Physiologia Plantarum

Magazine Overview

Title: Physiologia Plantarum
Issue: 111
Volume: 111
Date: 2001
Publisher: Physiologia Plantarum
Country: Ireland
Language: English
ISSN: 0031-9317

This issue of Physiologia Plantarum features a communication by Eltjo H. Haselhoff titled "Opinions and comments on Levengood WC, Talbott NP (1999) Dispersion of energies in worldwide crop formations. Physiol Plant 105: 615-624". The article, received on January 7, 2000, presents a critique and an alternative model to a previously published paper on crop circles.

Commentary on Levengood and Talbott (1999)

The communication begins by addressing Levengood and Talbott's (1999) paper concerning the effect of pulvinus length increase in crop-circle formations. Haselhoff offers a two-fold comment: first, a correction to the physical model used by Levengood and Talbott, and second, an alternative model.

Correction to the Physical Model

Levengood and Talbott (1999) suggested that electromagnetic radiation absorption causes pulvinus length increase due to local heating and thermal expansion. They proposed a linear relation: NL = b(I/Io), where NL is the stem pulvinus length, I is the fraction of absorbed energy, Io is the radiation source intensity, and b is a proportionality constant. Haselhoff points out that this equation implicitly assumes NL approaches zero at low energy levels, which is unrealistic. He suggests a more appropriate definition: NL - No = b(I/Io), where No is the undisturbed pulvinus length. Applying this corrected equation to Levengood and Talbott's data, Haselhoff found that the Pearson product moment correlation coefficient (R) decreased in one reported case. However, in the other two cases, no significant changes were observed.

Alternative Model: Electromagnetic Point Source

The second part of the comment focuses on the model for electromagnetic radiation involved in crop circle creation. Levengood and Talbott (1999) used an exponential decay formula, I(d)/Io = e-acd, which is valid for 'plane' electromagnetic waves. Haselhoff argues that the circular symmetry of many crop formations and eyewitness reports of 'balls of light' (BOLs) suggest an electromagnetic 'point source' rather than a plane wave. He proposes a model where a point source is located at a finite height (h) above the field. The distance (r) from the BOL to a point on the ground at distance (d) from the center of the imprint is given by r = sqrt(h² + d²). A linear regression analysis, with y-intercept forced to zero, was performed using Levengood and Talbott's data (NL, No, and d), optimizing for the parameter h to achieve the best fit to a 1/r² fall-off. The results for the 1994 Sussex formation, with h = 7.8 m, showed a high Pearson coefficient (R = 0.97). Similar analyses for other formations also yielded high correlation coefficients, indicating that the node expansion correlates well with the electromagnetic radiation intensity distribution expected from a point source at a finite height.

Analysis of a Hand-Made Formation

Haselhoff then applied the BOL analysis to a data set from a hand-made formation in Nieuwerkerk, Netherlands, investigated three days after its appearance. In this case, wheat stems were mechanically flattened, and pulvinus length increase was assumed to be an effect of gravitropism. The BOL analysis for this formation, with an optimized height h = 17 m, yielded a maximum Pearson coefficient of only 0.54. This result, illustrated in Figure 3, shows a lack of obvious linear dependence and a less structured character compared to the data from genuine crop formations.

Conclusions

The experimental data published by Levengood and Talbott (1999) suggest that pulvinus length expansion in crop circles is a thermo-mechanic effect, possibly induced by an electromagnetic point source. However, data from a simple hand-made formation did not exhibit the same characteristics. Haselhoff emphasizes that this is not a definitive 'lithmus test' to distinguish genuine crop formations from artificial ones, as more extensive data and statistical studies are required. Nevertheless, the position-dependent pulvinus length and the apparent organized character of the data analyzed are considered interesting and warrant further investigation.

References

The communication cites two references:

• Levengood WC, Talbott NP (1999) Dispersion of energies in worldwide crop formations. Physiol Plant 105: 615-624.
• Meaden GT (1991) Circles from the Sky. Souvenir Press, London.

Recurring Themes and Editorial Stance

This issue of Physiologia Plantarum appears to engage with fringe scientific topics, specifically the physics behind crop circle formations. The editorial stance, as represented by the publication of this critical commentary, seems open to exploring unconventional hypotheses related to unexplained phenomena, provided they are subjected to scientific scrutiny and analysis, even if the conclusions are tentative and call for further research. The themes explored include the physics of crop circles, electromagnetic phenomena, and the scientific methodology for distinguishing natural or anomalous events from human-made ones.