The jet from a colliding neutron star seems to travel seven times the speed of light.

The speed has seen when neutron stars collide. The impact energy can form the short-term warp bubble that allows the radiation to travel faster than it usually travels. 

Two other things are making it possible to make particles travel faster than the speed of light. 

A) Virtual crossing where high-speed particles are impacting each other. If the speed of both particles is 0,8 times the speed of light the impact speed is 1,6 times the speed of light. 

B) Rising the escaping velocity of the particle higher than the speed of light. So behind the black hole's event horizon, the speed of particles is higher than the speed of light.  The reason for that is that particles drop to the gravitational center at the same speed as escaping velocity. 

The fact is that crossing the speed of light is a paradox. That thing is quite easy to make in theory. The only thing that must do is to create an area where the light travels faster than light travels in the environment around it. 

Cherenkov's radiation or the blue light flash is a good example of how a particle can cross the speed of light. When a particle that travels with the speed of light impacting water. 

That thing causes a blue light shockwave. And the reason for that is simple: light travels in the air faster than it travels in water.  And when the particle's speed is slowing. It must release its kinetic energy as the blue light shockwave.  

Things like Cherenkov's radiation and Boötes void prove that the speed of light depends on the medium where the light travels. And there is an empty area in the universe there is no reflection or scattering effect that slows the speed of light. 

One reason that makes scattering effect slows the speed of photons is that scattering puts the photon travel a meandering trajectory. When a photon releases energy quantum every time it changes its direction. That thing makes it impossible to increase the photon's energy level.

There is a possibility, that regular high-energy radiation from the neutron star or magnetar can make the jet cross the speed of light. In that hypothetical situation. The intensive energy of the jet of the neutron star can wipe out other particles and quantum fields. And that thing makes the neutron star's beam travel at a higher speed than light. But the photon's speed is always on the top. So light travels faster in that high-energy beam that is outside it. 

So can spacecraft travel with the speed of light? 

The idea is the same with the warp bubble. There is the possibility that someday researchers can create a spacecraft where is a ball-shaped annihilation chamber inside it. The antimatter system detonates particle-antiparticle pairs in that chamber. The energy bubbles that are traveling outside the craft push material and electromagnetic fields like particles and quantum fields away from the craft. 

And that thing forms a small-size void around that thing. That allows light to travel faster than outside that bubble. That kind of system makes it possible to create a jet and an area where other particles increase at the same speed. 

https://www.livescience.com/can-anything-travel-faster-speed-of-light

https://www.newscientist.com/article/2342191-jet-from-neutron-stars-seems-to-travel-seven-times-the-speed-of-light/

https://artificialintelligenceandindividuals.blogspot.com/

The mystery of lost pulsars.

"Radio detection of an elusive millisecond pulsar, PSR J1740-5340B (NGC 6397B), in the Globular Cluster NGC 6397 with the Parkes radio telescope in Australia. Credit: NAOC/ScienceApe" (ScitechDaily.com/Why Have Pulsars “Gone Missing” – A New Finding Offers Some Answers)

Pulsars are fast-rotating neutron stars. And that means many forces affect that thing. There is the possibility that the extremely fast rotating neutron stars will stretch from their poles. And the neutron star turns to look a little bit like a dumbbell. That change in the form of neutron stars is not quite big but researchers can measure that change. 

Pulsars can turn away from the Earth. And that means they can be "missing". The changes in material symmetry can cause the pulsar will get an extra dose of positive or negative particles. So in that case the asymmetry in electricity of particles that impact with neutron star can cause the pulsar changes its position. 

All pulsars are neutron stars. The neutron star is a supernova remnant and molecular nebula surrounds neutron stars at least at the beginning of their existence. The radiation of the pulsar forms when particles impact the neutron star. There is the possibility that a neutron star blows its molecular nebula away. And that turns it invisible. 

One reason why pulsar is missing can be it simply turned away from the Earth. Or some pulsars are hard to detect. Because their radiation is turning to Earth all the time. In that case, the radiation of the pulsar continues all the time. Normally pulsars are detected because there are pauses in their radiation. 

When we think about extremely short-period pulsars like millisecond pulsars there is the possibility that those pulsars are just wobbling. That means their poles are moving only a little and that thing causes that pulsar will point to Earth for only a short time. The pulsar's radiation comes mainly out from the poles of the neutron star. So in this text pulsar and neutron star are the same. 

Or maybe we should say that neutron star. That sends radiation is a pulsar. 

All neutron stars are not sending radiation. If a neutron star is in a cosmic bubble, no material impacts them. Radiation of the neutron star comes from high-energy particle impacts to its core. And that's why molecular nebulas are important for making pulsars visible. 

There is one thing that can explain why some pulsars are missing. 

Pulsar radiowaves are born when material falls to a neutron star. When that material impacts that massive object it releases energy as radio waves. When particles impact with a neutron star. They face an extremely strong magnetic field that drives those particles to the poles of the neutron star. The radiation leaves the neutron star in the form of two narrow beams. 

There is the possibility that a neutron star just blows particles away from it. If no gas and dust can impact it no radiation can form in those impacts. So if neutron stars are just making the bubble around them that thing can cause they will be lost. 

But in some scenarios neutron stars are putting the nebula around them to shine so bright that the radiowaves cannot travel across that cloud. When molecular nebula around neutron star gets radiation the particles will sooner or later start to send emission radiation. When the particles are sending radiation the energy level is higher than the radiation that comes from the neutron star that radiation will close the pulsar in it. 

The thing is that the molecular cloud or particles of the molecular cloud around the neutron star or pulsar can send radiation only when their energy level rises higher than the energy that comes from the pulsar. So that thing can turn the molecular cloud into the giant Faraday cage that keeps the radiation of the neutron star inside it. 

Image and other sources. 

https://scitechdaily.com/why-have-pulsars-gone-missing-a-new-finding-offers-some-answers/

https://artificialintelligenceandindividuals.blogspot.com/