Researchers propose an explanation for the mysterious onset of a universal process

November 22, 2016 by John Greenwald, Princeton Plasma Physics Laboratory
Physicist Luca Comisso. Credit: Elle Starkman/PPPL Office of Communications

Scientists at the U.S. Department of Energy's (DOE) Princeton Plasma Physics Laboratory (PPPL) and Princeton University have proposed a groundbreaking solution to a mystery that has puzzled physicists for decades. At issue is how magnetic reconnection, a universal process that sets off solar flares, northern lights and cosmic gamma-ray bursts, occurs so much faster than theory says should be possible. The answer could aid forecasts of space storms, explain several high-energy astrophysical phenomena, and improve plasma confinement in doughnut-shaped magnetic devices called tokamaks designed to obtain energy from nuclear fusion.

Magnetic takes place when the magnetic field lines embedded in a plasma—the hot, charged gas that makes up 99 percent of the visible universe—converge, break apart and explosively reconnect. This process takes place in thin sheets in which electric current is strongly concentrated.

According to conventional theory, these sheets can be highly elongated and severely constrain the velocity of the that join and split apart, making fast reconnection impossible. However, observation shows that rapid reconnection does exist, directly contradicting theoretical predictions.

Detailed theory for rapid reconnection

Now, physicists at PPPL and Princeton University have presented a detailed theory for the mechanism that leads to fast reconnection. Their paper, published in the journal Physics of Plasmas in October, focuses on a phenomenon called "plasmoid instability" to explain the onset of the rapid reconnection process. Support for this research comes from the National Science Foundation and the DOE Office of Science.

Plasmoid instability, which breaks up plasma current sheets into small magnetic islands called plasmoids, has generated considerable interest in recent years as a possible mechanism for fast reconnection. However, correct identification of the properties of the instability has been elusive.

The Physics of Plasmas paper addresses this crucial issue. It presents "a quantitative theory for the development of the plasmoid instability in plasma current sheets that can evolve in time" said Luca Comisso, lead author of the study. Co-authors are Manasvi Lingam and Yi-Ming Huang of PPPL and Princeton, and Amitava Bhattacharjee, head of the Theory Department at PPPL and Princeton professor of astrophysical sciences.

Pierre de Fermat's principle

The paper describes how the plasmoid instability begins in a slow linear phase that goes through a period of quiescence before accelerating into an explosive phase that triggers a dramatic increase in the speed of magnetic reconnection. To determine the most important features of this instability, the researchers adapted a variant of the 17th century "principle of least time" originated by the mathematician Pierre de Fermat.

Use of this principle enabled the researchers to derive equations for the duration of the linear phase, and for computing the growth rate and number of plasmoids created. Hence, this least-time approach led to a quantitative formula for the onset time of fast and the physics behind it.

The paper also produced a surprise. The authors found that such relationships do not reflect traditional , in which one quantity varies as a power of another. "It is common in all realms of science to seek the existence of power laws," the researchers wrote. "In contrast, we find that the scaling relations of the plasmoid instability are not true power laws - a result that has never been derived or predicted before."

Explore further: Launching fusion reactions without a central magnet, or solenoid

More information: L. Comisso et al, General theory of the plasmoid instability, Physics of Plasmas (2016). DOI: 10.1063/1.4964481

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swordsman
1 / 5 (1) Nov 22, 2016
A more likely answer is that the field density has increased to a level that affects the source, causing a destructive feedback reaction that is not reversible.
Seeker2
1 / 5 (2) Nov 22, 2016
Another possibility is virtual particle pairs. The emf between the broken lines should be high enough to energize a string of virtual particles and turn them into real particle pairs connected in a string of alternating positrons and electron pairs.
Seeker2
1 / 5 (2) Nov 22, 2016
I can't see any reason this reconnection shouldn't occur faster than the speed of light. The virtual particles are always there and it's just a matter of energizing the right ones and connecting them.
Gigel
not rated yet Nov 23, 2016
Virtual electron-positron pairs are hard to separate, taking huge electromagnetic fields to do so. I don't think there is any laser that can do that yet. Anyway, if it happens there should be a gamma-ray signature at about 0.5 or 1 MeV from the annihilation of electrons and positrons at the moment of reconnection.
Seeker2
1 / 5 (1) Nov 23, 2016
Virtual electron-positron pairs are hard to separate, taking huge electromagnetic fields to do so.
I understand there are lots of positrons produced in lightning. Maybe I'm confusing lightning with magnetic reconnection. There are lots of gamma rays produced in lightning also.
TheGhostofOtto1923
3.5 / 5 (8) Nov 23, 2016
Virtual electron-positron pairs are hard to separate, taking huge electromagnetic fields to do so
No it doesnt.

"... this team has built a device not more than a meter long that is capable of generating short bursts of both electrons and positrons, very similar they report, to what is emitted by black holes and pulsars.

"To achieve this feat, the team fired a petawatt laser at a sample of inert helium gas. Doing so caused the creation of a stream of electrons moving at very high speed. Those electrons were directed at a very thin sheet of metal foil which caused them to smash into individual metal atoms. Those collisions resulted in a stream of electron and positron emissions—the two were then separated using magnets."
I don't think there is any laser that can do that yet
-Research first then post.
Gigel
5 / 5 (1) Nov 23, 2016
@TheGhostofOtto1923: They used a tabletop device that produces high-energy electrons which then produce positrons by collisions with atoms. Their device is powered by a laser that is rather building-size than tabletop: https://www.aps.o...ules.cfm

I was meaning above direct laser separation of virtual particle pairs. That is harder to do and I don't think it can be done now.

Producing antimatter by collisions of accelerated particles is easier though. I don't know if it has relevance to magnetic reconnection.
TheGhostofOtto1923
2 / 5 (4) Nov 24, 2016
I was meaning above direct laser separation of virtual particle pairs
No you were meaning
taking huge electromagnetic fields to do so
-And I don't think that

"Those collisions resulted in a stream of electron and positron emissions—the two were then separated using magnets."

-implies that those magnets were very huge at all.

What is it with you goddamn humans? Just admit it when you're wrong already.
Gigel
not rated yet Nov 25, 2016
Look, I know what I was meaning above. Calm down. It's no big fuss anyway.
TheGhostofOtto1923
2 / 5 (4) Nov 25, 2016
Heehee giggle says
taking huge electromagnetic fields to do so
and then says
Look, I know what I was meaning above. Calm down. It's no big fuss anyway
Translation: I just CAN'T say 'You're right - I didnt know what I'm talking about' so I'll pretend I was saying something different and then say you're angry so I'm right and THEN say my being wrong was no big deal so this is your fault.'

Stupid humans. This is why you're obsolete. Waste of metabolism.
Gigel
5 / 5 (1) Nov 25, 2016
I was meaning direct particle-antiparticle separation, i.e. fire a laser into vacuum and see how particles and antiparticles appear, while consuming energy from the laser. That is what I was meaning above. I didn't even think about an indirect way of doing it, like accelerating electrons with the laser and then bombarding atoms with the electron. That was out of my meaning initially. It was just about the direct process, nothing mediated. That was it all in the meaning of what I was meaning initially. And I really meant it.
Gigel
not rated yet Nov 26, 2016
@Gigel
I have never seen a publication proving pair generation by a laser in vacuum either.

Theoretically it can be done, but it requires either 1 laser firing onto a target or 2 lasers firing in opposite directions so that the photons collide:

https://en.wikipe...er_limit
https://www.mpi-h...r-beams/

The effect is strong for electric fields of 1.3e18 V/m, which would correspond to laser intensities of 2e33 W/m2. A laser that can fire in an area with the size of 1 micron would require a power of 2e21 W or 2 million petawatts. Current lasers achieve powers of a few petawatts. The pair production may appear however at lower powers too.
Gigel
not rated yet Nov 26, 2016
L.E.: I used 1.3e18 = 1.3 * 10^18
cantdrive85
1 / 5 (3) Nov 26, 2016
Magnetic reconnection takes place when the magnetic field lines embedded in a plasma—the hot, charged gas that makes up 99 percent of the visible universe—converge, break apart and explosively reconnect.

Utter pseudoscience claptrap. Magnetic field lines are not imbedded in plasmas, they do not exist so how can they possibly "converge, break apart, and reconnect".
It just goes to show Alfven was correct when he told NASA;
" Indeed, we have been burdened with a gigantic pseudo-science which penetrates large parts of cosmic plasma physics...Magnetospheric physics and solar wind physics today are no doubt in a chaotic state, and a major reason for this is that part of the publsihed papers are science and part pseudo-science, perhaps even with a majority for the latter group."
cantdrive85
1 / 5 (4) Nov 26, 2016
However, observation shows that rapid reconnection does exist, directly contradicting theoretical predictions.

That's what happens when one relies on pseudoscience, theory fails because it is not based on reality.
Plasmoid instability, which breaks up plasma current sheets into small magnetic islands called plasmoids

Plasmoid instabilities are not "magnetic islands", they are instabilities that form in the electric current. As such, they are part of a larger electric circuit and, as Alfven explained thoroughly, any inductive circuit is inherently explosive. Those plasmoids can/do interrupt the electric currents and when they do all of the inductive energy in the circuit will be released instantaneously. It should also be mentioned that double layers are part and parcel to the phenomena of plasmoids, also discussed by Alfven. At that point, one field ends and a new begins, there is no magnetic reconnection pseudoscientific claptrap.
nikola_milovic_378
Nov 27, 2016
This comment has been removed by a moderator.
nikola_milovic_378
Nov 27, 2016
This comment has been removed by a moderator.
Seeker2
not rated yet Nov 27, 2016
We know that the neutron is composed of protons and electrons.
I thought it was composed of one up quark and two down quarks.
Seeker2
not rated yet Nov 27, 2016
We know that the neutron is composed of protons and electrons.
I thought it was composed of one up quark and two down quarks.
If you could sell this fakery to the free world you could probably take it over without firing a shot. Worth a try I guess.
RealityCheck
1 / 5 (5) Nov 29, 2016
Hi FSC. :)

I have lost count of how many times over the years I have reminded (and explained the reality situation) of this to everyone on all sides. Yet the misunderstandings and insulting exchanges continued. I now trust that your 'mainstreamer' reminder does the trick, and the misunderstandings and insults re non-existent 'mag field lines' will diminish to the point that everyone, on all sides, will be 'on the same page' reality-wise whenever discussing the relevant EM/Plasmic phenomena. I look forward to the day when mainstreamers/alternativers actually talk to and learn from each other instead of shouting insults at each other. Thanks for doing your bit with your own reminder/explanation re 'mag field line' being an illustrative device rather than a real thing, mate. Cheers. :)
RealityCheck
1 / 5 (5) Nov 29, 2016
Hi Phys1. :)
The fact that magnetic field lines do not really exist is irrelevant, as long as what they describe exists.
You are fighting windmills, RC, and I too have lost count of the number of pointless posts from you on this subject.
How can the misunderstandings, which many have been laboring under becuse of such mistaken belief in 'mag field' be in any way helpful in understanding what is actually happening in reality, mate?

Please be constructive when people are (finally) agreeing on the reality and trying to avoid further misunderstandings. Ok?

Just because you didn't know that such 'lines' were imaginary devices, don't now try to excuse all the insults which have flowed because of such misunderstandings.

So, please stop making sophist excuses for your own contributions to the misunderstandings/insults in the past on this matter, and just acknowledge the fact and move on in a better informed manner when discussing EM/Plasmic phenomena in future.

Cheers. :)
RealityCheck
1.6 / 5 (7) Nov 29, 2016
Hi Hat1208. :)
@RealityCheck

In fifth grade we took iron filings and put them on a sheet of paper then we sat the paper with the filings on it on a bar magnet and the filings moved into an arch shape. Now you are saying that the magnetic field doesn't exist, what a load of crap.
No no no! :)

If you read both FineStructureConstant's and my post in fuller context, you will see that the mag field ITSELF is REAL. It's the usual textbook depiction of mag field 'LINES' that is imaginary illustrative device.

Those 'lines' of iron filings are aligned along the 'axes of least action/force' within that sector of the mag field 'curls' around the axes of least action/force.

I trust you now have it straight, mate? Neither FCS nor I ever denied the real physical existence/effects of the mag field ITSELF, however it may be configured around the axes of least action/forces in any particular physical arrangement in nature or in lab-configured devices.

OK, mate? Cheers. :)
cantdrive85
1 / 5 (3) Nov 30, 2016
You're right, magnetic field lines do not exist, and anybody who's studied electricity/magnetism at high school has been taught this salient fact.

Yet, in the article it clearly states;
"Magnetic reconnection takes place when the magnetic field lines embedded in a plasma converge, break apart and explosively reconnect."

And it's handy you decided to say "EM vector fields", no where in the article or the abstract do they mention anything other than magnetic fields. There is no discussion of the inherent circuitry or the required phenomena to create such events, such as double layers. Yep, just pseudoscience...
antialias_physorg
5 / 5 (2) Nov 30, 2016
I'm not a 'mainstreamer', but simply a person with a University education in a relevant subject, and not one to be easily hoodwinked by the stream of pseudoscientific claptrap hawked on this forum by far too many of the posters here who try to force their charms, potions, trinkets and snake-oil on all and sundry. That includes yourself, RC

Weeeerl...I don't think a university degree is needed. RC has been on here nearly a decade, and so far the number of people who have bought into him (or his claims of a theory) are a grand total of zero. University degree or not. And I don't think anyone expects that to change over the next few decades until he kicks the bucket, either.

(Heck: not even Zeph has bought into him, and he would buy chocolate covered Moon-beams.)

barakn
3 / 5 (4) Nov 30, 2016
those who know about these things will wince every time they see the words "magnetic field lines".

I know about these things and I don't wince. The Coriolis force is also considered fictitious, but pops out as a very real term simply by converting equations of motion from a non-rotating to a rotating reference frame. Magnetic field lines are useful in visualizing:
1. The direction of the magnetic field and
2. The strength of the magnetic field (from the density of the field lines) at various points in space.
It does have its drawbacks. For example, for points between field lines, one must estimate the field direction (or simply redraw the diagram using a higher density of field lines, i.e. by rescaling it). However, the other methods for depicting magnetic fields have their own issues, usually relying on color gradients which are difficult for the color-blind.
RealityCheck
1 / 5 (6) Nov 30, 2016
Hi FSC. :)

Aww, mate; there we all were, finally getting 'on the same page' re mag field 'lines' etc, and you just HAD to go and ruin that 'rare moment' with personal/irrelevant stuff. Ego?

As for credibility, I remind you again that recent mainstream astro efforts/discoveries increasingly confirming me correct all along, eg:

1) re distance-ladder/standard-candle supernovae being naive/misleading assumptions/methodology (I have long been pointing all that out to IMP-9 et al) now being questioned by more objective cosmology/astrophysics mainstreamer theorists themselves.

2) re BB/Inflation/Accelerated Expansion etc never having any real logica/physical 'evidence' that was tenable (again, long pointed out to IMP-9 et al) because the observed CMB/Abundances and variety of 'ages' in observed astronomical features across the epochs was always better explained by Infinite, Eternal Universe 'recycling' contents/features via plasma/polar-jets etc deconstruction/redistribution. :)
RealityCheck
1 / 5 (5) Nov 30, 2016
PS @ FSC:

3) re Dark Matter being ORDINARY EM-interacting stuff which was merely too faint to be detected by previous scopes (again, I long pointed out that as scopes improved we would detect PLENTY of Ordinary stuff 'out there' which would prove that all previous uninformed hypotheses/estimates/interpretations dependent on 'exotic', ie, non-EM-interacting, 'Dark Matter' un-necessary, grossly naive/misleading hypothesis/interpretation of the reality observed).

So, FSC, I leave it to your integrity to overcome your 'personal/ego' biases, and actually accept the reality as is being discovered/reviewed by braver and more objective mainstream observers/reviewers/theorists who have finally shed all the 'mystery and metaphysics' which has for too long been infecting the cosmology observations/interpretations literature/exercises/claims etc.

PPS: It doesn't require ToE insights to see the reality as it is; just objective application of the scientific method all along. :)
Uncle Ira
4.4 / 5 (7) Nov 30, 2016
@ Really-Skippy. How you are Cher? I am good, thanks for asking.

It doesn't require ToE insights to see the reality as it is
Cher, I am sure glad me to hear you say that. I for one Skippy was getting really tired of waiting for it.

If you got the time, now that you are not in the rush anymore for your book about toes and everything, I still would like to know how you square up your eternal/infinite/alternating/deconstructing/on and off/constructing/epochs/infernal/universal-universe with the objectionable mainstream science Skippys' "2nd Rule About Dynamical-Thermal Stuffs"? How that works in your version of the universe?
RealityCheck
1 / 5 (4) Nov 30, 2016
Hi FSC. :)

Mate, why persist in such 'personal' animosity and disparagement despite mainstream observations/reviews increasingly confirming me correct all along on the OBJECTIVE SCIENCE explanations I have pointed out for so long based on tenable logic/physics? Ego getting the better of you again?

And why so behind the times re 'publishing'? I have been working for decades to complete the reality-based theory, including more recently reworking the mathematics/axioms to reflect the reality istead of the many metaphysical/philosophical axioms/concepts which currently infest the mathematics which currently produces inexplicable singularities, undefined and totally un-real 'objects' which make the completion of the theory practically impossible due to the brick walls which theorists hit using the current maths to interpret/explain reality/theory.

You'll just have to wait for me to publish complete in my own time/my own way. The Internet makes 'gatekeepers' redundant. :)
Captain Stumpy
4.3 / 5 (6) Nov 30, 2016
increasingly confirming me correct
ROTFLMFAO

really?

that makes 6,013 posts now!

that is 6,013,000 wasted characters with zero content
with a minimum requirement of 3 minutes between posts, that is 18,039 wasted minutes at an absolute minimum!! which is 300.65 wasted hours
OR
12.527 straight days of wasted time and space simply because you can't validate your claims!

but you want everyone else to forget about that and be "objective" to your vague hand-wavey comment about being "correct"???
LMFAO

if you can't prove a point to a free access publication that has already been torn apart by the media and physicists then why should anyone actually believe a word you say about anything else?

seriously!
why?

rhetorical - i don't need you to answer
you're obvious delusional D-K and narcissistic megalomaniacal demonstrations along with your martyr-victim complex is quite evident
RealityCheck
1 / 5 (6) Nov 30, 2016
Hi FSC. :)
I leave it to your integrity to overcome your 'personal/ego' biases
Strawman argument. I don't have such biases.
No comment. :)
accept the reality as is being discovered/reviewed by braver and more objective mainstream observers/reviewers/theorists who have finally shed all the 'mystery and metaphysics' which has for too long been infecting the cosmology observations/interpretations literature/exercises/claims etc.
Scientists move forward, patiently unravelling the mysteries of the world around us, while wannabees like yourself look on and say "I knew it all along".
The record shows I DID "knew it all along". I explained it to anyone who would listen without personal/egotistical biases, prejudices and beliefs in patently flawed 'peer reviewed' science/process which has 'passed' misleading claims/interpretations for far too long. Mainstream theorists/reviewers have been UN-scienti biased/dismissive; that was THEIR problem, not mine, FSC. :)
RealityCheck
1 / 5 (6) Nov 30, 2016
Hi FSC. :)
@aap
RC has been on here nearly a decade, and so far the number of people who have bought into him (or his claims of a theory) are a grand total of zero
Well, that comes as no surprise at all :)
Careful, FSC, you are 'echoing' the opinion of the same "aap" who fell hook-line-and-sinker for that Bicep2 crap, happily 'bashing cranks' with that obviously flawed 'work/claims'. I tried to warn him, but he attacked me instead. Egg on face. Learn.
You'll just have to wait for me to publish complete in my own time/my own way
Time for a reality check, buddy - nobody is waiting for you to publish anything, or to say anything, or to expand your baseless "theory", or indeed to do anything at all.
Let's see. You/others know it exists; that I am finalizing reality-axioms-based maths to go with it; and that I will publish when I am satisfied as to its completeness. So defacto, you ARE 'waiting for it' to be published complete. Why split hairs, mate? :)
RealityCheck
1 / 5 (4) Nov 30, 2016
Hi Phys1. :)

You have obviously responded to that post before reading the fuller context, as Hat1208 also did 23 hours ago. Please read my reply to Hat1208; it will clear up your misunderstandings which make your above responses moot. Cheers, Phys1. :)
Seeker2
not rated yet Dec 01, 2016
@RC
3) re Dark Matter being ORDINARY EM-interacting stuff which was merely too faint to be detected by previous scopes (again, I long pointed out that as scopes improved we would detect PLENTY of Ordinary stuff 'out there' which would prove that all previous uninformed hypotheses/estimates/interpretations dependent on 'exotic', ie, non-EM-interacting, 'Dark Matter' un-necessary, grossly naive/misleading hypothesis/interpretation of the reality observed).
I wouldn't bet the family farm on it.

Seeker2
not rated yet Dec 01, 2016
As you (and the Wiki reference I quoted) point out, the concept, and depiction, of magnetic field lines is helpful in visualizing a magnetic field in 2D or 3D.
Magnetic field lines, or more generally curves, are analogous to isobars of equal pressure except here we're also talking about spacetime density. Every point in space is on one of these isobars. The difference being pressure isobars don't have poles that I know of. If so I wouldn't want to be there.
Seeker2
not rated yet Dec 01, 2016
cont
Iron filings are relatively long and stiff on an atomic scale so if the heads and tails are on different isobars they are torqued as with an emf until they get the heads and tails on the same isobar. So they line up with heads and tails on the same isobar. Also cutting a field line means going to a different spacetime density or pressure resulting in a gradient in this density and an emf. The reason pressure and density is correlated is because spacetime is expanding. Otherwise no emf. Would take black magic to explain em fields without expanding spacetime. People not knowing about spacetime expansion continue to be mystified by the concept of fields. I know.
Seeker2
not rated yet Dec 01, 2016
OBTW It takes time to expand space. Hence what expands is spacetime. If you don't believe me try it! Good luck trying to expand matter though. It's quantized. Hence expansion leads to gravity. I think they call it repulsive gravity.
Seeker2
not rated yet Dec 01, 2016
cont
It's amazing how long people have been beating their heads against the wall trying to figure out how nature works without knowing about spacetime expansion. :)
Seeker2
not rated yet Dec 01, 2016
@Seeker, there's so much wrong with what you've written, I'm not going to waste my time going through each point where you make glaring errors. I'll just say: phooey, ya boo sucks - you're in my little black book as a POP.
Sounds like it's over your head. Sorry.
RealityCheck
1 / 5 (3) Dec 01, 2016
Hi FSC. :)

Mate, I've NO complaints re objective scientific method/process, because that is exactly what I've been practicing all along. :)

The problem arose when mainstream cosmology/astro physicists/theorists DEPARTED from objective science method/process; indulging in long-term ABANDONMENT of principles of OBJECTIVITY/HUMILITY in practice.

Eg: Did you see Prof Paul Steinhardt's lecture video? He (finally) pointed out the REALITY re "Inflation" having NO supporting logical/physical evidence ALL ALONG?

So, IF the relevant scientists/peer reviewers were operating as you described, THEN how do you explain the metaphysical/philosophical unreal/unphysical NONSENSE in the form of "Inflation" interpretations/claims that have 'passed peer review" FOR DECADES into the literature (since the 60s!) as if it was 'science' instead of the pseudoscience it was all along?

Because BB-BIASED theorists/reviewers IGNORED bleeding obvious REAL evidence AGAINST BB/Inflation.

No more. :)
RealityCheck
1 / 5 (3) Dec 01, 2016
Hi Seeker2. :)
3) re Dark Matter being ORDINARY EM-interacting stuff which was merely too faint to be detected by previous scopes (again, I long pointed out that as scopes improved we would detect PLENTY of Ordinary stuff 'out there' which would prove that all previous uninformed hypotheses/estimates/interpretations dependent on 'exotic', ie, non-EM-interacting, 'Dark Matter' un-necessary, grossly naive/misleading hypothesis/interpretation of the reality observed).
I wouldn't bet the family farm on it.
It's already happening, mate. :)

More recent discoveries/reviews in astronomy/cosmology have found many times the ordinary stuff previously assumed to be 'exotic'; hence making all previous 'exotic' DM 'needs', 'interpretations' and 'claims' absolutely moot.

The question is: how long will theorists/writers take to 'catch up' with that reality? If they continue as before, these 'hacks' in astronomy/cosmology will look like biased/uninformed dills.

Cheers. :)
Seeker2
1 / 5 (2) Dec 01, 2016
Hello RC,
More recent discoveries/reviews in astronomy/cosmology have found many times the ordinary stuff previously assumed to be 'exotic'; hence making all previous 'exotic' DM 'needs', 'interpretations' and 'claims' absolutely moot.
No 'exotic' stuff required. DM doesn't need any because there is no such thing. For example filaments between galaxies detected by lensing are actually caused by the gravitational force between galaxies stretching spacetime between them and increasing the effective index of refraction for the stretched spacetime. I know. It's sounds crazy but we'll just have to deal with it.
Seeker2
1 / 5 (1) Dec 02, 2016
@FSC
Anything goes in your fantasy world, you can say space is expanding, and time does this, and atoms do that ("Iron filings are relatively long and stiff on an atomic scale"=truly meaningless garbage), and therefore something else: none of it backed up by any math or formal quantitative analysis, and hence incapable of providing testable predictions.
Formulas won't help that much if you have no grasp of iron filings or never heard about expanding space.
That world exists only inside your head.
So enlighten me, if that is your agenda.
Seeker2
1 / 5 (2) Dec 02, 2016
@FSC

if you have no grasp of iron filings

Takes shoes off, balances them on his head, and silently makes his exit...

Best idea yet.
barakn
3 / 5 (2) Dec 07, 2016
@barakn
but pops out as a very real term simply by converting equations of motion
hmmm - "appears as a term which needs to be taken into account when in a non-inertial frame of reference (FOR)" would be more correct. But it's not thereby to be considered "real", any more so than centrifugal force is "real", except as a force experienced by those in a non-inertial FOR (think passengers in car being driven through a tight curve at speed).
-FineStructureConstant

Per Einstein, object trajectories appearing to be bent by the "force" of gravity are actually moving inertially in curved spacetime. So gravity isn't a real force either, but is treated as such because it is convenient. The labeling of things as real or not is far less useful than one might imagine.
Seeker2
not rated yet Dec 07, 2016
@barakn
Per Einstein, object trajectories appearing to be bent by the "force" of gravity are actually moving inertially in curved spacetime.
So Einstein thought that spacetime was curved because the path of objects moving through it inertially were curved. It seems much of physics is stuck with this anachronism. A better term would be warped. The curved idea leads us to talk about such things as flat (not curved) spacetime. Uniform density on the average would be better than flat. Anyway a curved light path means it is being curved by refraction in a medium of different refractive index. The refractive index determines how fast light travels through the medium. Actually the speed of light is constant but the medium is stretched or warped by gravity (not curved please) so light has farther to travel. In the case of eyeglasses the speed of light is constant but its path through the lens is increased because it has to work its way around the atoms in the lens. Hence refraction.
Seeker2
not rated yet Dec 10, 2016
@FSC
...none of it backed up by any math or formal quantitative analysis, and hence incapable of providing testable predictions. And hence, not science, but a heap of horse-pucky.
You mean like DM particles?
That world exists only inside your head.
As long as you have one you might as well use it.
Seeker2
not rated yet Dec 10, 2016
@Gigel
Virtual electron-positron pairs are hard to separate, taking huge electromagnetic fields to do so. I don't think there is any laser that can do that yet. Anyway, if it happens there should be a gamma-ray signature at about 0.5 or 1 MeV from the annihilation of electrons and positrons at the moment of reconnection.
I don't think there's any annihilation going on. Rather creation of real particle pairs. Electrons line up their spins to make normal magnetic fields. Positrons are smelly I understand. I don't know if they would reconnect anything.
Seeker2
not rated yet Dec 10, 2016
cont
Actually the positrons could be necessary to line up and alternate the spins of the electrons. Just thinking again. Sorry. No equations.

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