One small step for [a] man… revisited using Audacity
July 20, 2011 1 Comment
On the 42nd anniversary of the Apollo 11 Moon landing, I look at a couple of ways that the FOSS application Audacity has been used to study that amazing event, and marvel at the sheer audacity (pardon the pun) of the Apollo programme.
Some of you may remember the 2006 audio analysis of Neil Armstrong’s famous words as he stepped onto the Lunar surface for the first time on 21 July 1969, 42 years ago tomorrow (the Lunar module landed on the 20 July). The analysis, which supposedly proved that Armstrong did say “That’s one small step for a man, one giant leap for mankind.”, was performed using the Windows application GoldWave. You can read the following BBC article about the analysis: Armstrong ‘got Moon quote right’.
But Linux users can analyse the recording for themselves using, for example, Audacity. You might want to do it to celebrate the 42nd anniversary of that momentous occasion. You can download an MP3 file (a11a1091545-1101226.mp3) of the recording from the following NASA Web page: One Small Step.
If you haven’t already got Audacity installed, you can install it using your Linux distribution’s package manager.
In KDE, an Audacity icon subtitled Sound Editor will be installed under Kickoff > Applications > Multimedia. So launch Audacity, click on File > Open and open the MP3 file you downloaded from the NASA Web site. It’s quite a large file, so it will take a little while to load into Audacity. You can click on the Play button to listen to the whole file — which I recommend you do as it’s simply awe inspiring — but then you can zoom in on those famous words (notice the Zoom In and Zoom Out buttons in the top right corner, and the scroll left and right buttons at the bottom of the Audacity window?). If you want to select only the relevant section, then you can enter the Selection Start as 00 h 08 m 38.000 s and the Selection End as 00 h 08 m 46.500 s. Then when you click on the Play and Stop buttons Audacity will play only that section. Or perhaps you prefer to hear just “That’s one small step for (a) man”, in which case set the Selection End as 00 h 08 m 41.100 s. Notice the smaller Play-at-speed button and speed slider about mid-way across the top of the Audacity control panel? You can even slow down the playback speed if you want. Try it. Now zoom in to the range 08 m 39.750 s to 08 m 40.000 s.
Well, the NASA Web page I referred to above states:
At the time of the mission, the world heard Neil say “That’s one small step for man; one giant leap for mankind”. As Andrew Chaikin details in A Man on the Moon, after the mission, Neil said that he had intended to say ‘one small step for a man’ and believed that he had done so. However, he also agreed that the ‘a’ didn’t seem to be audible in the recordings. The important point is that the world had no problem understanding his meaning. However, over the decades, people interested in details of the mission – including your editor – have listened repeatedly to the recordings, without hearing any convincing evidence of the ‘a’. In 2006, with a great deal of attendant media attention, journalist/ entrepreneur Peter Shann Ford claimed to have located the ‘a’ in the waveform of Neil’s transmission. Subsequently, more rigorous analyses of the transmission were undertaken by a number of people, including some with professional experience with audio waveforms and, most importantly, audio spectrograms. As of October 2006, none of these analyses support Ford’s conclusion. The transcription used above honors Neil’s intent.
What do you think? I’m not convinced he said the “a”.
Another twist to the tale is a dispute about the originator of the famous line itself: Apollo 11 Moon Landing: British scientist claims to have coined Neil Armstrong’s ‘one small step’ line.
While we’re at it, newspaper reports for the 21 and 22 July 1969 make fascinating reading. For example you can read on-line the UK Daily Telegraph pages about the Apollo 11 Moon landing here: Moon landings: How the Daily Telegraph reported on Apollo 11.
Also, I was fascinated to read about the Italian high school class that used Audacity to analyse the time delay between Mission Control’s and Armstrong’s replies — you can hear the delays in the MP3 file — and calculated accurately the distance between the Earth and the Moon: Echoes from the Moon. Now that is one science class those school students won’t forget. What a fantastic idea by the school teacher.
A wonderful demonstration of the laws of physics, albeit not on the Apollo 11 mission, was performed on the Moon by the Apollo 15 astronaut David Scott: he dropped a hammer and a feather simultaneously. For those of you who aren’t engineers or scientists, or who don’t remember your school physics classes, take a look at practice proving theory correct in a fun way: The Apollo 15 Hammer-Feather Drop.
Did you know that more than 300,000 people worked on the Apollo programme, and it cost between 20 and 25 billion US dollars (1969 US dollars, which would be much more today taking into account inflation between 1969 and 2011)? It also cost several lives.
As I look up at the Moon in awe, and recall watching on a black-and-white TV set in 1969 as Armstrong climbed down the ladder of the Eagle, I think the Apollo programme was one of Mankind’s most amazing technological achievements, and perhaps the most amazing of them all. To think that the Lunar Module was controlled by a computer with far less processing power and memory than the smartphone that I hold in my hand today is astounding. No wonder the Apollo astronauts came back to Earth changed men. After their mission, everything else must have paled into insignificance.
This article is a refreshed version of a post I made in 2009 Sabayon Linux Forums on the 40th anniversary of the Apollo 11 Moon landing. I used Audacity again recently, this time to reduce the loudness of an event sound for Mozilla Thunderbird, and I thought it would be nice to celebrate again both the Apollo 11 landing and the usefulness of Audacity and the fun that can be had with it.