h a l f b a k e r yPoint of hors d'oevre
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OK, I admit from the outset that this is a
suggestion for a 'naming convention',
and
probably against HB rules. But bear with
me for a moment and I'll delete if there's
an outcry.
Every time anyone (especially at HB)
mentions "centrifugal force" or
"centripetal
force" there is an
outcry about whether
they really mean centripetal or
centrifugal.
Either that, or they pre-emptively excuse
themselves for using "centrifugal".
The argument is largely semantic - it's
like
the argument over whether it's the dog
or
the owner who's tugging on the leash.
The force (visualised for simplicity as the
tension in a string when you swing a
weight in a circle) arises because the
spinning weight wants to keep going in
straight line, and the string doesn't want
to let it. Hence, a tension which acts
radially. Whether you say that the string
exerts a centripetal force on the weight
or
the weight exerts a centrifugal force on
the string is (in most contexts) irrelevant.
So, I propose "centripugal" (or, perhaps,
"centrifetal") as a term to stop these
semantic arguments, at least here on HB.
The centripugal force is the force acting
between a point on a spinning thing and
the centre as a result of the spinnng, end
of argument and we can all get on.
There. Now, if what we need is a
tangible
'invention', then I propose "A physical
embodiment of a device for avoiding
arguments", consisting of a bronze
plaque
with LEDs, on which the aforementioned
definition is inscribed in Helvetica 18pt.
:-)
Cosmonaut Centripetal
http://www.fonts.co...tail.asp?pid=401891
Comrade [DenholmRicshaw, Apr 05 2005]
C_________l Force
http://www.warren-w...050204CentfIcicles/
Who would want to argue after seeing this in the morning? [Giblet, Apr 06 2005]
Centrifugal force, GR, and inertial frames of reference
http://www.physicsf...trifugal_force.html
[robinism, Apr 06 2005]
Great, it is centrifugal, centripetal or centripugal?
http://xkcd.com/927/
XKCD Standards [AusCan531, Sep 11 2013]
[link]
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What's the problem? it's quite simple: centripetal force acts towards the center of rotation, while centrifugal is the opposite. They are two definitively different beasts though. (IE. Not the same force) |
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I was looking over various HB annos
when I thought of this. In many cases,
the argument over centripetal/
centrifugal seems to be exactly
equivalent to the argument over
whether the tension in a pulled string is
acting in one direction or the other (it's
a tension, and hence the semantics are
irrelevant in *most* - not all -
contexts). |
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[Laimak] Also, I'd disagree that
centriugal and centripetal force are
"different beasts". If I'm spinning a
weight on a string, they are two sides of
the same coin, equal in magnitude and
opposite in direction (just as, if I pull
two ends of string, the forces on the
ends are equal and opposite). If the
string breaks, both forces vanish and
the weight carries on at a tangent to the
circle. Can one have centrifugal force
without an equal-in-magnitude
centripetal force? |
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You mean circumputal force, surely? <snicker> |
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Actually, I thought "that weird going-
in-circles force" would be a good
alternative too. In most contexts it
would work just fine and would prevent
the arguments. As in "the rotors have
to
be carbon-fibre to avoid breaking due
to that weird going-round-in-circles-
force" etc. |
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Cosmonaut Centripetal 18pt would be better (link) |
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So what are we gonna call an apparatus consisting essentially of a compartment spun about a central axis to separate contained materials of different specific gravities, or to separate colloidal particles suspended in a liquid, or an apparatus in which humans or animals are enclosed and which is revolved to simulate the effects of acceleration in a spacecraft? |
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Centripuge?
Isn't this the same thing the Theory of Everything guys are
trying to figure out? One side thinks everything is push
and the other side thinks everything is pull. Maybe they
should call it quavity or gruantum dynamics. |
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Quite right. I have gotten into this arguement many times. |
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I would like to see your idea adopted by the powers-that-be, but unfortunately I don't have any pull. |
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For a completely confusing discussion of centrifugal force and general relativity, see link. |
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Some argue that "centrifugal" is a made-up name to describe a set of physical forces and actions, unlike centripetal, which is in fact a mechanical force. |
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*curls up in the centri-fetal position* |
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That's true too, [moPuddin]. Centripetal is the only force of the two I've found useful in calculations. |
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Centrifetal = the middle triplet. |
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//I propose "centripugal" (or, perhaps, "centrifetal") //
Yet you've named the idea "Centriputal Force". |
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How about we just stop talking about spinning things entirely, and then this won't come up? On second thought... |
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[Angel] - Ah, thanks for spotting that
one, error amended. One day I'll try
doing all this sober. |
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[moPuddin] - I think you're right, a
centripetal force is required to
overcome the momentum of the
spinning thing and stop it hurtling off in
a straight line. However, from the
perspective of the spinning system, this
force is opposed by the 'centrifugal'
force. I think. Blimey, it's always the
simple things that confuse me. |
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[robinism] Who *are* the powers that
be? I suspect it's never been officially
decided - why don't we (HBers en
masse) simply declare ourselves to be
Powers that Be. Being is one of the
things I do best. |
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Ah, one of my pet peeves . . . another good one from [Basepair]. |
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I say stick to the old-fashioned term "centrifugal" for the apparent going-away-from-center, as that is exactly what the elements of the word mean--"center-from-al" (I don't know the Latin roots, or even if they are Latin, but I know a "febrifuge" makes fever go away.) I have taken to saying "centrifugal inertia" as is done in the build-yer-own-UFO sites. They may be crazy, but they realize it is almost always inertia that folks refer to when talking about "centrifugal force". |
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"Centripetal" is a much more obscure term, but I take it to mean "toward the center". There is seldom a need to think of it as a "force" as it is always developed by a mechanical object, such as a string under tension. Sometimes it's gravity or magnetism. |
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I've seen a big rant by an alleged physicist who argues that an orbiting object is only acted on by gravity--he entirely forgets about inertia. So this is not a simple issue. Like I said, call it "centrifugal inertia" and forget the word "centrepital". |
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Tension sheet: In a bicycle wheel, the spokes are under tension, and the wheel rim is compressed slightly. From the hub's point of view, the tension is directed away-from-center; from the rim's point of view, the tension is toward-the-center.
It is all about points-of-view, and about semantics--the fact that "centrifugal" starts with "centr-" implies a central viewpoint. |
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Sorry, [Basepair] I have to go against your new words. But thanks for trying to clear things up--I'm writing up an idea that will require a clear understanding of centrifugal inertia. |
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<central pivot arguing with recently-
spinning weight over who broke the
string>"It was you and your damned
centrifugal inertia" "Bloody wasn't - if it
wasn't for your centripetal force the
string never woulda broke"</
cpawrswowbts>. |
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You're right, [bacon]. But I still think
that "centripugal" would be a nice fuzzy
term that would make life easier for
many when the distinction between
centripetal, centrifugal inertia and such
isn't essential to the argument. I'll bet
your idea, when posted, launches
another argument over centrithingy
semantics! |
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Centrifugal just sounds so much happier than "Lateral acceleration from a centripetal force causing deviation from linear movement". |
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*Pets the centri-Pug dog* |
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basepair, jutta is "the powers that be" |
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[DesertFox] //basepair, ----- is "the
powers that be"//
He spoke the
name, he spoke the name!!
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Actually, the name that was written is a substitute for the real name of the controller of the Halfbakery, a name that could only be written in Font-of-Gold, with which my computer is not equipped. |
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"Centrifugal Force", as [moPuddin] points out above, is, as [Basepair] asks for, a nice fuzzy term that substitutes for that which a physicist cannot describe without a blackboard and a degree in Greek symbols.
It's just that lately some pedants have noticed that "force" is included in the term, and "force" has a certain meaning to a physicist/pedant. Aren't there only four forces in physics? Gravity, magnetism, weak nuclear and strong coffee, or something like that?
My dictionary defines inertia as "a property of matter", and turns the page really fast. Centrifugal inertia is not what a physicist would call a force, and can only be produced by some force acting centripetally.
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The whole controversy is silly, and caused by pedants, psuedo-pedants and pretenders. I say we stick them all in a centrifuge, smash them against the walls with centrifugal force, and not let them out until they can convince the universe that there is no such thing as "centrifugal force". |
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I also say this is a perfectly appropriate topic for the Halfbakery (All praise to J_tt_!). We could move it over to a category for "Halfbakery/defining terms" if needed. We need to be able to understand each other when we start writing about parabolic pool tables and half the rest of the ideas around here. |
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Centrifugal force is the force carrying the object in circular motion outwards, centripetal is the force carrying the object inwards. Say the wheels on a turning car. |
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"the wheels on a turning car" |
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Okay, I said it. Now what happens? |
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[Bacon] support appreciated. HOwever,
I'm against the centrifuging-pedants
idea. Partly because I kinda have soft-
spot for pedants (oddly) and partly
because you should never put anything
unbalanced in a centrifuge.
[EvilPickels] No, centrifugal force is the
apparent force which when referenced
from a point on the spinning surface
appears to act radially outwards in such
a way as to.....AARGH!! This was how we
got into this argument in the first place! |
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How about an "Other/
pedantry" category where I can go and
mutter about centripugal forces,
Bernoullimobiles and all this other stuff
without worrying real folk? |
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[+] here here!!
hear, hear? |
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Centripedal?
gametrick.net/Centripede.htm |
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People who object to "centrifugal force" don't deserve the
honorable title of pedant. |
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There are two uses of the term 'centrifugal force'. |
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1) Reactive centrifugal force. This is the one that seems to be being discussed here, and is the simple equal-and-opposite Newtonian reaction to centripetal force. In this case it is probably mostly better to use the term 'centripetal', since it's more intuitive and useful to think of the force as causing the rotation, rather than the other way around. |
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2) Fictional centrifugal force. This is one of the apparent forces experienced by components of a non-inertial (e.g. rotating) reference frame. In this instance, centrifugal is the correct term, and it would be confusing and silly to insist on the use of 'centripetal'. (It is called a 'fictional' force because it is only useful when modelling the system in a rotating reference frame; if the same system is viewed in a non-rotating reference frame, it, like the Coriolis force, becomes meaningless). |
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Yeah, but, like, they're both centripugal, isn't it? |
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I focus in on the "pug" syllable and think of it as symbolizing fighting, just so I can keep the meaning the way I want it. |
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[Basepair] was a genius, and entertaining, too. This is one of the few of his ideas that I could not whole-heartedly support, mostly because I get so snarly about the misuse of "centripetal" by other people. This was a good idea, though. So, a bun for the old boy. May his "ghost" haunt the HB forever. |
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Perhaps [Basepair], [Ubie] and [Beanie] have clubbed
together to buy a remote tropical island, and are even now
preparing to fire up a Nuclear Custard Trebuchet of
unforeprecendented power... |
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Was re-reading this one and thought of XKCD's take on a similar attempt to end the confusion. |
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