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Quark Stars
BigGar' writes "Astronomers seem to have discovered a new type of star. It would lie between a neutron star and and a black hole in the hierarchy of stars and consist of quark matter. Further observations with the Chandra X-ray telescope will be needed to confirm the results."
Does anyone know if all up quarks are the same as all other up quarks...
Well the up quark, like any quark, is not as cleanly defined as the word "particle" might indicate. The up quark and the properties associated are not just a measure of how much "mass" or "spin" has been shoved into a sphere called the quark. The properties of quarks actually come from an extremely complex cloud of virtual particles that pop into and out of existence in close proximity to the area we call the quark. There seem to only be a few stable configurations of energy, spin, and charge that can result in a quark. The properties of the quarks seem to result from some intrinsic properties defining the way these virtual particles can interact, so you can't just put a little more of something into a quark, because that would require changing the rules of the interactions. Unfortunately, the precise details of all of the above is still a subject of some speculation, since no one quite knows for sure all the virtual particles that can pop in and out and all of their properties.
I had read once that black holes could be regarded as super-large elementary particles
Actually it's that statement you just made that doesn't fit with String theory. String theory predicts that black holes can retain information about the structure of objects that are sucked into them. If this turns out to be true, then they can't be regarded as large elementary particles, since elementary particles must be indistinguishable from each other.
The protons and electrons go through a reverse beta decay to form neutrons and neutrinos. Not all protons and electrons are consumed in this fashion which lets the following ideas progress, the outter shell of a neutron star is covered with a bunch of high energy electrons and protons exisiting in the crust of the neutron star can be in a super fluidic state making the neutron star a gigantic super conductor. Electrons being annhihilated on the surface release X-Rays which get funneled by the intend magnetic field of the super conducting protons into beams which create the effect we dub a pulsar.
I'm a loner Dottie, a Rebel.
It wasn't mentioned in the Chandra release or the CNN spot, but RX J1856.5-3754 is apparently the closest known neutron star. The Chandra site states it's distance at ~400 lyr and the APOD site cites 180 lyr, practically in our back yard!(in cosmological distances anyway)
- "Hear that?! The percolations are imminent! Cease your ingress!"
Why? One way of looking at the vacuum is that it is filled with virtual particles. A group of virtual particles can "borrow" energy to spring into existence, and then annihilate after a short period of time, returning the borrowed energy to the vacuum. The time scale they are allowed to exist is governed by Heisenberg's uncertainty relation. (E*t>=h-bar.) For massive particles like electrons, it's a short period of time.
If, during their short existence, the electric field can do more work on the particles than their borrowed energy, the "debt" to the vacuum can be "repaid", and the particles can become real.
-- ;-)
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Also, you've fallen prey to a terrible, terrible fallacy that afflicts even good astronomer: the dreaded Selection Effect. How do you think they "happened" to come across this odd object? Almost certainly, because they were already studying the nebula and remnant. In other words, it's not out of the many billions of stars that they chose. It was out of the much much smaller pool of SNRs.
The Mongrel Dogs Who Teach
I am one of the authors of a competing paper on RX J1856 that was published yesterday, as well as a co-discoverer of the pulsar in 3C58. In my opinion these results, while definitely a possibility are certainly very preliminary. And in fact, there are other possibilities that make quite a bit more sense.
In the case of RX J1856, there is a ~15% chance that the lack of pulsations (one of the biggest reasons for suspecting a quark star) is simply the result of an unfortunate emitting geometry or viewing alignment. Given that there are ~7 objects known that are similar to RX J1856, having at least one of them in this 15% seems quite likely to me -- and avoids having to invoke a new form of "star stuff".
As for 3C58, the neutron star cooling problem can be mitigated (but not completely removed) by assuming a larger age for the supernova remnant (and therefore the neutron star) -- which expansion measurements and pulsar timing measurements also suggest.
In other words, there are simpler explanations for the facts. Although those explanations certainly wouldn't get as much press...
In other news, degenercy isn't a LAW. If it was, then black holes couldn't exist. It's more of an aproximation of other forces, kind of like how we define Normal forces.
Degeneracy is a fundamental feature of the quantum theory of fermions. It isn't an "approximation of other forces". The concept of a force is only applicable at a higher level. Quantum theory is concerned with interactions.
Black holes exist because as a neutron star gets bigger, additional neutrons require more and more energy. All the low energy states are occupied. Soon the neutrons have more energy than you see in an accelerator, and they can react to form other particles. Particles that aren't neutrons won't compete with neutrons for the higher energy states.