
Theories can only be validated by experiemental evidence. A successful scientific theory has to both post-dict and predict observable phenomenon. Due to the scale of string theory, it is not currently possible to observe any of the predicted consequences of it. I think that this places it into the “neat idea” box. Add in the mathematical roadblocks and I think String Theory will struggle to be accepted by the scientific community as a whole, until there is actual evidence supporting it.
From a “Unification is Cool” standpoint, it’s a very compelling idea though. Remember that historically so many things have been considered ridiculous until they weren’t - a geocentric view of the universe is one obvious example!
I am very interested in what will happen next, ST-wise. Aren’t they nearly done building an accelerator which has the capacity to test some of the predictions?
Well, yes. But there’s alternatives to ST, as a ``theory of everything", surely? Why are these theories not getting TV shows, books, and so much attention from the scientific community? What is it about string theory that’s so appealling? Is there really some evidence that I’ve not heard of that hints towards ST being the right theory?
First of all, if you want to talk of “string theory” in general, you should speak of it as “M-theory” or the specific individual theories which comprise the former. Second, why so many dimensions, and why should they be “compactified”, or “out of phase”, or othewise hidden except for the standard three spatial dimenions and the one (rather peculiar) unidirectional time dimension? The reason is the math, or more specifically, being able to fill in all of the empty spaces in the matrices of the governing equations in a way that is symmetric and elegant. Ultimately, we’d like to believe that the underlying rules of the universe extend from a uniform, consistent set of basic principles, even if the expression of these is complicated, similarly to how mechanics and electrodynamics all thrash out in a very elegant way. This is very appealing and explains the adoration of M-theory, but it is admittedly a fad that has provided little in the way of testable, falsifiable hypotheses, and indeed one can essentially tune the model via selection of hidden constants to obtain essentially any result desired in the same way that Warner Brother’s animators create their own physics involving desert fowl and the predators that stalk them.
Regarding Lord of Ockham’s shaving apparatus and reasoning therefrom, the principle there stated is that given multiple explanations for an event, the one that requires the least gyrations or leaps of logic (which is not necessarily the simplest or having the least steps) is generallhy preferred. For instance, having the world created by being spat out of the mouth of a big tobacco-chewing pandimensional redneck with a propensity toward atavistic violence and a misogyny problem is a pretty simple explanation, but also one that lacks much in the way of physical evidence and requires a lot of “faith” in that the Chosen High Priest who makes a very good living off of the 10% tithes from his flock of followers isn’t just grifting on, while more complex explanations involving nucleosynthesis of heavy elements from Population II stars, tectonic plate theory, natural selection, et cetera is a heck of a lot more compex and requires several years study of various fields of basic and more advanced sciences to truly appreciate, but ultimately gives a more pragmatically satisfying answer. Ockham’s Big Sharp Blade is a principle of discriminating between equally founded alteratives but does not offer ultimate guidance.
That being said, many people are suspicious that M-theory is not really getting us any closer to actually knowing what it’s all about, and all but its most devout advocates don’t pretend that they’ve fully grasped the nettle and are ready to give us the Ultimate Answer to Life, the Universe, and Everything. But it is, from my somewhat superficial attempts to get into it in basic mathematical depth, joyously elegant until you get to the boundary to something not well explained, and then it gets mucked up like a traffic jam on the New Jersey Turnpike.
It’s still not as bad over arguments about interpretations of quantum mechanics, though.
Another person here who knows nothing about String Theory.
In one of the television programs that explored some of the excitement about the theory, there was some predictive quality or characteristic that worked out. It involved a chart. (I was reminded of the chart of elements that has to be in a certain order.) This chart had or has missing pieces and scientists were able to predict the qualities of what should fit there and then find something that fit the TOE that actually did.
Before you rip what I’m saying to shreds, remember that I don’t speak the “language,” I don’t understand the theory and my memory is similar to that of Ellen Degeneres’s character in that movie about the little renegade fish. I can accept criticism, but make it on topic. I know that this may not have been predictive of behaviors.
Is it science? Is it falsifiable? I just heard a program on the new collider in Switzerland with a scientist claiming we just might get evidence of extra dimensions.
The recently detected and inexplicable billions of light years across ‘void’ in our universe is being touted as evidence for string theory as it may be a predicted ‘shadow’ of an adjacent universe.
"It is the unmistakable imprint of another universe beyond the edge of our own," says Laura Mersini-Houghton of the University of North Carolina at Chapel Hill.
How can we have an imprint of another Universe, when that universe is “…beyond the edge of our own”?
Or, is the area in question supposed to be evidence of a collision of the 2 Universes? Might the “imprint” be some of the other Universe’s material that remained in ours after the collision?
I seem to remember that M Theory posits the collision of Universes.
The idea is that what we know of as our universe is really only the 13-14 billion light-year region of a much larger structure (i.e. the part that we can see). The claim that this “hole” is evidence of a second “universe” bumping up against ours like two soap bubbles is going to require a hell of a lot more proof that just “my paper says this should happen!”
For papers by Laura Mersini-Houghton you can look here at these.
Yeah, I read that article in the magazine. However, I got the impression that there’s only a few people who are taking it seriously, the rest being highly suspicious of it.
I know from reading NS that there’s plenty of other competitors for a ``theory of everything" but by far, ST seems to be the most popular. Why?
While I find the theory of the universe being made of string to be bizarre, the theory of the universe being made of cow poop sounds really bizarre, like something from a primitive tribal religion or a hallucinogenic drug experience.