Really weird quantum phenomenon spied lurking near neutron star A neutron star may have led astronomers to find signs of a strange quantum phenomenon in vacuum space that was predicted more than eighty years ago. In quantum electrodynamics (QED), space isn’t really empty. Virtual particle and antiparticle pairs continually pop up and disappear. In the presence of very strong magnetic …
A beam of light is mad up of a bunch of photons travelling along in the same direction, one after another. Each photon has a magnetic field and an electric field, aligned perpendicularly. If you imagine the photon travelling across your screen from left to right, you might see the magnetic field from the side, so it's a wave drawn on your screen, but if you did then you'd be looking at the electric field from the edge, so it'd be a wave going in and out of your screen. If you then imagine looking at the screen from the right hand side, the photon would be travelling towards you with the magnetic field looking like a vertical line and the electric field looking like a horizontal line. This is the cross that you can see in the polarised light image.
When light's emitted from a source like a star or a hot light bulb, the beams of light/the photons are aligned at random, so if you look at the light source all the photons will look like corsses rotated to random angles.
When you polarise the light, but shining it through a fine grid, polarising sunglasses or a weird quantum phenomenom this forces all the crosses to orient to the same rotation, so you get the polarised light image where all the crosses are like the one you'd see from looking at the side of your monitor.
Interestingly, as you can polarise light to different angles by forcing it through a grid that's rotated to differetn angles, you can convey information in the angle of polarisation. Your light beam could be continuous, pulsed, varying in colour and so on, but you can ignore all of that and look at the polarisation angle to read the information. It's not even effected by blue or red shift. Handy!
If you want to understand the phenonomon:
Buy a linear polarising filter (about a fiver on Amazon) and hold in front of your LCD monitor, then turn it into the view through it becomes black. This happens because light from an LCD monitor is only vibrating in one direction and the filter is now blocking all vibration in this direction.
Now hold something transparent and bendy between then monitor and the filter and notice how you can see some of the light from the monitor and not other bits, and there's weird patterns and colours and shit. Try bending it a bit and seeing the patterns do weird stuff.
Now you're in a better position to understand it. Or at least to act like you do to show off. Or something.
which is 10 000 Gauss to a Tesla, so 1 giga Tesla.
Given that fusion researchers are quite excited that their magnets can achieve about 20+T continuously that is a very powerful field indeed.
Impressive field. Impressive result.
They did think about that and considered some alternative models for why the star is emitting and where it is emitting from (surface or atmosphere). This led to a significant caveat in the article:
"For all the considered emission models..."
They considered two options - a condensing surface and a gaseous atmosphere - neither of which, in the absence of QED effects, would be expected to produce the degree of polarization detected.
However, they aren't sure what is causing the emissions, merely "a robust indication that optical/near-UV photons are thermal and come from the surface, possibly from a cooler, larger region than that emitting the X-rays". Even so, they aren't sure why it closely matches black body radiation...
So... maybe we don't understand neutron stars too well, or maybe we do and this is evidence for QED, or maybe we don't really understand much at all, despite how far we have come and the sophistication of our experiments.
But in this case, there is no (normal) matter to polarise, instead it's magnetising the virtual particles produced by quantum vacuum fluctuations.
(Short version: 'empty' space is actually full of particles popping into existence and then disappearing again a fraction of a second later. Sounds preposterous, but they can be detected. For the long version go read up on virtual particles, Casimir forces, quantum fluctuation and vacuum energy and prepare to have your mind blown).
Completely off-topic or maybe not, but while content chasing on the 'net-of-dreams. I came across a readable writeup about Verlinde's Gravity idea: The Case Against Dark Matter
Thank you. That was a most fascinating read - one which, remarkably enough, I actually understood.
"Are you certain?"
I tried that one once with the judge when in court for speeding.
"Aha!" I cried. "If the officer knew I was exceeding the speed limit, ipso facto he knew my velocity, therefore how could he be certain that I was at the scene of the crime? QED!!!"
Pftt! Contempt of court for inane stupidity indeed! Mutter mutter...
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