Acme

I don't feel good. ~ Luther Burbank

Arizona has agates as well. Take you rocks to the nearest university geology dept. and they'll be happy to help you. Or try this site for at-home ID. >> http://rockhounds.com/rockshop/rockkey/index.html

Damn why don't the quote button work? Not to mention I can't paste a copy of his post. :rant: No matter. Replying to Moontanman asking about carrying his shotgun.

In my state of Washington you can "open carry" any legal firearm down the street. Some restrictions apply to schools and such and private businesses set their own rules. Starbucks made a point of allowing openly carried guns until gun toters started making a regular habit of showing up en masse up to show they gunnage. What could possibly go wrong? (To be sure I'm not aware of anything actually going wrong.) I suspect all the swaggerin' is on account of havin' a little dink. Good luck with all that.

I'm having trouble with the Quote and Linking functions, but 2^nd photo looks like agate. Agate is a type of chalcedony and green chalcedony may be called chrysoprase. Search the underlined terms at Wikipedia. Hope that helps rockgirl.

...

And I don't care who says otherwise, even if it's on the BBC, if the energy isn't there- it doesn't happen.

Direct evaporation by shorter wavelength IR or visible light is possible- but that's not the range these guys are talking about.

My bad. I thought the theme was to be objective. Carry on then.

The bolded & underlined sentence, whoever said it, is false.

 

PROF GRAHAM FARQUHAR: There is a paradox here about the fact that the pan evaporation rate's going down, an apparent paradox, but the global temperature's going up.

NARRATOR: This was a puzzle. Most scientists reasoned that like a pan on the stove, turning up the global temperature should increase the rate at which water evaporated. But Roderick and Farquhar did some calculations and worked out that temperature was not the most important factor in pan evaporation.

DR MICHAEL RODERICK: Well it turns out in fact that the key things for pan evaporation are the sunlight, the humidity and the wind. But really the sunlight is a really dominant term there.

NARRATOR: They found that it was the energy of the photons hitting the surface, the actual sunlight, that kicks the water molecules out of the pan and into the atmosphere. And so they too reached an extraordinary conclusion.

Source: Global Dimming Program Transcript

I'm simply trying to find the factors that affect the coefficient of lift

I simply gave them. Good luck.

 

Acme, this is well understood and we all agree this is what happens when an ice mass is removed from a land mass. But this debate right now is about the claim that iNow made by posting;

 

OK. I was responding to the title and I'm only interested in the science and not the squabbling. Science is always amendable and if you have amendments worthy of publication, submit them to publishers. Best of luck.

I changed my mind. And It doesn't go into much detail.

Ok. You still haven't made it clear what the issue is for you? Are you trying to solve/find a specific coefficient of lift for a specific airfoil? Are you trying to find fault and/or discredit the 'standard' use of the term 'coefficient of lift'? Propose changes? What is the problem?

It actually didn't help at all. And I mean factors as in different things that affect it.

But you said it didn't help much? Were you mistaken? Confused? Changing your mind? Purposefully posting contradictory statements?

Again, the link I gave goes into great detail about the 'things' that affect the coefficient of lift. Do you think those 'things' are wrong? Do you think there are other 'things' needed to determine coefficient of lift? I honestly do not understand the difficulty you are having. Perhaps you have some specific example in mind for which the source I gave is inadequate. If so, please give it so I can understand the issue.

 

I am making a 2d grid out of a single array and need to access locations around a given index. The array represents a 2d grid, where the array spirals out from an origin location (index 0). The reason for the spiral is to allow my 2d grid to grow large in all directions.

How do I calculate the indices of the locations to the right, left, above and below the given index location?

Here is an image to help:

 

You represent a modified/generalized version of the Prime specific Ulam Spiral. When the origin is 1 rather than 0, cells can be indexed using specific forms of the generalized equation 4n² +bn + c.

It doesn't help very much. I wanted a list of factors.

So then it helped some. In what specifics was it helpful? Also, define factors as you intend the term please. I fail to understand your distinction.

The article in the OP incorrectly says the Hindenburg frame was balsa wood. d'oh! Fire and gas choice aside, the 400 foot full-scale vehicle proposed is just not going to play well in wind. No matter the engine configurations or [computer] controls such a large structure is going to be slow to react to control efforts. I expect it will/would sooner than later experience forces that cause loss of control resulting in a crash or cause structural failure also resulting in a crash.

While the Hindenburg is the most often cited dirigible disaster, the US Navy's helium buoyed Akron & Macon suffered catastrophic failures.

I don't mean based on the lift force. I mean the factors that affect the coefficient of lift itself

I don't understand your equivocation. The entire article at the link goes further into the mathematical constraints/techniques at play, and if that doesn't help you then it doesn't help you.

Thanks for fixing the equation.

 

I guess there isn't really anything special about it. I just found it interesting.

As to what it is called as your title asks, it is called a sequence just as you used the term yourself. I find sequences interesting as well and some sequences, such as the sequence of Primes, are Very Special. It is up to the individual mathematician to set forward such conditions and characteristics of a given sequence that demonstrate how and/or why it is deserves to be called Special.

I think it is a mistake to associate ocean research in a comparative manner to NASA or any other research field. It should be enough to focus on the merits of ocean research alone, especially if the goal is to convince lawmakers to spend more. Negatively portraying other research that some lawmakers favor/champion will lose them as an audience and lose their vote in the bargain.

_{English Rhotacism: traditional dialect,speech disorder,linguistic phenomenon}

I am a retired (Australian) English lecturer with an Ma (Hons) in Literature & Linguistics. I have spent some of my life as a journalist and features writer, part of it based in London in the early 1980's.

_{It was at that time, travelling widely through the U.K,. that I became fascinated by the asymmetric preponderance of rhotacism.}

_{I wish to avoid the amusing competitive internationalism which has developed in this thread, but I do not shy away from any controversy the following may stimulate in those equally fascinated by this issue.}

 

_{In line with some, I would agree that it is a 10/90 percentile split, far greater than in other english speaking countries.}

_{Significantly, the issue is concentrated far more with the English (as opposed to the Scottish,Cornish & Welsh - and I discount the claim that it actually begins with the specific burred Welsh 'r'). And the interesting percentile tends to suggest this to be far more than just normal speech impediment . Nor is it "just an accent".}

 

_{And as a linguist, I discount much of the technical phonic argument while recognising that the difficult 'trilled R' is often the last sound a child masters (or NOT).}

 

_{Furthermore, I would assert that - on a male/female basis - the rhotacism split is about 80/20, and between the higher educated/lesser educated, the split returns to to something like 90/10.}

_{I stress the above figures are assertions/guesstimations based only upon 30 years of personal observation/fascination.}

 

_{As a linguist and historian, I am doubly interested in the suggestion from this thread that English rhotacism (as opposed to true speech impediment) may have been initiated by the Norman conquest & in particular the centuries long 'cringe factor' among the English upper & business classes to be seen to 'fit' the imposed dialect/lifestyle.}

 

_{As a French speaker & teacher, I can attest to the english speaker's difficulty in mastering the gallic 'trilled uvula R', and to the resultant rhotacization compromise. It is at least a credible supposition that this could become partially embedded in the ongoing aristocratic system.}

 

_{But how to explain it's evolution into the 'apparently' classless twentieth & twenty first centuries?}

_{With the demise of the old aristocracy came the rise of the new : a more than proportional increase in the highly educated (the ongoing Oxbridge influence), and in the rise of the articulate media presenter/celebrity.}

 

_{Here I would refer to another element raised in this thread - the nature/nurture suggestion.}

_{A parental affectation which engenders an atmosphere of security and comfort will inevitably appeal to infantile needs for such to be mimicked/copied.}

 

_{It does at least serve to illustrate the possibility that once a significant portion of society develops an idiosyncracy, it may be passed on/communicated to the following generation by way of benign imitation.And so forth ...}

 

_{The argument that England is a more nurturing (viz. "softer") society than others, i will leave alone as unworthy of this thread.}

 

_{A further area of perhaps controversial interest might be to ask what proportion of the gay population ( & it has always been notable there, has developed the rhotacism. If greater, would this suggest it makes for an appealing affectation, over and above the 'incentives' already explored.}

 

_{As for my earlier assertion that} rhotacism is a predominantly (English?) male idiosyncrasy ... "Go figure!", as our American contributors might put it.

 

So, I certainly do view English rhotacism as more idiosyncratic than the other recognised ( & partially valid) explanations. If it is not fake, it is not exactly a speech impediment. More perhaps a self-perpetuating affectation, part hereditary, part learned, part mimicked.

 

I hope these propositions I have put forward will continue to stimulate discussion and I would be more than pleased to be challenged/updated/set straight. This is no life & death issue but one of pure academic interest. It is a topic that has fascinated me for decades, as much because the English are the depository of the language but seem to be in denial ("too close to the source to hear it") of the peccadillo.

I enjoyed reading that! I read the rest of the thread too and as an American I have something of a tongue-in-cheek contribution. Call it the 'Elmer Fudd Effect'. Having many of us Yanks gwown up with Elmer for the past 70 or so years, and Elmer having a pwonounced whotacism, and Elmer being a portwayal of a fool of sorts, Americans associate such a speak affectation negatively and practice not to exhibit it. Do Brit's share the Fudd exposure with Americans? If so, is Elmer held in higher or lower regard by the Brits than us Yanks?

Enqwiring minds want to know.

All-in-all, [current] climate change is causing geological activity. As ice loads on land masses lessen, the continental crust rebounds and as ocean levels rise the oceanic crust is compressed. Neither geologic activity nor climate are static. We're alive now -that is we personally here writing- and in geologic terms we'll soon be dead. It should be enough that we have such interesting things to do such as study geology and climate in the short time we [personally] have.

What are the factors affecting the coefficient of l.ift?

I'm no expert but I have recently had occasion to do some studying on the lift coefficient at some pages @ NASA. I found them very informative and perhaps you'll find them helpful as well.

The Lift Coefficient

The lift coefficient is a number that aerodynamicists use to model all of the complex dependencies of shape, inclination, and some flow conditions on lift. This equation is simply a rearrangement of the lift equation where we solve for the lift coefficient in terms of the other variables. The lift coefficient Cl is equal to the lift L divided by the quantity: density r times half the velocity V squared times the wing area A.

Cl = L / (A * .5 * r * V^2)

The quantity one half the density times the velocity squared is called the dynamic pressure q. So

Cl = L / (q * A)

The lift coefficient then expresses the ratio of the lift force to the force produced by the dynamic pressure times the area.

 

I' d propose the following:

 

...

When the carpenter uses its blade, it is always parallel to the wood grain (with the grain), the exerted force is perpendicular though and the thin peel of wood has absolutely no resistance to it, so it curls.

 

The carpenter often skews the plane so the blade is not perpendicular to the grain and in this case the curl comes out as a helix. Planing askew reduces tearout. Some planes have the blade skewed in the frame, such as rabbet planes which require the frame to stay parallel to the cut and which must also cut across the grain. (cross-grain planing does not make curls, rather it makes little chips.)

So I know most shapes have an inverse, some of which do and don't have defanite edges, I know that you can program a transformation of a shape to its inverse, but I don't get what you do exactly especially for 3-D shapes. If I have a square, the "inverse" of a square seems be some kind of infinitely stretched thing with an open hole in the middle with arc lengths whos endpoints correspond to the vertices of a square. How would I see what it looks like for say...an inverse of a tube?

Perhaps you mean as in a "dual"? Try this...

Duality_(projective_geometry)

...

Three dimensions

In a polarity of real projective 3-space, PG(3,R), points correspond to planes, and lines correspond to lines. By restriction the duality of polyhedra in solid geometry is obtained, where points are dual to faces, and sides are dual to sides, so that the icosahedron is dual to the dodecahedron, and the cube is dual to the octahedron. ...

PS Also check out the Peaucellier–Lipkin linkage. >> Peaucellier-Lipkin_linkage

 

Inversive geometry

Thus, by the properties of inversive geometry, since the figure traced by point D is the inverse of the figure traced by point B, if B traces a circle passing through the center of inversion O, then D is constrained to trace a straight line. But if B traces a straight line not passing through O, then D must trace an arc of a circle passing through O. Q.E.D.

...

I didn't see that goldbach conjecture or whatever it's called that relates all prime numbers in a predictable equation in Ulam's spiral. Has it been solved? I couldn't find solution for it.

The Ulam spiral does not relate all primes in a predictable equation.

Ulam_spiral @Wikipedia

The Ulam spiral, or prime spiral (in other languages also called the Ulam Cloth) is a simple method of visualizing the prime numbers that reveals the apparent tendency of certain quadratic polynomials to generate unusually large numbers of primes. ...

It's an interesting observation however, inasmuch as I have recently discovered/invented another pair of array spirals and mapped the primes on them. In accord with the OP, I think these are new but I leave it to others to determine how great they are. Feel free to discuss "my" arrays here, but please respect my copyright & do not reproduce them elsewhere.

These spirals proceed down & clockwise from the origin cell at 1. As the triangle spiral array of primes is not numbered I have also attached a numbered undifferentiated array for clarification.

Volcanic eruptions are dynamic complex events subject to many variables. For example, geologists studying Mt. St. Helens had no past evidence to suspect a lateral blast as occured in 1980. St. Helens has in the past had pyroclastic eruptions as in 1980, but from the summit, as well as eruptions of flowing lava similar [though of different chemistry] to those in say Hawaii. see Eruptive History of Mt. St. Helens

Many factors come into play in an eruption such as the character of the overburden from past eruptions, the amount of water and relative amounts of minerals in the melt, and the volume, temperature and shape of the magma chamber to name a few. One would not reasonably expect the same shape crater from any two eruptions from the same or different volcanoes any more than to expect two windows to break the same even if the same stone were thrown at them.

Hi.

Is there any living organism with a wheel+shaft-like appendage ?

 

There is feathers, cilia, tails, joints, paws, hooks, scales, wings, hair, and dozens more, but seems mother nature has not invented the wheel.

yes there is a biological wheel + shaft.

Wheel-like rotation

 

Though no known multicellular organism is able to spin part of its body freely relative to another part of its body, there are two known examples of rotating molecular structures used by living cells.^[

 

^...

 

 

The only known example of a biological "wheel", a system capable of providing continuous propulsive torque about a fixed body, is the flagellum, a propeller-like tail used by single-celled prokaryotes for propulsion. The bacterial flagellum is the best known example.^[6][18] About half of all known bacteria have at least one flagellum, indicating that rotation may in fact be the most common form of locomotion in living systems.^[19]

 

At the base of the bacterial flagellum, where it enters the cell membrane, a motor protein acts as a rotary engine. The engine is powered by proton motive force, i.e., by the flow of protons (hydrogen ions) across the bacterial cell membrane due to a concentration gradient set up by the cell's metabolism. (In species of the genus Vibrio, there are two kinds of flagella, lateral and polar, and some are driven by a sodium ion pump rather than a proton pump.)^[20] Flagella are quite efficient, allowing bacteria to move at speeds up to 60 cell lengths per second. The rotary motor at the base of the flagellum is similar in structure to that of ATP synthase.^[14] Spirillum bacteria have helically-shaped bodies with flagella at either end, and spin about the central axis of their helical body as they move through the water.^[21]

 

Archaea, a group of prokaryotes distinct from bacteria, also feature flagella driven by rotary motor proteins, though they are structurally and evolutionarily distinct from bacterial flagella. Whereas bacterial flagella evolved from the bacterial Type III secretion system, archaeal flagella appear to have evolved from Type IV pili.^[22] Some eukaryotic cells, such as the protist Euglena, also have a flagellum, but eukaryotic flagella do not rotate at the base; rather, they bend in such a way that the tip of the flagellum whips in a circle. The eukaryotic flagellum, also called a cilium or undulipodium, is structurally and evolutionarily distinct from prokaryotic flagella.^[23]...

^{Rotating locomotion in living systems}

I was thinking "swale". Usually a flood control swale has a grassy/earthen bottom however. ??

Stormwater Management