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Antimatter In Lightning
AMESN writes "The Fermi Gamma-ray Space Telescope, launched last year, detects gamma rays from light years away, but recently it detected gamma rays from lightning on Earth. And the energy of the gamma rays is specific to the decay of positrons, which are the antimatter flavor of electrons. Finding antimatter in lightning surprised researchers and suggests the electric field of the lightning somehow got reversed."
The decay of positrons in the largescale discharge of electronic particles may very well lead to gamma ray emissions, however it is crucial to understand the energy output required to reverse the polarity of the discharge so that we can reproduce the phenomenon in a controlled laboratory.
Or else the Romulans will destroy the Federation.
Reverse the polarity? Good god, next you'll be wanting to cross the streams.
This game will waste your life. Don't clicky!
The LHC was obsolete before it was even constructed.
It never stood a chance.
I thought it's purpose was eating baguettes.
What the fuck? You just graduate from the Academy?
Modulating the shields leaves you vulnerable to phased weapon attacks.
"The only way" is to reorient the tractor beam vectors to generate a harmonic subspace bubble around the vessel.
Fucking amateur.
Apparently they've detected gamma ray energies up to 20 MeV from thunderstorms, so given that amount of energy involved I wouldn't think it's that surprising that electron-positron pairs might be created in the process since an electron only has a mass of .511 MeV. The thunderstorms are basically operating like natural linear accelerators.
Antimatter in lightning does not suggest that the electric field got reversed; that's nonsense. The electric field is a vector, and it can point in any direction.
What it does suggest is either that the few positrons created or brought by cosmic rays are somehow concentrated by lightning, or that the strong electric fields in lightning are actually pulling a few positron-electron pairs out of the quantum electrodynamic vacuum. The first explanation is probably ruled out unless positron decay gamma rays are also seen all over in the atmosphere, just not as densely concentrated as in lightning.
The second explanation is perfectly possible, if the electric fields in lightning are simply strong enough over large enough volumes of space. Any potential difference greater than 2 m c^2/e will in theory produce positrons and electrons from nothing; this is called 'the Schwinger Effect'. But the rate is ridiculously low unless the field is enormous, and it has not yet been observed. Relatively straightforward calculations would allow one to estimate what sort of electric fields lightning would need to involve, for the observations to be due to the Schwinger Effect.
If they're detecting 511KeV gammas generated by "the direct conversion of electrons to energy" not involving positrons, then, yeah, it would be a hell of a discovery, seeing as how it would blow away all those stodgy conservation laws and symmetries and whatnot.
It’s a surprise to have found the signature of positrons during a lightning storm, Briggs said.
No, it's not.
There is a long history of observations and theorizing about gamma ray flashes from lightning strikes and ball lightning, starting in the early 1970's :
Is Ball Lightning caused by Antimatter Meteorites?
D. E. T. F. ASHBY, C. WHITEHEAD, Nature 230, 180-182 (19 March 1971).
This has also been observed in connection with "sprites".
And from thunderclouds without lightning.
Oh, and it's also been observed from space before :
RHESSI Observations of Terrestrial Gamma-Ray Flashes
Now, not all of these reports include a positron annihilation signature at 511 KeV. But, 511 KeV emissions were explicitly reported from lightning in the 1970's. And, considering that lightning / thunderstorm related gamma rays are routinely observed with energies up to 10 MeV, there is plenty of energy to create positrons, and so I wouldn't be surprised if all of these reports included the positron annihilation line (or, at least the ones with sensitivity in that energy range).
You're all off base.The explanaion is much simpler.
Did anybody shout "SHAZAM!" nearby?
No, you don't get annihilation from electrons and protons.
You do get radiation, if things are energetic enough. If the electron becomes bound to the proton, you get emissions at one of the Hydrogen lines.
If, for example, the electron went all the way to the Hydrogen ground state, you would have emissions at the limit of the Lyman Series, up in the hard UV at 91 nanometers.
If things are more energetic, you will get electrons and protons combining to form free neutrons. These will decay (this decay is called beta decay) and release gamma rays at 782 KeV, but since the half life of free neutrons is 10.3 minutes, this will be really spread out in time and hard to see. Free neutrons have been directly detected from lightning strikes, so some of this is presumably going on.
>Remember: In science, NEVER be arrogant, or too convinced of your theories.
Wow, you haven;t been around academics much have you?
I recall an old joke:
"How many PHDs does it take to change a light bulb?
One to unscrew it, one to pull the chair from underneath him"
Open Source Drum Kit, LPLC deve board - mjhdesigns.com
Electron-proton collisions will not lead to a 511 KeV line. That's due to electron-positron collisions.
Just to steer the conversation back on topic, your harmonic subspace bubble isn't going to do jack to protect you from the gamma-ray discharge from an antimatter/matter conversion on it's perimeter. In fact it might cause a toroid-effect and trap the gamma-rays inside your shields, interfere with your sensors and might even take some crucial subsystems offline.
Only a combined strategy of cryptographic spread-spectrum modulation of shields combined with aggressive targetted tractor beam vectoring can keep you safe from localized radiation effects and energy weapons. You really need to keep abreast of the technology in these matters or you could leave yourself, your crew, and very valuable data and equipment at risk.
Posted anonymously for obvious reasons.
From the first paragraph of the article:
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.
In other words, they have detected 17 gamma-ray flashes due to lightning, and some of them have the signature of antimatter (i.e. the electron-positron annihilation).
I'm not sure how that's not exactly what you're saying they didn't say. Just because they didn't say 511 KeV? If 511 KeV is the signature of electron-positron antimatter collitions, and they've found the signature of antimatter collisions in some (not all) of the storms, wouldn't that suggest they are seeing 511 KeV bursts?
Here's more:
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.
It seems pretty specific about what they are seeing, it is simply stated in a high-level language that the common interested-but-not-knowledgeable reader can understand.
This is essentially an online science news magazine, not a journal for published papers seeking peer review. They are only going to give you the gist of the information at a high-level, and from there if you have better knowledge of the subject you should have an automatic deeper insight into what they might be seeing.
It's not like it's some amature job either, the space telescope was built to find this sort of thing, so finding these signatures is not like some wack job pop-sci company pushing nonsense in a press conference to attract investors before folding in a few years.
Security is mostly a superstition... Avoiding danger is no safer in the long run than outright exposure. - Helen Keller
Does anyone know what the cross section of a lightning bolt looks like? I've always wondered if forces akin to the skin-effect are trying to spread out the electrons while it's constrained in a tube of plasma. Is it round? Is it a sheet? What's the electron density like? What sorts of pressures would you expect in the center of a bolt?
Just curious... but I'm unable to find a google hit and too dumb to simulate it.
http://www.masturbateforpeace.com/
Boiling water isn't a direct electrical source either, it's all about energy conversion. The easiest way to convert heat into electricity is to first convert it to kinetic energy. The easiest, cheapest, and safest way to convert heat energy to kinetic energy is to boil water and creat a pressure differential to drive a piston or turbine or what have you. It's very effective, and there isn't any compound likely to do the job better than H2O that isn't also prohibitively expensive.
Heat is the easiest form of raw energy to produce, and if boiling water is the easiest, cheapest, and safest way to convert heat energy into kinetic energy (which is then trivial to convert to electrical energy at very high conversion rates).
Heat engines are also still the most efficient form of energy conversion available to us. A typical modern steam turbine generator will convert close to 50% of the heat energy to electricity, and in some applications can convert as much as 90%. Combustion engines are typically in the 30% range, but getting higher, though they have a theoretical hard limit at 37%. Photvoltaic is coming along, but frankly it's still young and the readily available PV cells compare poorly to combustion and turbine engines. The theoretical limit for a single cell is about 40% efficiency (with light concentrators), but new techniques are working around that limit (they use multiple materials in the cell, effectively combining several cells in one) and the current record is around 43%.
The big problem PV has vs combustion or turbine engines is energy density - the fuel sources the later two methods use are significantly more energy dense than plain sunlight. Sunlight throws a lot of energy everywhere, but only a little in any particular spot. Concentrating it effectively has always been a problem.
Security is mostly a superstition... Avoiding danger is no safer in the long run than outright exposure. - Helen Keller