Galileo discovered hundreds of years ago that all items released simultaneously fall at the same rate regardless of mass.
Commander David Scott gave a live demonstration for the television cameras at the end of the final Apollo 15 moonwalk. He dropped a feather and a geological hammer at the exact same time to test a theory presented by the renowned astronomer, physicist and engineer Galileo Galilei hundreds of years ago. Galileo famously concluded that all items released simultaneously fall at the same rate regardless of mass. Since they were essentially in a vacuum while on the moon, there was no air resistance and the feather made contact with the surface of the Earth's only natural satellite at the same moment as the hammer, per NASA.
In an incredibly cool video of the experiment, the objects are seen doing exactly what was predicted by well-established theory. Although the result was expected, it was nonetheless reassuring given the large number of people who watched the experiment and the fact that the homeward journey was heavily dependent on the viability of this particular theory.
The demonstration was described in the "Apollo 15 Preliminary Science Report" by Mission Controller Joe Allen. "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," Allen wrote.
"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."
The video blew some minds on Reddit this week after it was shared by the u/Mr_R0mpers, with the caption: "Dave Scott performed the Galilean 'hammer and feather' experiment on the Moon, 1971." Since being posted on Wednesday, the video has racked up over 23,600 upvotes with many people expressing absolute delight at Commander Scott's extremely casual attitude about being on the moon while speaking of the experiment.
u/Most-Star-7094 commented, "I love how casually he says it. 500 years ago, that would have been a groundbreaking discovery, and he proved it by actually performing the experiment on the F*****G moon!" u/GetDownWithDave replied, saying, "Even as a society, we write off landing on the moon as some past achievement, despite the fact it’s still the coolest thing humans have ever done as a combined species."
u/Most-Star-7094 commented wrote, "The moon landing, taking a picture of a black hole, taking a picture of a single atom, the Hardon particle accelerator, and Shrek are all tied in first place for me."
u/TheGreenHaloMan commented about how Commander Scott looks cute in the video, "I don’t know why but the way he said it along with how he looks in that suit was really cute for some reason." u/digita1catt commented, "It's so ordinary a phrase that you almost forget he's saying it while standing on the fucking moon." u/Adorable-Effective-2 commented, "I watched large parts of the uncut Apollo 14 landing and you'd be surprised how absolutely casual they are the whole time."