But a scared cat would just beat the American to the tape; a kangaroo would leave him for dead, and a cheetah - capable of speeds of up to 65mph - would be lounging in the mixed zone by the time he crossed the line. Assuming the cheetah had nowhere better to go.
Fit human beings can run at a speed approaching 27mph and, at the highest level of athletic excellence, the difference between competitors is measured in blinks of an eye. Those are the facts. So why is the continuing question of who is the fastest human on the planet such a compelling one?
It is probably no coincidence that the earliest known athlete was a sprinter, Coreobus, Olympic winner in 776BC. The sprint was the big race of the ancient Olympics, in the form of a stade, a 192-metre run along the stadium's length.
The enduring fascination which the sprint holds for the watching world was evident in Lausanne's Stade de la Pontaise on Friday as the fastest men of the moment, Greene, his training partner, Ato Boldon, and Frankie Fredericks went to their marks.
One shaft of evening sunlight caught the rim of a stand over which flags hung motionless. The heat of the day remained in the stadium, where the runners faced a stretch of track renowned for its encouraging composition.
From somewhere high in the press box there came the sound of a radio reporter jabbering a running commentary. But that served only to emphasise the silence of the other 13,000 souls present. It was the hush of expectation that only seems to come before a big 100m race.
On this occasion, Greene proved not to be in sufficient shape to better the mark of 9.79sec he set in Athens last month. It fell to Boldon to win the race in 9.86sec.
Five years ago Boldon would have been celebrating equalling the world record. But in that space of time the prime athletics statistic has been reduced successively by Leroy Burrell, who ran 9.85 on the same track in 1994, Donovan Bailey, who won the 1996 Olympic title in 9.84, and most dramatically, Greene.
By small or, in Greene's case, large degrees, human beings are moving closer to optimum speed. Logically there has to be an optimum. But you will not get any sprinter, least of all Greene, to admit that. "Once you have achieved one goal, what motivates you is the next one," said the man known as the Kansas Cannonball, who plans to run 9.76 by the season's end.
John Smith, who has coached Greene, Boldon and a number of other elite athletes to the very top of their fields in recent years, echoes Greene's open-minded attitude. "I don't think a limit exists," Smith says. "I prefer to settle on objectives and advance little by little."
He points out that Greene had nothing by way of wind assistance in Athens - the record showed a minimal rating of 0.1m per second, well below the legally acceptable limit of 2m per second. "You can reckon that a metre of wind speed per second can make a difference of 0.08sec," Smith said. "Make the calculation: 9.79sec less 0.16 is equal to around 9.63..."
Dr Craig Sharp, an expert in exercise physiology, believes that the limits of human potential are not likely to be reached in the sprint for the next 50 years.
"I believe that 9.5sec is achievable," he says. "Below 9sec we shall see. But I doubt if that is a barrier that will ever be broken."
Whether or not Greene succeeds in his ambition of moving closer towards a final barrier, his efforts to do so will be followed with the utmost interest.
Because this is an event that grabs everybody, even those who do not follow the sport. It stirs up all our most basic instincts because it involves more than mere flight but flight and fight combined.
The race of the swiftest is essentially a battle for the winner; it is not just a case of saying "I'm the fastest" but "I'm the fastest - and you're not".
Who can forget the scornful gesture Ben Johnson made as he crossed the line at the 1988 Olympics in a time of 9.79sec - one finger held up to the sky, turning inside to register the gap between himself and those who laboured in his wake?
Within 48 hours Johnson's performance was infamously discredited by the emergence of his doping abuse. But his reaction at the line was, and remains, 100 per cent genuine.
The 100m is the edgiest of sporting events, a sustained adrenaline surge requiring channelled aggression from the gun to the line.
"It is concentration," says Ron Roddan, who coached Linford Christie to Olympic and world titles. "Sprinters must never be distracted; a distraction blows them to pieces. The race is so short, they cannot afford for anything to go wrong."
Yet, paradoxically, an event that appears so brutally short to the outsider feels different on the inside. "The 100m dash lasts about 10 seconds, but it seems like 10 years," says America's multi-Olympic champion Carl Lewis. "So much is happening - strategy, thinking, small adjustments - that the race seems slow." When Linford Christie was racing, his mind was set on technical aspects such as keeping his hips in the right alignment and remembering to maintain his speed right the way through the line.
Smith recalls that the first thing he did when Greene sought his assistance two years ago was to give him a new outlook on the event. "He only had a very general vision of the course," Smith said. "I got him to break his 100m into different sections."
Smith's next project is to work out how Greene can maintain the acceleration for up to 70m, rather than the current 60m. "I have to work on another 10m," Smith said.
In terms of general approach, Smith sums up the demands on a sprinter as follows: "You have to float like a butterfly, all the while possessing the mentality of an enraged bull."
He likens the balancing act to that of a dancer, pointing out that Barychnikov could lift 200 kilos. Maurice Greene as Barychnikov: perhaps; perhaps not...
Whatever the disciplines concerned in top-class 100m running, there is no question that it pays. Greene's asking price for appearances is now at least $100,000 (pounds 600,000) per meeting. His is a level to which the rest of the world's sprinters - including the emerging group of young Britons - must aspire.
Like a team of cyclists in the main peloton, Jason Gardener, who became the second fastest European after Christie with his 9.98sec run in Lausanne, European Champion Darren Campbell and Dwain Chambers, who has also broken the 10 second barrier this season, are effectively working together to catch the event's leaders.
Greene is far away over the horizon, but the chase is on.Reuse content