- Quote: The universe’s fields, from the electric and magnetic fields to the Higgs field, have been extensively studied in experiments, and we know a great deal about them. String theory, sitting at the next level of potential knowledge, represents an attempt to explain where the fields come from.
- Endnote: According to string theory, many types of elementary particles may actually be one type of string vibrating in different ways, and the universe’s many fields may be different aspects of a single string field.
A complex vibrating object can vibrate in many ways. For instance, a guitar string can vibrate up and down or side to side; and (as shown in Figure 25 in Chapter 11), it can vibrate in a variety of patterns.
The idea of string theory is that an extremely tiny string moving in a sufficiently complicated universe (typically including extra dimensions of space, see chapter 14 or this set of articles) can vibrate in all sorts of ways. To us, as giant macroscopic creatures, a single type of string with its different modes of vibration and motion will appear to be a wide variety of different types of particles.
As discussed in Chapter 17, particles arise from fields. One might naturally assume that strings similarly arise from string fields. Just as a single string with various modes of vibration can appear as many types of particles, a single string field can be viewed as a huge number of cosmic fields, of the sort discussed in detail in the Fields section of the book. If string theory truly describes our universe, then one might hope that a string field would contain the electric and magnetic fields, the Higgs field, the gravitational field, and all the others, along with huge numbers of fields as yet unknown. It would unify all the different types of fields into a single conceptual structure.
Perhaps someday this hope will actually be realized by theoretical physicists. But at this point, it is just an interesting idea, one which some people find compelling for technical and aesthetic reasons, but which others find less so, for other technical reasons.
Since a string field might not be relevant to the real world and is quite poorly understood even by professionals, I won’t go into more detail here. Instead I’ll leave it to string field theory experts to try to explain it, should they wish to.
