It's a powerful idea that could help to explain everything from black holes to hidden dimensions, and lead to a new understanding of gravity.

But string theory is also enigmatic and baffling, describing a realm that is, with current technology, too small for us to explore directly.

A new website, *Why String Theory*?, aims to tell the story of the theory's past, present, and (possible) future in a way that anyone can understand.

'We all instinctively want to explore the world around us. String theory gives us a chance to uncover the most fundamental laws of nature. So much of fundamental physics nowadays is completely inaccessible… We wanted to rectify this, conveying the excitement of contemporary research,' Edward Hughes, a Cambridge University undergraduate and member of the team behind the website, tells me.

'I'm still on the fence as to whether I think string theory is the right direction, but there are certainly elements of it that are very simple and appealing,' says team member Charlotte Mason, an Oxford University undergraduate. 'The idea that the myriad of particles in the universe could arise from different vibrational patterns of tiny strings is a very elegant explanation. Though the mathematics beyond that is often not so elegant!'

Joseph Conlon of Oxford University, another member of the team, explains that part of the theory's appeal lies in 'string miracles', these are 'calculations that look like they are going to fail and show that the theory is inconsistent, but then something comes in and suddenly saves the day. Once you see this happening several times you realise that the theory has a very deep structure and your understanding of it only scratches the surface.'

String theory is not the only approach that it is hoped might one day encompass the behaviour of everything from galaxies to sub-atomic particles, but it does appear to offer some tantalising insights. One of these concerns some of the universe's most mysterious objects: black holes.

'Objects in string theory called branes can be used to count the number of possible ways you can make a black hole,' Joseph tells me. 'For certain types of black holes this agrees with a famous calculation of Stephen Hawking of the entropy of the black hole.

'Entropy is a measure of how many ways there is of making something. Hawking used clever arguments to say what the answer must be. In string theory you can count the number of ways explicitly and find that it agrees with Hawking's answer.

'String theory can help solve problems with quantising gravity by treating particles as strings rather than points. This smears out interactions and makes infinite quantities finite.'

But, however powerful its insights, there is a problem: so far no one has been able to prove that those tiny vibrating strings the theory depends on actually exist. Joseph admits that they will be hard to find: it will, he thinks, take a major technological advance, a brilliant insight, or wonderful luck to turn up the right kind of evidence.

Yet string theory has a habit of turning up surprises, as Joseph says: 'Working on it is also good for humility, you are perennially aware that the theory is smarter than you.'

**Explore further:**
String theory researchers simulate big-bang on supercomputer

## vacuum-mechanics

Yes, but the problem is that objects in nature, electrons, earth, stars, etc. all are shaped in sphere (due to gravity), while in string theory in which elementary objects (something like spaghettis, noodles) are manmade. Worse, it has extra dimensions (from natural ones) in which no one knows how and why the extra dimensions has to curl up to hide from us! May be this physical view could help to visualize how the gravity works!

http://www.vacuum...=9〈=en

## antialias_physorg

You are aware that none of these are sphere? And that in the case of the electron a 'shape' definition is pure nonsense?

If you'd even read the article then you would have noticed that it says exactly that.

String theory is just a hypothesis among many. One that is elegant in certain respects and not so much in others. Elegant approaches have always had an appeal (E.g. E8 which also ties into string theory) because they are easy to grasp. So it is natural for us to look at these, first.

The universe, however, does not much care whether we can grasp something easily or not when it comes to the things that make it tick. So string theory will hang around (like all other theories) until a test can be devised.

## Noumenon

## theorist777

## Zahid Zakir

This conformal anomaly follows from the zero-point energy of string's oscillatory modes at quantization.

However, in the paper (Theoretical Physics, Astrophysics and Cosmology, 2008, 3, 9) I show that chiral symmetry (chiral charge conjugation) leads to the lack of zero-point energy for string's oscillatory modes (there are rotatory modes only, nor vibratory!).

As the result, relativistic strings have not conformal anomaly (no central extension of Virasoro alg.), spacetime dimensionality may be arbitrary.

Thus, string theory should be fully reformulated, after which it can not pretend to the role of fundamental theory.

## Simon Denman

## ValeriaT

## ant_oacute_nio354

al modern physics based on abstract mathematics is wrong.

Antonio Saraiva

Nature is classic.

## Richardmcsquared

## gwrede

We have these hordes of ignorants, who stumble upon "scientific sights" (sic), and believe everything written there. From that day on, they shut their ears and eyes from anything that contradicts those "teachings".

Well, I guess it's just part of the (sub)human condition. But now, that we have at least one site where somewhat more serious stuff is presented, one can only hope that many newbies land there first.

## Lurker2358

It's impossible for a model to be 100% accurate because we as observers are subject to the laws, and our "objective" view is therefor not objective after all.

We also cannot know all the variables, nor even the constants, nor certainly the unknown unknowns because we cannot even measure the size of the universe, never mind it's contents and their interactions, as far as any science we know of has presented, due to mechanical limitations.

If I say that the Earth is a sphere, most people would agree, but it is not a sphere, it's an irregular ellipsoid. Yet clearly the Earth is closer to a sphere than it is to a cube.

If you say it is a sphere your model is wrong. If you say it is an ellipsoid, you're still wrong, but closer.

## baudrunner

If we appreciate that space is as much a creation as the matter which displaces it and the temporal framework as the continuum within which this matter is displaced, then it isn't much of a stretch to understand that creation occurs in all directions simultaneously, and that it continues to do so at the periphery of the universe, to infinitude.

Given what we have to work with, that is, everything we see before us, I don't really see how we fit strings into a big bang scenario. I think those theorists imagine that there was space before everything and that the early universe was only stringy. I can't.

## RealityCheck

Brilliant choice of concept/paraphrase, by the way. Made me laugh into my tea and splash the keyboard! I'll be sending you the bill for a new one if it now malfunctions because of your really neat joke on string theory there. :)

## ValeriaT