Pulsar Gets the Munchies, Snacks On an Asteroid 54
astroengine writes "In research accepted for publication in the Astrophysical Journal, astronomers documented the anomalous spin rate of a pulsar that has been observed 'multiple times' between 1988 and 2012. In September 2005, the spin rate of the well-observed PSR J0738-4042 changed and a team of astronomers headed by Paul Brook, of the University of Oxford, think they know why. 'The data lead us to postulate that we are witnessing an encounter with an asteroid or in-falling debris from a disk,' they write in a paper published to the arXiv pre-print service. The moral of the story? It's not just black holes that get the asteroid munchies."
Pulsars need to eat, too (Score:1)
But when the get gas, it's gamma rays, phew, light a match!
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Re:Pulsars need to eat, too (Score:5, Insightful)
all jokes aside, if something as simple as debris falling into the pulsar will change it's spin rate, then maybe using these for navigation isn't so reliable after all.
just a thought.
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Any addition of mass to a pulsar will change it's spin rate, whether it be a large asteroid or an atom of water. I think the fact that we can detect the change created by something as small as an asteroid is incredibly cool. Besides, it's not the spin rate of the pulsar that would be used for navigation, it would be the object's location. The spin rate is just a convenient marker to identify the star. As long as the spin rate is within a certain margin of error they can assume they are looking at the ri
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Time measurement allows much more precise triangulation than angular measurement.
No, our instrumentation for angular measurement is less precise than our instrumentation for time measurement.
Either method should allow for precise triangulation, within the limits of the instrumentation.
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As I read it, AC is saying that trigonometry works better with lengths than with angles.
I say bullshit, the math is fine, the problem is comparing the 29 cent plastic protractor with a micrometer.
I also don't object to us using micrometers instead of protractors, since we know how to build a micrometer pretty well. I do object to indicting the math and saying "measuring angles doesn't work as well!" when the problem isn't the angle, but our ability to measure it.
Let's upgrade that protractor to a sextant a
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Any addition of mass to a pulsar will change it's spin rate, whether it be a large asteroid or an atom of water. I think the fact that we can detect the change created by something as small as an asteroid is incredibly cool. Besides, it's not the spin rate of the pulsar that would be used for navigation, it would be the object's location. The spin rate is just a convenient marker to identify the star. As long as the spin rate is within a certain margin of error they can assume they are looking at the right star.
Always remember, the pulsar you see is an emission which was sent out as long ago as is far away, with respect to the speed of light, it has likely traveled on a curved path as everything in the universe is in motion. It is by no means a fixed point.
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"There are hundreds of pulsars. If one of them eats an asteroid and changes its spin rate, you can use the others to figure out how it's changed, and recalibrate. It's fine as long as they don't all glitch at once - and they're hundreds of light-years apart, so there's nothing that could make that happen."
Good point! Maybe the Chinese led by engineers will work that out, as opposed to the USA led by lawyers?
http://singularityhub.com/2011/05/17/eight-out-of-chinas-top-nine-government-officials-are-scientists [singularityhub.com]
Thanks, must have missed that one (Score:2)
http://slashdot.org/story/13/08/26/0437213/using-pulsars-as-gps-for-starships [slashdot.org]
Of course, the source article is paywalled as a form of "artificial scarcity" dreamed up by lawyers. :-) Lawyers who base their work ultimately on the public domain of public law and court proceedings, but tell everyone else not to share...
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Thanks for the link. By the way, eight of the authors there are from China, including the first author. Four are from Australia, one from the USA.
BTW, to be fair to lawyers, it's true that some US lawyers do good things for the general benefit -- civil rights, environmental defense, open access journal articles, open government, FOSS licensing, etc.. Examples:
http://en.wikipedia.org/wiki/A_Civil_Action [wikipedia.org]
http://web.law.duke.edu/cspd/ [duke.edu]
I guess it comes down to who has the most money to pay the lawyers, and whethe
And when they pull the mask off the Pulsar. . . (Score:1)
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Ask ten different scientists about the environment, population control, genetics and you'll get ten different answers, but there's one thing every scientist on the planet agrees on. Whether it happens in a hundred years or a thousand years or a million years, eventually our Sun will grow cold and go out. When that happens, it won't just take us. It'll take Marilyn Monroe and Lao-Tzu, Einstein, Morobuto, Buddy Holly, Aristophanes .. and all of this .. all of this was for nothing unless we go to the stars.
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The second law of thermodynamics means that all of this is for nothing regardless of if we manage to escape the gravity well that birthed us before our star boils off the planet.
Since no information can travel between universes that means the heat death of THIS universe is the end of any coherent information whatsoever.
Not just atoms will fall apart but even protons will decay.
There may be a lot of time yet but entropy will win, in the end.
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Or the Bible. Or whatever else it is you have to use to escape the truth on a day to day basis.
Fact of the matter is now that we can receive safe and effective sterilization procedures there's no real need for any further suffering or the furtherance of fairy tales in the vain attempt to shelter against the cold hard reality of the absolutely, unequivocally, and horrifiying nothing.
We can stop the madness.
I know I have.
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Why is it? (Score:1)
Really? (Score:1)
The moral of the story? It's not just black holes that get the asteroid munchies.
Massive bodies attract other masses in their local neighborhood? Wow. This is amazing information!
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It is, kind of. One might think the area around a pulsar would be fairly cleaned out and you've got to wonder where the asteroid came from and what kicked it in. While we've detected planets and asteroid/dust belts around stars, this might be the smallest extra-solar object ever detected.
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Nope. The first anonymous coward is correct. Orbits do not suddenly change on their own. That would violate various conservation laws. The fact that an asteroid-mass object appears to have hit a pulsar means that something perturbed that astroid's orbit. This was probably an encounter with another asteroid.
not surprising (Score:3)
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but would we get longer days from massive asteroid collision?
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Yes. We certainly could. There are documented incidents of relatively trivial happenings slowing/speeding the Earth; earthquakes, tsunamis and the like.
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Depends entirely on if it hits going east or west. If going east it's impact would increase the Earth's spin, shortening the day. Similarly the north or south component will impact the inclination of the Earth's axis depending on the season and whether the impact is on the day or night side of the planet.
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"massive bodies om nom nom asteroids"
Say what?
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Pretend the Pulsar is a Kitteh and the asteroids are cheezburger "sliders"
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41,338,740 - sucker!
http://en.wikipedia.org/wiki/Asteroids_(video_game)#Highest_score [wikipedia.org]
Pulsars evolve? (Score:1)
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Based on my complete lack of understanding of these sort of objects, I imagine it's a race of sorts -- a contest between whatever intergalactic debris it might suck in versus its rate of burn.
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I would think that neutron stars likely eject very little matter - any incoming matter gets condensed until protons and electrons fuse into neutrons, which would then be unaffected by any of the electromagnetic disruptions that eject plasma from a "normal" star.
Hmm, though now I'm wondering how exactly a neutron star can maintain a magnetic field to begin with. Is it assumed to be ionized? Is their some sort of "quark soup" hocus pocus going on in it's core? And Google offers me no easy answers, grr.
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From my research last night that does sound like it's part of the explanation. It also sounds like the neutrons themselves have a magnetic moment due to the charged quarks composing them. And it sounds like the neutron gas core of the star is moving into territories where our understanding of the nature of matter are still quite tentative. Curious thing to think of something that massive being more strongly governed by the quantum wavefunction equations of state than classical physics.
Stop anthropomorphising inanimate objects (Score:2)
Stop anthropomorphising inanimate objects. It's patronising to us, and they really hate it.