5. On a Monochromatic Rainbow

1889 ◽  
Vol 15 ◽  
pp. 135-137
Author(s):  
John Aitken
Keyword(s):  
The Sun ◽  

A monochromatic rainbow looks like a contradiction in terms. As a rainbow of this kind was, however, seen lately, its occurrence seems worth putting on record. On the afternoon of Christmas day I went for a walk in the direction of the high ground to the south of Falkirk. Shortly after starting I observed in the east what appeared to be a peculiar pillar-like cloud, lit up with the light of the setting sun. What specially attracted my attention was that the streak of illumination was vertical, and not the usual horizontal band-form we are accustomed to. I looked in the direction of the sun to see if I could trace any peculiar opening in the clouds through which the light passed, but failed to do so.

What we are here to discuss concerns the Great Barrier Reef of Australia. It is very fitting that we should do so in this place, because the Royal Society was intimately concerned with events that led to its discovery in 1770. We go back to 1716, to a communication printed in Latin in the Philosophical Transactions by Edmond Halley, then Savilean Professor of Geometry at Oxford and Secretary of this Society. There, and for no less an objective than the more accurate determination of the dimensions of the Universe, he drew attention to the unique opportunities to that end to be presented by observing the transits of Venus across the face of the Sun due on 6 June 1761 and 3 June 1769. In the event international observations in the former year were largely fruitless, giving added reason for adequate observations in 1769. One of the conclusions of the specially appointed Transit Committee of the Society was that one site for observation should be in the South Seas.


2017 ◽  
Vol 467 (3) ◽  
pp. 3393-3398
Author(s):  
A. R. Ahangarzadeh Maralani ◽  
E. Tavabi ◽  
A. Ajabshirizadeh
Keyword(s):  
The Sun ◽  

In cases where it is necessary to separate true periodic changes from other variations, which during short periods of time often simulate periodicities, the method of the periodogram is at present the only one which can give definite results. In view of the importance of the questions connected with the changes in the frequency of the sun-spots, I have, therefore, undertaken the considerable labour of forming a complete periodogram of sun-spot variability as far as the data at my disposal allow me to do so. The following is a brief abstract of the results; the investigation will be presented shortly:— The periodogram, as already explained, is the diagram representing the intensity of periodic variations as determined from the sum of the squares of the two Fourier coefficients belonging to each assumed period. This diagram represents for any regular or irregular change exactly what the energy diagram gives us for a luminous disturbance which is analysed by a spectroscope.


2003 ◽  
Vol 21 (6) ◽  
pp. 1217-1228 ◽  
Author(s):  
R. B. McKibben ◽  
J. J. Connell ◽  
C. Lopate ◽  
M. Zhang ◽  
J. D. Anglin ◽  
...  

Abstract. In 2000–2001 Ulysses passed from the south to the north polar regions of the Sun in the inner heliosphere, providing a snapshot of the latitudinal structure of cosmic ray modulation and solar energetic particle populations during a period near solar maximum.  Observations from the COSPIN suite of energetic charged particle telescopes show that latitude variations in the cosmic ray intensity in the inner heliosphere are nearly non-existent near solar maximum, whereas small but clear latitude gradients were observed during the similar phase of Ulysses’ orbit near the 1994–95 solar minimum. At proton energies above ~10 MeV and extending up to >70 MeV, the intensities are often dominated by Solar Energetic Particles (SEPs) accelerated near the Sun in association with intense solar flares and large Coronal Mass Ejections (CMEs). At lower energies the particle intensities are almost constantly enhanced above background, most likely as a result of a mix of SEPs and particles accelerated by interplanetary shocks. Simultaneous high-latitude Ulysses and near-Earth observations show that most events that produce large flux increases near Earth also produce flux increases at Ulysses, even at the highest latitudes attained. Particle anisotropies during particle onsets at Ulysses are typically directed outwards from the Sun, suggesting either acceleration extending to high latitudes or efficient cross-field propagation somewhere inside the orbit of Ulysses. Both cosmic ray and SEP observations are consistent with highly efficient transport of energetic charged particles between the equatorial and polar regions and across the mean interplanetary magnetic fields in the inner heliosphere.Key words. Interplanetary physics (cosmic rays) – Solar physics, astrophysics and astronomy (energetic particles; flares and mass ejections)


2019 ◽  
Vol 12 (2) ◽  
pp. 245
Author(s):  
Satwika Paramasatya ◽  
Wing Witjahyo Poespojoedho

The conflict involving many countries in the South China Sea has notended nor subsided. Regional tension and claims between countries areincreasing and Indonesia participates in this round of conflict. As theworld’s largest archipelagic country and an ASEAN member country thatupholds peace, security and regional stability, Indonesia then has to playan active role in the conflict. In order to do so, Indonesia is using navaldiplomacy as a way to achieve effective conflict resolution within theregion. Regarding the phenomenon, this study used the concept of seapower and naval diplomacy to explain measures that have been taken bythe Indonesian government under Joko Widodo’s presidency in resolvingthe conflicts involving its territories in the South China Sea. The author’sanalysis showed that Indonesia’s policies of using naval diplomacy in theSouth China Sea conflict have a positive and effective outcome in achievingconflict resolution and peace condition that has been confined by longtermobstacles and challenges.


PMLA ◽  
1976 ◽  
Vol 91 (4) ◽  
pp. 535-536
Author(s):  
Edward W. Bratton

The 1976 convention of the South Atlantic Modern Language Association will be held at the new Peachtree Center Plaza Hotel in Atlanta, Georgia, on Thursday, Friday, and Saturday, 4-6 November. Chairmen of several of the eighty special interest and affiliated meetings comprising the convention have designated Bicentennial themes for their programs in keeping with the nation's celebration of her 200th birthday. Convention preregistration and special housing rates on rooms blocked for SAMLA use are restricted to members of the Association, but persons interested in joining SAMLA and receiving full convention information can do so by forwarding annual dues of $7.00 (graduate students, $2.00; joint husband-wife, $9.00) by no later than 1 October to: SAMLA, Box 8410, U. T. Station, Knoxville, Tennessee 37916.


Author(s):  
Ellen Wohl

The beaver meadow is quiet in January. For many plants and animals, winter is a season of subdued activity, or of waiting. North St. Vrain Creek remains open along the main channel, the water flowing clear but tinted brown as pine bark between snowy banks. Densely growing thickets of willow closely line the banks. Each stem starts pale brown near the ground, then grades upward to shades of maroon or yellowish orange at the branch tips. In a bird’s-eye view, these startling colors make the meadow stand out distinctly from the dark green conifers that define the edges of the meadow. Spruce and fir trees grow sharply pointed as arrows; pines present a slightly more rounded outline. Snow falls silently in thick flakes from the low, gray sky. The upper edges of the valley walls fade into snow and clouds. The sun appears briefly as a small, pale spotlight behind the clouds to the south. Snow mounds on the patches of ice in the shallow channel. The water flowing beneath creates flickers through the translucent ice like a winter fire of subdued colors and no heat. Tussocks form humps of straw-colored grass above the dark, frozen soil. Rabbit tracks line the snowy bank, sets of four paw marks with a large gap between each set. Something small crossed the bank, leaping one to two feet at a bound, two paws with slight drag marks behind them. In places the powdery snow has drifted deeply, but mostly it is shallow over a frozen crust. Beaver-gnawed sticks and stumps poke up through the snow. A large flood came through four months ago, in mid-September, washing out dams that the beavers have not yet rebuilt. Chunks of wood deposited among the willow stems by the floodwaters stand far above the January flow of the creek. A dipper fishes the creek, wading rather than swimming, at home in the cold water. The slate-gray bird is the only visible animal, busily probing the bed with its short bill, then pausing to stand and bob up and down.


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