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. :-)-- Basepair, Apr 05 2005 Cosmonaut Centripetal http://www.fonts.co...tail.asp?pid=401891Comrade [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] 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)-- Laimak, Apr 05 2005 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).-- Basepair, Apr 05 2005 [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?-- Basepair, Apr 05 2005 You mean circumputal force, surely? <snicker>-- Shz, Apr 05 2005 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.-- Basepair, Apr 05 2005 Cosmonaut Centripetal 18pt would be better (link)-- DenholmRicshaw, Apr 05 2005 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?-- FarmerJohn, Apr 06 2005 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.-- JesusHChrist, Apr 06 2005 Quite right. I have gotten into this arguement many times.-- DesertFox, Apr 06 2005 I would like to see your idea adopted by the powers-that-be, but unfortunately I don't have any pull.
For a completely confusing discussion of centrifugal force and general relativity, see link.-- robinism, Apr 06 2005 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.
*curls up in the centri-fetal position*-- moPuddin, Apr 06 2005 That's true too, [moPuddin]. Centripetal is the only force of the two I've found useful in calculations.-- Laimak, Apr 06 2005 Centrifetal = the middle triplet.-- 2 fries shy of a happy meal, Apr 06 2005 //I propose "centripugal" (or, perhaps, "centrifetal") //Yet you've named the idea "Centriputal Force".-- angel, Apr 06 2005 How about we just stop talking about spinning things entirely, and then this won't come up? On second thought...-- krelnik, Apr 06 2005 [Angel] - Ah, thanks for spotting that one, error amended. One day I'll try doing all this sober.
[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.-- Basepair, Apr 06 2005 [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.-- Basepair, Apr 06 2005 Ah, one of my pet peeves . . . another good one from [Basepair].
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".
"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.
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".
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.
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.-- baconbrain, Apr 06 2005 <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>.
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!-- Basepair, Apr 06 2005 Centrifugal just sounds so much happier than "Lateral acceleration from a centripetal force causing deviation from linear movement".
*Pets the centri-Pug dog*-- moPuddin, Apr 07 2005 Psuentrifle force?-- reensure, Apr 07 2005 basepair, jutta is "the powers that be"
You didn't know?-- DesertFox, Apr 08 2005 [DesertFox] //basepair, ----- is "the powers that be"// He spoke the name, he spoke the name!! -- Basepair, Apr 08 2005 Stone him! Stone him!
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.
"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.
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".
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.-- baconbrain, Apr 08 2005 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.-- EvilPickels, Apr 08 2005 "the wheels on a turning car"
Okay, I said it. Now what happens?-- baconbrain, Apr 08 2005 [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!
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?-- Basepair, Apr 08 2005 [+] here here!! hear, hear?-- xandram, Dec 20 2010 Centripedal? gametrick.net/Centripede.htm-- sqeaketh the wheel, Dec 20 2010 People who object to "centrifugal force" don't deserve the honorable title of pedant.-- mouseposture, Dec 21 2010 There are two uses of the term 'centrifugal force'.
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.
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).-- spidermother, Dec 21 2010 Yeah, but, like, they're both centripugal, isn't it?-- MaxwellBuchanan, Dec 21 2010 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.
[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.-- baconbrain, Dec 23 2010 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...-- MaxwellBuchanan, Dec 23 2010 Was re-reading this one and thought of XKCD's take on a similar attempt to end the confusion.-- AusCan531, Sep 11 2013 random, halfbakery