String Theory is a theoretical framework in physics that attempts to reconcile general relativity and quantum mechanics. Here are the main points:

1. Fundamental Objects: Unlike traditional particle physics, which treats particles as point-like objects, String Theory posits that the fundamental constituents of the universe are one-dimensional "strings." These strings can vibrate at different frequencies.

2. Vibrational Modes: The different ways in which strings vibrate correspond to different particles. For example, a string vibrating in one way may represent an electron, while another vibration may represent a quark.

3. Extra Dimensions: String Theory suggests that the universe has more than the four dimensions (three of space and one of time) we experience. Typically, it proposes 10 or 11 dimensions, with the additional dimensions being compactified or hidden at scales we cannot easily observe.

4. Unification of Forces: One of the primary goals of String Theory is to unify all fundamental forces of nature—gravity, electromagnetism, and the strong and weak nuclear forces—into a single theoretical framework.

5. Quantum Gravity: String Theory provides a potential framework for understanding quantum gravity, offering insights into how gravity operates at the smallest scales.

6. Supersymmetry: Many versions of String Theory incorporate supersymmetry, a theoretical symmetry that relates bosons (force-carrying particles) and fermions (matter particles). This leads to predictions of new particles.

7. Challenges and Criticism: While promising, String Theory faces challenges, including a lack of experimental evidence and difficulty in making testable predictions. Some physicists criticize it for being more of a mathematical framework than a concrete physical theory.

8. M-Theory: An extension of String Theory, M-Theory suggests that strings are actually one-dimensional slices of higher-dimensional objects called "branes." This theory is still being explored and developed.

String Theory remains a vibrant area of research, with ongoing efforts to understand its implications for the fundamental nature of the universe.

1. (physics) A candidate unified theory of all physical forces and particles; a theory which suggests that subatomic particles are one-dimensional strings rather than zero-dimensional points. It also suggests that space-time can have up to nine dimensions, plus the dimension of time.

   String theory denies the existence of a hypothetical eleventh dimension.