Personally, I think this has to do with thunderstorms being essentially linear accelerators, vertical SLAC’s if you will. Huge charge differentials from top of cloud to bottom makes for a nice particle slingshot. There’s plenty of opportunity for antimatter (positrons) to be created in energetic collisions from particles coming out of the tops of thunderstorms. Sprites and blue jets for example, may be indicators for energetic particles.
It could also be very energetic photons from lightning as seen in the diagram below. At the high photon energies (twice the rest energy of electrons at 511 keV) and above 1.022 MeV positron-electron pair production may take place. Getting energies of 1.022 million electron volts certainly seems easy enough in thunderstorms. – Anthony
From Sciencenews.org: Signature of antimatter detected in lightning
Fermi telescope finds evidence that positrons, not just electrons, are in storms on Earth
Washington — Designed to scan the heavens thousands to billions of light-years beyond the solar system for gamma rays, the Fermi Gamma-ray Space Telescope has also picked up a shocking vibe from Earth. During its first 14 months of operation, the flying observatory has detected 17 gamma-ray flashes associated with terrestrial storms — and some of those flashes have contained a surprising signature of antimatter.
During two recent lightning storms, Fermi recorded gamma-ray emissions of a particular energy that could have been produced only by the decay of energetic positrons, the antimatter equivalent of electrons. The observations are the first of their kind for lightning storms. Michael Briggs of the University of Alabama in Huntsville announced the puzzling findings November 5 at the 2009 Fermi Symposium.
It’s a surprise to have found the signature of positrons during a lightning storm, Briggs said.
The17 flashes Fermi detected occurred just before, during and immediately after lightning strikes, as tracked by the World Wide Lightning Location Network.
During lightning storms previously observed by other spacecraft, energetic electrons moving toward the craft slowed down and produced gamma rays. The unusual positron signature seen by Fermi suggests that the normal orientation for an electric field associated with a lightning storm somehow reversed, Briggs said. Modelers are now working to figure out how the field reversal could have occurred. But for now, he said, the answer is up in the air.
Recording gamma-ray flashes — which have the potential to harm airplanes in storms — isn’t new. The first were found by NASA’s Compton Gamma-ray Observatory in the early 1990s. NASA’s RHESSI satellite, which primarily looks at X-ray and gamma-ray emissions from the sun, has found some 800 terrestrial gamma-ray flashes, Briggs noted.
It’s true that there ought to be sufficient energy for pair production, but the atmosphere is also dense enough, even at 100km height, that very few electrons will reach the required energy before a collision resets them to zero KE. You’ll note that they aren’t seeing swarms of these gamma rays.
This will be more fun to think about than the health care bill.
Just to be correct, the photon does not have to strike the nucleus as illustrated above. It merely has to pass close to the nucleus to excite the pair production. The source of the paired particles is not from the “debris” of collision. GK
Having been too close (as in inside) thunderstorms,nothing would surprise me that they are capable of this. When you get a vertical ride from FL200 to FL280 in afew seconds
then spit out-there are some mighty strong forces out there.We humans are insignificant to this planet….
Wondrous and fascinating, just shows how much we have to learn about the science of this earth and the immensity beyond our little planet.
Thank goodness we have solved the science of AGW!?*!
I suppose if we want to be very correct about what people observe here, the picture of a gamma just coming sufficiently close to a nucleus is not right. The researchers are observing not the positrons themselves, but the gamma rays characteristic of a positron annihilating an electron. The two masses in such a collision effectively vanish and the energy, momentum, and parity of the original particles is carried away in one, two or three emitted gamma rays. The instruments detect gamma rays with 0.511Mev energy and the scientists infer that positrons are present.
So where do the positrons come from? If an electron can be accelerated to at least 1.022Mev, as Anthony says, there is enough energy to create an electron, positron pair. However, this is a bare minimum requirement. There must be other particles involved in order to explain the sudden appearance of a unit of positive charge.
There are so few of these gammas observed that perhaps some process other than just acceleration of electrons is involved?
The discoverer of nuclear anti-matter, Antonino Zichichi, seems to agree with Henrik Svensmark and Nir Shaviv,
Climate changes depend in a significant way on the fluctuation of cosmic rays.
http://www.zenit.org/article-19481?l=english
Antonino Zichichi :
http://www.ccsem.infn.it/em/zichichi/short_bio.html
Shocking New Scientific Finding!
Warmer Homes Mean Better Health For Poor People, Study Suggests
ScienceDaily (Nov. 8, 2009) — Being warm enough at home might lead to better health, according to a new review appearing online in the American Journal of Public Health.
http://www.sciencedaily.com/releases/2009/11/091106200738.htm
Gee, if winters were just a little warmer, people would be healthier…..go figure.
The following article is behind a pay-wall, but Goggle’s summary suggests that “The 0.511 MeV radiation is practically completely of atmospheric origin”
E. P. Mazets1, S. V. Golenetskii1, V. N. Il’inskii1, Yu. A. Gur’yan1 and T. V. Kharitonova1
(1) A. F. Ioffe Physical-Technical Institute, U.S.S.R. Academy of Sciences, Leningrad, USSR
Received: 7 August 1974
Therefore one “sees” gammas characteristic of positrons coming from the atmosphere, perhaps from thunderstorms, perhaps independently of them.
Anyway, what I said a moment ago about an electron needing 1.022meV, might not be correct, maybe an electron with kinetic energy of 0.511Mev is the minimum because one has to add enough energy to just create the positron…but then, there is still the issue of the charge.
Gene Nemetz (09:39:42) :
Nice. Thanks.
If X rays can be generated by sticky tape
http://physicsworld.com/cws/article/news/36357
I don’t have a problem believing positrons could be generated in electrical storms.
Next, someone will find dilithium crystals in South Africa.
Or something like this might happen!
Gene Nemetz (09:39:42) :
The discoverer of nuclear anti-matter, Antonino Zichichi, seems to agree with Henrik Svensmark and Nir Shaviv,
He has had a couple of choice things to say about the IPCC too:
“Scientists might not have human behavior to blame for global warming, according to the president of the World Federation of Scientists.
Antonio Zichichi, who is also a retired professor of advanced physics at the University of Bologna, made this assertion today in an address delivered to an international congress sponsored by the Pontifical Council for Justice and Peace.
The conference, which ends today, is examining “Climate Change and Development.”
Zichichi pointed out that human activity has less than a 10% impact on the environment.
He also cited that models used by the Intergovernmental Panel on Climate Change (IPCC) are incoherent and invalid from a scientific point of view. The U.N. commission was founded in 1988 to evaluate the risk of climate change brought on by humans.
Zichichi, who is also member of the Pontifical Academy of Sciences, showed that the mathematical models used by the IPCC do not correspond to the criteria of the scientific method.”
Duct Tape: More than the handyman’s secret weapon!
http://www.youtube.com/watch?v=5QFRSjWVTmY
Hey Kids! With just a couple of rolls of duct tape, you too can be a high energy particle physicist! Or try X-raying the cat, but it helps if you tape it to a plank first!
(Sorry, more Engineer Humor on a Sunday.
I come here for the AGW discussion and this is icing on the cake. Thank you Anthony.
Regards,
Steamboat Jack
How long before AGW is to blame for this as it was not observed before, never mind that Fermi telescope was not there to see it so it must not have happened and AGW cause it to happen. Lets spend some tax money to see if we could stop it from happening.
I also have some doubts that the “linear accelerator” model is viable. The “air” is not good enough vacuum to accelerate them sufficiently. Moreover, they’re probably seeing much sharper 511 keV lines than predicted from positrons created at high velocities, as implied by hugely energetic collisions.
So I prefer to think that some positrons are probably always in the atmosphere, they’re just being collected and/or focused by the lightnings.
See
http://motls.blogspot.com/2009/11/fermi-lightnings-produce-positrons.html
If you google van de graaf generator and positron, you will find several articles. Here’s one:
http://cat.inist.fr/?aModele=afficheN&cpsidt=13831420
Luboš Motl (11:00:51) :
“I prefer to think that some positrons are probably always in the atmosphere, they’re just being collected and/or focused by the lightnings.”
Now why didn’t I think of that? Oh, yeah, the PhD in physics. Didn’t know how much I was missing by studying rocks.
I would have thought the atmosphere would be too dense for this to happen at the altitudes where lightening happens?
Perhaps the huge electric current or the discharge sweeps the ionised air away and causes a vacuum for long enough for the process to happen.
Still lots to learn about our climate – the science will never be settled.
Idle speculation that the gamma rays could originate from space or from the centre of the earth, and lightning is precipitated along their tracks.
How do they measure the direction of travel of these gamma rays? And does the earth absorb them?
Kevin Kilty (09:46:42) :
First lets see where one can get the gamma rays.
There are electrons around nuclei and obviously since thunder storms have high electric fields they are spinning around , as well as the stripped nuclei as ions.
These can become accelerated following the electric lines. They can also be decelerated, against the lines and when this happens ( vortex conditions?) photons come out of the deceleration. Photons can come out also when these energetic charged particles( electrons or ions) whoosh close to the electric field of other nuclei.
If the energy of these photons is in the mev range the photons are gamma rays.
If the gamma ray has an energy over twice the electron mass it can break into an electron positron pair interacting with the electric field , either of the storm or with one of the ions floating around.
The positron will then annihilate with a characteritic spectrum when hitting one of the electrons still attached to the gas nuclei in the atmosphere.
It needs a monte carlo model to get the possible flux out :), i.e. how many one would expect, and model is a five letter word here :).
The first quest is to account for any possible alternative explanations for the gamma rays and their “signature” behaviour.
Then, identify the source of the energy either of positrons or other possible processes.
There is much we don’t know yet.
As an example of gammas generated on gas:
http://accelconf.web.cern.ch/AccelConf/e04/PAPERS/THPLT052.PDF
“Electrons interacting with residual gas atoms in the
storage ring vacuum vessels produce the emission of a
cone of electromagnetic radiation extending from long
wavelength photons down to gamma ray photons at the
energy of the electron beam. The majority of the emitted
radiation energy is in gammas with an opening angle of
1/γ rms, where γ is the relativistic factor of the electrons.”
this is 6 GeV electrons.
****************************
Doug in Seattle (11:13:06) :
Luboš Motl (11:00:51) :
“I prefer to think that some positrons are probably always in the atmosphere, they’re just being collected and/or focused by the lightnings.”
Now why didn’t I think of that? Oh, yeah, the PhD in physics. Didn’t know how much I was missing by studying rocks.
*******************
Well, I guess if one has a strong enough electric/magnetic field, it could tease virtual particles of of the vacuum – kind of like a black hole does.
Luboš Motl (11:00:51) : “I also have some doubts that the “linear accelerator” model is viable. The “air” is not good enough vacuum to accelerate them sufficiently.”
But thunder, I’m told, is caused by air refilling the vacuum created by a lightning strike. Similarly, microscopic vacua may be created by lifting adhesive tape. Tiny adhesive particles may adhere, then release suddenly, like a rubber band.
Kevin Kilty (09:30:42) :
Sorry Kevin… I wasn’t referring to your comment, but the above diagram:
http://go2.wordpress.com/?id=725X1342&site=wattsupwiththat.wordpress.com&url=http%3A%2F%2Fupload.wikimedia.org%2Fwikipedia%2Fcommons%2F8%2F84%2FPairproduction.png
Some great comments everybody!
This is the significant phrase:
“The17 flashes Fermi detected occurred just before, during and immediately after lightning strikes, as tracked by the World Wide Lightning Location Network.”
Distributions always have tails, and there are many distributions entering the problem. They are talking of a few hundred gamma rays and 17 positron signatures.
If I were writing the Monte Carlo program I would need a number of distributions, but I am sure I would be able to get, out of the trillion possibilities of phase space, 17 electron positron events.
Now you just need to work out how to channel 1.21 gigawatts from that lightning strike into your Flux Capacitor…..
anna v (11:25:07) :
Kevin Kilty (09:46:42) :
First lets see where one can get the gamma rays.
There are electrons around nuclei and obviously since thunder storms have high electric fields they are spinning around , as well as the stripped nuclei as ions.
1) The direct energy input is via electrons accelerated by the electric field. So, we must go from accelerating electrons to braking them (bremstralung), creating a photon, then having the photon collide with another nulceus and produce a particle pair.
2) Suppose the photons can be produced in the fist place. Up to an energy of about 10Mev these photons are involved in Compton scattering, above 10Mev or so they produce particle pairs.
3) So our electron acceleration has to produce several MEV anyway. But as I pointed out very early in this thread the atmosphere even at 100km is not thin enough to allow an electron to accelerate to several MEV (in a field of 1 million volts per meter the electron would need a free path of 1 meter to reach 1Mev). What is the free path length at 100km? I dunno, not one meter I’ll bet, and down in the region of lightning it is next to nothing.
So, I suggested maybe there are other mechanisms, and Luboš Motl (11:00:51) suggests that there are positrons around in the air anyway, and the lightning interacts with them in some way. Suppose we can get some positrons from Carbon 14or Nitrogen 13?
Here is another possibility. What if materials in the detector itself has a few decays now and then and produces the requisite positrons itself now and then. Look 17 gammas is such a low signal it could be randomness mascarading as signal, yes?
Let me clarify. Maybe we can get positrons from the gammas produced with Nitrogen 13. Carbon 14 produces no gamma, but there are always cosmic rays around.
tallbloke (10:37:03) :
Ha! It pays to check the sources. I thought the Pontifical Council for Justice and Peace conference was current until I checked Gene Nemetz’s link for Antonino Zichichi’s quote.
Sorry, but that conference couldn’t have taken place in 2007- the “Consensus” was in effect.
yonason (09:58:44) :
Love it – Seth Putterman and colleagues at the University of California, Los Angeles (Nature 455 1089) applying for a portable x-ray generated by sticky tape!
Seth Putterman and colleagues at the University of California, Los Angeles (Nature 455 1089) applying for a portable x-ray generated by sticky tape PATENT!
supercritical (11:19:43)
asked about cosmic rays and lighting?
Apparently that’s not so far fetched.
http://www.scientificamerican.com/article.cfm?id=experts-do-cosmic-rays-cause-lightning
“Decades of electric field measurements made inside thunderstorms have failed to find large enough electric fields to cause a spark, even when the effects of precipitation are taken into account. Since we know that lightning does occur—in fact, it strikes the earth about four million times a day—we must be missing something in our understanding.”
Apparently it might work like spark-gap detectors, where the particle shower resulting from cosmic particles entering the atmosphere “might provide a conductive path that initiates lightning”
“”” Kevin Kilty (09:30:42) :
I suppose if we want to be very correct about what people observe here, the picture of a gamma just coming sufficiently close to a nucleus is not right. The researchers are observing not the positrons themselves, but the gamma rays characteristic of a positron annihilating an electron. The two masses in such a collision effectively vanish and the energy, momentum, and parity of the original particles is carried away in one, two or three emitted gamma rays. The instruments detect gamma rays with 0.511Mev energy and the scientists infer that positrons are present.
So where do the positrons come from? If an electron can be accelerated to at least 1.022Mev, as Anthony says, there is enough energy to create an electron, positron pair. However, this is a bare minimum requirement. There must be other particles involved in order to explain the sudden appearance of a unit of positive charge. “””
There really isn’t any sudden appearance of a positve charge; the Positron/Electron pair are generated at the same time so there is no unbalance of charge generated. Presumably the positron and electon would fly off in opposite directions, so eventual anihilation of the positron, is not simply a recombination with its mirror image; they should never meet again.
There was a time I could have told you the origin of the pair; but too much water has probably gone under the bridge.
Anna v. probably can tell us where the pair comes from.
When I was at the university; we used to wait patiently for a good thunderstorm so we could go down to the harbor, and launch a hydrogen filled weather (radiosonde) balloon carrying an electronic system to measure the electric fields under the thunderclouds; well you don’t think we could afford to buy Helium, do you ? So far as I know, we all survived, and never got ourselves either zapped or hydrogenated. But this was all low altitude work; so not a chance of getting a mean free path long enough to get to the 1.022 MeV pair production threshold.
Now here’s something interesting.
http://astroparticle.uchicago.edu/DMfest/jd.pdf
It appears to be along the lines of what the SciAm paper discussed, and on page 8 we find “Relativistic Air Breakdown Due To X-Ray and Positron Feedback.”
Hmmm, have they actually measured that, or just modeled it? Looks like data from an experiment, perhaps?
OK, it’s going to take a bit to go through this next one, but it looks interesting, especially the bit about positrons on p.38, bottom left and continuing in right hand column.
http://www.phy.olemiss.edu/~jgladden/phys510/spring06/Gurevich.pdf
Any thoughts?
***********************
George E. Smith (16:26:05) :
There really isn’t any sudden appearance of a positve charge; the Positron/Electron pair are generated at the same time so there is no unbalance of charge generated. Presumably the positron and electon would fly off in opposite directions, so eventual anihilation of the positron, is not simply a recombination with its mirror image; they should never meet again.
*******************
But any positron would quickly find another electron somewhere and be annihilated.
“”” yonason (16:18:09) :
supercritical (11:19:43)
asked about cosmic rays and lighting?
Apparently that’s not so far fetched.
http://www.scientificamerican.com/article.cfm?id=experts-do-cosmic-rays-cause-lightning
“Decades of electric field measurements made inside thunderstorms have failed to find large enough electric fields to cause a spark, even when the effects of precipitation are taken into account. Since we know that lightning does occur—in fact, it strikes the earth about four million times a day—we must be missing something in our understanding.”
Apparently it might work like spark-gap detectors, where the particle shower resulting from cosmic particles entering the atmosphere “might provide a conductive path that initiates lightning” “””
I’m not so sure that that is surprising Yonason. I’ve seen plenty of cloud to ground strikes; I used to chase them in St Louis Mo. And I have flown over enough midwestern thunderstorms (wall to wall) and watched cloud top strikes from one cloud to another.
The point is that these lightning strikes are not “in the cloud”, but are from cloud to ground or cloud to cloud. I suspect that thunderclouds are likely to be conductive enough (at relatively low fields) to be essentially closed conductors; which does not stop the cloud from building up a very large charge; but the Biot-Savart law would prevent fields inside a closed conductor; and presumably severely limit the field inside a weakly conductive body; so one would not expect spark discharges to occur inside the cloud; but eventually you can get enough charge on the cloud to get a zap to ground ( or whichever way they say the zap currently goes).
I knew at one time what the limit fields were that they generated inside the tube of the Stanford Linear Accelerator (in a vaccuum). We studied the design details of the original 220 ft prototype, that they made before the 2 mile long full sized machine was built. The whole accelerating tube was made of OFHC, and the microwaves that were injected into that, to create the wave that the electron ride on, were limited in power by the maximum electric field that the thing could stand, before it started peeling stuff of the copper. I’m thinking that was somewhere around 3 MV/cm; but it might have been 3MV/m, which seems somewhat puny to me. I think X-ray Linacs run in the fractional MV/m range.
As to what finally trips the cloud discharge in the lightning case; it very well could be cosmic ray trigegred but I don’t know that for sure; in fact not sure enough to even say that’s my opinion. But inside the cloud zapping seems a no0no to me, because of Biot-Savart.
Quoting:
“1.022 million electron volts certainly seems easy enough in thunderstorms.” – Anthony
Comment:
Well, I remember hearing somewhere that a single bolt of lightning can produce as much as 1.21 Jigawatts. 😉
George E. Smith (16:50:02) :
Are you taking their “inside thunderstorms” to mean “inside clouds?” Because I thought they meant the whole environment in which the storm, i.e., the discharge, took place, from ground to cloud and/or between clouds.
I don’t know enough of the details. I’m just looking for potentially reliable sources around keywords lightning, positron, “cosmic ray” and then with the primary authors I snagged in the fist search.
Did you see my yonason (16:39:01) ? Because they get into the theory, including some of the physics and what the numbers should and do look like. With your experience, you sound like you are more equipped to pick up on what they are saying faster than I am. I would have copied what I thought were some relevant comments, but my mouse isn’t working (right click is dead).
“”” Jim (16:46:52) :
***********************
George E. Smith (16:26:05) :
There really isn’t any sudden appearance of a positve charge; the Positron/Electron pair are generated at the same time so there is no unbalance of charge generated. Presumably the positron and electon would fly off in opposite directions, so eventual anihilation of the positron, is not simply a recombination with its mirror image; they should never meet again.
*******************
But any positron would quickly find another electron somewhere and be annihilated. “””
“””” so eventual anihilation of the positron, is not simply a recombination with its mirror image; they should never meet again. “”””
Did you read that Jim ?
Of course anihilation of a positron happens when it encounters an electron; I simply said that electon that anihilates along with the positron, is NOT the electron generated along with the positron, because they fly apart in opposite directions.
As for positrons sitting around in the atmosphere; I doubt it; there’s far too many free electrons always, for any isolated positron to exist for very long.
I don’t know about everybody else; but I’m afraid that when somebody tells me that anti-matter is being generated, I do NOT think of electron/positron pair production in that context (even though I do agree that positrons are anti-matter.
Pair production from MeV plus photons, as described by Anna.v is so common; that is is hardly something to write home about.
In my mind it is akin to saying that polar bears are dying up in the arctic from lack of ice.
When you find some anti-protons or something even weirder flying around the clouds; then give me a shout; but positron/electron pair production is not woth the phone call.
“Using very low frequency (VLF) wire antennas that look like clotheslines, Price and his team monitored distant lightning strikes from a field station in the Negev desert. Observing lightning signals from Africa, they noticed a strange phenomenon in the lightning strike data – a phenomenon that slowly appeared and disappeared every 27 days, the length of a single full rotation of the sun. “We noticed that this bouncing was modulated by the sun, changing throughout its 27-day cycle. The variability of the lightning activity occurring in sync with the sun’s rotation suggested that the sun somehow regulates the lightning pattern.” ”
http://www.jpost.com/servlet/Satellite?cid=1257455212868&pagename=JPost%2FJPArticle%2FShowFull
It seems like the more we learn the more we realise how much we don’t know.
“surprising” “puzzling findings” “It’s a surprise”
What sensible reason is there to be surprised to learn that there are things we did not know?
Furthermore, what advantage is there in admitting (publicly) to lacking imagination?
Very amusing.
Just The Facts (19:27:28) :
“We noticed that this bouncing was modulated by the sun, changing throughout its 27-day cycle.
Thanks for the link, I will be following this one with real interest. If we find an accurate way to measure solar rotation it will answer many questions.
A link to the solar rotation paper using VLF can be found here:
http://www.tau.ac.il/~royyaniv/ILAN_website/solar.pdf
Re: Geoff Sharp (21:08:56) & Just The Facts (19:27:28)
thank you — interesting
Just The Facts (19:27:28)
Nice Find!
If we look at the image provided with this post with the exotic elves and sprites, if there is an accelerator phenomenon it would be there with the fields at the top where the density is very low, no? I am trying to find an open link for a table or figure of density versus height in the atmosphere unsuccessfully .
As for positrons existing transiently anyway, it is true, from decays of isotopes of gasses, but why would they concentrate where the lightening strikes in order to create bursts? Sounds more difficult to find a mechanism than an acceleration phenomenon.
There could be a lot wrong with this, but it suggests that the production of anti-matter reactions is not all that hard. Kind of like Christopher Lloyd dancing around in the 1960’s shouting 1.21 gigawatts:
Maybe our first star ship doesn’t have to wait until the 23’rd or 24th century. Maybe we don’t all have to become subsistence farmer/peasants in the 21st century.
George E. Smith (16:26:05) :
I was speaking at 9:30 of direct conversion of electron KE to the pair of particles. See my 15:30 post about why it is unlikely we can get electrons to a few Mev in the atmosphere.
I don’t think lightning does this directly…something else is up.
anna v (21:58:25) :
If we look at the image provided with this post with the exotic elves and sprites, if there is an accelerator phenomenon it would be there with the fields at the top where the density is very low, no? I am trying to find an open link for a table or figure of density versus height in the atmosphere unsuccessfully .
As for positrons existing transiently anyway, it is true, from decays of isotopes of gasses, but why would they concentrate where the lightening strikes in order to create bursts? Sounds more difficult to find a mechanism than an acceleration phenomenon.
At 86 km height, which is the end of the standard atmosphere model, the density is 6 milligrams per cubic meter. That is far too much gas to allow a needed path length. Maybe once in a very great while some electron performs the unthinkable feat of traveling a meter or two, but is the field in these regions more than million volts per meter? And the article implies that the gammas come from lightning which is much lower and in far denser air.
I just think the signal is so small that I am skeptical of any interpretation, and perhaps skeptical of the observation itself. Please, convince me that there is a reasonable signal strength, that coincidence detectors show that these gammas come from beyond the sensor, and that the events are so unlikely to occur with lightning strikes by chance that we must conclude that lightning produces them. Even then I’ll suggest alternative mechanisms by which pre-existing positrons are involved, though.
Kevin Kilty,
At 96km meters the pressure is 10^-5 atmospheres, and the ionosphere goes up to 1000km I think.
I would expect the densities would be thin enough to allow for the tail of the electron distribution to travel enough and be accelerated. I would need to research this but all relevant articles I can google are behind pay walls. Must be a lucrative business this ionosphere .
*************************
Kevin Kilty (07:32:15) :
I don’t think lightning does this directly…something else is up.
*************************
What about the sea of virtual particles that are always present, even in a vacuum. I might point out there is a lot of space between particles in the rarefied upper atmosphere. All it takes is a field strong enough to pull the virtual particle pair apart to create real particles. In a black hole, gravity accomplishes this by eating one of the pair leaving the other to escape. Could the magnetic fields around lightning be strong enough to do this? What about the electric field?
“”” Kevin Kilty (07:32:15) :
George E. Smith (16:26:05) :
I was speaking at 9:30 of direct conversion of electron KE to the pair of particles. See my 15:30 post about why it is unlikely we can get electrons to a few Mev in the atmosphere.
I don’t think lightning does this directly…something else is up. “””
Well I did catch that Kevin, and I have to admit to being a bit hazy on how such a mechanism would work.
But the important thing is that any such mechanism would produce a pair, so there is no charge creation problem that Jim was hinting at.
As far as I know the only way to get isolated positrons; rather than a pair creation is by the radioactive beta decay of some appropriate isotope; and that would be the result of either spontaneous decay of such an isotope or the result of a nuclear collision with some charged particle; well I suppose it could be neutrons as well generating temporarily on e of these isotopes that beta decays via positron emission.
The table of the isotopes in any CRC handbook of Chemistry and Physics, lists a huge number of positron emitter isotopes; and the ones that aren’t natural may be readily produced in nuclear collisions.
These days, positron emission is hardly earth shattering news; heck you can go to a clinic and get your picture taken inside and out with PET scanners.
People would freak out if you told them you wanted to take their picture with anti-matter.
They already had to change the name of Nuclear Magnetic Resonance imaging (NMR), to just Magnetic Resonance Imaging (MRI) because people freaked out over the “Nuclear” connotations.
I’ve been CAT scanned, and NMR’d; but I haven’t been PET’d yet.
But I don’t think that any free positron is going to hang around anywhere for very long; there’s just too much free electrons everywhere, and those things just like to anihilate positrons as soon as they encounter them.
The problem of gas density seems to be easy to side step.
Imagine a column of gas being heated by a multi-million volt
electric discharge. The gas will heat up. Molecules of gas will
speed away from the center of the column with great energy.
As they leave — radially — from the center of the column, a
vacuum is created. The discharge continues, and some of
the remaining particles get accelerated to very high velocities.
Photoelectric effects or very high local electric fields strip away
electrons, and perhaps even decompose water so there are
free protons around.
In a 100km long discharges happening 10^7 times a day, there will
be plenty of random, transient, high vacuum conditions a few meters
long.
Look at it the other way. How could this _not_ happen. How could
it be prevented?
A quick look at the light elements shows that bB8, 6C10, 6C11, 7N12, 7N13 are all b+ emitters.
None of those are natural isotopes so they would have to be produced in some atmospheric collision; perhaps by cosmetic rays. The 6C10 decay also emitts two gamma rays at 0.72, and 1.04 MeV, and ALL of those b+ decays are characterized by anihilation radiation which is the 511keV gamma from the anihilation of the positron.
The half lives of those beta decays range from 0.78 seconds for the Boron to 20.5 minutes. Well the Nitrogen12 is particularly unstable with a half life of 0.011 sec. But really all of those are relatively long lived compared to some of the transuranic isotopes.
So you need some atmospheric transmutation from CRs or somesuch collision to create one of those isotopes, or else you have to get a pair production event.
Note, that it is the light unnatural isotopes that decay by positron emissions. Then you go through the heavier stable natural isotopes, and then when you get to the heavier unstable isotopes they are b- emitters.
Talking about one element here such as Nitrogen in all its isotopic varieties.
Positron emission turns a proton into a neutron, so the atomic weight remains unchanged, but you go down one in the periodic table, so 7N12, and 7N13 decay to 6C12, and 6C13 respectively, both of which are stable.
So the neutron light isotopes are unhappy about that, and want to move down the periodic table to where they are happier; and conversely if you try to stash too many neutrons in the nucleus, they want to beta devcay by electron emission which turns a neutron into a proton, and moves you up the periodic table to the next element.
The lighter elements like a 1:1 neutron to proton ratio; but as you go higher up the table, it takes a higher fraction of neutrons to keep the nucleus stable.
It also seems that a nuclear neutron capture event from cosmic rays, produces a neutron rich isotope nucleus, which if unstable would decay by regular electron emission. So it would seem that a proton capture event is most likely to result in positron emission, in those lighter atmospheric elements.
Well the lightest positron emitter I could find is 5B8 which b+ decays with a 0.78 second half life. They list the decay energy as 18.0 MeV, and the particle energies as 14.0MeV
6C10 is also a b+ emitter with a 19.0 sec half life. The positron energy is 1.9MeV
6C11 is also a p[ositron emitter, with a 20.5 min half life and a b+ energy of 0.96MeV. There also are two gamma rays of 0.72, and 1.04 MeV.
All three of the above decays are accompanied by anihilation radiation the 0.511 MeV gamma ray from the positron anihilation.
7N12 and 7
I have no idea how the result above occurred; I thought the latter posting got eaten by some trick M$ keyboard slip; but it reappeared after I entered the first item; fancy that.
FROZEN LIGHTNING
http://www.techeblog.com/index.php/tech-gadget/plexiglass-gets-zapped-with-2-2-million-volts-captures-lightning
total protonic reversal!
George E. Smith (11:57:15) :
I think his blog hoster is glyching, or something. My post didn’t appear right away, and then I got an email saying there was a new post, but it wasn’t there until I refreshed my browser a couple of times.
yonason (12:21:16) :
FROZEN LIGHTNING
And with Christmas coming, here it is with the lighted frames…
http://www.capturedlightning.com/frames/interesting.html
Off the thread but not topic, I’d like to propose the notion that blue jets and sprites, and possibly ‘elves’ are on a continuum with solar flares and other similar phenomena.
George E. Smith (11:55:12) :
Radon, which is not light but is a gas and can be found high up and has many isotopes, and has a long decay chain down to the stable lead. There must be a beta+ there somewhere.
I found it in a plot correlating it with ionisation in the atmosphere but do not seem to have kept the link.
Doesn’t matter-antimatter collision create annihilation??? Or is it part of the storm!!!
Chirag Patel (11:45:37) :
Their mass is totally converted into a pair of high energy photons (two particles of light) of a characteristic wavelength, which is why detecting light of that wavelength (energy) is called a “signature.”