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D H
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Everything posted by D H
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Even more applicable is the Transhab, which was to be a module on the ISS. NASA did patent that technology: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=6321746.PN.&OS=PN/6321746&RS=PN/6321746 It is this technology that Bigelow is using for its inflatable. Bigelow licensed it from NASA, obtaining exclusive rights via a Space Act agreement.
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US think tank offers money for poking holes in IPCC AR4
D H replied to bascule's topic in The Lounge
How bias in media affects the type of and manner in which information is presented is not genetic fallacy. It is quite relevant. The article at hand is the one guilty of genetic fallacy. The article is the one that links the AEI to the Bush administration and to ExxonMobil in an attempt to belittle the work by the AEI. You, Bascule, promulgated the fallacy by exaggerating the already exaggerated claims in the original article. BTW, here is a link to one of the letters sent out by the AEI: http://www.met.tamu.edu/people/faculty/dessler/AEIscan.pdf. Aside: It appears some climate change Nazis want to burn climate change deniers at the stake. (For example, see http://climate.weather.com/blog/9_11396.html.) Doing so would be a mistake, as it would contribute to global warming. -
US think tank offers money for poking holes in IPCC AR4
D H replied to bascule's topic in The Lounge
Starting from the end of the original post, I don't. It might be wrongheaded and stupid, but not sickening. What I find is sickening is the blatant attempt to label as "climate change deniers" (with an obvious association to Holocaust deniers) those who have any disagreement with the climate change establishment. This label now appears to apply not only to the degree to which human activities result in climate change but also to public policy response to anthropogenic climate change. The source of this Yahoo! article is The Guardian (a rather biased source). FYI, here is the original article: http://environment.guardian.co.uk/climatechange/story/0,,2004397,00.html The original article says "The AEI has received more than $1.6m from ExxonMobil," but does not say over what time those contributions occurred. The truth is, the AEI has received more $1.6m from ExxonMobil over a span of many years. The AEI budget is over $25 million per year, and only 0.66 percent of that comes from ExxonMobil. This hardly qualifies as "largely funded by". Just to give a clue to the bias in the source, here is a quote from the original article: Ben Stewart of Greenpeace said: "The AEI is more than just a thinktank, it functions as the Bush administration's intellectual Cosa Nostra. -
This sounds a bit ominous: http://www.sea-launch.com/ "A Sea-Launch Zenit-33l vehicle carrying the NSS-8 satellite, experienced an anomaly today during launch operations. All personnel at the launch site are safe and accounted for." So what exactly was the nature of this "anomaly"? The video is on youtube:
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Woelen was correct. Euler's formula is easy to prove using the Taylor expansions of exp(x), sin(x), and cos(x). To start, here are the expansions (if you want the derivations, just ask): [math]\exp(x) = \sum_{n=0}^\infty \frac {x^n}{n!}[/math] [math]\sin(x) = \sum_{n=0}^\infty (-1)^n \frac {x^{(2n)}}{(2n)!}[/math] [math]\cos(x) = \sum_{n=0}^\infty (-1)^n \frac {x^{(2n+1)}}{(2n+1)!}[/math] Expanding exp(ix), [math]\exp(ix) = \sum_{n=0}^\infty \frac {i^nx^n}{n!}[/math] Split the series into even and odd parts. [math]\exp(ix) = \sum_{n=0}^\infty \frac {i^{(2n)}x^{(2n)}}{(2n)!} + \sum_{n=0}^\infty \frac {i^{(2n+1)}x^{(2n+1)}}{(2n+1)!}[/math] Simplify using [math]i^{(2n)} = (-1)^n[/math], [math]i^{(2n+1)} = (-1)^n i[/math]: [math]\exp(ix) = \sum_{n=0}^\infty (-1)^n\frac {x^{(2n)}}{(2n)!} + i \sum_{n=0}^\infty (-1)^n\frac {x^{(2n+1)}}{(2n+1)!}[/math] or [math]\exp(ix) = \cos x + i\sin x[/math]
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I have one of those! We once had a fouled drain on said device, in August, in Houston. The water soaked our carpeting.
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That is exactly the formula that computerages posted originally (just not reduced to simplest form): [math]A(s)=\frac{s}{2}\sqrt{s^2 - \frac{s^2}{4}} = \frac{s^2}{2}\sqrt{1 - \frac1 4} = \frac{s^2}{2}\sqrt{\frac3 4} = s^2\frac{\sqrt3}4[/math]
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Here are a couple of articles/editorials that pertain to the question raised in the original post. This one is by NASA Administrator Michael Griffin. http://www.chron.com/disp/story.mpl/editorial/outlook/4485901.html [ The Columbia ] report declared that if we are going to send humans into space, the goals ought to be worthy of the cost, the risk and the difficulty. A human spaceflight program with no plan to send people anywhere beyond the orbiting space station certainly did not meet that standard. President Bush responded to the Columbia report. The administration looked at where we had been in space and concluded that we needed to do more, to go farther. The result was the Vision for Space Exploration, announced nearly three years ago, which commits the United States to using the shuttle to complete the space station, then retiring the shuttle and building a new generation of spacecraft to venture out into the solar system. Congress has ratified that position with an overwhelming bipartisan majority, making the Vision for Space Exploration the law of the land. On the Space Review, http://www.thespacereview.com/article/791/1 A Moon full of opportunity NASA gave six reasons for going back to the Moon when only one was needed The 2nd Space Exploration Conference held December 2006 in Houston outlined several reasons for a human return to the Moon. Remarkably, some complain that the reason for going to the Moon is still unclear. Possibly the sheer scope of the envisioned surface activities diffuses its impact. Almost 200 activities were described for the Moon, grouped under six major “themes” (as the agency calls them), including settlement, global cooperation, science, and preparation for Mars.
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That doesn't answer the original question. The short answer is "no". A smart-alecky answer is the Fundamental Theorem of Calculus, [math]F(x) = \int f(x) dx \Leftrightarrow f(x) = \frac {dF(x)}{dx}[/math] In other words, you know you have the right answer if the derivative of that answer is the function to be integrated. How to get that right answer, though, is tricky. There is no general rule on how to integrate a function. You need to learn many rules and learn which of those rules is of use on a particular problem.
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Oh no! Looks like we have to throw out all of our C-14 dates on the age of the Earth! So, how long before God tells this guy he doesn't have to pay taxes and that its OK to fool around with his secretary? Any takers?
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Physicists have more-or-less abandoned the concept of relativistic mass. It is messy and unnecessary. Defining relativistic mass as "E=mc2" is superfluous. One might as well just use energy. The relativistic mass does not work with "F=ma". Physicists used to have concepts of longitudinal and transverse mass to enable the use of "F=ma". Sound waves travel at the speed of sound because of the "stiffness" and density of the underlying medium: [math]v_{sound}=\sqrt{\frac C \rho}[/math]. There is no aether that "carries" electromagnetic radation. Characteristics of space itself -- the permittivity and permeability of free space -- give rise to the speed of light: [math]v_{light} = \frac 1 {\sqrt{\varepsilon_0 \mu_0}}[/math].
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You better stop eating then. Nothing is safe. Eating raw meat, fruits and vegetables is definitely unsafe. You are potentially eating live pathogens. Proper cooking kills those pathogens, but also creates carcinogens. Never, ever eat barbequed meat. It is potentially loaded with carcinogens. D.H. (Emphasis mine) Is this what you are afraid of? Do you think the microwave creates potassium out of thin air? Any form of cooking (versus simple warming) will rupture blood cells and change the blood chemically. The problem with using a microwave to warm blood is that microwaves have local hot spots. The blood in these hot spots is cooked, not just warmed. Neither those papers nor the courts said anything about the silliness one sees on the web. The problem with microwaving blood for transfusion is that the typical microwave may cook the blood. When you microwave meat, you want it to be cooked. Avoiding eating microwaved meat because microwaving blood for transfusions is harmful is indeed silly.
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Photons are massless. But don't just take my word for it. http://en.wikipedia.org/wiki/Photon In modern physics, the photon is the elementary particle responsible for electromagnetic phenomena. It mediates electromagnetic interactions and makes up all forms of light. The photon has zero invariant mass and travels at the constant speed c, the speed of light in empty space. However, in the presence of matter, a photon can be slowed or even absorbed, transferring energy and momentum proportional to its frequency. http://math.ucr.edu/home/baez/physics/Relativity/SR/light_mass.html Does light have mass? The short answer is "no", but it is a qualified "no" because there are odd ways of interpreting the question which could justify the answer "yes". Light is composed of photons so we could ask if the photon has mass. The answer is then definitely "no": The photon is a massless particle. According to theory it has energy and momentum but no mass and this is confirmed by experiment to within strict limits. Even before it was known that light is composed of photons it was known that light carries momentum and will exert a pressure on a surface. This is not evidence that it has mass since momentum can exist without mass. http://math.ucr.edu/home/baez/physics/ParticleAndNuclear/photon_mass.html Is there any experimental evidence that the photon has zero rest mass? If the rest mass of the photon was non-zero, the theory of quantum electrodynamics would be "in trouble" primarily through loss of gauge invariance, which would make it non-renormalizable; also, charge-conservation would no longer be absolutely guaranteed, as it is if photons have vanishing rest-mass. However, whatever theory says, it is still necessary to check theory against experiment. It is almost certainly impossible to do any experiment which would establish that the photon rest mass is exactly zero. The best we can hope to do is place limits on it. A non-zero rest mass would lead to a change in the inverse square Coulomb law of electrostatic forces. There would be a small damping factor making it weaker over very large distances. The behavior of static magnetic fields is likewise modified. A limit on the photon mass can be obtained through satellite measurements of planetary magnetic fields. The Charge Composition Explorer spacecraft was used to derive a limit of 6x10-16 eV with high certainty. This was slightly improved in 1998 by Roderic Lakes in a laborartory experiment which looked for anomalous forces on a Cavendish balance. The new limit is 7x10-17 eV.
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A lot of it is urban myth. See http://www.snopes.com/science/microwave/plants.asp The person behind this silliness appears to be one "William P. Kopp". The best way to tell a lie is to tell a partial truth. Heating blood to be used for transfusions above 47 C, by any means, is very bad. Microwaves do have a tendency to have localized overheating. A realistic view of this issue can be found by searching PubMed, http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?CMD=search&DB=pubmed, for "microwave blood warmer".
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That is not correct. The full form of the equation is [math]E^2 = m^2c^4 + p^2c^2[/math] For a massless particle such as the photon, this reduces [math]E = pc[/math] Per general relativity, gravity curves spacetime. Light follows a geodesic in this curved space. In other words, a light beam curves because space itself is not "straight". That light has been observed to behave this way is taken as confirmation of relativity. Just because photons have momentum does not mean they have mass. Photons have energy, given by [math]E = pc[/math] for a massless particle. Equating this result with the quantum mechanical result [math]E = hf[/math] yields the momentum of a massless photon, [math]p=hf/c[/math]. No cop out. Photons (or any other massless particles) in vacuum travel at the speed of light and at no other speed.
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"Dark energy" is a hypothetical form of energy that accounts for the apparent acceleration in the expansion of the universe.
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A 'Who's Online" search, http://www.scienceforums.net/forum/online.php?sort=username&order=asc, shows that SFN is infested with spiders: MSNBot Spiders, Google Spiders, Google AdSense Spiders, and a horde of Yahoo! Slurp Spiders. I have noticed a marked decrease in performance from SFN as of late. Is this spider infestation the cause of this degradation?
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The flaw in your reasoning is quite simple: Photons are massless.
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I am sure you have seen this equation, better written in the form [math]x=x_0 + v_0\Delta t + \frac 1 2 a\Delta t^2[/math]
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Remember Michael Brown, the man who was qualified to run FEMA because he ran horse shows? His number 2 man at FEMA was equally well qualified: Former television reporter Patrick Rhode. Now the Bush administration has blessed NASA with Rhode's space expertise. From http://www.washingtonpost.com/wp-dyn/content/article/2007/01/12/AR2007011201671.html: Patrick Rhode, who was chief of staff and deputy director of FEMA under Michael Brown, was hired as a senior adviser to NASA Administrator Michael Griffin on communications issues, NASA spokesman David Mould said.
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It is indeed all situation/sensational/ideological. Both extremes, pure government ownership (communism) versus no government ownership (anarchy) have been attempted and both have failed miserably. However, imagine a world in the government owned and controlled all means of information exchange. I would not like that in the least.
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Well, it does happen. Computer-induced ABS failures have plagued Ford and General Motors. Software glitches have caused the Toyota Prius to stall. Lawyers see a pot of gold in this arena. There are now lawyers who specialize in problems related to automotive computers. The simple fact of the matter is that avionics failures remain one of the leading causes of spacecraft failures. This is particular so with unmanned missions, which do not undergo the level of scrutiny to which human-rated spacecraft are subjected.
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The sidereal year measures how long it takes for the sun to return to the same apparent location against the "fixed" stars. We use a calendar to mark seasons. Summer would eventually occur in December if we used the sidereal year as the measure of a "year". The driving factor that determines whether it is winter, spring, summer, or fall is the orientation of the Earth's rotational axis with respect to the vector from the Sun to the Earth. A tropical year marks how long it takes for the Sun to return to the same apparent orientation with respect to the Earth's rotational axis.
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From that, you should see that each of these derivatives appears to be of the form [math]\frac {d^n}{dx^n}\exp\left(\frac 1 x\right) = p_n\left(\frac 1 x\right) \exp\left(\frac 1 x\right)[/math] where [math]p_n(u)[/math] is a polynominal. It is obviously true for [math]n=0\text{, as\ }p_0(u)\equiv 1[/math]. Use induction to show that the general form is valid and to determine an inductive form for [math]p_n(u)[/math].
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You got a completely different answer because you used the wrong rule. See the corrected answer in my previous post.