Reflections on the Historian’s Craft—Chance, Coincidence, and Other “Freaks” of Research

2015 ◽  
Vol 46 (1) ◽  
pp. 124-125
Author(s):  
Darcy Ingram
Keyword(s):  
Chance Coincidence

scholarly journals Collinder 135 and UBC 7: A physical pair of open clusters

2020 ◽  
Vol 642 ◽  
pp. L4
Author(s):  
Dana A. Kovaleva ◽  
Marina Ishchenko ◽  
Ekaterina Postnikova ◽  
Peter Berczik ◽  
Anatoly E. Piskunov ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Observational Evidence ◽  
Open Clusters ◽  
Line Of Sight ◽  
Kinematic Parameters ◽  
Current Line ◽  
Chance Coincidence ◽  
The Past ◽  
Link Type ◽  
Spatial Coordinates

Context. Given the closeness of the two open clusters Collinder 135 and UBC 7 on the sky, we investigate the possibility that the two clusters are physically related. Aims. We aim to recover the present-day stellar membership in the open clusters Cr 135 and UBC 7 (300 pc from the Sun) in order to constrain their kinematic parameters, ages, and masses and to restore their primordial phase space configuration. Methods. The most reliable cluster members are selected with our traditional method modified for the use of Gaia DR2 data. Numerical simulations use the integration of cluster trajectories backwards in time with our original high-order Hermite4 code φ−GRAPE. Results. We constrain the age, spatial coordinates, velocities, radii, and masses of the clusters. We estimate the actual separation of the cluster centres equal to 24 pc. The orbital integration shows that the clusters were much closer in the past if their current line-of-sight velocities are very similar and the total mass is more than seven times larger than the mass of the most reliable members. Conclusions. We conclude that the two clusters Cr 135 and UBC 7 might very well have formed a physical pair based on the observational evidence as well as numerical simulations. The probability of a chance coincidence is only about 2%.

Extinction from a paleontological perspective

1993 ◽  
Vol 1 (3) ◽  
pp. 207-216 ◽  
Author(s):  
David M. Raup
Keyword(s):  
Mass Extinction ◽  
Fossil Record ◽  
Mass Extinctions ◽  
Evolutionary Time ◽  
Widespread Species ◽  
Chance Coincidence ◽  
Independent Events

Extinction of widespread species is common in evolutionary time (millions of years) but rare in ecological time (hundreds or thousands of years). In the fossil record, there appears to be a smooth continuum between background and mass extinction; and the clustering of extinctions at mass extinctions cannot be explained by the chance coincidence of independent events. Although some extinction is selective, much is apparently random in that survivors have no recognizable superiority over victims. Extinction certainly plays an important role in evolution, but whether it is constructive or destructive has not yet been determined.

scholarly journals Near Infrared and Radio Observations of Distant Galaxies

1983 ◽  
Vol 104 ◽  
pp. 85-86
Author(s):  
R. A. Laing ◽  
F. N. Owen ◽  
J. J. Puschell
Keyword(s):  
Near Infrared ◽  
Angular Size ◽  
Radio Galaxies ◽  
Radio Observations ◽  
Chance Coincidence ◽  
Distant Galaxies ◽  
Upper Limits

This paper is concerned with the distant radio galaxies in a sample of bright sources selected at 178 MHz by Laing, Riley & Longair (1982). This sample is 96% complete for sources with θ < 10′ and the bias of the 3CR catalogue against sources of large angular size has also been reduced. Deep optical searches have located many candidate identifications, but the probability of a chance coincidence with an unrelated object is appreciable, especially in the faintest cases, unless the area to be searched is small. We have therefore mapped the sources with candidate identifications having V > 20, using the VLA at a wavelength of 6 cm (Laing, Owen & Puschell, in preparation), in order to search for radio cores. We have so far located cores in 16/23 sources and set 5σ upper limits of 0.6 mJy for the remainder. None of the cores had been detected previously. In all cases, the cores coincide with optical objects, although one source (3C 340) had been misidentified. Several ambiguities have now been resolved.

THE THEORY OF CHANCE-COINCIDENCE

2011 ◽  
pp. 1-28
Author(s):  
Edmund Gurney ◽  
Frederic William Henry Myers ◽  
Frank Podmore
Keyword(s):  
Chance Coincidence

Null and Vetoed: Chance Coincidence?

CHANCE ◽  
2010 ◽  
Vol 23 (4) ◽  
pp. 43-46
Author(s):  
Philip B. Stark
Keyword(s):  
Chance Coincidence

The thermal decomposition of aliphatic aldehydes

1963 ◽  
Vol 276 (1365) ◽  
pp. 278-292 ◽  
Keyword(s):  
Nitric Oxide ◽  
Thermal Decomposition ◽  
Chain Reaction ◽  
Chance Coincidence ◽  
Limited Success ◽  
Molecular Reaction ◽  
A Chain ◽  
The Stability ◽  
Oxide Inhibition ◽  
Chain Propagation And Termination

The thermal decomposition of acetaldehyde, propionaldehyde, n -butyraldehyde and iso-butyraldehyde, as investigated by the static method, is essentially homogeneous, inhibitable by propylene, isobutene and small amounts of nitric oxide, and generally catalyzed at high inhibitor concentrations. The kinetic order of the uninhibited decomposition exhibits little obvious regularity, but that of the maximally inhibited reaction is approximately 1.5 for all three inhibitors. Kates of the uninhibited decomposition do not follow the sequence in the homologous series, and there is no systematic variation in the extent of inhibition from one aldehyde to another. For each aldehyde, the minimum rates for the three inhibitors in general are not identical, nevertheless exhibit a correspondence probably close enough to eliminate chance coincidence. The kinetic and analytical results of the uninhibited decomposition can be approximately described by a Kice-Herzfeld-type mechanism, with the kinetics in each case largely determined by the stability of radicals and their reactions in chain propagation and termination. The question whether the maximally inhibited reaction is a molecular reaction or a chain reaction is surveyed. Although the results cannot be completely accounted for by a molecular reaction alone, a chain mechanism for propylene inhibition involving allyl radicals likewise has only limited success. For nitric-oxide inhibition, it is not certain how far the results are affected by the occurrence of the subsequent catalyzed reaction. No definite conclusion can thus be reached about the nature of the maximally inhibited reaction.

The Dioscuri in the Balkans

Slavic Review ◽  
1967 ◽  
Vol 26 (3) ◽  
pp. 363-381 ◽  
Author(s):  
Marian Wenzel
Keyword(s):  
Fifteenth Century ◽  
Chance Coincidence ◽  
The Balkans ◽  
Initiation Ritual ◽  
The Village

This article is an attempt to establish a certain number of conclusions concerning the Dioscuri which are different from previous surmises. These conclusions are: First, an individual, on horseback or on foot, shown stabbing another figure beneath need not represent the triumph of good over evil, or the vanquishing of a foe, and in a set number of cases does not represent this. Second, at least one kind of antique mystery cult did not develop from a puberty initiation ritual, but from something else. Third, much of pre-Greek, or perhaps Thracian, religion, as indicated by contemporary ethnographic survivals, may have consisted of one extended ritual which could be segmented for a number of different purposes, excluding that of puberty initiation, for which, in this context, I have found no trace. Finally, the Dioscuri were an anthropomorphized object, of an ascertain-able kind. The evidence leading to these conclusions is given below.In the village of Mijatovci, in Hercegovina, at the site known as “Kalufi,” there was a tombstone dated to the fifteenth century on which is depicted a woman between horsemen (Figure 1). The same, or a similar, motif appears on other tombstones in neighboring graveyards (Figure 2, d, e). These horsemen have been identified with the Dioscuri. That is to say, they exhibit such striking features in common with classical monuments known to be representations of the Dioscuri that the possibility of chance coincidence is, in fact, eliminated.

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