Antigravics

http://www.plasmaphysics.org.uk/research/redshift.htm

>> My previous research has already revealed several hitherto unknown effects in the area of ionospheric physics which clearly show the importance of temporal and spatial characteristics of the random plasma fluctuation field for the emission and propagation of electromagnetic waves, and I am suggesting that it is the plasma 'micro'field which is also responsible for the redshift of galaxies.

The important difference of the intergalactic plasma compared to other plasmas is that, due to its low density, the associated electric field can be considered to be quasi-static and quasi-homogeneous for most electromagnetic waves, not only with regard to the wavelength, but even with regard to the coherence length of the electromagnetic wave field (i.e. the length of the wave trains), as both are much smaller than the distance over which the electric field varies.

The latter is directly determined by the average distance of charged particles and could probably be around 1m in intergalactic space. Obviously, this redshift effect would only occur below a maximum wavelength or coherence length and hence there would be a (wavelength dependent) maximum distance beyond which the redshift factor would saturate and approach an asymptotic value.

Interestingly, the 3 oK microwave background radiation could in fact be evidence of this: the coherence length of light produced by stars is of the order of 10-2cm (the original coherence length of 100 cm is shortened by collisions in the radiating plasma); with a redshift factor of the order of 104 this would translate into a length of about 100 cm. If the average distance between charged particles in intergalactic space has about the same value, the redshift effect will saturate and hence all stars beyond a certain distance will be redshifted by the same amount (i.e. to 3 oK).

Another point to consider in this context is the circumstance that, once the wavetrain is stretched to a length comparable to the distance of charged particles in the plasma, it can not be considered to travel in a homogeneous electric field (gradient) anymore.

The stretching of the wavetrain will therefore become randomly inhomogeneous and the coherency of the light will be progressively destroyed, which eventually will lead to its complete indetectability (see my page regarding the Photoeffect on my website physicsmyths.org.uk), hence resolving Olbers' Paradox for a steady state universe.


Schematic illustration of the suggested redshift mechanism
due to the electric field of free charges in the intergalactic plasma


>> It could probably be compared to a refraction effect (albeit one independent of wavelength): the point is that here the effect of the plasma field in the direction of propagation of the wave always has the same sign, that is the stretching of the wave (and thus the redshift) is additive (i.e. it is a scalar effect) and will, despite the random nature of the field, result in a very sharply defined redshift.


On the other hand, the transverse deviation of the direction of propagation caused by the plasma field has vector properties and thus a random walk character given the anisotropy of the medium. >>

Comment my bold, the spin fields are anisotropic, they have a specific direction created by differential spin from extraneous field spins.

http://www.livescience.com/forcesofnatu ... c_ice.html

>> Miles above Earth in cumulonimbus clouds, tiny ice crystals are constantly bumping against larger ice pellets. The two kinds of ice rubbing together act like socks rubbing against carpet. Zap! Before you know it, the cloud is crackling with electric potential—and a bolt of lightning explodes to the ground.

It may seem hard to believe that a powerful bolt of lightning, which heats the air in its path three times hotter than the surface of the sun, could spring from little pieces of ice. But that's how it is, according to theory, and indeed laboratory experiments have confirmed that you can generate electricity from ice-ice collisions.

Still, it does sound fantastic. So, "we decided to check it out," says Walt Petersen, a lightning researcher at the National Space Science and Technology Center in Huntsville, Alabama.

Over a three year period, Petersen and his colleagues used the Tropical Rainfall Measurement Mission (TRMM) satellite to look inside more than one million clouds. "TRMM has a radar onboard to measure the amount of ice in a cloud. And it has an optical detector called LIS (lightning imaging sensor) to count lightning flashes." By comparing the ice content of a cloud to its flashes, they could tell if ice and lightning really go together.

They do. "We found a strong correlation between ice and lightning in all environments—over land, over sea and in coastal areas." On global scales, the correlation coefficient between lightning "flash density" (flashes per square-kilometer per month) and "ice water path" (kilograms of ice per square-meter of cloud) exceeded 90 percent. Even stronger correlations were found on the smaller scale of individual storm cells where, for example, about 10 million kilograms of ice would produce one lightning flash per minute.

10 million kilograms. No wonder you couldn't get a spark going in your freezer. A great deal more ice is required to make lightning.

In a real thundercloud, millions of pieces of ice are constantly bumping together, pushed by updrafts ranging in speed from 10 to 100 mph. Tiny ice crystals become positively charged and waft to the top of the cloud, while bulkier ice pellets (called "graupel") become negatively charged and plummet to the bottom. This separation creates mega-volts of electrical tension--and hence the lightning.

Now that the correlation between ice and lightning is so well established, it can be put to good use. Petersen explains:

"Computer programs we write to predict weather and climate need to know how much ice is in clouds. The problem is, ice is hard to track. We can't station a radar over every thundercloud to measure its ice content. To improve our computer forecasts, we need to know where the ice is."

Lightning can help. "Because there's such a strong correlation between lightning and ice, we can get a good idea of how much ice is 'up there' by counting lightning flashes." Sensors like LIS, which are inexpensive and can be stationed on the ground as well as in Earth orbit, make this easy to do. >>

http://www.physorg.com/news90253248.html

[img]http://www.physorg.com/newman/gfx/news/clusternewin.jpg[/img
Artistic view of electrons, responsible for aurora, spiralling down magnetic field lines. The U-shaped potential structure illustrates the region where electrons get accelerated on their way down to the upper atmosphere. Here they are stopped by collisions with neutral atoms and molecules, primarily oxygen and nitrogen, at altitudes of a few hundreds kilometres down to 80 kilometres. Each collision transfers part of the electron energy to these atmospheric particles. In turn, they get rid of this energy excess by emitting visible emissions in specific wavelength (or colours) such as green (oxygen) or purple (nitrogen). Credits: ESA

>> The deep mechanisms that rule the creation of the beautiful auroras, or polar lights, have been the subject of studies that are keeping solar and plasma scientists busy since years. While early rockets and ground-observations have already provided a few important clues for the understanding of these phenomena, the real break-throughs in our knowledge have started with dedicated auroral satellites, such as S3-3, Dynamics Explorer, Viking, Freja and FAST, and have now come to full fruition with ESA's multi-point mission Cluster.

The basic process generating auroras is similar to what happens in an old TV tube. In the TV tube, accelerated electrons hit the screen and make its phosphore glow; electrons in the atmosphere get accelerated in an 'acceleration region' situated between about 5000 and 8000 kilometres altitude, and rush down to the Earth's ionosphere – a region of the upper atmosphere. Here, they crash into ionospheric atoms and molecules, transfer to them some of their energy and so cause them to glow, creating aurorae.

It is today well established that almost-static electric fields, parallel to the Earth's magnetic fields, play an important role in the acceleration of the electrons that cause the auroras to shine. The auroral electric circuits in the near-Earth space involve almost-static 'electric potential' structures through which electrons and ions are accelerated in opposite directions - towards and away from Earth's atmosphere -at high latitudes.

It had been observed that these electric potential structures are mainly of two types - symmetric (U-shaped) or asymmetric (S-shaped). In 2004, Prof. Göran Marklund from the Alfvén Laboratory, at the Royal Institute of Technology, Stockholm (Sweden), noted that the U-shaped and the S-shaped structures typically occurred at the boundaries between magnetospheric regions with different properties.

The former type (U-shaped) was found at a plasma boundary between the so-called 'central plasma sheet', situated in the magnetotail at equatorial latitudes, and the 'plasma sheet boundary layer', an adjacent area located at higher latitudes. The latter type (S-shaped) was found at the boundary between the 'plasma sheet boundary layer' and the polar cap, further up in latitude.

Marklund was then in the condition to propose a model to explain this difference. The model suggested that both the asymmetric and symmetric shape of the potential structures, observed at the different plasma boundaries, depended on the specific conditions of the plasma (such as differences in plasma density) in the two regions surrounding the boundary. According to the 2001 observations, he concluded that the plasma conditions at the lower-latitude boundary (where U-shaped structures were observed) are in general more symmetric, while the ones at the polar cap boundary (where the S-shaped structures were observed) are more asymmetric.

However, new Cluster measurements did not seem to be consistent with this picture. On 1 May 2003, one of the Cluster spacecraft crossed the auroral arc at high altitude in the Earth's magnetotail. As expected, it detected the presence of a U-shaped, symmetric potential structure when crossing the boundary between the 'central plasma sheet' and the 'plasma sheet boundary layer'. Only 16 minutes later a second Cluster spacecraft, moving roughly along the same orbit and crossing the same boundary, detected an asymmetric, S-shaped potential structure, 'typical' of the polar cap boundary and therefore unexpected in that region.

However, within the 16-minute time frame between the crossing of the two spacecraft, the plasma density and the associated currents and fluxes of particles decreased significantly in the plasma sheet boundary layer. In this way this boundary ended up in resmbling the asymmetric conditions typical of the polar cap boundary.

So, the scientists interpreted that the 'reconfiguration' from a U-shaped to a S-shaped potential structure, and of the associated electric circuits that sustain the auroral arcs, reveal the change in the plasma conditions on the two sides of the boundary.

The results represent a major step forward in understanding the auroral electrical circuits, but important questions still remain open, such as: how do the process that accelerate the electrons to form auroras get triggered and maintained? Cluster measurements in the 'acceleration' area to be performed in 2008 and 2009 should help us to find out.

Source: European Space Agency >>

http://www.abc.net.au/news/newsitems/20 ... 844561.htm

>> Severe thunderstorms in the Adelaide River district, about 110 kilometres south of Darwin, have caused widespread damage to the Mount Bundey Station.

A storm hit the station about 6:30pm ACST and lasted for four minutes, bringing down about 40 trees and power lines at the station.

John Griffin, the caretaker of a bed and breakfast on the station, says it looked like a mini tornado and he had to hide in a bus on the property to escape the winds.

"We lost about 40-odd trees and some are just snapped off two metres or so from the top," he said.

"The actual root system hasn't come out - it's just snapped them off like matchsticks.

"Water tanks have come off our stands and there's a big tree come down on the stables and powerlines are down in some areas." >>

http://www.physorg.com/news90775923.html

>> An estimated 90 percent of the world's electricity - from power plants to car engines - is created through this indirect conversion of heat. In the process, a great deal of heat is wasted and released. Anyone who has ever had a car engine fail because of a malfunctioning radiator has experienced firsthand this excess heat.

"Generating 1 watt of power requires about 3 watts of heat input and involves dumping into the environment the equivalent of about 2 watts of power in the form of heat," said Arun Majumdar, UC Berkeley professor of mechanical engineering and principal investigator of the study. "If even a fraction of the lost heat can be converted into electricity in a cost-effective manner, the impact it would have on energy can be enormous, amounting to massive savings of fuel and reductions in carbon dioxide emissions."

Unfortunately, the temperature at which the heat is released is too low to be effectively used by traditional heat engines.

For the past 50 years, utilizing this wasted heat has been a major focus of research into thermoelectric converters, which employ a simpler, more direct method of generating electricity. Such converters rely upon the Seebeck effect, a phenomenon in which a voltage is created when the junctions of two different metals are kept at different temperatures.

However, such thermoelectric generators operate at a paltry 7 percent efficiency, compared with the 20 percent efficiency rate for traditional heat engines. Moreover, such converters are made up of exotic, expensive metal alloys, such as bismuth and tellurium, making them too costly and impractical for widespread use.

The new UC Berkeley study marks the first time the Seebeck effect has been measured in an organic molecule, laying the groundwork for the development of more cost-effective thermoelectric converters.

The researchers coated two gold electrodes with molecules of benzenedithiol, dibezenedithiol or tribenzenedithiol, then heated one side to create a temperature differential. For each degree Celsius of difference, the researchers measured 8.7 microvolts of electricity for benzenedithiol, 12.9 microvolts for dibezenedithiol, and 14.2 microvolts for tribenzenedithiol. The maximum temperature differential tested was 30 degrees Celsius (54 degrees Fahrenheit).

"The effect may seem quite small now, but this is a significant proof of concept, and the first step in organic molecular thermoelectricity," said Pramod Reddy, a graduate student in UC Berkeley's Applied Science and Technology Program and co-lead author of the paper. "We are going down the road of cheap thermoelectric materials."

Majumdar, who is also a faculty scientist in materials science at Lawrence Berkeley National Laboratory, said the field of organic thermoelectricity could open doors to a new, inexpensive source of energy. "The use of inexpensive organic molecules and metal nanoparticles offers the promise of low-cost, plastic-like power generators and refrigerators," he said. >>

http://www.livescience.com/forcesofnatu ... tning.html

>> Volcanoes can trigger earthquakes, avalanches and devastating lava flows. Add to this list lightning, which has now been detected striking from the mouth of a mountainous beast.

A new study reveals the first direct observations of this well-known but poorly understood volcano-electrical phenomenon.

“Lightning is often seen during [a] volcanic eruption,â€

http://physorg.com/news103997338.html

>> “Developing organic solar cells from polymers, however, is a cheap and potentially simpler alternative,â€

http://www.physorg.com/news121451912.html

>> Squeeze a crystal of manganese oxide hard enough, and it changes from an electrical insulator to a conductive metal. In a report published online this week by the journal Nature Materials, researchers use computational modeling to show why this happens.

The results represent an advance in computer modeling of these materials and could shed light on the behavior of similar minerals deep in the Earth, said Warren Pickett, professor of physics at UC Davis and an author on the study.

Manganese oxide is magnetic but does not conduct electricity under normal conditions because of strong interactions between the electrons surrounding atoms in the crystal, Pickett said. But under pressures of about a million atmospheres (one megabar), manganese oxide transitions to a metallic state.

Pickett and colleagues Richard Scalettar at UC Davis, Jan Kunes at the University of Augsburg, Germany, Alexey Lukoyanov at the Ural State Technical University, Russia, and Vladimir Anisimov at the Institute of Metal Physics in Yekaterinburg, Russia, built and ran computational models of manganese oxide.

Using the model, the researchers were able to test different explanations for the transition and identify the microscopic mechanism responsible. They found that when the atoms are forced together under high pressure, the magnetic properties of the manganese atoms become unstable and collapse, freeing the electrons to move through the crystal.

Manganese oxide has similar properties to iron oxide and silicates (silicon oxides), which make up a major part of the Earth's crust and mantle. Understanding how these materials behave under enormous pressures deep underground could help geologists understand the Earth's interior, Pickett said.

Source: University of California - Davis >>>

http://www.physorg.com/news175527058.html

>> Every year, scientists learn something new about the inner workings of lightning. With satellites, they have discovered that more than 1.2 billion lightning flashes occur around the world every year. (Rwanda has the most flashes per square kilometer, while flashes are rare in polar regions.) Laboratory and field experiments have revealed that the core of some lightning bolts reaches 30,000 Kelvin (53,540 ºF), a temperature hot enough to instantly melt sand and break oxygen and nitrogen molecules into individual atoms.

And then there is this: each of those billion lightning flashes produces a puff of nitrogen oxide gas (NOx) that reacts with sunlight and other gases in the atmosphere to produce ozone. Near Earth’s surface, ozone can harm human and plant health; higher in the atmosphere, it is a potent greenhouse gas; and in the stratosphere, its blocks cancer-causing ultraviolet radiation.

In 1827, the German chemist Justin von Liebig first observed that lightning produced NOx -- scientific shorthand for a gaseous mixture of nitrogen and oxygen that includes nitric oxide (NO) and nitrogen dioxide (NO2). Nearly two centuries later, the topic continues to attract the attention of scientists.

Fossil fuel combustion, microbes in the soil, lightning, and forest fires all produce NOx. Scientists think lightning's contribution to Earth's NOx budget—probably about 10 percent—is relatively small compared to fossil fuel emissions. Yet they haven't been sure whether global estimates of NOx produced by lightning are accurate.

"There's still a lot of uncertainty about how much NOx lightning produces," said Kenneth Pickering, an atmospheric scientist who studies lightning at NASA's Goddard Space Flight Center in Greenbelt, Md. "Indeed, even recent published estimates of lightning's global NOx production still vary by as much as a factor of four. We're trying to narrow that uncertainty in order to improve the accuracy of both global climate models and regional air quality models."

New research suggests that the bulk of NOx produced during lightning storms ends up significantly higher in the atmosphere—and thus has a stronger impact on ozone and the climate—than previously thought. Credit: Lesley Ott, NASA

Using data gleaned from aircraft observations and satellites, Pickering and Goddard colleague Lesley Ott recently took steps toward a better global estimate of lightning-produced NOx and found that lightning may have a considerably stronger impact on the climate in the mid-latitudes and subtropics—and less on surface air quality—than previously thought.

According to a new paper by Ott and Pickering in the Journal of Geophysical Research, each flash of lightning on average in the several mid-latitude and subtropical thunderstorms studied turned 7 kilograms (15.4 pounds) of nitrogen into chemically reactive NOx. "In other words, you could drive a new car across the United States more than 50 times and still produce less than half as much NOx as an average lightning flash," Ott estimated. The results were published July.

When the researchers multiplied the number of lightning strokes worldwide by 7 kilograms, they found that the total amount of NOx produced by lightning per year is 8.6 terragrams, or 8.6 million metric tons. "That's somewhat high compared to previous estimates," said Pickering.

More remarkable than the number, however, is where the NOx is produced. A decade ago, many researchers believed cloud-to-ground lightning produced far more NOx per flash than intracloud lightning, which occurs within a cloud and far higher in the atmosphere.

The new evidence suggests that the two types of lightning produce approximately the same amount of NOx per flash on average. But since most lightning is intracloud, this suggests a great deal more NOx is produced and remains higher in the atmosphere. Compounding this effect, the research also shows that strong updrafts within thunderstorms help transfer lower level NOx to higher altitudes in the atmosphere.

Central Africa receives the most flashes of lightning per square kilometer, while the polar regions receive the least. This global map of lightning flash density was created with data from the Lightning Imaging Sensor (LIS) aboard the Tropical Measuring Mission (TRMM) and the Optical Transient Detector (OTD) aboard the Microlab-1 spacecraft. Credit: Jeff De La Beaujardiere, Scientific Visualization Studio

"We've really started to question some of our old assumptions as we've gotten better at measuring lightning in the field," said Ott.

The observations spring out of field projects conducted in Germany, Colorado, Florida, Kansas, and Oklahoma between 1985 and 2002. For example, in a NASA field campaign called the Cirrus Regional Study of Tropical Anvils and Cirrus Layers Florida - Florida Area Cirrus Experiment (CRYSTAL-FACE) aircraft flew headlong through anvil-shaped thunderheads to measure the anatomy of the thunderstorms. Sensors sampled the pressure, humidity, temperature, wind, and the amount of trace gases such as NOx and ozone.

Later, Ott input this data, as well as additional data from the U.S. National Lightning Detection Network and NASA's Total Ozone Mapping Spectrometer (TOMS), into a complex computer model that simulated the six storms and calculated the amount of NOx that the average flash of lightning produced. With that number, she could then estimate the amount of NOx that lightning produces globally each year.

"One of the things we’re trying to understand is how much ozone changes caused by lightning affect radiative forcing, and how that might translate into climate impacts," said Pickering.

There's a possibility that lightning could produce a feedback cycle that accelerates global warming. "If a warming globe creates more thunderstorms," Pickering noted, "that could lead to more NOx production, which leads to more ozone, more radiative forcing, and more warming," Pickering emphasizes that this is a theory, and while some global modeling studies suggest this is indeed the case, it has not yet been borne out by field observations.

The new findings also have implications for regional air quality models. Scientists from the U.S. Environmental Protection Agency (EPA), for example, are already plugging the new numbers into a widely-used air quality model called the Community Multi-scale Air Quality Model. "Lightning is one of the smaller factors for surface ozone levels, but in some cases a surge of ozone formed from lightning NOx could be enough to put a community out of compliance with EPA air quality standards during certain times of the year," said Pickering.

Pickering offered one important caveat to the findings: The value of 7 kilograms per flash was derived without consideration of lightning from storms in the tropics, where most of the Earth’s lightning occurs. Only very recently have data become available for tropical regions, he noted. >>>

http://www.crystalinks.com/lightning.html

>> The first process in the generation of lightning generation is the separation of positive and negative charges within a cloud. Ice crystals inside cumulonimbus clouds rub against one another due to the strong updrafts in these clouds, thus building up a strong static charge.

Positively charged crystals tend to rise to the top causing the cloud top to build up a positive static charge and negatively charged crystals and hailstones drop to the middle and bottom layers of the cloud building up a negative static charge. Cumulonimbus clouds that do not produce enough ice crystals usually fail to produce enough static electricity to cause lightning.

Lightning can also occur as a result of volcanic eruptions or violent forest fires which generate sufficient dust to create a static charge.

The second process is the build up of positive charges on the ground beneath the clouds. The Earth is normally negatively charged with respect to the atmosphere. But as the thunderstorm passes over the ground, the negative charges at the bottom of the cumulonimbus cloud cause the positive charges on the ground to gather along the surface for several miles around the storm and becomes concentrated in vertical objects including trees and tall buildings. If you feel your hair stand up on end in a lightning storm beware. The negative charges from the cloud are pulling the positive charges inside your body to the top of your head and you could be in danger of being struck.

The third process is the generation of the lightning. When sufficient negatives and positives gather in this way, an electrical discharge occurs within the clouds or between the clouds and the ground, producing the bolt.

Negative Lightning

A bolt of lightning usually begins when an invisible negatively charged stepped leader stroke is sent out from the cloud. As it does so, a positively charged streamer is sent out from the positively charged ground or cloud. When the leader and streamer meet, the electrical discharge takes place up the streamer into the cloud. This return stroke is the most luminous part of the strike, and the part that is really visible.

Most lightning strikes usually last about a quarter of a second. Sometimes several strokes will travel up and down the same leader strike, causing a flickering effect. Thunder is caused when the discharge rapidly super heats the air around the strike, causing a shock wave to be sent out.

Research published in 2002 indicates that every lighting bolt also causes a similar but weaker electrodynamic pulse in the mesosphere, located 50 to 80 km (31 to 53 miles) above the earth, and above into the thermosphere.

This type of lightning is known as negative lightning due to the discharge of negative charge from the cloud, and accounts for over 95% of all lightning.

Statistics: an average bolt of negative lightning carries a current of 30 kiloamperes, transfers a charge of 5 coulombs, has a potential difference of about 100 megavolts, and lasts a few milliseconds.

Positive Lightning

Positive lightning makes up less than 5% of all lightning. It occurs when the stepped leader forms at the positively charged cloud tops, with the consequence that a positively charged streamer issues from the ground. The overall effect is a discharge of positive charges to the ground.

Research carried out after the discovery of positive lightning in the 1970s showed that positive lightning bolts are typically six to ten times more powerful than negative bolts, last around ten times longer, and can strike several miles distant from the clouds. During a positive lighting strike, huge quantities of ELF and VLF radio waves are generated.

As a result of their power, positive lightning strikes are considerably more dangerous. At the present time aircraft are not designed to withstand such strikes, since their existence was unknown at the time standards were set, and the dangers unappreciated until the destruction of a glider in 1999. It has since been suggested that it may have been positive lightning that caused the crash of Pan Am flight 214 in 1963. Positive lighting is now also thought to be responsible for many forest fires.

Positive lightning has also been shown to trigger the occurrence of upper atmospheric lightning. It tends to occur more frequently in winter storms and at the end of a thunderstorm.

Statistics (based on a small number of measurements): an average bolt of positive lightning carries a current of 300,000 amperes, transfers a charge of up to 300 coulombs, has a potential difference up to 1 gigavolt (a thousand million volts), and lasts for tens or hundreds of milliseconds.

Bipolar Lightning

Bipolar lightning occurs when bolts of negative and positive lightning alternately use the same channel through the air.

Various Types of Lightning

Some lightning strikes take on particular characteristics, and scientists and the public have given names to these various types of lightning.

Intracloud Lightning, Sheet Lightning, Anvil Crawlers

Intracloud lightning is the most common type of lightning which occurs completely inside one cumulonimbus cloud, jumping between different charged regions within the cloud. Intracloud lightning is commonly known as sheet lightning because it lights up the cloud and the surrounding sky with an apparent sheet of light. One special type of intracloud lightning is commonly called an anvil crawler. Discharges of electricity in anvil crawlers travel up the sides of the cumulonimbus cloud branching out at the anvil top.

Cloud-to-Ground Lightning, Anvil Lightning, Bead Lightning, Ribbon Lightning, Staccato Lightning

Cloud-to-ground lightning is a great lightning discharge between a cumulonimbus cloud and the ground initiated by the downward-moving leader stroke. This is the second most common type of lightning. One special type of cloud-to-ground lightning is anvil lightning, a form of positive lightning, since it emanates from the anvil top of a cumulonimbus cloud where the ice crystals are positively charged, and is a form of positive lightning. In anvil lightning, the leader stroke issues forth in a nearly horizontal direction till it veers toward the ground. These usually occur miles ahead of the main storm and will strike without warning on a sunny day. They are signs of an approaching storm.

Another special type of cloud-to-ground lightning is bead lightning. This is a regular cloud-to-ground stroke that contains a higher intensity of luminosity. When the discharge fades it leaves behind a string of beads effect for a brief moment in the leader channel. A third special type of cloud-to-ground lightning is ribbon lightning. These occur in thunderstorms where there are high cross winds and multiple return strokes. The winds will blow each successive return stroke slightly to one side of the previous return stoke, causing a ribbon effect. The last special type of cloud-to-ground lightning is staccato lightning which is nothing more than a leader stroke with only one return stroke.

Cloud-to-Cloud Lightning

Cloud-to-cloud lightning is a somewhat rare type of discharge lightning between two or more completely separate cumulonimbus clouds.

Ground-to-Cloud Lightning

Ground-to-cloud lightning is a lightning discharge between the ground and a cumulonimbus cloud from an upward-moving leader stroke. Most ground-to-cloud lightning occurs off of tall buildings, mountains and towers.

Heat lightning

Heat lightning is nothing more than the faint flashes of lightning on the horizon from distant thunderstorms. Heat lightning was named because it often occurs on hot summer nights. Heat lightning can be an early warning sign that thunderstorms are approaching. In Florida, heat lightning is often seen out over the water at night, the remnants of storms that formed during the day along a seabreeze front coming in from the opposite coast. >>

>> Lightning has been observed on other planets, such as Venus and Jupiter, and electrical discharges between Jupiter and Io often occur.

Lightning on Jupiter is estimated to be 100 times as powerful, but fifteen times rarer, than that which occurs on Earth.

Lightning on Venus occurs so often that it is speculated that, were colonization to ever occur on Venus, lightning would be a primary power source. >>

http://www.physorg.com/news183883466.html



>. When volcano seismologist Stephen McNutt at the University of Alaska Fairbanks's Geophysical Institute saw strange spikes in the seismic data from the Mount Spurr eruption in 1992, he had no idea that his research was about to take an electrifying turn.

"The seismometers were actually picking up lightning strikes," said McNutt. "I knew that I had to reach out to the physicists studying lightning."

With McNutt’s curiosity about volcanic lightning sparked, he teamed up with physicist and electrical engineer Ronald Thomas and Sonja Behnke, a graduate student in atmospheric physics at the New Mexico Institute of Mining and Technology in Socorro, N.M. for a unique collaboration in order to learn more about volcanic lighting.

When the Mount Redoubt volcano started making seismic noise in January 2009, McNutt alerted Thomas and Behnke that this would be a great opportunity to capture some new volcanic lightning data. By the time the volcano erupted in March, the team had four Lightning Mapping Arrays set up to monitor the lightning from the eruption.

"The LMA is basically an old TV antenna set to pick up channel 3 -- the same frequency that lightning radiates from," said Behnke.

Setting up LMAs about 50 miles away from the volcano across a body of water called Cook Inlet in south central Alaska may not seem like an ideal location, but the team explained that there are obstacles to setting up LMAs near the volcano.

"We saw lots of lightning -- 20 to 30 minutes of lighting," said Thomas. "We saw even more lightning than we would typically see during a major thunderstorm."

Not only was the amount of lightning unusual, but so was the kind of lightning coming from the volcano.

"At the moment the eruption started, there were these sparks of lightning coming from the vent of Redoubt that only lasted 1 to 2 milliseconds," said McNutt, " This was a different kind of lighting that we have never seen before."

The residents and scientists who witnessed Mount Redoubt’s explosive eruptions described the events as a breathtaking display.

"They all said that it was the most spectacular lightning display that they have ever seen," said Thomas.

The team has also been studying how the newly-discovered volcanic lighting compares to familiar thunderstorm lightning.

"It's fascinating as we learn how volcanic lighting is the same and yet different form thunderstorm lightning," said Behnke. >>>

http://www.dailygalaxy.com/my_weblog/20 ... %26+Beyond)







>> Lightning bolts appear above and around the Chaiten volcano as seen from Chana, some 30 kms (19 miles) north of the volcano, as it began its first eruption in thousands of years, in southern Chile May 2, 2008. Cases of electrical storms breaking out directly above erupting volcanoes are well documented, although scientists differ on what causes them. More than 150 times in the past two centuries, volcanic eruptions have been accompanied by spectacular displays of lightning with broad bolts of lightning streaking across the sky, or as St. Elmo's fire (ball lightning) that cascades from above. >>>

http://www.physorg.com/news187421719.html


In cryogenic electron emission, at first as temperature decreases, the dark rate decreases. But at about 220 K, the dark rate levels off, and with further cooling, it begins rising again. Image credit: Meyer.

>>> At very cold temperatures, in the absence of light, a photomultiplier will spontaneously emit single electrons. The phenomenon, which is called "cryogenic electron emission," was first observed nearly 50 years ago. Although scientists know of a few causes for electron emission without light (also called the dark rate) - including heat, an electric field, and ionizing radiation - none of these can account for cryogenic emission. Usually, physicists consider these dark electron events undesirable, since the purpose of a photomultiplier is to detect photons by producing respective electrons as a result of the photoelectric effect.

In a recent study, Hans-Otto Meyer, a physics professor at Indiana University, has further investigated cryogenic electron emission by performing experiments that show how the electron firings are distributed in time. His results reveal that electrons are emitted in bursts that occur randomly, although within a burst the electrons are emitted in a peculiar, correlated way. He suggests that the correlations indicate some kind of trapping mechanism, but the unusual behavior is inconsistent with any spontaneous emission processes currently known. At least at the moment, there seems to be no physics explanation of the observations.

“Cryogenic emission is a physics phenomenon that defies an explanation,” Meyer told PhysOrg.com. “The physics responsible for it may or may not be fundamental, only the future will tell. Photomultipliers happen to offer the environment in which the phenomenon may be observed, but I doubt if my work will be of great significance to the users of photomultipliers.”

In his experiments, Meyer placed a photomultiplier inside an empty container, which he then submerged in liquid nitrogen or helium. Using radiation cooling, he cooled the photomultiplier to a temperature of 80 K (-193° C) after about one day, and to 4 K (-269° C) in another day. With this setup, he could detect cryogenic dark events, which are shown to be caused by single electrons emitted from the cathode of the photomultiplier.

As previous research has shown, starting from room temperature, the dark rate decreases as temperature decreases, but only up to a point. Below about 220 K (-53° C), the dark rate levels off. With further cooling, it begins to rise, and continues to increase at least down to 4 K (-269° C), the lowest temperature for which Meyer has data. Most of Meyer’s experiments were performed at around 80 K (-193° C).

In his experiments, Meyer found that electrons are emitted in “bursts” - numerous electron firings that occur close together in time. Although these bursts occur randomly, they last for different lengths of time, with their duration distribution following a power law. Further, Meyer found that the individual firing events within a burst are highly correlated. Specifically, within a burst, events first occur rapidly, and then less and less frequently as the burst “fades away.”


Electrons are emitted in bursts that last for different lengths of time, with their duration distribution following a power law. Image credit: Meyer.

Perhaps this last observation of progressively longer intervals between firing events within a burst is the most interesting. Meyer suggests that this peculiar distribution of events could be the result of a trapping mechanism. If caught in a trap, an electron could either exit the trap (to be observed as a dark event) or it could recombine with an electron hole. When a trap of electrons is emptied, the emission rate would be proportional to the number of electrons remaining in the trap. This scenario could possibly explain the initial gush of events in a burst, followed by a few remainders that trickle out.

In agreement with previous observations of correlations between temperature and dark rate, the electron emission rates in Meyer’s experiments were also affected by temperature. As the temperature decreased, both the rate of bursts and the number of events per burst increased. This observation that emission rate grows with decreasing temperature fits well with the trap hypothesis, in which it would be the consequence of recombination becoming less important, resulting in more electrons exiting the trap.

As Meyer notes, a process that becomes more probable with decreasing temperature, as cryogenic electron emission does, is very unusual in physics. Among his interesting observations are that the cryogenic emission rate does not depend on whether the device is cooling or warming up, but only on the current temperature. Overall, the properties of cryogenic electron emission don’t fit with any other known spontaneous emission process, including thermal emission, field emission, radioactivity, or penetrating radiation such as cosmic rays. For example, unlike the well-known thermionic and field emission processes, cryogenic emission doesn’t depend on the electric field at the emitting surface. At least for now, the phenomenon of cryogenic electron emission remains a mystery.

“Nature at very low temperatures has a lot of surprises up her sleeve,” Meyer said. “I don't want to speculate as to what will turn out to be the explanation of cryogenic emission, but I would not be surprised if the band structure of semiconductors plays an important role.”

He added that his next step will be investigating how universal the effect is.

“Is there cryogenic emission from surfaces other than the cathode of a photomultiplier?” he asked. “This is the next question to be answered by an experiment. Hopefully there also will soon be theoretical models leading to predictions that may be tested by future experiments.” >>>

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Dr Martin Füllekrug from the University’s Department of Electronic & Electrical Engineering presented his new work on Wednesday 14 April at the Royal Astronomical Society National Astronomy Meeting (RAS NAM 2010) in Glasgow.

His findings show that when particularly intense lightning discharges in thunderstorms coincide with high-energy particles coming in from space (cosmic rays), nature provides the right conditions to form a giant particle accelerator above the thunderclouds.

The cosmic rays strip off electrons from air molecules and these electrons are accelerated upwards by the electric field of the lightning discharge. The free electrons and the lightning electric field then make up a natural particle accelerator.

The accelerated electrons then develop into a narrow particle beam which can propagate from the lowest level of the atmosphere (the troposphere), through the middle atmosphere and into near-Earth space, where the energetic electrons are trapped in the Earth’s radiation belt and can eventually cause problems for orbiting satellites.

These are energetic events and for the blink of an eye, the power of the electron beam can be as large as the power of a small nuclear power plant.

Dr Füllekrug explained: “The trick to determining the height of one of the natural particle accelerators is to use the radio waves emitted by the particle beam.”

These radio waves were predicted by his co-worker Dr Robert Roussel-Dupré using computer simulations at the Los Alamos National Laboratory supercomputer facility.

Giant natural particle accelerator discovered above thunderclouds

A sprite formed by an intense thunderstorm (Credit: Oscar van der Velde, Universitat de Catalunya, Spain and Serge Soula, Laboratoire d'Aerologie, France)

A team of European scientists, from Denmark, France, Spain and the UK helped to detect the intense lightning discharges in southern France which set up the particle accelerator.

They monitored the area above thunderstorms with video cameras and reported lightning discharges which were strong enough to produce transient airglows above thunderstorms known as sprites. A small fraction of these sprites were found to coincide with the particle beams.

The zone above thunderstorms has been a suspected natural particle accelerator since the Scottish physicist and Nobel Prize winner Charles Thomson Rees Wilson speculated about lightning discharges above these storms in 1925.

In the next few years five different planned space missions (the TARANIS, ASIM, CHIBIS, IBUKI and FIREFLY satellites) will be able to measure the energetic particle beams directly.

Dr Füllekrug commented: “It’s intriguing to see that nature creates particle accelerators just a few miles above our heads. Once these new missions study them in more detail from space we should get a far better idea of how they actually work.

“They provide a fascinating example of the interaction between the Earth and the wider Universe.”

http://www.physorg.com/news190485260.html

>> The notion of harnessing the power of electricity formed naturally has tantalized scientists for centuries. They noticed that sparks of static electricity formed as steam escaped from boilers. Workers who touched the steam even got painful electrical shocks. Famed inventor Nikola Tesla, for example, was among those who dreamed of capturing and using electricity from the air. It's the electricity formed, for instance, when water vapor collects on microscopic particles of dust and other material in the air. But until now, scientists lacked adequate knowledge about the processes involved in formation and release of electricity from water in the atmosphere, Galembeck said. He is with the University of Campinas in Campinas, SP, Brazil.

Scientists once believed that water droplets in the atmosphere were electrically neutral, and remained so even after coming into contact with the electrical charges on dust particles and droplets of other liquids. But new evidence suggested that water in the atmosphere really does pick up an electrical charge.

Galembeck and colleagues confirmed that idea, using laboratory experiments that simulated water's contact with dust particles in the air. They used tiny particles of silica and aluminum phosphate, both common airborne substances, showing that silica became more negatively charged in the presence of high humidity and aluminum phosphate became more positively charged. High humidity means high levels of water vapor in the air ― the vapor that condenses and becomes visible as "fog" on windows of air-conditioned cars and buildings on steamy summer days.

"This was clear evidence that water in the atmosphere can accumulate electrical charges and transfer them to other materials it comes into contact with," Galembeck explained. "We are calling this 'hygroelectricity,' meaning 'humidity electricity'."

In the future, he added, it may be possible to develop collectors, similar to the solar cells that collect the sunlight to produce electricity, to capture hygroelectricity and route it to homes and businesses. Just as solar cells work best in sunny areas of the world, hygroelectrical panels would work more efficiently in areas with high humidity, such as the northeastern and southeastern United States and the humid tropics.

http://www.physorg.com/news201958072.html