Nature's Nifty Movers; ANSWERS TO CORRESPONDENTS
Byline: Compiled by Charles Legge
QUESTION Does any animal have a faster moving body-part than the hummingbird' swing?
THE maximum wing beat recorded for a bird is for the Horned Sungem (Heliacatin bilophus), a South American hummingbird, at 90 beats per second. Similar rates have been claimed for the Amethyst Woodstar (Calliphlox amethystina), another hummingbird from South America, and several other members of the family have been recorded at 70-80 beats a second.
There have been claims for wing beats of up to 2,000 beats a second during the courtship flights of ruby-throated hummingbirds and rufuous hummingbirds. These relate to the narrow tips of the primary feathers only and not for the complete wing.
However, all this pales by comparison with certain members of the insect world, particularly various species of midge. In the Fifties and Sixties the Polish researcher, O. Sotavalta, painstakingly analysed the wing beat frequencies of various insects using a beat-frequency oscillator as well as personal auditory analysis (Sotavalta had perfect pitch).
He found that certain species of midge Chironomous (Diptera: Chironomidae) had a wing beat frequency between 650-700 Hz (cycles/sec), and that one member of the biting-midge genus Forcipomyia (Diptera: Ceratopognidae) achieved a wing beat frequency of 1046 Hz, an extraordinary 62,760 beats a minute.
Dr Ian Smith, Cambridge.
THE fastest single movement in biology is thought to be the predatory strike of the trap ant Odontomachus bauri, an ant native to Central and South America.
This ant can snap its mandibles shut at speeds of up to 64 metres per second, about 145 miles per hour. The average duration of a strike is a mere 0.00013 seconds, 2,300 times faster than the blink of an eye. The jaws accelerate at 100,000 times the force of gravity, with each jaw generating forces exceeding 300 times the insect's body weight.
Muscles alone cannot generate this speed; some type of spring loaded mechanism with a trigger is needed. The mandibles are cocked by a pair of huge, contracting muscles in the head. These are sprung when their corresponding latches, each on a shield-like plate called the clypeus, are triggered.
The action is also used as an escape mechanism. The ants can snap their jaws against the ground and rapidly propel themselves about 40cm away.
Mrs J. E. Overton, Pirton, Herts.
QUESTION Is Karl Marx's famous quotation: 'Religion is the opium of the people' in fact a misquote?
GERMAN philosopher, sociologist, economic historian and revolutionary socialist Karl Heinrich Marx (1818-1883) developed the socio-political theory of Marxism, the ideological basis of communism.
This supposed quote is, at best, a crude paraphrasing of what Marx had to say about the function of religion, which was more nuanced and sympathetic.
The complete quote is taken from the introduction of his 1843 work Contribution To Critique Of Hegel's Philosophy Of Right:
'Religion is, indeed, the self-consciousness and self-esteem of man who has either not yet won through to himself, or has already lost himself again. But man is no abstract being squatting outside the world. Man is the world of man -- state, society.
'This state and this society produce religion, which is an inverted consciousness of the world, because they are an inverted world. Religion is the general theory of this world, its encyclopaedic compendium, its logic in popular form, its spiritual point d'honneur, its enthusiasm, its moral sanction, its solemn complement, and its universal basis of consolation and justification. It is the fantastic realisation of the human essence since the human essence has not acquired any true reality.
'The struggle against religion is, therefore, indirectly the struggle against that world whose spiritual aroma is religion. Religious suffering is, at one and the same time, the expression of real suffering and a protest against real suffering. …