Nothing on Snopes, but here's the Wikipedia entry:
wikipedia Wrote:
Evidence that cow tipping is an urban myth
There is no evidence, aside from mostly unreliable eyewitness reports, that any cows have ever been tipped in this manner. In addition, there are a number of problems with typical accounts of cow tipping. Unlike horses, cows do not 'lock their legs' when they sleep. Cows lie down while sleeping [1]. Most of their sleep is very light and easily disturbed — typical of herd prey animals; they take only short naps at regular intervals throughout a 24 hour period, which means that at any given time, some members of the herd are aware and alert. The vision field of a cow is larger than that of a human, and they have acute senses of hearing and smell. Thus, cows are not easy to sneak up on. If startled, they quickly communicate to the rest of the herd that something is amiss.
Cows are large, and would be very difficult to tip, even for several people working together. A grown cow can be over 1.5 m (5 feet) high with a mass on the order of 540 kg (1,200 lb) all the way up to 900 kg (2,000 lb). By way of comparison, a typical sumo wrestler masses only 140 kg (310 lb). The four corners of a large "American-style" domestic refrigerator fairly closely approximate the spread of a cow's legs. If the refrigerator were cut down to 1.5 m (5 feet), filled with 400 kg (880 lb) of weights, and placed in a muddy field, tipping it would offer a comparable challenge to tipping a cow.
Variants of the legend claim that successfully tipping a cow will result in its death. Although cows can die if prevented from sitting upright for an extended period of time, briefly forcing a cow onto its back will not kill it. Under typical circumstances, a cow knocked onto its back would be able to restore itself to an upright position.
Other versions of the cow tipping story attempt to evade these objections by claiming, for example, that although cows lie down to dream, they can still doze while standing. Others appeal to a paper published by the University of British Columbia's Zoological Physics department, which calculates that, in certain circumstances, five people could topple a cow. Such a situation, however, would be highly unlikely, meaning they effectively debunked it as an urban legend. [2]
Finally, attempting to tip a cow is a patently dangerous activity. Despite the animal's reputation for being placid and slow-moving, a cow is easily capable of hurting someone when provoked or nervous; a herd of cows or a bull (easily mistaken for a cow in the dark) would be even more dangerous.
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Possibility that cow tipping may be achievable
The Times (London) of 8 November 2005, contains two letters on the subject, including one that appears to describe a method by which the task might be achievable by three people. This follows some earlier discussions on the subject in The Times (see reference under External Links, below).
A reader in Hawaii wrote:
"Cow tipping is possible, it is very simple and I've done it. It requires three people (note: be very quiet, but sobriety may be a hindrance), one person on one side of the cow, two on the other. The lone person pushes very hard on his side, and waiting for the balancing response from the startled animal, the other two then push very hard on their side to overbalance her. Works like a charm."
Another reader, a post-doc at Cambridge, suggested one person could slam a cow down with a running start: "I have calculated that an 80kg (175lb) person would only need to run at the cow at about 18km/h (12mph) in order to tip it."