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That explanation fails because sailors and airplane pilots also see the rising or setting Moon (particularly a full Moon) appear to be large. Photographic proof that it is an illusion in this overlaid sequence of photographs of the Moon rising over Seattle:

Nope. Just something to do with your eyes (and your mind). The effect is called the Moon illusion; you see the same thing happen with a full moon. If you took a series of pictures of the Sun or the Moon you would see that the change in size is purely a matter of perception. You can google for Moon illusion and get a host of different explanations.

"The map is not the territory."

This is exactly the piece of plywood I talked about in post #11. An object whose lower surface accounts for the majority of the lift makes for an incredibly lousy lifting body. A good lifting body maximizes lift and minimizes drag. A wing whose lower surface provides the majority of the lift does exactly the opposite. Here are three models of force that NASA deems to be incorrect: The "equal transit" model. This explanation incorrectly invokes Bernoulli's principle to explain the pressure difference between the windward and leeward surfaces as a result of different transit times. One problem with explanation is that it fails to explain how a plane can fly upside down. The "skipping stone" model. This explanation incorrectly invokes Newton's third law to explain lift as a result of action by the windward surface of the wing. One problem with this explanation is that it ignores the action by the leeward surface of the wing, and it is this surface that does most of the airflow deflection in a well-designed wing. Venturi effect. This explanation incorrectly invokes Bernoulli's principle to explain the pressure difference between the windward and leeward surfaces as resulting from a constricted flow along the upper surface of the wing. One big problem with this explanation is that an airfoil is not a Venturi nozzle. Lift can be explained in terms of pressure differences (http://www.grc.nasa.gov/WWW/K-12/airplane/right1.html) or from a downward deflection of the airflow (http://www.grc.nasa.gov/WWW/K-12/airplane/right2.html) of the airflow, and it is this downward deflection that ultimately gives the body lift.

You are missing that our modern society is a lot more fragile than is the environment as a whole. You will here this message if you listen to the more reasoned members of the global warming community. The media is more likely to pay attention to the less-than-reasonable but more vocal members of this community. Their rantings make better press. Some of these more members warming crowd do not particularly like humanity. They talk instead about the damage global warming will do to polar bears and frogs. Life will survive whatever we dish out. Modern society on the other hand is very fragile. A significant number of people live in areas that might well be inundated by rising seas. We will find it hard to feed 6.6 billion mouths if the climate changes much at all. We are "nine meals from anarchy." By way of analogy, farmers in the 1930s used very poor land management techniques. These techniques coupled with drought led to significant erosion and soil loss. Did farmers point to the Grand Canyon and proclaim that nature is much worse than anything they did? Of course not. They changed their ways, and human-induced erosion has decreased as a result. Humanity would not survive a catastrophe that pales in comparison to the Chicxulub impact or the Siberian Traps volcanism. These extinction-level events the death of 90+ percent of all extant species of life. Pointing at the Grand Canyon to make human-induced erosion look small in comparison is a red herring. So is showing graphs of immense changes in the climate over geological ages that include extinction-level events to make human-induced global warming look small.

In a way, both explanations are both right and wrong. Newton's third law is key in the sense that any wing that does not push air downward offers zero lift. Bernoulli's law when misapplied (i.e., the pressure differential explanation) doesn't say anything at all about redirecting the airflow. Bernoulli's law when properly applied is key in the sense that in a well-designed wing, it is the upper surface of the wing that does most of the work in redirecting the air flow downward. Newton's third law doesn't say a thing about why a flat sheet of plywood held at some angle with respect to horizontal makes for an incredibly bad lifting surface. Bernoulli's law does. With the hunk of plywood, it is the bottom surface that does the work, and it accomplishes this through friction (i.e., drag). The same thing happens when a kid sticks his hand out of a car window and pretends the hand is an airplane. That is not what happens with an airplane wing.

I had Symbolics machine #2 (second hand), so yes, I have heard of Lisp. Lisp is a functional paradigm lanugage. I was talking about procedural paradigm languages. You are ducking the question. Moreover, there was no such thing as standard Lisp until 1999. Every dialect was different from the others. The simplest dialects of Lisp had little more than cons cells (and hence lists) as built-in data structures. If you wanted anything more complex than that you had to roll your own.

Think years. If we see something massive coming straight at us a few months before impact there is nothing much useful we can do. There are some very harmful things we could do. Nuking it is one of those harmful things. Nuking a potential impactor a very short time before impact would be far worse than doing nothing. We'd still be hit, but we'd be hit with a bunch of rocks and nuclear byproducts instead of a small number of big, non-glow-in-the-dark rocks. Most of the Earth is ocean, and most of the land is lightly inhabited. A biggish rock most likely won't do all that much damage. A bunch of irradiated rocks might well tear a hole through the ozone layer and spread the nuclear contaminants world-wide. We need to do something years in advance. Fortunately, that is not so far-fetched. Congress has mandated NASA to have identified 90% of the larger (more than 1 kilometer in diameter) near-Earth objects by the end of this year. The greatest known threat is one with a 1 in 300 chance in hitting the Earth 800 years from now. The threat of this one asteroid outweighs the threat of all other known asteroids combined.

Arrays and pointers are different entities in C. You appear to be conflating the two. double x[3]; double *x_ptr = x; int x_size = sizeof(x); int p_size = sizeof(x_ptr); On most computers, x_size will be 24 and p_size will be 4 or 8. x_ptr is a valid l-value, x is not. They are conceptually different things. I will admit that C's treatment of arrays is poor. This is the biggest misfeature of C that make many Fortran programmers reluctant to turn to C. (They also decry the lack of an exponentiation operator.) Note well: die-hard Fortran programmers most likely view languages such as python with even greater disdain they view C. You have ignored structures and you have ignored that other languages of the same timeframe do not offer built-in or library support for things like lists, hash tables, trees, ...

Arrays are "data structures" and data structures (i.e., structures) are not? Please! C, like most procedural/imperative languages of its time, provides built-in support for arrays and user-defined data structures. C, like most procedural/imperative languages of its time, provides no support for generic data structures such as hashes, b-trees, etc. If that is your main gripe against C, it also applies to Ada, Fortran, Pascal, PL/I. Those languages are not assembler. Programming in assembler requires a different mode of thinking than programming in one of those 1956-1990 era procedural/imperative languages.

FILE (stdio.h), tm (time.h), div_t and ldiv_t (stdlib.h)

(2,3) is not a complex number. It is a point in R2. [math]n=2+3i[/math] is a complex number, and [math]n^2=4+2*2*3i+(3i)^2=-5+12i[/math]

The dereferenced value still has a type. In the case of your example, it is a char. The type depends on the underlying array type. C is not weakly typed in this regard. You just don't like the fact that 2[foo] can be used in lieu of foo[2]. "Doctor, it hurts when I do this." "Don't do that then." C is a statically typed language. It does compile time type checking, not runtime. yes, you can override the static type checking in C with a cast. Once again, "Don't do that then." The former statement makes me wonder if you have ever used C. Regarding the latter statement, most other languages from the era don't provide these constructs either. If the lack of hash tables makes a language equivalent to assembler, then that means that Ada, Fortran Pascal, PL/I, etc. are also equivalent to assembler. In short, you don't like C for religious reasons. You are among many who think C is bad for the environment, causes global warming, and kills puppies.

Procedural/imperative languages are all pretty much the same. Layering object-oriented concepts on top oif a procedural/imperative language involves a slightly new style of thinking. Jumping to a completely different programming paradigm such as a functional or logical language involves a quite different style of thinking. The paradigm in part dictates the way one thinks and solves a problem. This is why it is a good idea to learn multiple languages and different programming paradigms. A linguist who knows only one spoken language is not much of a linguist. A linguist who knows only languages from one branch of one language family is not much of a linguist, either. A good linguist has some familiarity with languages from multiple language families. The same goes for computer scientists.

In short, you don't like C on some religious basis. C is little different conceptually from Fortran, PL/I, Ada. Algol, Pascal, and other languages of the procedural/imperative programming paradigm. All have functions/procedures, arrays and pointers, structured programming, data structures. On top of these basic procedural/imperative programming concepts, C adds the ability to access memory absolutely (so does Ada, as do many other languages) and the ability to manipulate memory at a very low level. People who write device drivers appreciate the ability to access memory absolutely. Without this ability they would have to write their device drivers in assembly. Hardly anybody else ever uses this capability. The same goes for the ability to embed assembly language in C. Just because C adds the ability to access and operate on memory at a very low level does not mean C is a low-level language.. Very few people use these capabilities. To the vast majority of programmers, C is much closer to Java than it is to assembler. Edited to add Even Java (Java SDKs, to be precise) provides the ability to access memory absolutely. This ability is critical for writing device drivers, and that is exactly one of the things that Sun aimed for in developing Java.

I agree with much of what bascule said except classifying C as low-level. Yes, you can imbed assembler code inside C, but hardly anyone does that. C is much closer to Java than it is to assembler. C is a purely procedural language. Java is an object-oriented langauge with a lot of procedural language with concepts and has a distinctively C-like syntax. If you want to learn assembler, learn assembler. This is not a bad idea, because in the end practically every programming language boils down to assembly. An exception to this are the old Lisp machines, but nobody uses them anymore. I recommend learning a language based on some other programming paradigm. For example, Lisp or Scheme for functional programming, Prolog or CLIPS for logic programming.

From what I have seen, posts with egregious spelling and grammar errors are almost inevitably made by those who purportedly use English as their primary language. That people for whom English is a second language can write better than native speakers of the language is a bit telling. Non-native speakers of English exhibit a non-English thought pattern in their writing. It is usually the sentence structure rather than grammar that serves as a better indicator that I am reading a post by a non-native speaker. This puts the burden on me to explain things a bit more carefully than normal and to curtail my use of idioms and the vernacular. Crackpots are breed by themselves. Their thought patterns are bizarre regardless of the language they speak natively. Text speak is rude, off-putting, and written by native speakers. The writer is essentially telling me that his time is much more valuable than mine. In short the author is an arrogant git.

Driving 90 mph from B to A, back to B, and then back to A makes the average speed 60 mph over two round trips, not one round trip. Besides, this is not what ecoli proposed as a solution. Ecoli made what is a very typical mistake in calculating the average speed. The average speed on a trip is not the arithmetic mean of the speeds attained on individual legs of the trip. The point of this exercise is to highlight that common mistake.

Many sans serif fonts put serifs on the "I" and on "1" because without them "1", "I", and "l" are completely indistinguishable. It's still a sans serif font.

There is not too much information. For example, a solution would exist if it took 45 minutes to go from A to B rather than 60 minutes. The information given does not yield a solution. Insane Alien got the answer in post #4. DJBruce, think of it this way: If you want to have an average speed of 60 mph or more, you will need to make the round trip in one hour or less. If you start at noon you have to be back to the starting point by 1 PM. You have a deadline. If the deadline passes and you still on the road, game over. It took an hour to go from A to B, so the deadline passed when you reached point B. Game over.

Since we are not allowed to discuss religious issues on this forum it is probably best to avoid discussion of the serial comma. I gather Skeptic was not talking about the serial comma but the comma between "this" and "that" in in "this, that, and the other thing".

A lot of work was done on computer fonts back in the day when 640x480 was high resolution. Seriffed fonts had a big dazzling (pun intented) problem then, so development work was almost exclusively on sans serif fonts. Its not such a big issue now, but we are basically stuck with the fonts developed for use 640x480 monitors. We will be stuck with Arial for about as long as we have been stuck with QWERTY keyboards. Nah, don't bother. It's just a minor pet peave. I used fonts as an analogy for why capitalization is important. TOO MUCH CAPITALIZATION OF COURSE HINDERS UNDERSTANDING, WHICH IS WHY IMPORTANT LEGAL CLAUSES ARE ALMOST ALWAYS PRINTED IN ALL CAPS.

No, it's not. It is just Newtonian mechanics applied erroneously. The Usenet Physics FAQ page on the relativistic rocket is relativistic rocket science.

No. A Level II civilization almost certainly will use Unobtanium.

I disagree. Capitalization is much more important than are periods as far as recognition and understanding are concerned. Those leading capitals scream "A sentence starts here". That little period is a nice addition. As an aside, a font with serifs is also a great recognition aid. I really don't like the sans serif font used here at Science Forums. The reason for having a font with serifs is simple: Our eyes are excellent shape recognizers. It is very easy to tell whether a journal uses LaTeX or some lesser layout scheme just from a glance. Knuth did a lot research on fonts, kerning, and spacing in the development of the original TeX. TeX-based articles are a pleasure to read because the printed result provides excellent visual cues for recognizing words and separating sentences and paragraphs. Knuth of course did not research how best to deal with sentences without capitalization.