Apollo 16 unexpected sounds?

[mako88sb]

Somebody brought this up today:

"NOTHING outside of the suits could be heard... Ahem... EXCEPT on Apollo 16 where apparently sound defied the rules of science and you hear them hammering with tools and such. At one point, Astronaut Charlie Duke tosses a cable 15 feet away from him, it hits the LM and YOU HEAR IT!!!  The LM was not mic'd, in fact it was powered down. So HOW, did this outside sound travel through zero atmosphere and was heard?"

I thought I remembered some discussion here about why you would hear the hammering sounds. I can't seem to find it now. Something with vibrations being transmitted through the hammer to the astronaut I believe? Not sure about the cable hitting the LM and being heard? I know they had a video camera inside the LM during the landing and I'm assuming it was kept on while Young and Duke were on their eva's? I haven't had a chance to find that particular moment on the eva videos so not even sure if it really happened.

[raven]

Ask them to provide the video in question. That will help narrow it down, hopefully.

[bknight]

I have seen some of these videos.
AS15 

and

There was another that I can't find that had a piece of equipment hitting the LM and making a sound, but I can't locate it.

[JayUtah]

LM was mic'ed; it had a cabin recorder.  It was not "powered down" in the least; it was the relay for the suit circuit.  The suits used a sort of daisy-chained VHF circuit which was picked up by the VHF antennas on the LM and upconverted to the S-band to Earth.  Outside the range of the LM, the LRV played the role of VHF-USB relay.

[mako88sb]

LM was mic'ed; it had a cabin recorder.  It was not "powered down" in the least; it was the relay for the suit circuit.  The suits used a sort of daisy-chained VHF circuit which was picked up by the VHF antennas on the LM and upconverted to the S-band to Earth.  Outside the range of the LM, the LRV played the role of VHF-USB relay.

Thanks Jay. I suspected something along those lines but it's great to hear specific details. Hope you don't mind if I quote you for my response. I don't think the guy actually believes the landings were hoaxed . Just curious about something he thought odd.

[bknight]

LM was mic'ed; it had a cabin recorder.  It was not "powered down" in the least; it was the relay for the suit circuit.  The suits used a sort of daisy-chained VHF circuit which was picked up by the VHF antennas on the LM and upconverted to the S-band to Earth.  Outside the range of the LM, the LRV played the role of VHF-USB relay.

I rather suspected the sound of Jim Irwin throwing something against the LM and making a sound, picking up vibrations in skin in an open mike on board.

[ka9q]

LM was mic'ed; it had a cabin recorder.  It was not "powered down" in the least; it was the relay for the suit circuit.  The suits used a sort of daisy-chained VHF circuit which was picked up by the VHF antennas on the LM and upconverted to the S-band to Earth.  Outside the range of the LM, the LRV played the role of VHF-USB relay.

I don't think this is fully correct. While the LM did act as a relay (unless the LRV performed that function) I don't think there were any microphones other than those on the astronauts.

Electronics are sometimes sensitive to mechanical vibration, a phenomenon naturally known as "microphonics" that is especially common with vacuum tubes used as low-level audio amplifiers, but I'll have to watch the video in question.

[ka9q]

OK, I've watched those two clips of the Apollo 15 core tube being hammered.

The sound is obviously traveling up his arm. It could easily have been conducted through the hammer to his hand, through the glove and then to the air inside the suit before reaching his microphone. It's never particularly loud or consistent.

The video that brushes off conduction doesn't seem to consider this possibility. It also shows an old Mr.Wizard-like demonstration of a bell in a bell jar, but note that the bell is hanging by very thin wires precisely to minimize sound conduction. Over the past couple of weeks I've seen similar demonstrations in two science museums (London Science Museum and Palais de la Découverte in Paris). In both cases some residual sound was still audible due to conduction through the mounting of the bell and/or the solenoid striking it.

[raven]

Oh, so many problems with this claim. I mean, good grief, even some conspiracy theorists claim it was filmed in a vacuum  to try and account for evidence of such even they can not deny. Also, given that the astronauts have their gold visors down over 90% of the time, it would be the easiest thing in the world to dub in silence and a retake of the 'line' if something like this happened 'on set'. It's not like they have to worry about lipflap synching, and the sound quality of the mics is low.

[bknight]

I didn't find the video, but here is a forum discussing what happened in the video.  Jim Irwin threw "something" at the lander and a distinct noise was heard.  I thought it was vibrations going into a microphone on board.  Anyway here is the link.  The producer of the video was filminco very possibly.
http://forum.moonzoo.org/index.php?topic=4199.15 

[ka9q]

I just deleted a message I posted theorizing that the sound was that of the LCRU being acquired on the ground. The LCRU appears to be turned on sometime later than I thought. I'm still investigating.

[bknight]

After reading all the way through the form I linked, I found the original video in the ALSJ
http://www.hq.nasa.gov/alsj/a15/a15v.1205113.rm
It is has a real media format and I don't know anything about conversion to a YT, but here it is.  Look around 1:45 for the thrown object.

[Allan F]

You can upload it as it is.

[bknight]

Thanks, but I'll probably not do that with this video.  That is unless we come to a conclusion as to what the noise is and how it is generated.  Since the mission occurred then there must be an explanation for why/how the noise is generated.

[Allan F]

The only open microphones were in the spacesuits, so it has to be from one of the astronauts - his suit.