Monday, January 11, 2010

Pulsar Bursts Move 'Faster Than Light'

More fascinating results from the world of astronomy. What was seen in the NEC experiment from many years ago of the apparent superluminal group velocity in an anomalous dispersive medium has apparently being seen in radio pulses from a distant pulsar.

Jenet's group thinks that anomalous dispersion should be added to this list. Using the Arecibo Observatory in Puerto Rico, they took radio data of the pulsar PSR B1937+21 at 1420.4 MHz with a 1.5 MHz bandwidth for three days. Oddly, those pulses close to the centre value arrived earlier than would be expected given the pulsar's normal timing, and therefore appeared to have travelled faster than the speed of light.

The cause of the anomalous dispersion for these pulses, according to the Brownsville astrophysicists, is the resonance of neutral hydrogen, which lies at 1420.4 MHz. But like anomalous dispersion seen in the lab, the pulsar's superluminal pulses do not violate causality or relativity because, technically, no information is carried in the pulse. Still, Jenet and colleagues believe that the phenomenon could be used to pick out the properties of clouds of neutral hydrogen in our galaxy.

When the NEC's anomalous dispersion paper came out, the crackpots were falling over each other out of the woodwork proclaiming that Relativity has been "proven" to be wrong, without even bothering to understand the paper and why such claim was utterly silly. I'm just dreading to think what this new paper will cause.


1 comment:

Anonymous said...

Yo Zapper: it's hard for some of us to tell the difference between the crackpots and the sages. For example this guy

arXiv:0912.1475v1 [quant-ph]

who seems to have very good credentials says, in this major presentation piece, that nonlocal correlations are an express violation of special relativity. Just read the last sentence.

You views, sir?

I remain, as always

Clueless in Corvallis