Faster-Than-Light Pulsar Phenomena

by Nancy Atkinson on January 6, 2010

Want to stay on top of all the space news? Follow @universetoday on Twitter


Observational data from nine pulsars, including the Crab pulsar, suggest these rapidly spinning neutron stars emit the electromagnetic equivalent of a sonic boom, and a model created to understand this phenomenon shows that the source of the emissions could be traveling faster than the speed of light. Researchers say as the polarization currents in these emissions are whipped around with a mechanism likened to a synchrotron, the sources could be traveling up to six times light speed, or 1.8 million km per second. However, although the source of the radiation exceeds the speed of light, the emitted radiation travels at normal light speed once it leaves the source. “This is not science fiction, and no laws of physics were broken in this model,” said John Singleton of Los Alamos National Laboratory at a press briefing at the American Astronomical Society meeting in Washington, DC. “And Einstein’s theory of Special Relativity is not violated.”

This model, called the superluminal model of pulsars, was described by Singleton and colleague Andrea Schmidt as solving many unanswered issues about pulsars.”We can account for a number of probabilities with this model,” said Singleton, “and there is a huge amount of observational data available, so there will be ample opportunities to verify this.”

Pulsars emit amazingly regular, short bursts of radio waves. Within the emissions from the pulses, the circulating polarization currents move in a circular orbit, and its emitted radiation is analogous to that of electron synchrotron facilities used to produce radiation from the far-infrared to X-ray for experiments in biology and other subjects. In other words, the pulsar is a very broadband source of radiation.

However, Singleton said, the fact that the source moves faster than the speed of light results in a flux that oscillates as a function of frequency. “Despite the large speed of the polarization current itself, the small displacements of the charged particles that make it up means that their velocities remain slower than light,” he said.

These superluminal polarization currents are disturbances in the pulsar’s plasma atmosphere in which oppositely-charged particles are displaced by small amounts in opposite directions; they are induced by the neutron star’s rotating magnetic field. This creates the electromagnetic equivalent of a sonic boom from accelerating supersonic aircraft. Just as the “boom” can be very loud a long way from the aircraft, the analogous signals from the pulsar remain intense over very long distances.

Rapid condensation of water vapor due to a sonic shock produced at sub-sonic speed creates a vapor cone (known as a Prandtl–Glauert singularity), which can be seen with the naked eye.

Back in the 1980s, Nobel laureate Vitaly Ginzburg and colleagues showed that such faster than light polarization currents will act as sources of electromagnetic radiation. Since then, the theory has been developed by Houshang Ardavan of Cambridge University, UK, and several ground-based demonstrations of the principle have been carried out in the United Kingdom, Russia and the USA. So far, polarization currents traveling at up to six times the speed of light have been demonstrated to emit tightly-focused bursts of radiation by the ground-based experiments.

Although Singleton and Schmidt’s highly technical presentation was admittedly over the heads of many in attendance (and watching online), LANL researchers said the superluminal model fits data from the Crab pulsar and eight other pulsars, spanning electromagnetic frequencies from the radio to X-rays. In each case, the superluminal model accounted for the entire data set over 16 orders of magnitude of frequency with essentially only two adjustable parameters. In contrast to previous attempts, where several disparate models have been used to fit small frequency ranges of pulsar spectra, Schmidt said that a single emission process can account for the whole of the pulsar’s spectrum.

“We think we can explain all observational data using this method,” Singleton said.

When asked, Singleton said they have received some hostile reactions to their model from the pulsar community, but that many others have been “charitably disposed because it explains a lot of their data.”

Lead image caption: Artist’s impression of an anomalous X-ray pulsar. Credit: ESA

Papers: Singleton et al,, Ardavan, et al, Ardavan, et al
Sources: AAS press conference, LANL,

About 

Nancy Atkinson is Universe Today's Senior Editor. She also is the host of the NASA Lunar Science Institute podcast and works with Astronomy Cast. Nancy is also a NASA/JPL Solar System Ambassador.

ND January 8, 2010 at 7:01 AM

Aodhhan: “if I listed my information… you wouldn’t beleive it.”

Interesting you says this. Why would we not believe you when you list your credentials? This does not appear to be an issue with most people that post here. The problem is your belligerent tone. You seem to have a chip on your shoulder.

Olaf January 8, 2010 at 7:27 AM

I found this simulation on the internet:

http://www.physics.purdue.edu/MOJAVE/superluminal.swf

Interesting to see ho stuff appears to move faster than light but in reality never moved faster.

Olaf January 8, 2010 at 7:50 AM

@Aodhhan

“So if the pulsar is the hub, moving near the speed of light, the end of the wheel will be moving much faster. In excess of the speed of light.
Since it is commonly known… on a wheel, the outside edge is moving much faster, with the same amount of force than the hub providing the energy.”

Your explanation is confusing, here you clam that the pulsar is moving at the speed of light. This is not what the article tells us.

Also your explanation violates the speed of light at the end of the wheel. It does not conform to what the article explains.

Your explanation is as silly as saying that if you travel at light-speed and shine a light towards your direction it doubles the speed of light.

This part in the text “the sources could be traveling up to six times light speed, ” is a bit misleading.

Lawrence B. Crowell January 8, 2010 at 7:55 AM

Olaf, this is similar but different. This is an apparent superluminal velocity due to an angular effect.

I am a bit curious as to why this Aodhhan fellow has taken such an emnity towards me. It gives me a slight errie feeling this guy is somebody I know or knew in the past and has some long standing grudge. Why target me exclusively with this pile of hogwash? Yet it is clear Aodhhan would fail a sophmore level exam in electromagnetism or mechanics. I suppose I should just blow him off at this point.

LC

Olaf January 8, 2010 at 8:11 AM

I just found another demonstration of superluminal motion.

http://gregegan.customer.netspace.net.au/APPLETS/20/20.html

Olaf January 8, 2010 at 8:25 AM

Yes LBC you used the magic word “apparent”.
Aodhhan his description did not.

The sources themselves do not move faster than the speed of light but the appear to be moving faster than light.

One way to visualize this is you have a series of lights. All connected to some electronics with equal length of wiring. You program it or create a running light. So you see the lights move front the start to the end. Now speed this up so fast that the first light appears to reach the end of the series faster than light. This can be perfectly done since you trigger the light at the electronics and they have to travel the same length of wire not violating the speed of light but once reached the light the series of appears to be triggered faster than the speed of light provide you put a very tine picosecond or lower delay for each light trigger.

Lawrence B. Crowell January 8, 2010 at 9:17 AM

There is a little detail section in Egan’s (I know this guy a bit) which gives a quick calculation of this. In a sense these are all an example of angles or phases. A beach wave might reach the shore at a slight angle and the pont where the crash happens will move along the shore much faster than the wave is moving.

LC

Olaf January 8, 2010 at 9:38 AM

Another example I heard was the movement of a caterpillar. While the legs itself did not violate the speed of light the body movement appears to exceed speed of light. LOL

Or in human words: The body of the caterpilar appear to move faster than its legs.

No harm was done to any caterpilla. LOL

Olaf January 8, 2010 at 9:46 AM

There is one thing that I can’t get a complete grasp of the article. The sources are triggered in a sequence that appears top be faster than the speed of light. And it is possible because of the rotating magnetic field.

These sources are in the pulsar his surface, so the fast rotating magnetic field triggers the sources just like in my running light explanation. The sources do not move by themselves or not much so no violation of the speed of light. But because you have so many sources in the surface and is triggered as a running light, it appears to be on single source that moves around the surface of the pulsar faster than light-speed.

Lawrence B. Crowell January 8, 2010 at 9:51 AM

I will first confess I am not deeply educated in plasma physics. Yet there is a wave which propagates along the plasma which induces a charge separation. This would be something like an Alfen wave. This then makes the charge source for this radiation move on a group velocity that is very rapid. Yet this happens without any actual charged particles moving faster than light.

LC

Olaf January 8, 2010 at 10:55 AM

I think I have the picture now. The sources are atoms, you have a whole bunch of them and everywhere where this magnetic field touches it through plasma it becomes a source giving the appearance that it moves but in reality is a series of atoms triggered in charge just like a running light.

Cool!

Lawrence B. Crowell January 8, 2010 at 11:40 AM

That is basically it. Again I am not a plasma maven, so there are details missing. It is some form of charge separation wave with a group velocity.

LC

Olaf January 8, 2010 at 5:30 PM

I am not an abstract formula guy, I need some visual to understand it.

I was thinking a bit further when I was driving to get my GF.

It could be even simpler visualized assuming that you have a laser at the centre of the pulsar. Probably a laser at the 2 endpoints. Now spin it very fast, everywhere the laser gets to the surface it activates the atoms and that point become a source. Interesting the laserlight (plasma/magnetic field) does not violate the speed of light since the light from the lase still flies at near speed of light depending on the material of the star.
Now spin the laser realy realy fast and the light even travels like a spiral upwards because of the distance towards the surface.

Lawrence B. Crowell January 8, 2010 at 5:57 PM

Think of the laser light as like a machine gun in one of those old video games where the pixel lights would fly around. If you rotate that gun around the screen that is not to different from what happens to a laser pointer when it angle of aim changes.

LC

Vanamonde January 9, 2010 at 1:48 AM

Lawrence B. Crowell, even if I fail to understand all you post, your posts have Great Value and it is my own lack of background that is the fault, a situation I own myself.

Let no one who narrow mind is smaller than their wide mouth (or trollish fingers in the case) trouble you.

Torbjorn Larsson OM January 9, 2010 at 6:19 PM

Ah, thanks Olaf and LBC! Now I can visualize some models of geometry that can fit the process. At times you need to “shoot the crap” with others to get what’s going on.

RUF January 14, 2010 at 2:33 PM

“It’s just a model…” –Patsy, Monty Python & the Holy Grail.

Comments on this entry are closed.

Previous post:

Next post: