Document Type

Article

Publication Date

2024

DOI

10.1119/5.0168101

Publication Title

The Physics Teacher

Volume

62

Issue

5

Pages

403

Abstract

Question 2: Assuming θ ≈ 2° = π/90 rad, estimate the distance R to the aircraft. Assume that R ≫ d. Question 1: Suppose that the observed “period of oscillation” is 1 min, and the speed of the aircraft is 200 km/h. Estimate the diameter d of the aircraft path (assuming that it is circular). Estimate the banking angle of the aircraft at this speed. While still a teenager (and aspiring astronomer), I became interested in the subject of UFOs (more appropriately named UAPs—see Ref. 1). The region in which I lived (50 km west of London) was in the local news because of a UFO “flap”: several sightings of objects exhibiting strange and erratic behavior (e.g., sudden changes of direction in the sky) over a period of a month. One particular observation was of a tiny object, low on the horizon, moving back and forth, seemingly in a straight-line segment. Fortunately, one cloudy night, I was able to see this object in the distance, and I trained my telescope on it. What I saw were lights from a distant airplane, presumably flying in a circular holding pattern, but so low on the horizon for me that to the naked eye, its apparent path appeared to be a line segment (AB, say). It was a long time ago, but at the time I estimated the angular diameter of AB (θ) to be about 2° of arc (i.e., 4 full-moon widths). This was very subjective, however, because on that cloudy night, there was no obvious reference point. Upon later reflection, I realized that I could have compared it with the angular diameter of a nearby house or tree.

Rights

© Copyright 2024 AIP Publishing LLC. All rights reserved.

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in

Adam, J. (2024). Refracting UFOs. The Physics Teacher, 62(5), 403.

and may be found at https://doi.org/10.1119/5.0168101.

Original Publication Citation

Adam, J. (2024). Refracting UFOs. The Physics Teacher, 62(5), 403. https://doi.org/10.1119/5.0168101

ORCID

0000-0001-5537-2889 (Adam)

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