Exotic "Electroweak" Star Predicted 68
astroengine writes "A new type (or phase) of star has been characterized by Case Western Reserve University scientists in a paper submitted to Physical Review Letters. The 'electroweak' star is a stellar corpse too massive to be a quark star, yet too light to collapse into a black hole. It crushes and burns the quarks inside, generating an outward radiation pressure that acts against gravity. Interestingly, the interior is predicted to be a 'Big Bang factory,' forcing the electromagnetic and weak forces to collapse as one (hence 'electroweak') — a condition that hasn't been seen elsewhere in our universe since moments after the Big Bang." The article notes that the first calculations on electroweak stars pegged them as an intermediate stage on the way to a black-hole collapse, lasting at most a second. The new calculations suggest that electroweak stars could persist for millions of years.
Precision of calculations (Score:1)
As always with physics, you have a pretty huge margin of error...
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On a Pentium [wikipedia.org].
Re:Precision of calculations (Score:5, Insightful)
This isn't physics. It's math and programming, with someone interpreting it as a physical possibility.
That's what theoretical physics is. It's the experimentalists and observationalists who confirm or refute the theorists' predictions.
Re:Precision of calculations (Score:5, Informative)
Someone said: "This isn't physics. It's math and programming, with someone interpreting it as a physical possibility."
Someone replied: "That's what theoretical physics is. It's the experimentalists and observationalists who confirm or refute the theorists' predictions."
The replier here is absolutely correct. Many kinds of stellar objects were first predicted by Theoretical Physicists before being observed. Why? Well, predictions like this can tell an observerational astronomer what to look for. In fact, black holes were predicted to exist in the 18th Century(!) but were largely ignored until the Einstein's theory of General Relativity proposed a radically different idea about what gravity is which also predicted a method by which light (then thought to be a massless wave and therefore totally unaffeted by gravity) could be "trapped" or bent around a black hole. Einstein predicted a gravitational lensing effect around masses of sufficient size, later confirmed during an eclipse of our own sun. Still later, Stephen Hawking predicted the existence of Hawking Radiation that should be detectable as well coming from near the event horizon of black holes. They were both right, but observational astronomers would not have known what the f#ck they were looking at once a black hole was first observed without the theortical groundwork that was laid first.
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black holes were predicted to exist in the 18th Century(!)
Would you provide us with a link, please?
Re:Precision of calculations (Score:5, Informative)
If the semi-diameter of a sphere of the same density as the Sun were to exceed that of the Sun in the proportion of 500 to 1, a body falling from an infinite height towards it would have acquired at its surface greater velocity than that of light, and consequently supposing light to be attracted by the same force in proportion to its vis inertiae, with other bodies, all light emitted from such a body would be made to return towards it by its own proper gravity. —John Michell[2]
In 1796, mathematician Pierre-Simon Laplace promoted the same idea in the first and second editions of his book Exposition du système du Monde (it was removed from later editions).[3][4] Such "dark stars" were largely ignored in the nineteenth century, since light was then thought to be a massless wave and therefore not influenced by gravity. Unlike the modern black hole concept, the object behind the horizon of a dark star is assumed to be stable against collapse.
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Also, light is a massless wave/particle that is not influenced by gravity. Gravity affects the space that the light is traveling through.
You confuse me. For all intensive purposes, "gravity" does not exist as Newton described it. Every action has an equal and opposite reaction. He couldn't find the opposite reaction for a falling object, so he made one up: gravity.
That being said, gravity does not affect the space through which light travels, but a body's mass does. Mass distorts space, creating a "gravity" effect.
This distortion of space is essentially synonymous with the concept of "gravity"; this is what affects light.
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Theoretical physics is what Sheldon does
Experimental physics is what Leonard does
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As always with cosmology, you have a pretty huge margin of error
Fixed that for you.
Seriously, that's just a few orders of magnitude off. Seen the error bars on intergalactic distances?
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Re:Precision of calculations (Score:5, Informative)
Despite the parent post's snideness, the GP is basically right. Parent poster: (1) It's not just "a few" order of magnitude off, it's 14 orders of magnitude. That's a lot, by any standard in science. (2) The paper [arxiv.org] is not about cosmology, it's about astrophysics. (3) Although this is not about cosmology, your perception of cosmology as a low-precision science is about 15 years out of date. Cosmology is currently enjoying a golden age of high-precision measurements. For example, the Hubble constant is now known to a precision of a few percent, whereas 20 years ago there were still people disagreeing to each other by factors of 2. (4) Intergalactic distances aren't particularly relevant here, but anyway the ladder of cosmic distance scales [wikipedia.org] isn't uncertain to anything like 14 orders of magnitude.
And by the way, could we let the "fixed that for you" meme die? It's rude, and it's getting old.
Re:Precision of calculations (Score:5, Funny)
Step 1. Quote a sentence from parent.
Step 2. Replace a word from the quote with another one, put it in bold.
Step 3. Write "Fixed that for you".
Step 4. Make stuff up, starting the sentence with "Seriously,".
Step 5. ??
Step 6. +5 Insightful.
Re:Precision of calculations (Score:5, Insightful)
Step 5. ???
Fixed that for you.
Seriously, there's always three question marks!
?? is the c# null-coalescing operator (Score:2)
with step 5's two question marks, parent post was trying to say "if step 5 is null, then replace it with something"
http://msdn.microsoft.com/en-us/library/ms173224.aspx [microsoft.com]
fixed that for you
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And by the way, could we let the "fixed that for you" meme die? It's rude, and it's getting old.
Did it died?
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Not by cosmology's standard, not really. Most estimates about cosmology - from Universe's age to the distance to nearest stars - were off by far greater amount until the last century or so, and some of them - such as the size of the Universe - still could be.
Do not want.
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Most estimates about cosmology - from Universe's age to the distance to nearest stars - were off by far greater amount until the last century or so...
So at what point in history did scientists believe the age of the universe to be 137.5 uS and the distance to Alpha Centauri 401 m?
14 orders of magnitude is _enormous_, unless you're talking about the relative strengths of the fundamental forces [wikipedia.org].
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Ratio of 1 million years to 1 second is about 3x10^13, or 13 orders of magnitude; not a few.
Re:Precision of calculations (Score:5, Funny)
As always with physics, you have a pretty huge margin of error...
And I've been wondering all the time why they use the logarithmic scale. It makes the errors look smaller!
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Re:Precision of calculations (Score:4, Interesting)
It doesn't say whether they revised their estimate due to new data or due to finding a mistake, but the latter would be entirely understandable: humans tend to have very little day-to-day experience of exotic matter on which to base a reality check.
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It doesn't say whether they revised their estimate due to new data or due to finding a mistake, but the latter would be entirely understandable:
This post further down [slashdot.org] says that the estimate went from ~ 10^-7 to 10^7.
Could it have just been a sign error, or flipped numerator/denominator in an equation? Curious. :)
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Cool news... (Score:1, Troll)
Sounds pretty lame to me.
Re:Cool news... (Score:5, Funny)
Wrong (Score:4, Insightful)
From TFA:
If you're going to pretend to quote the article at least try to get it right. It says nowhere that the stars themselves can't exist now. It says that the cores of these stars, if they do exist, have conditions that haven't been seen for perhaps 10 billion+ years.
seconds, millions of years (Score:3, Funny)
What's a few orders of magnitude between friends...
Phew... (Score:5, Funny)
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Then refreshing it a few hundred times. All of you.
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It's more fun if you script something to repeatedly spider the site at the maximum rate the server can put out, and let that run for a few days.
paper (Score:5, Informative)
Here [arxiv.org] is the scientific paper.
As a physicist, I feel that this is a little far out. It assumes violation of the conservation laws for baryon number and lepton number. They claim that this nonconservation is actually predicted by a loophole in the standard model, which may be true, but it's never actually been observed -- if anyone observed such a violation experimentally, they'd definitely get the Nobel prize.
It's also built on a particular model of quark-quark interactions. (The strong nuclear force is not an interaction for which we have an exact formula. All we have is various models of it.) All the predictions are therefore going to be dependent on this model, as well as on the other approximations they have to make. People have predicted other weird objects, such as quark stars, using similar models, and the predictions have turned out to be very hard to pin down in any model-independent way. Some theorists use different methods, and come out with completely different predictions. Nor has any really compelling experimental evidence turned up for quark stars, although there are a couple of candidate objects that seem too dense to be ordinary neutron stars. If there's no solid evidence for quark stars, it seems like quite a stretch to go beyond that and predict things about even more exotic objects. The landscape is littered with predictions of exotic objects along these lines: quark stars, strange stars, black stars, gravastars, fuzzballs, boson stars, q-balls, ...
They recently revised their estimate of the lifetime of these objects, making it ~10^7 years rather than a fraction of a second (only 14 orders of magnitude different). Even though 10^7 years is fairly long, it's really not very long on cosmic timescales, so we would expect these to be fairly rare and hard to find, even if they did exist.
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The bright side is that if such a thing IS observed, it says a lot about the underlying models. Small probability of a big payoff.
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Hmmmm... Perhaps I have misunderstood my Cosmology professor, but a number of different experiments have observed CP-violations. None that exactly fit the bill to explain the total discrepency between matter and anti-matter in the observable Universe, but these experiments still point to the fact that the standard model's baryon/lepton number symmetry is not quite so sacrosanct as previously believed.
You can read about some of the observational experiments here:
http://en.wikipedia.org/wiki/CP-violation [wikipedia.org]
If it
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So was this the Nobel Prize you were talking about?
http://nobelprize.org/nobel_prizes/physics/laureates/1980/index.html [nobelprize.org]
Re:Silly Particle Pysicists (Score:4, Informative)
If you have to spend enormous energy to blast a proton to unlock a hypothetical quark then how do you know the energy itself doesn't manifest as particles that don't even play a role in ordinary matter?
You don't have to blast a proton with enormous energy to see quarks. All it takes are some simple electrons. If you use electrons with small enough wavelength (i.e. high enough energy) to get good resolution, and you look at a proton, lo and behold, you see these three little thingies whizzing around in there.
When this was first done, it caused a bit of consternation among one Dr. Gell-Mann and one Dr. Zweig, who had initially proposed quarks merely as mathematical mechanisms for aiding certain types of calculations -- nobody actually thought the quarks were real. But then some assholes at SLAC decided to probe the proton with high speed electrons, and God forbid it, they saw the damned things. Still, a few dumb people such as Dick Feynman weren't convinced the quarks were actually real. It wasn't until numerous further experiments were performed that physicists grudgingly accepted that the quarks were actual particles, not mathematical oddities.
In short, why don't you go fuck a goat?/p?
Quashed Optimism (Score:3, Interesting)
Hopefully now that they know what to look for, we can turn the prediction into observation.
...a very small fraction of the energy will be emitted as electromagnetic radiation (i.e. light), making these objects very hard to detect.
oh...
Well then, for the time being I'm more inclined to side with the other guy in the article:
"It highly implausible that such an electroweak star would exist," said Paolo Gondolo of the University of Utah.
Re:Quashed Optimism (Score:5, Informative)
A couple of things to note here. (1) You're discussing this as if this was a calculation predicting the existence of strange quark stars. It's not. Predictions of strange quark stars date back at least a couple of decades. This paper is predicting the existence of something weirder than a strange quark star. (2) The short half-life of strange particles in accelerator experiments is something that the authors of the paper know about; their calculation used the standard model of particle physics, which already describes those short half-lives. There are good reasons [wikipedia.org] to suspect that the situation might be different in bulk matter at high pressure. We just don't know for sure.