133 research outputs found
Shamanism, Imagery Cultivation, and Psi-Signal Detection: A Theoretical Model, Experimental Protocol, and Preliminary Data
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Shamanism, Imagery Cultivation, and Psi-Signal Detection: A Theoretical Model, Experimental Protocol, and Preliminary Data
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On the correspondence between dream content and target material under laboratory conditions: a meta-analysis of dream-ESP studies, 1966-2016
In order to further our understanding about the limits of human consciousness and the dream state, we report meta-analytic results on experimental dream-ESP studies for the period 1966 to 2016. Dream-ESP can be defined as a form of extra-sensory perception (ESP) in which a dreaming perceiver ostensibly gains information about a randomly selected target without using the normal sensory modalities or logical inference. Studies fell into two categories: the Maimonides Dream Lab (MDL) studies (n = 14), and independent (non-MDL) studies (n = 36). The MDL dataset yielded mean ES = .33 (SD = 0.37); the non-MDL studies yielded mean ES = .14 (SD = 0.27). The difference between the two mean values was not significant. A homogeneous dataset (N = 50) yielded a mean z of 0.75 (ES = .20, SD = 0.31), with corresponding significant Stouffer Z = 5.32, p = 5.19 Ă 10-8, suggesting that dream content can be used to identify target materials correctly and more often than would be expected by chance. No significant differences were found between: (a) three modes of ESP (telepathy, clairvoyance, precognition), (b) senders, (c) perceivers, or (d) REM/non-REM monitoring. The ES difference between dynamic targets (e.g., movie-film) and static (e.g., photographs) targets was not significant. We also found that significant improvements in the quality of the studies was not related to ES, but ES did decline over the 51-year period. Bayesian analysis of the same homogeneous dataset yielded results supporting the âfrequentistâ finding that the null hypothesis should be rejected. We conclude that the dream-ESP paradigm in parapsychology is worthy of continued investigation, but we recommend design improvements
Response to howard (2018): Comments on âa meta-reanalysis of dream-ESP studiesâ
Dream-ESP is a form of extra-sensory perception (ESP) in which a dreaming perceiver ostensibly gains information about a randomly selected target without using the normal sensory modalities or logical inference. We conducted a meta-analysis on dream-ESP studies (dating from 1966 to 2016), and found a number of significant effects indicating support for the ESP hypothesis (Storm et al., 2017). Howard (2018) critiqued our study, and found much weaker effects based on a re-analysis of our data, to which he applied inverse-variance weights to the study values. Although Howard replicated a number of our findings, his other findings can be challenged. We discuss meta-analytic approaches, including the controversial issues of publication bias and what to do with outliers, and we present some re-analyses.N/
Spiral Density Waves in a Young Protoplanetary Disk
Gravitational forces are expected to excite spiral density waves in
protoplanetary disks, disks of gas and dust orbiting young stars. However,
previous observations that showed spiral structure were not able to probe disk
midplanes, where most of the mass is concentrated and where planet formation
takes place. Using the Atacama Large Millimeter/submillimeter Array we detected
a pair of trailing symmetric spiral arms in the protoplanetary disk surrounding
the young star Elias 2-27. The arms extend to the disk outer regions and can be
traced down to the midplane. These millimeter-wave observations also reveal an
emission gap closer to the star than the spiral arms. We argue that the
observed spirals trace shocks of spiral density waves in the midplane of this
young disk.Comment: This is our own version of the manuscript, the definitive version was
published in Science (DOI: 10.1126/science.aaf8296) on September 30, 2016.
Posted to the arxiv for non-commercial us
Spiral density waves in a young protoplanetary disk
Gravitational forces are expected to excite spiral density waves in protoplanetary disks, disks of gas and dust orbiting young stars. However, previous observations that showed spiral structure were not able to probe disk midplanes, where most of the mass is concentrated and where planet formation takes place. Using the Atacama Large Millimeter/submillimeter Array, we detected a pair of trailing symmetric spiral arms in the protoplanetary disk surrounding the young star Elias 2-27. The arms extend to the disk outer regions and can be traced down to the midplane. These millimeter-wave observations also reveal an emission gap closer to the star than the spiral arms. We argue that the observed spirals trace shocks of spiral density waves in the midplane of this young disk
Grain Growth in the Circumstellar Disks of the Young Stars CY Tau and DoAr 25
We present new results from the Disks@EVLA program for two young stars: CY Tau and DoAr 25. We trace continuum emission arising from their circusmtellar disks from spatially resolved observations, down to tens of AU scales, at λ = 0.9, 2.8, 8.0, 9.8 mm for DoAr 25 and at λ = 1.3, 2.8, 7.1 mm for CY Tau. Additionally, we constrain the amount of emission whose origin is different from thermal dust emission from 5 cm observations. Directly from interferometric data, we find that observations at 7 mm and 1 cm trace emission from a compact disk while millimeter-wave observations trace an extended disk structure. From a physical disk model, where we characterize the disk structure of CY Tau and DoAr 25 at wavelengths shorter than 5 cm, we find that (1) dust continuum emission is optically thin at the observed wavelengths and over the spatial scales studied, (2) a constant value of the dust opacity is not warranted by our observations, and (3) a high-significance radial gradient of the dust opacity spectral index, ÎČ, is consistent with the observed dust emission in both disks, with low-ÎČ in the inner disk and high-ÎČ in the outer disk. Assuming that changes in dust properties arise solely due to changes in the maximum particle size (a_(max)), we constrain radial variations of a_(max) in both disks, from cm-sized particles in the inner disk (R 80 AU). These observational constraints agree with theoretical predictions of the radial-drift barrier, however, fragmentation of dust grains could explain our a_(max)(R) constraints if these disks have lower turbulence and/or if dust can survive high-velocity collisions
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