It might just be one of the most famous quotes of all time: "That’s one small step for man, one giant leap for mankind." These were the first words that Neil Armstrong said when he set foot on the Moon on July 21, 1969.
Or were they?
Armstrong himself has always said that he actually said "One small step for a man." Grammarians have long argued which one was more likely.
Try listening to the recording to see what you hear.
If we assume that Armstrong remembered correctly, it could be true. There are any number of things that could have interfered with the sound: the noisy radio link, the 250,000-mile distance, the excitement in his voice, or his accent.
It could also be how our brains perceive speech.
In 2006, some news stories found that the "a" was there, it was just hidden behind static. However, it largely remained debated amongst professionals.
Now, there is some intriguing new information.
In experiments published in PLOS ONE and The Conversation, the team analyzed not only the recordings from Armstrong, but also looked at the recording to Midwestern Accents. They found that speakers do have trouble detecting the accent on the "for" and "for a."
This means that whatever Armstrong said, it was probably indistinguishable. Many of use would still here "for" when he really said "for a."
Does it really matter?
Well, Armstrong passed away in 2012, so it doesn't matter either way to him.
Still, it says something about dialects and how we hear speech patterns.