SciAm: Faster-than-light electric currents

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SciAm: Faster-than-light electric currents

Post by bystander » Sun Jun 20, 2010 4:36 pm

Faster-than-light electric currents could explain pulsars
Scientific American | Observations | 18 June 2010
Claiming that something can move faster than light is a good conversation-stopper in physics. People edge away from you in cocktail parties; friends never return phone calls. You just don't mess with Albert Einstein. So when I saw a press conference at the American Astronomical meeting this past January on faster-than-light phenomena in the cosmos, my first reaction was to say, Terribly sorry, but I really have to go now.

Astrophysicists have been speaking of FTL motion for years, but it was always just a trick of the light that lent the impression of warp speed, a technicality of wave motion, or an exotic consequence of the expansion of the universe. These researchers were claiming a very different sort of trick. Dubious though I was, I put their press release in my "needs more thought" folder and today finally got around to taking a closer look. And what I've found is utterly fascinating.

The researchers ... have built a sort of wire in which an electric pulse can outpace light. They get away with it because the pulse is not a causal process. It does not ripple down the line because charged particles are bumping into each other, a process that is subject to Einstein's speed limit. Instead, an external controller drives the particles and can synchronize them to make a pulse pass through the wire at whatever speed you want. ...

This method of breaching the speed barrier might seem like cheating -- after all, no material object is breaching the barrier. But electromagnetically it doesn't matter. Whatever the origin of the pulse in a wire, it involves the motion of electric charge and emits electromagnetic radiation. The radiation propagates outward at the speed of light, but is forever shaped by the speed of whatever generated it. ...

Not only is the radiation tightly focused in space, it is tightly focused in time -- a pulse that originally takes, say, 10 seconds to generate might be squeezed into 1 millisecond as all the electromagnetic wavefronts get jammed together. The temporal focusing causes the radiation to spread out over a wide swath of the electromagnetic spectrum. In addition, the focusing provides a degree of amplification, causing the intensity of the radiation to diminish not with the inverse square of the distance but with the inverse distance. ...

Singleton and Schmidt's main interest is applying the idea to astrophysics -- in particular, to pulsars. Astrophysicists think these objects are hyperdense neutron stars that generate radio pulses as they spin, much like a lighthouse. But they have struggled to explain why the radio pulses are so sharp and why they appear over such a broad range of the spectrum. ...

The researchers are now applying their model to another mystery of astrophysics, gamma-ray bursts. Astrophysicists typically estimate the intrinsic power generation of these bursts by assuming the inverse-square law, and the values they get are off the charts. But if FTL effects are involved, the inverse-square law might be overestimating the power and astronomers should really be using a simple inverse law. ...

The basic principle of FTL currents goes back to work by English physicist Oliver Heaviside and German physicist Arnold Sommerfeldt in the 1890s, but was forgotten because Einstein's theories dissuaded physicists from thinking about FTL phenomena, even those that evaded the theories' strictures. ...
Faster-than-Light Pulsar Phenomena | Los Alamos National Laboratories | 05 Jan 2010
Lawbreakers? Faster-than-light Polarization Currents, the Electromagnetic "Boom" and Pulsar Observational Data

Pulsars are neutron stars that emit amazingly regular, short bursts of radio waves, so regular that they were originally thought to be signals from little green men! Though their discovery over 40 years ago was very widely reported and resulted in a Nobel Prize, the reasons how and why they send these bursts has remained a mystery; to quote Jean Eilek of NRAO, "we know why they pulse, but why do they shine?"
A new mechanism for generating broadband pulsar-like polarization Comparison of multiwavelength observations of 9 broad-band pulsars with the spectrum of
the emission from an extended current with a superluminally rotating distribution pattern
A Maximum-Likelihood Analysis of Observational Data on Fluxes and Distances
of Radio Pulsars: Evidence for Violation of the Inverse-Square Law