Cosmic blast mystery solved in neutron star's intense death throes A pair of European astrophysicists believe they've solved the mystery of exceedingly bright, never-repeated flashes of radio waves that come to us from the distant past. The source of those brief, intense flashes can be defined in two ways, depending upon whether you'd prefer to look at the event as a death or a birth. "We …
The subheading 'As if millions of voices suddenly cried out in terror and were suddenly silenced' clearly goes too far.
Let's leave out the duplicate "suddenly" and more correctly state:
'As if millions of magnetic field lines cried out in stress and were suddenly expelled'
Those magnetic field test charges around the neutron star sure must feel whoozy as the generator formed by the massive fermionic tower exponentially disappears underneath them. I think the lab equivalent would be to drop the electromagnet into a superconducting liquid.
Firstly: Let's NOT leave out the duplicate "suddenly" because the original quote has the duplicate, and we don't dare correct Ben Obi-Wan Kenobi.
Secondly: I claim boasting rights for the tagline on this article!!! See the first comment on last week's article.
In fairness, I'd search it too before posting the quote. Not because I don't know where it's from, but because memory sometimes plays tricks on us. And I wouldn't want to be doing a "Play it again Sam"* on a well known Star Wars quote.
*Correct quote is probably:
"You played it for her, you can play it for me," and "If she can stand it, I can! Play it!"
although it might be:
"Play it once, Sam, for old times' sake." After he feigns ignorance, she responds, "Play it, Sam. Play 'As Time Goes By'."
source: http://en.wikipedia.org/wiki/Casablanca_%28film%29#Quotations
This post has been deleted by its author
OK Uffish, some friendly advice:
Before you watch the Star Wars movies for the first time, you should also Google "Star Wars Machete Order", which will explain why you shouldn't watch the movies in order of release, or in chronological order. In short, when you watch them for the first time, watch them in this order:
Episode IV (A New Hope) - Episode V (The Empire Strikes Back) - Episode II (Attack of the Clones) - Episode III (Revenge of the Sith) - Episode VI (Return of the Jedi).
Note that Episode I (The Phantom Menace) is not in that list. That's because 1) it's utter shite, and 2) it adds nothing to the story that cannot be inferred from watching the other movies. Watching the movies in this order, called "machete order" sets up the storylines such that the big climax in Return of the Jedi is greatly intensified by the dramatic events in Revenge of the Sith, and adds a lot more depth to the characters of Darth Vader and Luke Skywalker.
If you watch the movies in machete order, the impact they'll have on you is much greater, and the story will make a lot more sense, than if you watch them in traditional order. If you want more afterwards, you can go back and watch Episode I after you've seen all the other movies, as a kind of "supplemental" movie as it were. But watch them in the above machete order first. You'll enjoy them that much more!
Crap advice.
Like Highlander, there is only one trilogy and you watch them in released order.
Episode III was as much crap as Episode I. There is no building pathos that causes Skywalker to become Vader. It happens only because the plot requires it. Lucas simply isn't the person to write the kind of script that episode III required. He does okay and sometimes well with heroic stories, but episode III is a Miltonesque fall story. The only movie in the second released arch that was marginally passable was II. Even it would probably have been done better as a made for TV single episode event. If you think about the overall story arch episode II needs to do a LOT of groundwork for episode III, and that will detract from the heroism of it as an episode. If you like, episode II needs to be the Gawain vs Lancelot episode of the movie (drawing on the Excalibur interpretation of the Arthurian legend).
Like Highlander, there is only one trilogy and you watch them in released order.
Agreed, though for Highlander I'm not sure there's any point in watching anything after the first movie.
As for the later Star Wars disasters, for extra credit (and in place of watching the films themselves, which is an excruciating exercise) you might want to try Mr Plinkett's reviews, which are solid critiques of what's wrong with the films, done in a drunken-degenerate-critic style that some find amusing.
Isn't a magnetic field an effect, rather than a "thing" itself?
So if the star collapses inside its event horizon, the field just "stops", it is not "left outside"?
Of course anything previously caught in the field that "stops" could escape from just outside the event horizon due to its own intrinsic velocity at the point in time when the field ceases being functional, depending on its direction of travel at that instant.
Probably.
A magnetic field has energy which when it collapses or something is moving through it is released.
So with a generator the wires cut through the field which generates the electricity in the wire.
Whereas this scenario is closer to a transformer where the wires stay in the same place but as the current oscillates the field collapses and generates a very high voltage spike (if you touch both terminals of an induction coil and remove the power you will get one hell of a shock - as my sister discovered when I used her a a guinea pig for one of my electrical experiments when I was a kid - I still have a vivid memory of her flying across the room :o).
This collapse of the field also generates a radio pulse (build my first radio transmitter that way for morse code).
So the collapsing magnetic field around a massive neutron star must be awesome :D
> Whereas this scenario is closer to a transformer where the wires stay in the same place
It's only marginally closer though. In this case, the whole spool and battery disappear down an evil finger from the universe's future, leaving a place in place that is not accepting magnetic field lines really quickly. That magnetic field is orphaned!
Physically Yes, however from the point of the magnetic field in both situations what causes the field i.e. an electric current flowing has stopped.
in the case of the induction coil the current is stopped by disconnecting the battery, whereas with the neutron star the electric circuit disappears from the 4 dimensions of space-time same outcome :)
"This collapse of the field also generates a radio pulse (build my first radio transmitter that way for Morse code)."
Yes I did likewise in the 1950s, and very successful it was too, apart from the bandwidth. Which seemed to covered just about all the HF & VHF. frequencies including those that were used for television.
As I was living in a residential area at the time, well, I'll say no more!
Awesome indeed.
http://en.wikipedia.org/wiki/Magnetar
A magnetar's 10^10 tesla field, by contrast, has an energy density of 4.0×10^25 J/m3, with an E/c2 mass density >10^4 times that of lead.
remarkable things happen within a magnetic field of magnetar strength. "X-ray photons readily split in two or merge together. The vacuum itself is polarized, becoming strongly birefringent, like a calcite crystal. Atoms are deformed into long cylinders thinner than the quantum-relativistic de Broglie wavelength of an electron." ... At 10^10 teslas, a hydrogen atom becomes a spindle 200 times narrower than its normal diameter.
The magnetic field of a magnetar would be lethal even at a distance of 1000 km due to the strong magnetic field distorting the electron clouds of the subject's constituent atoms, rendering the chemistry of life impossible
Does anyone know what is the maximum magnetic field strength that could exist in even wierder circumstances? Is it where the engergy density of the field would cause collapse of space-time into a black hole, or is there some other limitation?
For a complete description you will probably have to go to Quantum Field Theory (and even then there will be doubts)... but:
1) The magnetic field has energy associated with it. That must go somewhere. Think of a normal spool-and-battery setup on your tabletop, if you open the circuit you get a solid spark as the magnetic field breaks down and induces a high voltage in the conductor.
2) The magnetic field is definitely a "thing" that can act in and of itself. This is why light exists: A changing magnetic field induces a changing electric field which induces a changing magnetic field etc. No charges are anywhere in this picture. The vacuum is not vacuumish, but actually (superconducting) stuff bearing fields (in a sense it is the gravitational field)
3) It is true that magnetic fields and electric fields can be mutated into each other depending on the observer (i.e. Lorentz transformations allow you to take different viewpoints of the same physical setup). In particular, the magnetic field generated by a current and seen by a moving test charge (a still charge does not see the magnetic field, of course) can be interpreted as the electric field generated by the distribution of the current's charges in the rest frame of said moving test charge after a suitable Lorentz transformation. It's geometrical, like rotating a cube and then describing what what faces you see.
4) Now I won't either understand nor do the calculations but I am pretty certain that the idea that the magnetic field is "expelled" in the rest frame of an observer hovering above the neutron star is as valid as (and completely matches) the view of any other rest frame that sees more (or less) of the magnetic forces and more (or less) of the uneven distribution of charges created by the original currents in the neutron star.
5) Sadly, there don't seem to be any magnetic charges in the vacuum (only in solids), this would make it even clearer that B is as hardcore as E.
I didn't bother going down this route (even though I did study quantum mechanics at university) as trying to apply it to a very large scale is speculation as the maths becomes a nightmare (plus you can't model the effects of gravity in quantum mechanics yet - maybe one day when we understand the universe better).
Classical mechanics should be fine as you can calculate the event horizon of a black hole with A'level physics and an this magnetic field is definitely large enough to be a standard classical problem (hence induction coil and battery).
:)
>Classical mechanics<
This issue I have with this is the term "classical" as apposed to "quantum" for a true event horizon to exist you MUST be able to exceed the speed of light. To me as a large mass collapses the gravitational hole created will slow the collapse to extremely close to zero, so to actually create an event horizon you would actually need to exceed the speed of light in the gravitational hole to be able to collapse it further.
Maxwells equations elegant as they are are not the way to look at this. There is one four vector 'field' (mathematically a field but usually called a potential as the normal magnetic and electric field is derived from it. There is only one equation and it is obvious the electric and magnetcic fields are just observer specific ways of looking at it.
Well yes, there is the electromagnetic field tensor ... but it's all the same. Isn't it?
so Maxwell's equations have the full symmetry that would result from it:
Feel free to write the equations with full symmetry. Then there's a supplementary equation that you use to generate the more useful but less symmetric forms, because as far as we know magnetic monopoles do not exist.
There's actually a proof that in a universe with spherical topology, at least two magnetic monopoles must exist. It's the same as the one that says you can't get all the hairs on a (perfect, seamless) tennis ball to lie parallel to the surface at once. So either the universe has a toroidal or more complex topology, or magnetic monopoles do exist somewhere out there. (Possibly, outside the observable universe, at which point things start to get a bit philosophical. )
My guess: a spherically symmetrical collapse wouldn't.
Two neutron stars or black holes orbiting each other will eventually merge. They lose energy by gravitational radiation ( and probably by drag induced by infalling gas, etc.), and get closer, which increases the radiation, until there should be a realy intense pulse just as the two stars or holes merge. Bigger, I think, than any single-body collapse could accomplish. (Caveat: "obvious" answers in GR, often aren't)
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