Prof. J.E. Carroll

Electrical Group

Introduction

Prof. John Carroll is an Emeritus Professor from the Staff of Cambridge University Engineering Department. He still enjoys contact with the Photonics and Sensors Group in the Electrical Engineering Division. He is a Life Fellow of Queens' College.

Short CV

Research

Semiconductor Lasers

"Distributed feedback semiconductor lasers" by John Carroll, James Whiteaway & Dick Plumb.
Awarded IEE Rayleigh Book Prize 2000.

Space-Time Vortices

The key concept of this work is that there is a lot to be said for discussing how to derive Maxwell’s equations using a three-dimensional-time + three-dimensional-space . Some initial ideas were presented at the Rochester Conference in June 2001. Using Powerpoint, you can access a poster set given at the Rochester Conference June 2001 here. Quantisation arises from boundary conditions in spacetime with allowance for waves travelling back in time as well as forward in time - these are the spacetime vortices. These ideas were also presented at PIRT VIII in September 2002 and can be accessed at the PIRTVIII website. However these ideas again have moved on and the latest version derives Maxwells classic equations with fields, potentials, positive and negative charges in 3+1 spacetime solely from the symmetry that is required by the Geometric Algebra of a 3+3 spacetime. The observed direction of time is augmented by two additional orthogonal temporal dimensions forming a complex plane where i is the bi-vector determining this plane. Variations in the transverse time determine a zero rest mass. Real fields and sources arise from averaging over a contour in transverse time. Positive and negative charges are linked with poles and zeros generating traditional plane waves with ‘right-handed’ E, B, with a direction of propagation k. Conjugation and space-reversal give left-handed plane waves without any net change in the chirality of 3+3 spacetime. Resonant wave-packets of left- and right- handed waves can be formed with eigen frequencies equal to the characteristic frequencies (N+½)fo that are observed for photons. The use of the term 'spacetime vortices' has been curtailed in this paper as previous referees thought this was too contentious. This new paper will be available under J.E.Carroll on arxiv.org math-ph/0404033 (after April 16 2004) and has yet to be reviewed and clearly represents ongoing work to be refined and corrected.

Further related work connects correlations, relativity and quantum theory in a paper to be presented to PIRT IX in September 2004 (click here). Some of these ideas showed how correlations could help one to understand Geometric Algebra at a conference in Sept 2002 (Trinity College Cambridge) but have not yet been published.

Internet Traffic

My lecture note on Internet Traffic is available to be browsed using Powerpoint from here.

Recent Publications

Awarded in 2001 with Dr. Paul Kirkby of Nortel Networks the IEE the IERE Benefactors Premium for the paper on
"Proportionally fair pricing: dynamics, stability and pathology"
Awarded in 2001 with Eddie Pratt the IEE JJ Thomson prize for the paper on "Gain modelling and particle
balance in semiconductor lasers"
September 2002 “Relativity with three dimensions of time: spacetime vortices”
Physical Interpretations of Relativity Theory VIII, London, Imperial College
September 2002 "Correlations and Geometric Algebra" Conference on Applications of Geometric Algebra Trinity College Cambridge 2002
"Traditional Vectors as an introduction to geometric algebra" Eur.J.Phys 24 (2003) 419-427

Contact Information

E-mail: jec@eng.cam.ac.uk
Department Address: University of Cambridge, Department of Engineering, Trumpington Street, Cambridge CB2 1PZ
Telephone: +44 1223 3 32829
Fax: +44 1223 3 32662

[ Cambridge University | CUED| Electrical Group ]

Updated: April 14 2004

J.E. Carroll - jec@eng.cam.ac.uk