Physics experts exploring the “landscape” of string theory–an expansive set of mathematical solutions providing equations needed to describe reality–have found one solution with an extraordinary property known as S-duality that links quantities that had previously been considered separate, such as large and small distance scales as well as strong and weak forces.
1. It Unifies Particle Physics
As soon as Isaac Newton realized that an apple falling to Earth and the Moon orbiting around Earth could both be explained by one force of gravity, Maxwell’s electromagnetic theory like /h3xqzgxoc5q brought together electric and magnetic phenomena as different aspects of one electromagnetic field; Einstein’s general relativity theory combined space, time and the weak and strong forces into an entirely new quantum theory.
One of the earliest precursors to this quest for unity was string theory, an idea developed by particle physicists during the 1950s and 1960s. This theory describes particle behavior as oscillations within an oscillating string-like structure.
To better communicate its unifying properties, the theory incorporated concepts related to supersymmetry – an imaginary geometric relationship connecting fermions (particles with spin 1/2) and bosons (particles with spin 0 or 1) particles – creating an intricate set of mathematical equations which were difficult to read and comprehend; to make their data easier to interpret some experimental high energy physicists “sonified” them.
2. It Provides a Quantum Theory of Gravity
String theory offers an alternative model for particle physics known as the Standard Model. It has numerous appealing qualities that make it attractive to physicists.
At first glance, quantum theory naturally avoids the types of infinities that plagued particle physics in the mid-20th century. Consider two electrons with similar charges; when put close together they attract. But if placed infinitely close together they are repulsed by an infinite force; this kind of infinitesimal forces is what shatters any attempts to draw predictions from theories that are sound.
Einstein introduced this idea of unifying quantum mechanics and gravity for his general theory of relativity in 1919, then refined by Gerardus ‘t Hooft to incorporate into string theory by Leonard Susskind and Joseph Polchinski as “holographic duality or correspondence,” meaning our four-dimensional universe with gravity is actually just an image projected onto much lower-dimensional spaces such as holograms; making studying some difficult problems in physics much simpler.
3. It Requires 26 Dimensions
Though among the most fascinating scientific theories ever developed, string theory remains one of the least understood. This may be because its prediction of extra dimensions (26 for bosonic strings and 10 for superstrings) can be difficult for even experienced string fans to comprehend; even their dedicated supporters often struggle explaining it all effectively to non-scientists – contributing significantly to any negative reactions many non-scientists might have toward it.
Physical scientists generally have a very clear grasp on why string theory predicts additional dimensions. There’s an objective criterion known as critical dimension that must be satisfied for string theory to remain consistent with conformal field theory’s predictions of vanishing conformal anomalies and flat spacetime solutions.
Criterion 1 for string theory dictates that it must be possible for it to oscillate in multiple dimensions that cross each other in flat spacetime; these dimensions are known as Calabi-Yao manifolds after two physicists who first described them mathematically.