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No, for two reasons. You gave one: Even more importantly, hose extremely accurate accelerometers on the GOCE cannot measure the acceleration due to gravity for the simple reason that no accelerometer can. What those accelerometers do do is measure everything but the acceleration due to gravity. The GOCE ground systems propagate the vehicle's state (position and velocity) over time using those accelerometer readings and gravity models (Earth, the Sun, the Moon, and the planets). This propagated state will of course deviate from the measured state, with the errors increasing over time. These errors result from errors in the accelerometers, errors in the measured state, errors in planetary ephemerides, and errors in the gravity models -- particularly the Earth gravity model. These errors can be used to refine the Earth gravity model. To do so takes a good history of data and a *lot* of computing power.

Cap'n beat me to the punch. Double quotes interpolate, single quotes don't.

Exactly, Mokele. The primary effect of eccentricity is to narrow the habitability zone. A planet with too high an eccentricity is not habitable.

You've done this same stuff before at other sites, Widdekind: Oversimplifying and leaping to unjustified conclusions. In this case, you are ignoring that a planet radiates. A planet with a high eccentricity will spend too much time away from its star. If the planet is Earth-like (~70% ocean), that time away from the star will make the planet freeze over, thereby drastically increasing its albedo, thereby drastically increasing the amount of incoming energy needed to make the planet hospitable for at least part of the year.

Thread moved to speculation. The cited website is nonsense. For example, It is mathematically evident that the gravitational pull upon an object is not the same at all points upon the earth, varying by some eleven percent from equator to pole. is nonsense, both numerically and in terms of what the author is attempting to imply. The Earth's gravitational strength varies by about 0.5%, not 11%, and we know what makes these measurable variations occur. We however may be intrigued to behold how this gravitational force finds its birth by way of “movement into movement upon a twofold inertia". Word salad. And while it may seem acceptable to us that objects are attracted unto one another proportional to their masses, the evidence in both law and experiment are stacked against it. Scientific laws and theories do not provide evidence of anything. They have to conform with evidence or they cease to be scientific laws and theories. The evidence is very much in favor of both Newtonian gravity and its refinement, general relativity. Hence, the property of mass that gives rise to its force of attraction is found to be “its own movement". More word salad. With such an incredibly wrong-headed and poorly-worded intro, that is quite enough for me.

By far the largest effect is the 26,000 year lunisolar precession, which is somewhat analogous to the precession of a spinning top: The angle between the Earth's rotation axis and the Earth's orbital plane remains roughly constant (about 23.5 degrees or so), but the orientation of the rotation axis rotates. There are lots of motions, collectively called nutation, on top of that big, slow precession. The largest of these results from the 18.6 year lunar orbital precession. Others include the Chandler wobble (about 433 days). After accounting for all the effects that can be explained there remains motion that we cannot yet explain with some causal model. (We don't know enough about the interior of the Earth.) These unmodeled "wobbles" are empirically called polar motion and are determined after-the-fact. For more info, see the International Earth Rotation and Reference Systems Service (IERS) at http://www.iers.org or the US Naval Observatory at http://www.usno.navy.mil.

Thanks for that. There has been a lot of nonsense in this thread. So long as you do so years in advance. A meteor discovered a day or so before impact is going to impact. Blow it up into lots of little pieces and all (or almost all) of those little pieces would still impact the Earth were it not for impacting Earth's atmosphere first. Being small, all of those little pieces will blow up in the upper atmosphere. Good bye, ozone layer. This is essentially an engineering project rather than a science project. At some point the incoming meteor will cross a "point of no return". Once past this threshold the meteor will hit. "No can defense", to quote Mr. Miyage. The same thing happens to airplanes en-route between cities and ships coming into dock. An airplane can not return to its city of origin once it has consumed more than half the fuel in its tanks. A big ship coming into dock cannot be turned away after it has crossed some threshold distance. Many of you posting in this thread are considering neither the theoretical nor practical points of no return when it comes to meteor defense.

This question doesn't make sense. This rule immediately leads to contradictions. It immediately leads to 1=2, for example. It also conflicts with your original post, Your original post contradicts itself:

No. The real numbers are called the unique complete ordered field for a very good reason. A field is an algebraic structure with a pair of operations (typically called addition and multiplication) that satisfy a specific set of axioms. You can add and multiply integers, but the only integers that have a multiplicative inverse are 1 and -1. The integers do not form a field. The extension of the integers to the rationals do form a field, as do the reals and the complex numbers. An ordered field has comparison operators in addition to the algebraic operators. Integers, rationals, and reals can be compared: One can meaningfully ask whether a<b for any two integers, any two rationals, and two reals. The complex numbers cannot be compared. Is 1-2i > 2-i? Finally, there is completeness. The rationals are not complete in the sense that not all Cauchy sequences in the rationals are convergent in the rationals. That all Cauchy sequences in the rationals do converge to a real number is a tautology. That all Cauchy sequences in the reals converge to a real number means the reals are Dedekind-complete. The kicker: Any field that is orderable and Dedekind-complete is homeomorphic with (completely indistinguishable from) the reals.

There is a third law reaction here: The exhaust gases push on the rocket itself. A rocket works just fine in the vacuum of space far removed from anything to push on. (In fact, rockets work better in the vacuum of space.) Imagine that you are standing alongside a pile of baseballs on slab of wood that in turn is on a huge air hockey table. Start throwing baseballs horizontally and you will start moving in the opposite direction. To throw a baseball you must exert a force on the baseball to make it accelerate. By Newton's third law, the baseball exerts an equal but opposite force on your hand. That reaction force propagates from your hand to your arms and eventually to your feet and the slab of wood. The slab and everything on it accelerate each time you throw a baseball. The same kind of thing happens with the rocket. Some force makes the escaping exhaust molecules speed up. That same force in turn makes the rocket speed up in the opposite direction.

You are asking two distinct questions, Vindhya: How did the elements form, and why do planets have different compositions? How the elements formed is the subject of nucleosynthesis. Google that term. I have denoted some key terms and phrases in bold. Google these for more information. The big bang only created the lightest of elements: hydrogen, helium, and lithium. Stars produce heavier elements by means of fusion, up to and including iron (and only very massive stars can produce iron). Iron is the most stable of all nuclei. Getting past iron requires a vert special circumstance: A supernova. So, three very distinct processes are needed to explain the elements: big bang nucleosynthesis, stellar nucleosynthesis, and supernova nucleosynthesis. How the planets formed and why their compositions differ is the subject of the nebular hypothesis. Where and when a planet formed are the key factors that lead to the composition of the planet. The protoplanetary disk from which the planets formed had a temperature gradient, warmest near the newly-forming star. Get close enough to the protostar and things like water, ammonia, and methane are gases rather than solids. Outside some radius (the frost or ice line), the planetesimals could include stuff like water, ammonia, and methane ice. Inside the frost line they couldn't. The planets outside the frost line had more stuff (a lot more stuff) to work with. The outer planets could and did get huge, and did do so rather quickly. Inside the frost line, only rocky and metallic materials could coallesce to form planetesimals.

You didn't carry enough terms. Suggestion: Try expanding the exponential after doing the cosine expansion. In other words, use [math]\cos(xe^x)\approx 1-\frac 1 2 (xe^x)^2 + \cdots[/math] BTW, the answer is neither zero nor 1/2.

That distinction is particular to astronomers. Because they are astronomers.

Cancer is a general descriptor of a whole slew of different symptoms. It is not a specific symptom, let alone a specific disease. There is no magic bullet. A lot of medicines used to fight diseases are poisons. They are poisonous to the disease-causing agent -- and to us. A lot of candidate cures that kill disease-causing agents in test tubes kill the patient as well. Not good. A lot of those that don't kill us in small doses don't cure the disease in small doses. A lot that kill the disease in a test tube environment don't kill the disease in humans (or in test animals) because our active chemistry alters the medicine. Pharmaceutical companies reject many potential candidates because they are too poisonous, they don't work at all in vivo, because they work, but only slightly. They reject even more because they can't figure out how to manufacture the medicines in bulk.

A google search on Garry Potter reveals he is a misanthropic post-postmodernist. I'm with Mokele.

An example: The last graph, "Los Hermanos". Using the horizontal midpoint of each vertical bar as the beak depth for that bar, I read (beak depth, frequency) pairs as (2.875,0.08), (3.125,0.18), (3.375,0.08), (3.625,0.42), (4.125,0.24). Note well: 0.08+0.18+0.08+0.42+0.24 = 1. Make sure that is the case (otherwise you need to divide by the total frequency). The frequency-weighted mean is 2.875*0.08+3.125*0.18+3.375*0.08+3.625*0.42+4.125*0.24=3.575.

Did you (1) read the article you posted, and (2) look at the date? From the article, In the view of most astronomers, the juxtapositions are just due to chance. The filamentary connection became less convincing as better images became available. John Bahcall and collaborators made a noteworthy contribution when they showed that NGC 4319 absorbs some of the light from Mrk 205, just as expected if NGC 4319 is projected in front of Mrk 205 (Astrophysical Journal 1992). In time, many quasars were found to lie in galaxies with exactly the same redshift, providing powerful evidence that quasars are an event that occurs in the nucleus of galaxies. Today the redshift controversy has almost faded from view. Only a few astronomers still think there is reasonable evidence for noncosmological redshifts; a recent summary making their case was published by Geoffrey Burbidge (Publications of the Astronomical Society of the Pacific 2001). The vast majority of astronomers think that the evidence is overwhelming that redshifts show distances to objects in the expanding universe. The date of the article is also important. The Sloan Digital Sky Survey (2000-2005), released after this article was published, has found over 120,000 quasars. The redshift controversy is explained solely as coincidence.

Go out into a forest at night and take pictures of the night sky as you wander through the forest. In some of those pictures tree branches will appear to be connected to the Moon or to stars. That connection is not real, of course. To get a good, clear picture of the Moon in this forest you will have to search hard for a gap in the trees. Suppose on the other hand you searched for a view in which the very end of tree branch seems to touch the Moon. Does this picture prove that the Moon is a glow ball attached to the end of the branch? Of course not. This is just what Halton Arp has done. He searched for images where objects appear to be connected. Seek and ye shall find. Just because he found objects that appear to be connected does not mean they are connected. Just because two objects appear to be connected in a photograph does not mean they are. The Moon is not a glow ball attached to the end of a tree. Arp is using the logical fallacy of hasty conclusion. The null hypothesis here is that the connection is not real. That null hypothesis must be rejected to prove that the objects are connected based solely on imagery rather than on physics. Arp has not rejected this null hypothesis and he has not provided a physical model that can explain the phenomena he purports to have seen. He has merely provided images of apparently connected objects. We have now discovered 120,000 quasars, thanks largely to the Sloan Digital Sky Survey. Spread over less than 4 pi steradians (the Milky Way blocks our view of a good chunk of the remote universe), some of those quasars will by chance appear to be close to nearby objects. They aren't. The apparent connection between nearby galaxies and some quasars is no more real than the connection between the Moon and a tree in a forest.

That's a bit too simplistic. As Klaynos already noted, this ignores works against friction, parasitic losses inside the engine, etc. Mechanical advantage typically comes at a cost of increased energy expenditures. Those non-conservative forces are a real drag.

Sure it does, but I should have been clearer in what I said. You appear to have implied from post #1 that laws or parts of a state constitution should be stricken as soon as the US Supreme Court declares them unconstitutional. That is what my "absolutely not" response refered to. Whether such clauses should be removed in general is a different question. There is a procedure for doing so, and the Supreme Court is not a part of that procedure.

Yes, it's a discriminatory and unconstitutional law. It should not and cannot be enforced. Should it be removed? Absolutely not. As a starter, what if some future Supreme Court overturns the prior ruling? It's not going to happen here, but it has happened elsewhere. When that happens, those old laws once again become enforceable. Removing laws by judicial fiat grants the courts the power to write law rather than interpret law. Removing discriminatory and unconstitutional laws is the responsibility of the legislature, not the judiciary.

By this logic, arguments that the world will end in 2012 are also scientific.

Not a morning person, are you? Venus is moving toward superior conjunction and will not be visible in a month or so (late March). A few weeks later in will then be visible in the early morning, just before sunrise, and will remain visible in the morning (but not in the evening) for most of the rest of the year.

You have it the other way around. These laws are unconstitutional and unenforceable. Just because a law is on the books doesn't mean it is or even can be enforced. In the case of Texas, the clause "provided he acknowledge the existence of a Supreme Being" is a part of the Texas Constitution. Changing it would require a constitutional amendment to "remove the need to acknowledge the existence of a Supreme Being from Article I, Section 4 of the Texas Constitution." You're from Texas. Be honest: What are the odds such a proposed amendment would even appear on the ballot, and if it did, what are the odds it would pass? Getting Texans to vote to remove that phrase would require an act of god.

I've experienced -40°F=-40°C in northern Minnesota, and -30°F (-34°C) in Minneapolis (Jan 1, 1974). I don't remember that New Year's Eve much, other than that lots and lots of antifreeze helps one think the cold is bearable, even bare-able (had a naked roll in the snow) and that a football at -30°F is very, very hard. I've been moving southward ever since that winter. It snowed in Houston 4 years ago, enough to make a snowman. This is what he looked like: Notice the bare yard. That snowman used up my full quota of snow (plus some more from the neighbor's yard). We got a dusting of snow this year. It's a bit warmer now. Today's high was 79°F (26°C). It looks like we're in for a cold front this weekend; high of only 63°F (17°C) on Saturday.