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Die Lösung dieses scheinbaren Paradoxons steht im Apollo 15 Lunar Surface Journals:
Sowohl die angegebene Fallzeit als auch die angegebene Fallhöhe sind falsch, auch wenn sie auf den ersten Blick plausibel erscheinen!
Die Wiedergabegeschwindigkeit ist hingegen korrekt und unverfälscht!
[AFJ Editor David Woods calls our attention to the following from the Apollo 15 Preliminary Science Report: "During the final minutes of the third extravehicular activity, a short demonstration experiment was conducted. A heavy object (a 1.32-kg aluminum geological hammer) and a light object (a 0.03-kg falcon feather) were released simultaneously from approximately the same height (approximately 1.6 m) and were allowed to fall to the surface. Within the accuracy of the simultaneous release, the objects were observed to undergo the same acceleration and strike the lunar surface simultaneously, which was a result predicted by well-established theory, but a result nonetheless reassuring considering both the number of viewers that witnessed the experiment and the fact that the homeward journey was based critically on the validity of the particular theory being tested."]
[Two of the numbers given in this experiment description have been called into question.]
[Journal Contributor Andrea Sondag notes that the given weight (0.03 kg = 30 g) for the feather is much too large. She contacted an ornithology club in Bayern, Germany, who introduced her to Hermann Rank, the owner of an extensive collection of falcon feathers. "He choose a primary flight feather (H7) of a female gyrfalcon (Falco rusticolus) which fits the Apollo 15 feather best, and measured it for us: length, 31.5 cm; weight, 1.19 g."]
[Journal Contributor Joonas Helminen notes that the stated height - 1.6 meters - from which the hammer and feather were dropped is in error. Although the important part of the experiment is the fact that these two objects of very different weight experienced the same motion, for completeness we offer the following. If we concentrate on the hammer, Helminen has stepped through the mpeg clip and finds that the time between Dave's release of the hammer and its impact is 36 frames. The framing rate is 30 frames per second, giving a fall time of 1.2 seconds. We have three separate estimates of the height. Helminen estimates the height as 120 cm and writes, "My estimation was simply from thinking how far you would bend forward with the PLSS on your back and from noticing how Dave did not hold his arms straight out parallel to the ground. I am just below 180cm tall and, when put myself in the same posture, 120 cm was a close estimate of the height of the bottom of the hammer head." An independent estimate is provided by the known length of the hammer, which is 39 cm. By noting the point on the ground where the hammer hits, a measurement can be made on the image of the initial height of 2.9 hammer lengths or 113 cm. A final estimate can be calulated knowing that the distance a dropped object falls is 0.5*acceleration multiplied by the square of the time in free fall. Gravity at the lunar surface is 163 cm/sec/sec. After falling for 1.2 seconds, a dropped object will have travelled 117 cm.]
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APOLLO 15 UND DIE FALLBESCHLEUNIGUNG AUF DEM MOND - EINE ÜBERLEGUNG FÜR DEN ASTRONOMIE- UND PHYSIKUNTERRICHT
11.07.2021, Roger LeifertSowohl die angegebene Fallzeit als auch die angegebene Fallhöhe sind falsch, auch wenn sie auf den ersten Blick plausibel erscheinen!
Die Wiedergabegeschwindigkeit ist hingegen korrekt und unverfälscht!
https://history.nasa.gov/alsj/a15/a15.clsout3.html#1672243 (ganz am Ende des Eintrags zu Zeitindex 167:22:58 (Mission Elpsed Time)
[AFJ Editor David Woods calls our attention to the following from the Apollo 15 Preliminary Science Report: "During the final minutes of the third extravehicular activity, a short demonstration experiment was conducted. A heavy object (a 1.32-kg aluminum geological hammer) and a light object (a 0.03-kg falcon feather) were released simultaneously from approximately the same height (approximately 1.6 m) and were allowed to fall to the surface. Within the accuracy of the simultaneous release, the objects were observed to undergo the same acceleration and strike the lunar surface simultaneously, which was a result predicted by well-established theory, but a result nonetheless reassuring considering both the number of viewers that witnessed the experiment and the fact that the homeward journey was based critically on the validity of the particular theory being tested."]
[Two of the numbers given in this experiment description have been called into question.]
[Journal Contributor Andrea Sondag notes that the given weight (0.03 kg = 30 g) for the feather is much too large. She contacted an ornithology club in Bayern, Germany, who introduced her to Hermann Rank, the owner of an extensive collection of falcon feathers. "He choose a primary flight feather (H7) of a female gyrfalcon (Falco rusticolus) which fits the Apollo 15 feather best, and measured it for us: length, 31.5 cm; weight, 1.19 g."]
[Journal Contributor Joonas Helminen notes that the stated height - 1.6 meters - from which the hammer and feather were dropped is in error. Although the important part of the experiment is the fact that these two objects of very different weight experienced the same motion, for completeness we offer the following. If we concentrate on the hammer, Helminen has stepped through the mpeg clip and finds that the time between Dave's release of the hammer and its impact is 36 frames. The framing rate is 30 frames per second, giving a fall time of 1.2 seconds. We have three separate estimates of the height. Helminen estimates the height as 120 cm and writes, "My estimation was simply from thinking how far you would bend forward with the PLSS on your back and from noticing how Dave did not hold his arms straight out parallel to the ground. I am just below 180cm tall and, when put myself in the same posture, 120 cm was a close estimate of the height of the bottom of the hammer head." An independent estimate is provided by the known length of the hammer, which is 39 cm. By noting the point on the ground where the hammer hits, a measurement can be made on the image of the initial height of 2.9 hammer lengths or 113 cm. A final estimate can be calulated knowing that the distance a dropped object falls is 0.5*acceleration multiplied by the square of the time in free fall. Gravity at the lunar surface is 163 cm/sec/sec. After falling for 1.2 seconds, a dropped object will have travelled 117 cm.]