CaptainPanic

Excellent point. That's like saying that there are no stupid laws... and that your laws are flawless. That's an attitude that I would expect from religious people towards their religion and/or God. Not towards a democratically chosen government which is by definition not perfect for everybody, but a compromise of what everybody wants and doesn't want. There are plenty of examples of people who were disobedient, and turned out to be a hero. Mandela - but also in American history - Rosa Parks: the woman who wouldn't move to the back of the bus. On a sidenote: I am afraid that our OP has created a fire-and-forget post. I doubt he or she will be back.

LOL The question whether the universe has a center is in fact the same question as what shape it is, or whether it is infinite. Bottom line, as far as I know, is that we're not 100% sure. We don't know if there's a center or not. All we know is that we can not determine (for reasons explained in the video with the dots) if we are ourselves in the center. All we know is what we don't know. Or, to use Donald Rumsfeld's words:

I don't believe there is a miniature that is "perfectly detailed"... and I think that's the main reason. Take this picture on wikipedia for example: it is nearly perfect, but it lacks some details. The flags for example are fake (not enough "motion" in it). Furthermore (as a layman) I don't see anything in optics that cannot be scaled up or scaled down. Optics, as far as I'm concerned, can be made dimensionless - and therefore deal with ratios of height, width and length... not with their exact numbers.

So, boiling water doesn't freeze faster, except under very specific conditions. The point in the link by Incendia (above) that makes the most sense to me (i.e. I think it has the greatest effect) is the convection as a result of the cooling process. The difference in heat transfer between a completely stagnant layer of water and a layer with any convection is large. p.s. thanks for the link, Incendia.

LOL So true. But I assume that left/right is a relative scale, which has its center in the middle of the national political landscape. Compared to European countries, the USA's left is quite right-wing. However, compared to most European governments, the USA is already more center (or: less right-wing). What I mean to say is that the left wing parties are often not part of a government... Why that is is something that I would discuss later (when I have also taken a better look at all the coalitions in Europe - my statement here is somewhat of a guess rather than a fact). The main difference then between the USA and the European democracies is that European countries often have coalition governments (because of the different voting system). Left wing parties will get seats in the parliaments where they are able to represent their voters - but mostly in oppositions.

Just google for wood CHP (CHP = combined heat and power). You will find many suppliers for wood burning systems that generate both heat and electricity. If I were you, I would talk to several suppliers and see what they have to offer... Also talk to some companies who already have an installation that you want, and ask them for a contact where you can buy a similar installation (and perhaps more information and experiences, if they're willing to share that). You're not asking for rocket science. You're just looking for existing technology to make some electricity (and heat) from wood chips. This is already available on the market on many different scales. You therefore don't need a science forum full of enthusiastic scientists and engineers. You need engineering advice from suppliers. Don't design anything yourself. Just go with the existing stuff. Much easier and safer.

It has been a long time since I saw such a poor argument in favor of banning weed. Your argument goes something like this: 1. Marihuana is illegal, so you should not use it. 2. Because you shouldn't use it anyway, it should be illegal. That is a circular argument... and therefore flawed. I live in the Netherlands. Marijuana is tolerated here (de-criminalized). We have shops (like bars) where you can simply buy it if you're over 18. It is a topic which can be openly discussed in our free society. I know plenty of people (students and working people) who smoke pot. These can be accomplished scientists and engineers. In our country, despite the fact that it's freely available, the amount of habitual smokers is less than in the countries around us - there are multiple sources (summarized in this article) which support that. It's a pity that people like you abuse your freedom of speech to write such complete nonsense.

I get the feeling that somewhere on the internet, a computer is really, really close to passing the Turing test. It took 12 replies to call it.

The thread title is: "Why is it assumed the universe has no centre?" The part with the 6x6 matrix of dots in the video (at around 9 min) explained why every point in the universe will seem to the observer to be the center of the universe. However - in that 6x6 matrix, 4 dots are awfully close to the actual center of that universe. The observer on those dots has no way to know it... but that particular universe has an actual center. The initial question, as far as I can see (with my layman's eyes), remains unanswered. To have no center, it must either be a geometrical shape that has no center, or it must be truly infinite.

Fashion can change fast... and this could be an excuse for people to constantly show off their phone. I think it could be more popular than you realize.

Almost 2000 posts on SFN. I like to read the news, both the "regular" news and technology/science-news. I watch streaming movies/series/documentaries (streaming-madness.net is a good one). Youtube too, obviously. Social stuff goes through email alone now. I never chat anymore. Don't use other social media. Somehow I replaced chatting with real-life chatting somewhere in the past years. Can't say it was intentional, either. XKCD Slashdot And I used to keep a blog, but although I have motivation, I don't make the time anymore now. That's about it.

I think the net is just like any other group of friends... and your sex matters, btw. First of all, you can be motivated to join a certain group of people, but they might not accept you at first. Nobody does. You can't simply join a group, and expect to be accepted immediately. It takes time to become friends. This can happen fast, or it can take time. It may also fail completely. It's really hard to tell what makes people decide they're friends. (Certainly for an engineer like myself, this type of soft science is difficult. You can't put it in a formula). These kinds of processes happen all the time, everywhere. I've observed this from both sides of the equation (as group member and as lonely outsider) since I was in primary school until now in my professional life. I guess friends are in a sort of agreement where they have a mutual benefit. This can range from humor, insight, sharing opinions, to very practical things and even bribery (where you buy friends). But I think everybody has to offer something in a friend-relationship (hahaha - I may not quantify it and find a formula, but hell, I am modeling it). So, there's your practical tip: offer something in the group that you want to have as friends. It's also hard to say when you've "arrived". Perhaps when people start offering something back (which you may not even notice, other than a feeling of comfort)? The definition of a friend is vague... and there is no tested method for making friends. You just have to find a group or person and get a *click*. Now, the internet, of course, is a harsh place. It's like the biggest school yard in the world, and you enter all alone. Since there are so many places, nobody feels obliged to accept you. You can experience that as something negative. You can also be positive and think that you now have an infinite number of possible friends from which you only have to select a few. And about you being a girl. You just have to deal with the fact that men are always looking for women. It's like a subprocess that's always running in the background of our brains, and it cannot be shut down... We're all very sorry if you don't like it... but we can't change it. Our main purpose is to meet and mate with a woman, and we try to rule the world just to achieve that (let's see how many remarks I get about that). It has interfered with professional relations a near-infinite number of times in the world. Men's interests do not change when they go online, but the code of conduct does change. There is a form of anarchy. You just have to live with that. You can try to avoid the issue by being vague (like I don't know the sex of the majority of forum members here) or you can try to use it to your advantage. That's up to you.

I can tell from experience that it sometimes pays off to give someone a phone call. Try to find an expert in your country, and make a call... it may solve things so much faster (Oh, and make sure to post a summary of your answer here for our entertainment). Sorry that this email didn't help at all... I just fear that we may not have an expert in this particular field here. I hope the future will prove me wrong

Given that there are countries like Iran and North Korea out there, and not too long ago Iraq, not to mention Somalia, Darfur, recent events in Bosnia, etc, is there anything actually wrong with point #2? In fact, there's another example of contrary reasoning right there. You're saying that America should do all the international heavy lifting, but of course only at the direction of international agreement -- goodness, we wouldn't want Americans do decide for themselves how their military hardware is used! But more to the point, you're absolutely not going to help Americans do this heavy lifting because that would just be "bullying!" Apparently Canada disagrees with you, and still sees value in international military participation. Good for them. Your main argument - although you choose your words carefully - is that I am a leftist European surrender monkey who will come begging at the USA when we get into trouble again... like we always do (hidden reference to WWII). I counter that argument by saying that you're a typical American war hawk. There, we've called each other names. Now, let's look at the assumptions and content again. You do nothing at all to support the assumption that countries cannot handle their own business without the mighty USA. Indeed, your argument goes like this: 1. Military strength is the only way to ensure safety. 2. The USA is the most powerful. 3. Logically, anyone who wants to live in peace then needs the USA's help. 4. You're all unthankful if you don't support the USA in it's military adventures. I have to say that the foundation on which you build all the rest of your arguments is false... Point 1 is not necessarily true, and therefore the whole argument fails. Also, I never said that America should do all the heavy lifting. The underlying assumption that I would agree that there is any lifting to be done is false too. A trade agreement is a weapon which is grossly underestimated by too many. Example: Switzerland. It has not joined in any agreements (except human rights). It doesn't join in any military adventures. It doesn't support anyone. Yet is has enjoyed peace for the last 500 years or so. Obviously, Switzerland has some army and airforce (and logically no navy). But compared to the whole world, it's insignificant. Regarding all the rest of your post: I am not saying that we shouldn't help each other. I am not saying that we should abandon armies altogether. I am however saying that (1) we can do with less power and (2) there are other ways to achieve peace that are not explored fully. I think that the JSF is too expensive.

I guess incest is just bad for the gene pool (link to wikipedia)... And a bad gene pool is bad for a country or society. A single incident is obviously no significant problem to a society, but if incest would be popular it could be disastrous. I guess that's why law forbids it and why religions say it's forbidden by God (I admit that I am a poor judge to check the value of that link - can someone with a better knowledge of any religion comment on this?).

Why need an army Countries (esp. Western countries) have armies so that they can: 1. Bully other countries into submission. 2. Help each other to do that. Canada has an army and an airforce mostly for point #2. To help friends... especially their neighbors, the USA. Of course, everybody still calls their war ministeries "ministry of defense". All kinds of words are being used... but ultimately, Western countries are fighting wars in other people's countries since 1945. Why need (specifically) the JSF Now, I think a more interesting story is the Joint Strike Fighter in itself. It's a typical defense project: it's delayed and over budget, has many technical problems, and there are concerns about performance. The Netherlands isn't so sure it wants to buy it anymore. The large majority of the population doesn't want it. The only reason we are still considering to buy it will probably be revealed by Wikileaks any day now: Some secret promises to the USA's pentagon and weapons industries. So, all-in-all, Canada is really (really!) doing the American defense industry a favour by signing that contract. The industry needs it, because they spend money like water, and they might lose customers. This is some money in their pocket... Money, by the way, that may well evaporate if the Americans and British pull the plug on the project altogether. [edit] Adding another reply: How to influence the people and media Interesting, sounds very cold war. I'm surprised NATO hasn't been more sensitive about Russia's militarization of the Arctic. From the article: Emphasis mine. In short: The whole Russian story was just a little trick to convince a few more people to buy those expensive fighter planes.

Both. All vibrations represent energy, and therefore heat. The energy for expansion comes from heat in general. When the gas expands to equalize the pressure on both sides of the plug, the gas cools down (quite a lot!). And in colder molecules, there is less vibration. n increases, and P increases as a result. In fairness, I am not sure if the temperature would change just because of the creation of more molecules. The heat of reaction (or: reaction enthalpy) would certainly play a role in changing the temperature. And that in turn has again an effect on the pressure, because of PV=nRT. Reactions that create more molecules would often be exothermic (combustion, explosion), so the temperature would go up because of the reaction enthalpy. Hope that helps.

I am worried that the Western democracies are entering a dark age out of fear of Islam (or using it as an excuse to oppress people). Liberties are being exchanged for a feeling of safety and security... But there is no actual substantial threat from Islamic countries: Muslim countries have little or no military power compared to Western countries, Russia or China. Only those Islamic countries which get help from the West (especially Saudi-Arabia) have modern armies and airforces - but only because the West sells them the technology in exchange for money that we all paid them for their oil. Muslim countries have no strong economies. In a generalized and simplified model, their only income is from oil. And they get all their income from the West. And in a hypocritical way, the political parties that oppose Islam the most (right wing) also oppose the sustainable energy the most - which would cut the income of Muslim countries a lot. Muslim countries are adopting Western movies, MTV, and other technology much faster than we're adopting to their culture. Islam is a religion in the same family of religions as Judaism and Christianity. Many characters from the Bible also feature in the Qu'ran. I see no fundamental difference. Barbarisms happen where the people are poor, and where conflicts rage uncontrollably. Also non-Muslim countries like Congo, Rwanda had horrible barbarisms... To call Islam a violent religion has been the greatest trick of the right wing media in the last decade. As for the actual adoptation of the Islam - the religion -, I don't see any valid argument why the Muslims would be successful in converting large numbers of people. History has shown many religion rise and fall. Religions always try to expand their "flock". But converting people was only possible if there's someting to gain. It's only possible of there are fundamental differences between religions. I think that the growth of atheism will turn out to be much larger than the growth of Islam. We're exchanging our liberties in exchange for safety and security against a threat that is no actual threat. I hope that people will actually open their eyes, and be rational about it for once.

What plastic is your bag? Some plastics cannot withstand 130 degrees C. Also, maybe your resin is dissolving into your plastic, which changes the properties. Just my 2 cents. Keep searching on the internet. A first google search showed quite a lot of information about the process.

You can store magnetic energy by pushing two magnets to each other with the same pole. The force however only gets really strong at close distances. Since: Energy = force * distance You can have a large force, but always a small distance... the result will be very little energy stored. So, when you release the energy into your "engine", it will stop as soon as you try to do something with the energy. It don't think it will ever be practical... but maybe you should do some calculations.

Because that's how it was derived. If you use another scale, results don't make sense (you can get negative efficiencies, or efficiencies higher than 100%). The definition of "zero Kelvin = absolute lowest temperature" was part of the derivation of the formulas.

A phone battery contains 100-250 W·h/kg of energy. In practical terms, assuming a single battery weighs 30 g, that is 11-27 kJ of electric energy. A solar cell can generate 100-150 W/m2 if it is in the full (summer, daytime) sunshine... If you make that a practical 30x30 cm (or 1 square foot), you get 10-15 W per cell. That could generate enough electricity for your phone to charge in approx. 15-45 min. It's a back-of-the-envelope calculation. I hope I didn't make a mistake.

I was quite surprised to read the following news article (from which the text below is a quote). I wanted to know if, especially according to Americans, there is any fundamental difference between: 1. Taxing everyone, then using the money for everyone's benefit 2. Forcing everyone to spend money on something that will benefit everyone To me, the 2nd point sounds just like the 1st, with the only exception that they took out the middle man (the government's tax office in this case). How about this one: In summary: I think that it's just a flawed argument to make people think that this is somehow fundamentally different from other things paid with tax money. Can someone explain me the outrage?

Allow me to help you find the problem. (Although I have a feeling that you personally don't need this explanation - perhaps it helps someone else to see the light). Let's take the first two (the easiest for me as a non-American). Admittedly, I am not up to date with American laws. In Europe, they still use millions of animals for testing... and I really don't know many tests done on human fetusses... although it may be necessary for some specific fields of study (stem cell research). Anyway, I think that it would be absolutely out of the question to use human fetuses for just any kind of testing (make up products like eye-liner). It's a false comparison, because the scale is different, the tests are different, and certain tests just need to be done on human cells. In a country with unemployment, it is guaranteed that some people cannot find work. It's not a matter of searching. It's a matter of job availability. Certainly, there are some lazy creatures that don't want to work... but it is not proven that the majority of unemployed people are content with their situation. In fact, I would go as far as suggesting that there is more evidence that the unemployed people search for jobs quite hard. I conclude that from the fact that there are very few vacancies. If unemplyed people were indeed so lazy, then logically it would be a lot harder to match vacancies with employees (because those lazy unmotivated unemployed people would not cooperate, and would refuse most jobs). So, we just established that "people who don't want to work" are a minority among the unemployed. Most search for jobs, and accept jobs when they find them. If we then change your statement to "We take money from those who work hard for it and give it to those who cannot find work despite trying"... then it doesn't sound so bad anymore, does it? The other two things you wrote confuse me - Where I live, there is no discussion at all.

Just calculate PV = nRT twice, please. Once at the beginning. Once at the end. Both times your n is the only unknown. The difference between the two is how many moles of air leaked in or out of the pipe. And you're done.