Speed of light

[Qev]

Harry! Exellent idea. I also just discovered I might be able to boost my moped's miles per gallon by placing a strong magnet near the combustion chamber's air-fuel intake port .. the field allowing gas and air molecules to mix more efficiently.

Won't do you any good, I'm afraid. The molecules aren't polar, and aren't going to interact meaningfully with a magnetic field, especially not a static one.

[Doum]

Harry! Exellent idea. I also just discovered I might be able to boost my moped's miles per gallon by placing a strong magnet near the combustion chamber's air-fuel intake port .. the field allowing gas and air molecules to mix more efficiently.

Won't do you any good, I'm afraid. The molecules aren't polar, and aren't going to interact meaningfully with a magnetic field, especially not a static one.

My thought exactly! For a mix of air-fuel to react in a magnetic field it must be ionise and if it is ionise then it mean the combustion is happening outside the combustion chamber. Not good. It's a good thing that the mix aint ionise. And the metal all around (Engine) deviate the magnetic field also.

[makc]

From what I understand, Nietzsche wrote 'God is dead' as a commentary on the lack of love in his society.

No, this is not correct (afaik). Look up buddah tale in his "gay science".

[harry]

G'day from the land of ozzzzzz

Mate, I'm kind of stuck in this forum.

My computer does not allow me to go to other places.

Darn thing every time I press the button it takes me here,,,,,,,,,,smile

As for jet fuel to undergo magnetic pinch,,,,it will not work.

You may have to look at

Plasma Cosmology
http://www.plasmacosmology.net/tech.html

Magnetar Driven Bubbles and the Origin of Collimated Outflows from GRBs
Authors: N. Bucciantini (1), E. Quataert (1), J. Arons (1), B.D. Metzger (1), Todd A. Thompson (2) ((1)Astronomy Department, UC Berkeley, (2)Department of Astrophysical Sciences, Princeton)
http://arxiv.org/abs/0710.1326

Observation of a stable dense core within an unstable coronal plasma in wire-initiated dense Z-pinch experiments
http://adsabs.harvard.edu/abs/1993PhRvL..71.3806K

Dense z-pinch plasmas initiated from a single 25-100 μm diam aluminum wire using a 100-350 kA, 100 ns current pulse have been studied with <=1 ns time resolution. Rapid unstable expansion of a coronal plasma formed around the wire was observed with a subnanosecond pulsed nitrogen laser, while a dense core, which expanded more slowly and stably, was observed with 1-2 ns x-ray backlighting pulses. The core contained most of the initial wire mass, but there appeared to be little or no current flowing in it.

http://adsabs.harvard.edu/abs/1999PPCF...41A.175M
Fast z-pinches as dense plasma, intense x-ray sources for plasma physics and fusion applications
Abstract

As a result of advances in fast pulsed-power technology and cylindrical load fabrication, the Z pulsed-power accelerator at Sandia National Laboratories drives currents approaching 20 MA with a rise time of approximately 100 ns through cylindrically-symmetric loads (typically a cylindrical array consisting of a few hundred wires) to produce plasma densities in excess of 0741-3335/41/3A/011/img21, x-ray output energies approaching 2 MJ, radiation pulses as short as 4 ns and peak x-ray powers as high as 0741-3335/41/3A/011/img22. More than 15% of the stored electrical energy in the Z pulsed-power accelerator is converted into x-rays. The plasma pressures at peak compression are several TPa with electron temperatures that can exceed 3 keV at containment magnetic fields exceeding 1000 T. Depending on the atomic number and composition of the imploding plasma, these z-pinches can be tailored to produce intense sources of thermal x-rays, keV x-rays or neutrons. Although applications of these x-ray sources have included research in radiation material interaction, equations of state, opacity, astrophysics and x-ray lasers, the principal focus of the present research is to use them for indirect-drive inertial confinement fusion (ICF).

The experiments are just the tip of the iceberg

[aristarchusinexile]

Thanks Guys .. I can't even remember where I read about magnetization and air-fuel mix. Does this mean I have to install an anti-magnet?

[aristarchusinexile]

From what I understand, Nietzsche wrote 'God is dead' as a commentary on the lack of love in his society.

No, this is not correct (afaik). Look up buddah tale in his "gay science".

For someone who is said not to have believed in God, he sure talked about him a lot. (From Nietzsche Quotes)

Also this from Wiki: At the age of 24 he was appointed to the Chair of Classical Philology at the University of Basel (the youngest individual ever to have held this position),[1] but resigned in 1879 because of health problems, which would plague him for most of his life. In 1889 he exhibited symptoms of insanity, living out his remaining years in the care of his mother and sister until his death in 1900." Perhaps resulting from the stress of denying what he knew to be true? Oh well, I wish I could be in the care of my mother .. she lives beside the ocean on Molokai, in Hawaii.

[harry]

G'day from the land of ozzzzzz

Hello aristarchusinexile

Focus fusion maybe the energy of the future.

=======================================

Back to jets

http://arxiv.org/abs/0803.2509
Twisted coronal loops in uniform gravity

Authors: G.J.D. Petrie
(Submitted on 17 Mar 2008)

Abstract: Coronal loop emission profiles are often of remarkably constant width along their entire lengths, contradicting expectations based on model coronal magnetic field strengths decreasing with height. Meanwhile Paul Bellan has produced a theoretical model in which an initially empty, twisted force-free loop, on being filled with plasma via upflow at each foot point, in the absence of significant gravitational effects, forms a narrow, filamentary loop of constant cross-section. In this paper, we focus on equilibrium states that include stratification by uniform gravity while retaining the effects of magnetic field twist. Comparing these with related force-free equilibria, it is found that injection of low-$\beta $ plasma under coronal conditions is not likely to change the shape of a loop significantly. These linear equilibria apply to the interiors and boundaries of loops only, with external influences modeled by boundary total pressures. The effects of total pressure balance with surroundings and of gravitational stratification are to inhibit the pinching of a loop to a constant cross-section. Only if the plasma $\beta$ were high enough for the plasma to reconfigure the external field and the hydrostatic scale height much greater than the loop size could the final state have nearly constant cross section. We do not expect this to occur in the corona.

and

http://arxiv.org/abs/0802.2034
Extragalactic jets with helical magnetic fields: relativistic MHD simulations

Authors: R. Keppens, Z. Meliani, B. van der Holst, F. Casse
(Submitted on 14 Feb 2008)

Abstract: Extragalactic jets are inferred to harbor dynamically important, organized magnetic fields which presumably aid in the collimation of the relativistic jet flows. We here explore by means of grid-adaptive, high resolution numerical simulations the morphology of AGN jets pervaded by helical field and flow topologies. We concentrate on morphological features of the bow shock and the jet beam behind the Mach disk, for various jet Lorentz factors and magnetic field helicities. We investigate the influence of helical magnetic fields on jet beam propagation in overdense external medium. We use the AMRVAC code, employing a novel hybrid block-based AMR strategy, to compute ideal plasma dynamics in special relativity. The helicity of the beam magnetic field is effectively transported down the beam, with compression zones in between diagonal internal cross-shocks showing stronger toroidal field regions. In comparison with equivalent low-relativistic jets which get surrounded by cocoons with vortical backflows filled by mainly toroidal field, the high speed jets demonstrate only localized, strong toroidal field zones within the backflow vortical structures. We find evidence for a more poloidal, straight field layer, compressed between jet beam and backflows. This layer decreases the destabilizing influence of the backflow on the jet beam. In all cases, the jet beam contains rich cross-shock patterns, across which part of the kinetic energy gets transferred. For the high speed reference jet considered here, significant jet deceleration only occurs beyond distances exceeding ${\cal O}(100 R_j)$, as the axial flow can reaccelerate downstream to the internal cross-shocks. This reacceleration is magnetically aided, due to field compression across the internal shocks which pinch the flow.

Jets small or large have similar origin via a pinching of magnetic fields. The question is why do small jets fizzer off and larger jets are found to go for millions of years in one direction. How do they keep their stability. If the origin was around the disc of a black hole, its stabilty would be very weak. If the origin was from a combination of the core and the dics, maybe a stronger stabilty. These I think are critical to research for they play an important part in recycling matter from degenerate to normal matter.

[JimJast]

It's rather a long thread and I didn't read everything so maybe someone already answered the question why speed of light is as it is. if so then ignore my answer.

The reason for speed of light being fixed is that in Einstein's theory there is a tensor in which all four 4 diagonal elements must sum to zero. The elements 1, 2, and 3 are all minus average preasure density in all the objects of the universe and the 4th element is average mass density of all objects of the universe times c^2 (c being a speed of light). if sum is to be zero then c must be equal sqrt(3 x avarage preasure density / average mass density). We know that mass density of the universe is 6x10^{-27} kg/m^3 and speed of light is 3x10^8 m/s so we may figure out the average preasure density being (9x10^16 x 6x10^{-27})/3 = 1.8x10^{-10} N/m^2 and so it together with the density of mass determines the speed of light in the universe.

[JimJast]

sorry for hitting "a" instead of "s" in some places...
-- Jim

[JimJast]

... and writing "pressure density" where it should be just "pressure". I must need some sleep, I guess ...
-- Jim

[bystander]

... c must be equal sqrt(3 x avarage preasure density / average mass density). We know that mass density of the universe is 6x10^{-27} kg/m^3 and speed of light is 3x10^8 m/s so we may figure out the average preasure density being (9x10^16 x 6x10^{-27})/3 = 1.8x10^{-10} N/m^2 and so it together with the density of mass determines the speed of light in the universe.

So, you use c to determine APD from AMD, then you use that result to determine c? I'm impressed, so simple and so circular.

[JimJast]

You must have overlooked the fact that out of 3 variables (speed of light, mas density, and pressure) we we don't know only the pressure so I just calculated only this one. I didn't calculate the speed of light since we know it. And the nature determines it possibly from the same relation that I used but having as given the mass density and the pressure. Hope it helps.

[aristarchusinexile]

Hello aristarchusinexile,

I suggest that we often do not recognize what we see because we have never seen it before, or because of what our normal associations are, or because of what we want to see.

And this would apply to.................whom?

To everyone human, Astrol.

[aristarchusinexile]

Just dont forget that void is so big that a few billion stas being inside it, it will still not be visible to us because we can't detect or see a single star in there for now. So what i am telling you is that the void is fill with matter but it is very disperse compare to the galaxies abondances we live in.

Inside the Boötes Void which is under discussion, there are at least 60 galaxies alone. So while the average density is very low compared with other parts of the Universe, it is far from empty.

Or are the galaxies separate from the void, and what is thought of as being one big Bootes void really two or three or four or more smaller voids?

[aristarchusinexile]

Hi Aricharchusinexile,

Just dont forget that void is so big that a few billion stars being inside it, it will still not be visible to us because we can't detect or see a single star in there from here. So what i am telling you is that the void is fill with matter but it is very disperse compare to the galaxies abondances we live in. Gravity create the void naturaly and it is also logical for it to exist. The void have nothing magic in it. It's a natural phenomenon. No mystery there. There are still matter in there but we dont see it with the today's tool. It is my opinion.

My opinion, in case you missed it Doum, is that the voids are completely empty of matter, being filled with anti-gravity .. possibly anti-matter?

[bystander]

You must have overlooked the fact that out of 3 variables (speed of light, mas density, and pressure) we we don't know only the pressure so I just calculated only this one. I didn't calculate the speed of light since we know it. And the nature determines it possibly from the same relation that I used but having as given the mass density and the pressure. Hope it helps.

... c must be equal sqrt(3 x avarage preasure density / average mass density). We know that mass density of the universe ... and speed of light ... so we may figure out the average preasure density ... and so it together with the density of mass determines the speed of light in the universe.

[aristarchusinexile]

Hello aricharchusinexile,

An example: someone sent me an email one time .. an illustration of dolphins .. but all I could see was a naked woman. But for sure, after questioning the person who sent me the email, asking if they had made an error, and being told to look harder, yes, several very clear dolphins made up the dark areas of the woman. Perhaps if I had associated with dolphins more I would have seen them right away .. but children don't often associate with dolphins, and children instantly recognize dolphins instead of the naked woman. The naked woman was also there

AH! Nevermind.

Does that wink mean 'Dolphins are sexy'?

[aristarchusinexile]

What force would you propose to cause galaxies to "continue on through"? It is the absence of any such forces, or the absence of any that approach the attractive forces present in the filaments and walls, that keeps the galaxies where they are.

I propose that it is the energy within the void, energy unknown to us, which prevents the galaxies penetration.

You missed the point of my question. What force would cause the galaxies to fall in towards the voids in the first place? That is, what force is it that this proposed force of yours is opposing? You don't doubt Newton's First Law, do you?

I do not propose galaxies falling towards the voids, as I propose anti-gravity filling the voids .. rather, the voids are compressing the galaxies together into filaments .. galaxies between voids being squeezed.

[Zarathustra]

I have yet to see any answer to my question. The closest thing to an answer offered here seems to be that it is the current theory that it was a sigularity in the beginning. I know that, hence the question in the first place. But, besides an inference from regresion, why a sigularity? All that followed the first attempt to answer the question seems to be misguided gibberist about Nietzsche. For the record, I am not a Nietzschian. I just like the name Zarathustra. I am however well versed in his philosophy. I would politely like to request that those here who clearly are not please refrain from posting your ignorance.

[aristarchusinexile]

Back to jets

http://arxiv.org/abs/0803.2509
Twisted coronal loops in uniform gravity

Okay .. in nature the larger seems to mimic the smaller: as in our solar system somewhat mimics atomic structure (or is this comparison so outdated as to be thought dead?) Spiral galaxies somewhat resemble solar systems (objects circling a centre). Can there be any possible comparison between Loop Quantum Gravity and Coronal loops in uniform gravity? I am willing to be thought completely absurd on this one as my total reading on Loop Quantum Gravity adds up to only several minutes.

[makc]

oh damn, someone stroke a nerve here...

My backround is philosophy, not physics. I started this topic out of a dissatisfaction with the alternatives of a "big rip" or a "big chill". This is a philosophic dissatisfaction... The reason I like the big crunch is that it opens the idea that there is a cycle.

What if a demon were to creep after you one day or night, in your loneliest loneness, and say: "This life which you live and have lived, must be lived again by you, and innumerable times more. And mere will be nothing new in it, but every pain and every joy and every thought and every sigh— everything unspeakably small and great in your life—must come again to you, and in the same sequence and series__" Would you not throw your self down and curse the demon who spoke to you thus? Or have you once experienced a tremendous moment, in which you would answer him: "Thou art a god, and never have I heard anything more divine!" [The Gay Science (1882), p. 341 (passage translated in Danto 1965, p. 210).]

but ok, back to topic,

But, besides an inference from regresion, why a sigularity?

I don't know, Occam razor maybe?

[Doum]

You ask why a singularity? That link have 2 short paragraphs about it. What i understand is that the closer the matter get the hotter it became and the known law of physic say that it is possible at high temperature to have all matter stuck together in a singularity. Sry if it isnt helping.

http://archive.ncsa.uiuc.edu/Cyberia/Co ... nning.html

[Qev]

Okay .. in nature the larger seems to mimic the smaller: as in our solar system somewhat mimics atomic structure (or is this comparison so outdated as to be thought dead?)

This comparison is so outdated as to be thought dead. Although the solar system would be an utterly amazing thing to experience, if planetary orbits mimicked atomic orbitals instead. Basically, atomic orbitals aren't orbits, they're clouds of probability where you can say an electron is likely to be found at any given time.

Spiral galaxies somewhat resemble solar systems (objects circling a centre).

When it comes down to it, these two really are the same thing. It's just masses orbiting a common center due to gravity, the only differences being in the details.

Can there be any possible comparison between Loop Quantum Gravity and Coronal loops in uniform gravity? I am willing to be thought completely absurd on this one as my total reading on Loop Quantum Gravity adds up to only several minutes.

I've tried to read about LQG, and my brain has the scars to prove it. The only relation between these two that I can fathom is a vague one involving the meaning of the word 'loop'. A coronal loop is plasma following a path of constant force, and the loops in LQG have something to do with 'paths' around nodes in spin networks... I think.

[Qev]

I think you're basically running into an Occam's Razor problem, here. You're adding complexity to the model without adding any greater explanatory power, as pure attractive-only gravity already seems to be able to produce the structures astronomers observe.

[harry]

G'day from the land of ozzz

My mentor has given me a load of reading so that I may understand the subject.


OOPs i have to go, forgot to pick up the kids.

Just before I go

http://arxiv.org/abs/0710.1326
Magnetar Driven Bubbles and the Origin of Collimated Outflows from GRBs

Authors: N. Bucciantini (1), E. Quataert (1), J. Arons (1), B.D. Metzger (1), Todd A. Thompson (2) ((1)Astronomy Department, UC Berkeley, (2)Department of Astrophysical Sciences, Princeton)
(Submitted on 5 Oct 2007)

Abstract: We model the interaction between the wind from a newly formed rapidly rotating magnetar and the surrounding progenitor. In the first few seconds after core collapse the magnetar inflates a bubble of plasma and magnetic fields behind the supernova shock, which expands asymmetrically because of the pinching effect of the toroidal magnetic field, as in PWNe, even if the host star is spherically symmetric. The degree of asymmetry depends on the ratio of the magnetic energy to the total energy in the bubble. We assume that the wind by newly formed magnetars inflating these bubbles is more magnetized than for PWNe. We show that for a magnetic to total power supplied by the central magnetar $\sim 0.1$ the bubble expands relatively spherically while for values greater than 0.3, most of the pressure in the bubble is exerted close to the rotation axis, driving a collimated outflow out through the host star. This can account for the collimation inferred from observations of long-duration gamma-ray bursts (GRBs). Given that the wind magnetization increases in time, we thus suggest that the magnetar-driven bubble initially expands relatively spherically (enhancing the energy of the associated supernova) while at late times it becomes progressivelymore collimated (producing the GRB). Similar processes may operate in more modestly rotating neutron stars to produce asymmetric supernovae and lower energy transients such as X-ray flashes.

I just like sharing what I read.