Describing the shape of electric and magnetic fields is complex. A useful approach in mathematics and physics is to break up a complex problem into smaller pieces. One example of this is the Taylor series expansion for continuous functions, expansions like sin(x) ~ x - (1/3!)x^3 +…. Like the Taylor expansion, the field from a complicated source can be broken up into a multipole expansion. Every field has a monopole term, plus a dipole term, plus a quadrupole, and an octopole, etc. By manipulating the physical source of the field, we can eliminate the other multipoles and create a pure dipole, pure quadrupole, or even a pure octopole. In this talk we will explore the math behind the multipole expansion, explain how we created the pure multipole sources, and describe how one can measure these fields using internal sensors in a smartphone.
Monday, November 27
4PM - 5PM - CNS 204
Lite refreshments will be provided.