All modern particle physics is described by quantum field theories. When you combine these two concepts, you get quantum field theory: a field theory that obeys the principles of quantum theory. This refers to principles that lead to seemingly bizarre physical phenomena, which nonetheless seem to occur in the subatomic world. In topics 7 and 8, you find out about one of the most important achievements of the 20th century: the development of quantum theory. A field theory, then, is a set of rules that tell you how some field will behave, such as how the temperature in the room changes over time. For example, you can think about the temperature in a room as a field - it may be different near an open window than near a hot stove, and you could imagine measuring the temperature at every single point in the room. Physicists use fields to describe the things that don’t just have a particular position, but exist at every point in space. These properties and relationships - called by jargon such as various symmetries and dualities, the cancellation of anomalies, and the explanation of black hole entropy - are described in topics 10 and 11. String theory uses no experiments that provide new insights, but it has revealed profound mathematical relationships within the equations, which lead physicists to believe that they must be true.
#Strings theory unvibrating string how to
The major achievements of string theory are concepts you can’t see, unless you know how to interpret the physics equations. The established theory of gravity, general relativity, has a fluid, dynamic space-time, and one aspect of string theory that’s still being worked on is getting this sort of a space-time to emerge out of the theory. Because string theory is a quantum field theory, this means that string theory would be a quantum theory of gravity, known as quantum gravity. This is the power of string theory - to use the fundamental strings, and the way extra dimensions are compactified, to provide a geometric description of all the particles and forces known to modern physics.Īmong the forces needed to be described is, of course, gravity. It’s a quantum field theory (see the sidebar “What is quantum field theory?”) that describes the particles and forces in our universe based on the way that special extra dimensions within the theory are wrapped up into a very small size (a process called compactification). String theory is a type of high-energy theoretical physics, practiced largely by particle physicists. Using tiny and huge concepts to create a theory of everything Physicists have created simplified versions of the equation, but it doesn’t quite describe our universe. Scientists have some vague notions about the general elements that will exist within the theory, but no one has come up with the final equation that represents all of string theory in our universe, and experiments haven’t yet been able to confirm it (though they haven’t successfully refuted it, either).
In this topic, I avoid the mathematics and try to get to the heart of what the theory is telling us about the physical universe.Īt present, no one knows exactly what the final version of string theory will look like. If you’ve never studied physics before, this may seem odd, but all physical theories are expressed in the language of mathematics.
It’s based on mathematical equations that can be interpreted in certain ways. Let me reiterate something important: String theory is a mathematical theory. One important result of string theory is that gravity is a natural consequence of the theory, which is why scientists believe that string theory may hold the answer to possibly uniting gravity with the other forces that affect matter. All of the matter in our universe consists of the vibrations of these strings (and branes). The theory also predicts other fundamental objects, called branes. These strings of energy represent the most fundamental aspect of nature. String theory is a physics theory that the universe is composed of vibrating filaments of energy, expressed in precise mathematical language.