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What you just did is not correct. You need to do it like this: [math] \frac{3000\;\text{km}}{600\;\text{km/hr}-w} + \frac{3000\;\text{km}}{600\;\text{km/hr}+w} = 12\;\text{hr}[/math]

For the first trip, the constant speed (not velocity) is 6000km/10hr = 600 km/hr, or 166.7 m/s. This is presumably without a wind. The key point here is that the plane flies 600km/hr with respect to the wind, not with respect to the land. During the outbound trip, the plane flies against the wind, reducing it's ground speed to 600km/hr - w. On the return trip the ground speed increases to 600km/hr + w. Solve for the wind speed w that yields a total trip time of 12 hours.

Not only that, he passed it off as being from the Washington Post. The real source is warresisters.org. Not only that, to get those numbers, warresisters.org appears to double-count spending on Homeland Security and attributes the following to military spending 80% of the payments on the national debt This alone inflates the military budget by 376 million. Half of NASA's budget None of NASA's paltry goes to the military. A quarter of the Agency for International Development's budget Subcategory 152 of the federal budget. Some of this funds foreign militaries fights against drugs. Maybe liberals are more intelligent than conservatives. This goes well beyond Creative Accounting 101.

You forgot about electrical potential energy. The particles lose this potential energy as they fall toward each other.

That was my sole contribution to this thread. I'm surprised no one made the connection between the article cited in the OP and the thread "Why Most Published Research Findings are False". Positive results might well result even if the underlying hypothesis is false. I suspect this is not the case here. They simply didn't measure what they purported to measure.

Correct. \frac takes two arguments. You only need to use the brackets if an argument is non-atomic. You don't even need the space if you use brackets. The space exists to separate arguments. It does not print. You can even take advantage of the fact the digits cannot be part of a name and hence separate arguments without a space. For example \frac1a, which displays as [math]\frac1a[/math]. Nontheless it's a good practice to use the braces even when they aren't needed. One problem with the way LaTeX treats spaces is if when you define a macro (in a .tex or .sty file, not here) that prints something. For example suppose you define \mbsp as shorthand for "My Big Software Package version 3.1": \newcommand{\mbsp}{My Big Software Package version 3.1} Now you can brag about a specific version of your big software package with \mbsp: The following capabilities are now available in \mbsb:\begin{itemize}\item Feature 1 ... This will work fine: The following capabilities are now available in My Big Software Package version 3.1: Feature 1 ... Now someone redlines this as passive voice. You change it to \mbsb offers the following capabilities:\begin{itemize}\item Feature 1 ... But this prints as My Big Software Package version 3.1offers the following capabilities: Feature 1 ... There is no space between 3.1 and offers. You need to force the space, for example \mbsb\ offers the following capabilities:\begin{itemize}\item Feature 1 ...

It doesn't matter a bit what font you use. A journal (a real journal that is) will their own fonts, not yours. Look at any journal: All articles are in the same font. A journal will not accept a PDF for this reason. They want your LaTeX or word file (or whatever). Regarding Tree's comment: Look at a scientific journal. Its very likely to be printed in a font with serifs. Your eyes have built-in edge detectors. Those little serifs give your eyes something to grab onto. The lack of serifs means those low-level edge detectors can't function as well. The brain has to work harder to interpret what the eyes are seeing. Study after study has shown that sans serif fonts are much harder to read that serif fonts.

Use a left,right pair where the left element is invisible: \left.\frac F G \right|^R_1 [math]\left.\frac F G \right|^R_1[/math]

The statement you quoted does not talk about gravity or about how time varies because of a gravitational field. It talks about time dilation because of motion. Guess what? That is exactly what LET talks about as well. SR cannot address the behavior of a clock in different gravitational field because SR is limited to inertial reference frames. Hence the disclaimer "special". General relativity, published a decade later, covers all reference frames. That is why it is "general". Did I ever say that? I said that even though LET and SR are equally up to the task of explaining the Michelson-Morley experiment, we prefer SR in part because of its aesthetics. Given two theories that are indistinguishable mathematically but are very different in formulation (i.e., the underlying axioms), which would you prefer? I know this is off-topic, but you started it. Like I said in my first post in this thread, stick to biology.

Even the y-component of momentum is conserved if one observes from a proper inertial frame. The Earth-fixed frame is not inertial because it is accelerating toward the raindrops as they fall to the Earth. Consider a single raindrop that is just about to hit the railcar. In the Earth+car+raindrop center of mass frame, the raindrop's downward momentum is balanced by the Earth+railcar's upward momentum. The net vertical component of momentum is zero. After the collision, the y-components of the Earth's and railcar+raindrop's momentum are zero. Momentum is conserved.

What is the proper pronunciation for this trademarked technique?

This obviously has gone far from evolution. Then again, creationists tend to conflate evolution, abiogenesis, geology, astronomy, and cosmology into one single body of study. For a specific refutation of the "sun is shrinking" argument, see this page.

Special relativity does not predict that clocks are different in different gravitational fields. That is the domain of general relativity, not special relativity. LET and special relativity are mathematically equivalent, right down to E=mc2. Physicists do evaluate theories in part based on simplicity. Physicists prefer special relativity over LET in part because Einstein used simpler and deeper axioms that generate Lorentz contraction while Lorentz contraction is merely axiomatic in LET. LET is ugly while special relativity is elegant. Physicists strive for aesthetics in their theories. Move forward in time to general relativity. One reason Einstein delayed publishing was that he wanted a theory that postdicted known results (the precession of Mercury) and at the same time did not need any special scale factors. The end result only has one "magic number", the universal gravitational constant G.

There's the answer. The spokes are of nearly negligible mass. In reality, they add about 5-10% to the rotational inertia. Not truly neglible, but close enough for government and introductory physics.

The underlying statistical paradox (can't remember the name) is the same as this scenario: You go to the doctor. One possible cause of your symptoms is a very rare but fatal disease. The disease affects 1/1000 adults, apparently at random. The doctor sends you to the lab for a blood test for this disease. The test has yields 1% false positives and 0.01% false negatives (a very good screening test). The results come back positive. Since the test has a paltry 1% false positives, is it time to rewrite your will? Surprisingly, the odds remain better than 9 to 1 that you are not diseased. A similar thing is happening here. The false hypotheses outnumber the true ones in the soft sciences. Testing in the soft sciences is statistical. Just because a hypothesis passes statistical tests does not mean it is valid. What does this mean for physics, where experiments like gravity probe B are becoming the norm? Physics used to blessed with the equivalent of six or more (and often many more) nines of accuracy, thereby avoiding the statistical morass that plagues the soft sciences. Just as an example, the mass of the photon has been experimentally confirmed to be less than 10-64 kilograms, or 10-32 electron masses. In comparison, the results from gravity probe B have been delayed in part because of statistical issues.

The elliptical orbit arises in the two body problem (e.g., a universe that comprises the Sun and the Earth and nothing else.) The general solution of the two body problem is a conic section: a hyperbola, a parabola, an ellipse, or a circle. A truly circular orbit is essentially impossible to achieve. Everything has to be just right for an orbit to be circular. As soon as you add in influences other than the Sun, the planets no longer follow truly elliptical paths. The paths are close to elliptical because the Sun dominates over even Juputer by three orders of magnitude.

Even though its proprietary, that is my recommendation as the undergraduate language of choice for most hard sciences and engineering (but not for computer science or software engineering majors).

From my reading of the Slate article, this is not an intelligence test. It tests visual acuity and reaction time, both of which are highly correlated with age. A person's political orientation is also highly correlated with age. It is not surprising at all that the testers found a correlation between the test results and policical orientation. This made it into Nature????

insane_alien and Lockheed are right. This is either spam or a flyby nutcase.

Here's a Salon.com article on Van Flandern. The article discusses Van Flandern's claims regarding GPS, his claims regarding relativity, and other items. Basically, Van Flandern went off the deep end and has been van floundering ever since.

This must be none other than Tom Van Flandern. He was at one time a very good astronomer but lately has been into psychoceramics. Yes, he was consultant on GPS. He did not design, develop, implement, operate, or maintain the system. He was just a consultant. Big goverment projects hire lots of consultants who often contribute nothing. Van Flandern is wrong about GPS not using relativistic corrections (they do; both general and special relativistic clock corrections are needed). The myth is that they don't.

One significant cause of death (particularly among the elderly) is slipping in the shower. Death occurs when the head hits the hard wall or tub, often breaking the neck. This slip in the tub is much less than a two story fall. Bicycle accidents (particularly endos) often result in a direct collision between the head and the pavement. 24 mph is a good pace on a bicycle. A 24 mph collision in which the head absorbs the full impact of the collision is deadly. Those helmets save lives. (Mine, for example.)

Stick to biology. The MM experiments did not prove the aether didn't exist. It proved that the assumed behavior of the aether was incorrect. Lorentz developed the Lorentz-Fitzgerald contraction assuming an absolute reference frame and an aether that behaved in concordance with length contraction. The Lorentz-Fitzgerald contraction is also derivable from Einstein's special relativity postulates, which reject the concept of an absolute reference frame. Since special relativity and Lorentz' formulation are mathematically identical, falsifying one would falsify the other. We prefer special relativity not because it predicts different results but because the predicted results are derived in special relativity from two very simple postulates. In contrast, length contraction is axiomatic in Lorentz' formulation. Physicists prefer simple and deep axioms. This ad hoc hypothesis fully explains the observed result. It had better explain it, because the exact same result is derived in special relativity.

One possible explanation: That which is eminently reasonable is also very forgettable, while that which is eminently unreasonable lingers forever in our memories. To the left, Hillary's espousal of universal health care in the 90s was eminently reasonable, but it was eminently unreasonable to most of the nation and to the right in particular. That one action forever made Hillary a far-left liberal in the minds of many. The same is true for her initial support of the war. That action was eminently reasonable to most of the nation at that time. It didn't mark her as a warmonger, just reasonable. Even liberals can succumb to reason some of the time. On the other hand, this initial support forever damns Hillary as a conservative warmonger in the minds of some of the far left. Oh, and don't forget the importance of right-wing talk radio. Bill Clinton is the devil incarnate and Hillary is his witch.

Theoretical physics without experimental validation is the same as philosophy: Mental masturbation. (Or so said an experimentalist to me many years ago in an attempt to divert me from going into theoretical physics. My adviser did a better job, different story). Of course, theoreticians have similar nice words about experimentalists. Both are needed. How exactly does "imaginary science" differ from pschoceramics? Einstein was very aware of the need for experimental validation of his theories. It is the experimental validation that distinguishes relativity (for example) from wishful thinking. Some call string theory alchemy now. Or even worse, such as "not even wrong". Mainly because to date nothing out of string theory is measurable. What is this cold, arrogant and cynical stereotype? Scientists can be a bit avant-garde, a bit quirky, and a small minority admittedly fit the socially inept stereotype. Einstein grandfatherly? He was a two-timing (make that six-timing) womanizer.