Talk:Bob (physics): Difference between revisions
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--> My (elementary) OR also shows that [[plumb bob]]s (under whatever name) are believed to have been in use for at least 4,269 years longer than pendulum clocks, so it would be surprising coincidence if the term ''bob'' started being applied to plumb bobs, in English, as late as multiple centuries after ''bob''<nowiki>'</nowiki>s hanging-mass sense became a logical step. (In fact, [[James Thurber#look it up|You could look it up]]: [[Oxford English Dictionary]] will provide you first-known published uses of each sense, in context, each with its date.)<br>--[[User:Jerzy|Jerzy]]•[[User talk:Jerzy|t]] 05:37, 20 July 2010 (UTC)<br> |
--> My (elementary) OR also shows that [[plumb bob]]s (under whatever name) are believed to have been in use for at least 4,269 years longer than pendulum clocks, so it would be surprising coincidence if the term ''bob'' started being applied to plumb bobs, in English, as late as multiple centuries after ''bob''<nowiki>'</nowiki>s hanging-mass sense became a logical step. (In fact, [[James Thurber#look it up|You could look it up]]: [[Oxford English Dictionary]] will provide you first-known published uses of each sense, in context, each with its date.)<br>--[[User:Jerzy|Jerzy]]•[[User talk:Jerzy|t]] 05:37, 20 July 2010 (UTC)<br> |
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== mass vs escapement power == |
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Quote from the Article: |
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On the other hand, the heavier the bob is the more energy must be supplied by the clock's power source and more friction and wear occurs in the clock's movement. |
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Why should the mass matter to the power needed to keep in motion in steady state? Pivot friction is small, it says earlier: |
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Since most of the energy loss in clocks is due to air friction of the pendulum... |
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according to me the cited sentence should be changed |
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Etymology
I removed this irresponsible folk-etymology:
== Origin of the term == The term 'bob' may have originated just after the pendulum clock was invented in 1657. Early verge clock pendulums were short and had very wide swings of 80° or more. They were often mounted on the back of clock cases, and when running the weight appeared to 'bob' out from behind the case on each side. These became known as bob pendulums.<ref>Britten, Frederick J. (1894). Former Clock and Watchmakers and their Work. London: E.& F.N. Spon., p.170</ref> Possibly the term spread to all pendulum weights.
which -- besides being excludable simply as our contributor's OR -- clearly reflects the relaxed scholarship of both the cited author and our contributor, each having felt no need for an essential step (whether or not each omitted the same step).
Anyone who writes peripherally on etymology must recognize it as a science unto itself, practiced by linguists on the basis of exhaustive surveys of old texts and sophisticated science that elaborates on the example of Grimm's law. Contributor and author each should have taken the elementary steps of
- looking in any good dictionary for the accepted knowledge on the matter, and
- -- finding, as they did or would have, that accepted knowledge ignores what i'll call the bobbing pendulum theory -- either backing down or mentioning favorably the more authoritative account.
The established knowledge on the matter is that Middle English (thru about 1470) had both a noun bobbe, whose derivatives cluster around "bunch" (e.g., of fruit, flowers, hair, yarn, etc.), and a verb boben or bobben, whose derivatives cluster around limited motion (one of my three favorite dictionaries puts it "up and down motion", and says its origin is "probably expressive" -- IMORO sharing the feel of "bop", "bubble", "bump", "boink", and maybe "bounce"). And their etymological grouping puts the suspended-weight senses with the bobtail senses, not the bobber senses.
My (elementary) OR also shows that plumb bobs (under whatever name) are believed to have been in use for at least 4,269 years longer than pendulum clocks, so it would be surprising coincidence if the term bob started being applied to plumb bobs, in English, as late as multiple centuries after bob's hanging-mass sense became a logical step. (In fact, You could look it up: Oxford English Dictionary will provide you first-known published uses of each sense, in context, each with its date.)
--Jerzy•t 05:37, 20 July 2010 (UTC)
mass vs escapement power
Quote from the Article: On the other hand, the heavier the bob is the more energy must be supplied by the clock's power source and more friction and wear occurs in the clock's movement.
Why should the mass matter to the power needed to keep in motion in steady state? Pivot friction is small, it says earlier: Since most of the energy loss in clocks is due to air friction of the pendulum...
according to me the cited sentence should be changed