173 research outputs found

    Luminous electrical phenomena in Huntsville, Alabama, tornadoes on April 3, 1974

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    Unusual lightning and varicolored luminous phenomena were observed on the evening of April 3, 1974, when severe tornadoes passed through Madison County, Alabama. Photographs and eyewitness accounts of this electrical activity are related to the trajectories of the tornadoes and the damage areas they produced

    Thunderstorm observations from Space Shuttle

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    Results of the Nighttime/Daytime Optical Survey of Lightning (NOSL) experiments done on the STS-2 and STS-4 flights are covered. During these two flights of the Space Shuttle Columbia, the astronaut teams of J. Engle and R. Truly, and K. Mattingly II and H. Hartsfield took motion pictures of thunderstorms with a 16 mm cine camera. Film taken during daylight showed interesting thunderstorm cloud formations, where individual frames taken tens of seconds apart, when viewed as stereo pairs, provided information on the three-dimensional structure of the cloud systems. Film taken at night showed clouds illuminated by lightning with discharges that propagated horizontally at speeds of up to 10 to the 5th m/sec and extended for distances on the order of 60 km or more

    Lightning observations from the Space Shuttle

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    Motion pictures were taken at night from the space shuttle that show lightning discharges spreading horizontally at speeds of .00001 m/sec for distances over 60 km. Tape recordings were made of the accompanying optical pulses detected with a photocell optical system. The observations show that lightning is often a mesoscale phenomenon that conveys large amounts of electric charge and energy derived from an extensive cloud system into a cloud-to-ground discharge. Several video tape recordings of lightning discharges were obtained on shuttle flights since the termination of the NOSL program. The size and location of the lightning illuminated cloud images is now being analyzed, and comparisons are made with meteorological data concerning the cloud system obtained from the McIDAS

    Nighttime observations of thunderstorm electrical activity from a high altitude airplane

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    Nocturnal thunderstorms were observed from above and features of cloud structure and lightning which are not generally visible from the ground are discussed. Most, lightning activity seems to be associated with clouds with strong convective cauliflower tops. In both of the storms lightning channels were visible in the clear air above the cloud. It is shown that substances produced by thunderstorm electrical discharges can be introduced directly into the stratosphere. The cause and nature of the discharges above the cloud are not clear. They may be produced by accumulations of space charge in the clear air above the cloud. The discharges may arise solely because of the intense electric fields produced by charges within the cloud. In the latter case the ions introduced by these discharges will increase the electrical conductivity of the air above the cloud and increase the conduction current that flows from the cloud to the electrosphere. More quantitative data at higher resolution may show significant spectral differences between cloud to ground and intracloud strokes. It is shown that electric field change data taken with an electric field change meter mounted in an airplane provide data on lightning discharges from above that are quite similar to those obtained from the ground in the past. The optical signals from dart leaders, from return strokes, and from continuing currents are recognizable, can be used to provide information on the fine structure of lightning, and can be used to distinguish between cloud to ground and intracloud flashes

    Nighttime/daytime optical survey of lightning and convective phenomena experiment (NOSL)

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    The Nighttime/Daytime Optical Survey of Lightning experiment was selected for flight on Orbital Flight Test 2 of the Space Shuttle. The background and rationale for the experiment are presented and the experiment hardware, the operating procedures, and the data analysis technique are discussed. Some preliminary results from the prototype hardware development are also presented

    Mesoscale observations of lightning from Space Shuttle

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    Motion pictures have been taken at night by astronauts on the space shuttle showing lightning discharge that spread horizontally at speeds of 100,000/msec for distances over 60 km. Tape recordings have been made of the accompanying optical pulses detected with a photocell optical system. The observations show that lightning is often a mesoscale phenomena that can convey large amounts of electric charge to Earth from an extensive cloud system via a cloud to ground discharge

    String theory and the crisis of particle physics II or the ascent of metaphoric arguments

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    This is a completely reformulated presentation of a previous paper with the same title; this time with a much stronger emphasis on conceptual aspects of string theory and a detailed review of its already more than four decades lasting history within a broader context, including some little-known details. Although there have been several books and essays on the sociological impact and its philosophical implications, there is yet no serious attempt to scrutinize its claims about particle physics using the powerful conceptual arsenal of contemporary local quantum physics. I decided to leave the previous first version on the arXiv because it may be interesting to the reader to notice the change of viewpoint and the reason behind it. Other reasons for preventing my first version to go into print and to rewrite it in such a way that its content complies with my different actual viewpoint can be found at the end of the article. The central message, contained in sections 5 and 6, is that string theory is not what string theorists think and claim it is. The widespread acceptance of a theory whose interpretation has been obtained by metaphoric reasoning had a corroding influence on the rest of particle physics theory as will be illustrated in several concrete cases. The work is dedicated to the memory of Juergen Ehlers with whom I shared many critical ideas, but their formulation in this essay is fully within my responsibility.Comment: A dedication and an epilog to the memory of Juergen Ehlers. Extension of the the last two sections, removal of typos and changes in formulation, 68 pages late
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