Since the 1960s, there have been several variations of the string theory which have been developed. The bosonic string theory is the original version of this idea as it only contained bosons within the spectrum.
In string theory, the original idea was that the pointed particles in particle physics could be replaced by 1D objects. These objects, called strings, were propagated throughout space and could interact with each other. From a distance, strings would look like any other pointed particle, but up close, their mass and charge would help to influence its vibrational state.
The bosonic string theory was abandoned for other quantum theories, but is still currently used in theoretical science with the idea of quantum gravity.
What Is a Boson and Why Does It Matter?
Bosons are particles that follow Bose-Einstein statistics. In the field of quantum mechanics, they are one of two classes of particles, with the other being a fermion. Bosons include several different types of fundamental particles, including gluons and photons.
The Higgs boson is another elementary particle that would be included within this grouping.
What is important about bosons is that their statistics don’t restrict the number that can occupy the same quantum state. This is what differentiates them from fermions, which cannot occupy the same quantum space. That means that bosons are essentially the glue that keeps matter held together.
Using Bose-Einstein statistics, identical bosons are encouraged to crowd into one quantum state. It does not need to be a convenient state for the crowding process to occur.
Bosons can be one of two types: elementary or composite.
Elementary bosons are like photons. Composite bosons are like mesons. Most of them are going to be composite particles, but the standard model does include 5 bosons that are elementary. A graviton is another hypothetical particle that would be conceivably included as a boson if it is determined to exist.
What Are the Different Types of Bosonic Strings?
According to the bosonic string theory, there are four different possible theories that are applicable. It depends on whether an open string is allowed in the theoretical concept and if the strings are given a specific orientation. Since a theory of open strings must also include closed strings, this creates the differentiation.
Bosonic string theory is therefore valid as closed or open and closed, while being oriented or unoriented. Each string theory does have two features in common: they must include a negative energy tachyon and have a massless graviton.
Built into the structure of bosonic string theory is the idea that there are 26 total dimensions instead of the four dimensions that Einstein proposed. One of the dimensions is time, while the others are usually thought of in terms of directional need. The mathematics of the bosonic string theory fall apart if there are not 26 dimensions present.
That is due to the vibrations of the strings that occur. Each string has a movement pattern that is like a sound or light waves. The only difference is that the waves do not involve travel. They’re 1D waves because they only move along the length of the string itself.
Then, as the ends of the string move, 2D is required to describe the motion. This is how the various dimensions begin to build within the theory.
How Does the Bosonic String Theory Fall Short?
The bosonic string theory was the original string theory because if offered several attractive features, but in the physical model, it has two significant issues.
The first issue is the fact that most physical particles are fermions. The bosonic string theory predicts only the existence of bosons.
The second issue is that it predicts a mode of the string with imaginary mass as part of its prediction. This would imply that the bosonic string theory is relatively unstable.
There are also inconsistencies with general space-time dimension because of what is called the conformal anomaly, which is a common issue that faces all string theories.
With 22 extra dimensions, it can be difficult to understand how the universe works. We can understand plotting a coordinate in three dimensions, while we all recognize time, but what about the others? The bosonic string theory suggests they must remain hidden in some way. One theory suggests that they are “rolled up,” but no one has any direct experience with these other dimensions.
This means that although we know more about our universe today than ever before, we have also only begun to scrape the surface of how complex our reality happens to be.