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Everything posted by Sisyphus
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Revolving but not rotating: I walk in a circle around you, but I'm always facing north. Watching me, you therefore see every part of me as I face towards you when I'm south of you, and away when I'm north of you. If, to the contrary, I stayed facing you as I was walking around, I would be facing south when I was north of you, and north when I was south, etc. Clearly, then, I would be rotating AND revolving, just like the Moon around the Earth.
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It's the vector component in the original direction which doesn't change. The bike is still going at 10km/s (wow! fast bike!) in the direction it was to begin with, and ALSO has the speed of the truck in the perpendicular direction.
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Wouldn't psychology be just about the most difficult career choice possible for someone with aspergers?
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Just think how the ancient Sumerians must have felt.
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But it IS important. You say "force on the body is F1 = m x v." But that's just the body's momentum, and is nothing acting on the body. And you use the two different meanings interchangably in your conclusion, rendering it meaningless.
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That depends on where you are. http://en.wikipedia.org/wiki/Power_outlet
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Because the Earth revolves about the Moon at the same rate that the Moon is rotating, so it keeps up. You gave an example of a hammer thrower. For him, the hammer is always directly in front of him, because he is rotating at the same rate that the hammer is revolving around him. The thrower is obviously rotating, though. It is all just a matter of perspective. (By the way, we appreciate good punctuation and capitalization here. It's easier to read, and makes you seem less like a crazy person.)
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I'm not sure exactly what you're asking, but, depending on the material, the light will either be reflected, absorbed, or pass through. If the inside is a perfectly reflective mirror, the light will just bounce around endlessly inside. If it's transparent, like glass or diamond, it will refract and pass through. For most materials, though, it will just be absorbed. Different materials will absord and reflect different wavelengths of light, which is perceived by us (at least with regards to visible wavelengths) as the material's color. One photon is absorbed by one atom, which then has higher energy electrons. That energy can be reemitted as a different photon, of very specific wavelengths which depend on the orbital states of that specific atom.
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Why are you using the word force there for two different things? mv is momentum, not force.
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No, you don't. It stays in one place in the sky. But I don't see how that's "the point."
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You're going to have to be more specific about that. Atheist didn't say anything that was incorrect. "Gravity" is really just the particular relationships between observed behaviors of objects. Whether you describe it as forces or fields or anything else is just a matter of preference. There is certainly no PROBLEM with treating it as a force, however, as I and others have explained.
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Human/Ape Crossbreeding
Sisyphus replied to lordmagnus's topic in Evolution, Morphology and Exobiology
Which I assume you're against? I guess you have to ask yourself, would it be ok to intentionally genetically alter a group of human beings to be retarded, or to be deformed in some way, as long as we treat them almost as though they were normal? It seems to me to be the same question. If you think it's different, then how is it different? An interesting thought about the chimps. If they were successfully and happily raised as if they were human children, doesn't that indicate they lack the capacity to tell the difference, and that a humanzee with higher capacity might not be so lucky? My dog treats me as if I was the alpha male of his pack. He interacts with me as a dog because he lacks the capacity to do otherwise, and I interact with him as a heavily anthropomorphized version of his real self because I'm a softie and I find it amusing. Would a humanzee be amused? -
Further, it is not just a matter of the Moon revolving around the Earth. Both of them together revolve around their common center of gravity. Because the Earth is much larger, that center is actually inside the Earth, but it's certainly not the center. The Moon affects the Earth just as much as the Earth affects the Moon.
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Sorry, no. I don't have the patience for incoherent, weirdly confrontational ramblings. Summarize in one English paragraph what you're trying to say without calling your reader stupid, and then we'll talk about it.
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shape of universe..worked out...
Sisyphus replied to young-albert's topic in Astronomy and Cosmology
No, the universe is not a sphere, because the Big Bang was not an "explosion" in the sense you're thinking. There was not some point in space from which all the matter in the universe expanded outward. Rather, it is space itself which is expanding, with all objects equalling getting farther apart from one another, even though there is no actual "motion" involved. The analogy that first made sense to me is as follows. The universe is the surface (but not the interior) of a balloon. Thus, it's two dimensional, but it "folds back" on itself, so travelling in one direction eventually brings you back to where you started. The expansion of space is like the inflation of the balloon. Points on the surface, representing objects in space, are not "moving," per se, because moving means travelling along the surface. They are, however, getting farther apart, because there is more surface. That said, the "shape" of the universe is not at all settled. It might just be infinite and have no shape at all. It might, like the balloon, fold back on itself in some way. The only thing that IS clear is that it is not a simple, three-dimensional shape like a sphere, which has boundaries. This should make perfect sense. The universe cannot have boundaries. Boundaries between what and what? The universe, by definition, is everything that is, and so there cannot be anything "outside" it. -
Gravity is not changed. What you've done by adding salt is slightly increasing the density of the water. When the egg was denser than the water, it sank, because there was more force pulling down on the egg than on the water it would have to displace (and thus push upwards). Once the salt was added, it was the water that was pulled down more, and the egg was pushed up out of the way.
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I don't think any of those "personality traits" (really, positions) you listed are actually anti-science except for the first one, they're just things you disagree with. Well, arguably the last one, too, depending on what is meant by "questions" and "accepted science." But I agree in principle that there are certain "sacred" beliefs held by stereotypical liberals, which MUST be true in spite of science or reason. Most of them are variations on the "equality" theme, like, men are absolutely equal to women, there is no difference between people of different races or countries, and (sometimes) there's no such thing as "disability." The irrational outrage over the Harvard president's speech about women in science is a prime example of this. Another is the contingent of the deaf community that was deeply offended about a possible cure for most deafness, because they're "a culture, not a disease" or something. Honestly, most beliefs held by the mindless mainstreams of right and left would still be held irregardless of any science to the contrary. However, it seems to me that a bigger chunk of the left's dogma actually IS in line with science. That, in my opinion, is a major reason why scientifically-minded people appear to be more leftist in general, even if the LCD of the left is no more inherently "scientific" than that of the right.
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It's impossible to have a double no-hitter because the game couldn't end. If there has ever been a double no-hitter, then that game is still technically in progress.
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How would you fare in a post-apocalyptic world?
Sisyphus replied to MolotovCocktail's topic in Speculations
Obviously, 25 kilos of duct tape. And yes, I would survive much better than most. I have broad practical scientific knowledge and a ruthless survival instinct. You guys should probably make me warlord. -
Earwax, saliva, tears, and snot?
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The whole concept of mutually assured destruction which prevented cataclysmic war between NATO and the Soviet bloc was more or less what Nobel had in mind, I think. In a certain sense, Vietnam was miraculous in being so contained, when the real powers at work were so much, much greater. Of course, there was and is always a very uncomfortable relationship between these weapons and the scientific community. I think it was Carl Sagan who described the nuclear arms race as analogous to "two men standing waste-deep in gasoline, one with three matches, the other with five." A terrifying and ridiculous situation to be in, but one which combined with any shred of sanity will guarantee peace.
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Maybe an example would help. You're floating in space. A rock is flying towards you at 500mph. Both of your velocities are constant, so there's no forces at work. The rock hits you. Now there's a great deal of force, as the rock exerts force on you (accelerates you in the direction of its movement) and you exert on the rock (you "deccelerate" the rock). If the rock has come to a stop, it's done on YOU the full amount of work needed to accelerate it from 0 to 500. More aptly, it's done the work on the part of you the rock hit, which will be violently accelerated with respect to the rest of your body. Most likely, more than the tensile strength of your body can withstand, and it will break free, and the rock will pass through you, having slowed down by as much work as was needed to rip that hole in you.... yay physics!
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Does gravity pull straight down or down and around?
Sisyphus replied to Lekgolo555's topic in Classical Physics
Ok. First, in order for it to be "equal," it would have to be quantities of the same thing. Force is mass*distance/time^2, which can't be directly compared to mass^2/distance^2. This can be resolved in two ways. First, you can multiply one by some constant such that they end up in the same units. You can multiply the second by some quantity of "distance/mass*time^2," and then they would both be quantities of mass*distance/time^2," i.e. force. Of course, what that quantity actually IS would depend on what units of mass, distance, and time you are using. The constant would be numerically different if you were using, say, meters or feet as your unit of distance. The other way avoids all that, and just says that the two quantities "vary as " one another, meaning that they are directly proportional. So, they're not equal, but increasing one will proportionately increase the other. So, for example, doubling r will decrease the quantity on the right by 75%, which also decreases the force by 75%.