-Adam Zacharia Anil

Superstring theory may give us the long-awaited physics unification that Einstein failed to achieve. Here's a glimpse at where the quest stands right now. Greene (a professor of physics and mathematics at Cornell and Columbia) begins by highlighting modern physics' core challenge. Both quantum mechanics and general relativity operate flawlessly, yet neither can be correct. Quantum theory works for small objects, while relativity works for large, massive ones.

In most cases, the two worlds can be maintained apart. However, physics increasingly deals with phenomena such as black holes, where conflicts are unavoidable. String theory arose from the desire for a more comprehensive explanation. Gabriele Venizano, who discovered that a two-century-old formula by Leonard Euler characterised subatomic particles more eloquently than existing theories, lay the groundwork for it 30 years ago.

If elementary particles were extended and vibrating, like tiny musical strings, the relationships would make sense—in a way, a modern version of the ancient metaphor of the song of the spheres. String theory took a long time to be accepted by physicists: for one thing, it seemed to predict phenomena that no one had ever seen before.

And, despite its great explanatory power, its mathematical expressions were often much more challenging to understand, let alone solve. Greene described some of the equations as practically impossible to comprehend, let alone solve.

Nonetheless, it has the correct appearance, and two waves of enthusiasm (one in the mid-1980s, the other 10 years later) have persuaded many physicists of the theory's likely veracity.

Greene masterfully recounts these results in domains ranging from subatomic particle theory to cosmology, with ventures into deeper seas like the ten-dimensional structure of the cosmos, in which several dimensions are folded undetectably back into themselves.In the next century, string theory, according to the concluding chapter, will become the conventional physical model.

Entertaining and well-written, this is arguably one of the most accessible public expositions of this complex subject to date.