Voici un des rares (le seul à ma connaissance) article "scientifique" relatant du sujet (je me contente juste d'un cut and paste plutot qur d'en faire un pale résumé). En anglais mais tres drôle...
Which came first — the chicken or the egg?
The question has a reputation for being difficult, perhaps even impossible, to answer. Philosophers treat it as a conundrum. But in the hands of an experimental scientist, the question is simple and straightforward, and the answer is easily obtained.
I doubt that I am the first to solve the chicken-and-egg problem, but a search of the scientific literature turned up surprisingly few accounts — none, in fact — of previous work. Here, then, is an account of my work on what turns out to be a trivial question.
How the Problem was Solved
Which came first — the chicken of the egg? I tackled the question experimentally, using a chicken, an egg, and the United States Postal Service (USPS).
I mailed the chicken and the egg, each in its own separate packaging, and kept careful track of when each shipment was sent from a post office in Cambridge, Massachusetts, and when it subsequently arrived at its intended destination in New York City.
The Chicken
In mailing the chicken, I was careful to adhere to the restrictions described in the Postal Service’s Domestic Mail Manual [DMM] 57, as updated in Postal Bulletin [PB] 2209, April 3, 2003. (See Figure 1.) This, the most recent, version of the DMM states that:
"Adult chickens must be sent by Express Mail. The Express Mail containers used must pass the standards in International Safe Transit Association (ISTA) Test Procedure 1A (detailed in Publication 2, Packaging for Mailing); be designed to remain intact during normal handling; be constructed to totally confine the chickens; contain shavings or other material to prevent damage to the bottom of the container; and be ventilated properly to ensure humane treatment in transit. The number of birds in each parcel must not exceed the container manufacturer’s limit."
I mailed the chicken in a crate obtained from a colleague who does research with poultry at a midwestern university. Details are available on request, for anyone who wishes to replicate this experiment.
The Egg
I mailed the egg in standard packaging obtained through an industrial supplier. Details are available on request, for anyone who wishes to replicate this experiment.
Bon Voyage
I mailed both the chicken and the egg at 9:40 a.m., on a Monday morning, from the Harvard Square post office, in Cambridge. The staff there told me that this was the first chicken anyone had mailed from Harvard Square in recent memory, and perhaps ever. Nonetheless, the postal employees handled both the chicken and the egg deftly, with dispatch, and with courtesy.
The intended destination for both packages was the James A. Farley General Post Office, which is located in Manhattan right next to the Penn Station train terminal.
I took the subway from Harvard Square to the Boston train station, and from there boarded a train to New York City, a distance of approximately 200 miles, arriving that afternoon at Penn Station. I immediately went to the post office, to await the arrivals of the chicken and the egg.
Results
The James A. Farley General Post Office is open 24 hours a day, so I was able to wait there until both items arrived.
I inquired once per hour for both the chicken and the egg.
That day, Monday, neither the chicken nor the egg arrived.
The next day, Tuesday, neither the chicken nor the egg arrived.
The chicken arrived at 10:31 a.m. Wednesday. The staff at the post office told me that this was the first chicken anyone had mailed to the James A. Farley General Post Office in recent memory, and perhaps ever.
The egg arrived that same day, at 9:37 p.m., eleven hours after the chicken.
Conclusion
It has now been empirically determined that the chicken came first, the egg second.
However, seeing the history of previous questions that were taken up first by philosophers and only later by scientists, I am loath to predict that these results — clear as they are — will settle the question to everyone’s satisfaction.