CaptainPanic

I am interested I'd like to see the results, and if you want I can give some feedback. I applaud the initiative, but I'm skeptical about the financial side of it. I really hope that it can work. I work in the field of sustainable fuels (bio fuels, but not biodiesel)... I consider myself as part of the "good guys" here... I'll be trying to help you. The more info you post here, the more feedback you will get. Of course you can also just ask questions.

First of all: I really do not think that economics belong on a Science forum... Even professors in economics do not understand the economics, and main theories (for example Keynes) have recently been proven wrong (admitted by no less than Keynes himself). Having said that... the currency exchange market does play a big role here. It's not like Zimbabwe has become millions of times cheaper for us. They've had an inflation rate of 11,200,000%, or even more. I just googled for a random article from last year. I believe the only reason that governments and economies want to have low inflation or deflation is stability. What worries me the most is that the coupling between production of goods and money has been lost. If we were economists, then we could talk about exchange rates and all kinds of flations forever, without ever realizing that every euro or dollar should stand for a product that has been produced somewhere. Money was invented as a way to trade. It was replacing goods. First people traded goods. Then they started using money for goods. Then people started trading money for money.

Hey! You bunch of cheaters! When I voted, there were only 4 options. Now there are 6! I demand to have my vote back! (I cannot vote again). I vote other: please specify and also chemistry... the result is chemical engineering. *mutters something about democracy*

Those kinds of data are notoriously hard to find online, or even in literature. I run into such problems with work all the time. I checked Perry's Chemical Engineers' Handbook for you, but I found nothing. There are specific heats and also heat transport coefficients in that book, but none for plastics or mineral oils. To my surprise however, the wikipedia entry for polycarbonate (which is not plexiglass (plexiglass = PMMA), but might come close enough) is very good. It contains both heat transfer coefficient and heat capacity. I didn't search for the oil. Is that silicon oil that you're planning to use? [edit] If you stir the oil, then at least you know for sure that the heat will be distributed rather uniformly in the oil... might make your model a lot easier. If cooling is your goal, then I'd even recommend it.

Personally, I'd rather kill myself than use Excel, but I do agree that it is easy to use. If you have to make more than 1 graph though, I recommend Octave and Matlab... It will take a bit of time to learn... but in the end it is worth it. Octave is the GNU GPL (GNU general public licence) version of Matlab. It is free to download for Windows and Linux (yes, both). Octave and Matlab use the same programming language to make the scripts (.m files). You have to write a script, which you then run, and you get a result after that. They are, imho, more flexible, and will generate nicer plots as well. And scripts are really very easy: if you want to calculate some simple formula, you just type in your .m file (which you can write using notepad or some text editor) A = 10 B = 20 C = A*B If you run that, it will give the result of C (and also tell you A and B). It starts this simple, and it can get as complicated as you like.

I'm afraid that insane_alien is onto something: most people with experience in fluidization will have experience with air/gas flows going up through a bed of particles... because that's what is used in industrial application in chemical engineering. The question that you are looking to answer is: how to scale up the previous version? You already made a vibrating bed of liquidized (fluidized) particles. So, does power increase linearly with bed thickness? Does it change linear with the surface area (diameter ^2)? I'd guess that the 2nd question is answered "yes". Bigger area means equally bigger power. The thickness... I tend to say that it's linear with the thickness as well... or (assuming constant density) weight. Therefore the power you need is a function of the volume: go form 1 m3 to 2 m3 of volume, you'll need twice the power.

What is the goal of the assignment? -Do you have to write about recent news (showing that you read the newspaper)? -Do you have to show that you can write in "newspaper style" (showing that you have the skills in the English language)? -Something else? An important thing when you are writing anything is: know your audience! If you keep in mind who you're writing it for, then you know which style you must use... and also if you should include a long introduction to explain basics to the newbies, or if you can make it more complicated for the experts (there are more variations on this theme, but choosing whether it's for experts or n00bs is a good start).

Is it because "sun" and "moon" are nouns (just like "cat", "rock" etc.) and Venus and Mercury are names (like "John", "Harrie" etc.)? I put a question mark behind the previous sentence because English is my second language... and because I'm an engineer, not a linguistics expert. However, I cannot find a single example in which the reasoning is not true... in English, or Dutch.

Matlab is for calculations for chemical engineers. Aspen is for designing the flowsheets of factories and for doing modeling calculations. Both are pretty huge programs and have a big price tag. Sorry that I always spam about the engineering side of chemistry.

How about talking about the story of the 2 satellites that crashed into each other? http://news.yahoo.com/s/ap/20090211/ap_on_sc/satellite_collision It seems the coolest article in today's news.

It is not just infrared coming from the sun, but also a lot of visible and UV light coming to earth (incoming). The outgoing radiation is indeed almost purely infrared. The CO2 absorbs the infrared, and therefore only blocks the outgoing heat.

If you have a rope, with varying thickness, then I'd find it a nightmare to cut a piece that burns for exactly 1 hr. The real challenge is not to solve this logic question, but to do it in reality

Because Social Science is as much science as economy? (I.e. educated guessing)? *hides behind his maths professor*

It made me think of a XKCD cartoon. Google for [xkcd global warming], and check the little guy with the long monologue. I have little to say about China's growth. Europe and the USA, with more money to spend per person, are only managing to achieve a few percent in growth of their sustainable energy. Our sustainable energy growth percentage is less than China's economic growth percentage. Therefore, if Europe and the USA are the example to follow, China should be expected to pollute more and more. Conclusion: there is no good example to follow in the world. (At least, no example on a scale that really matters).

I agree that I should have attempted to describe the problem in general with the forum, rather than seemingly cherrypick one nice example. So allow me to correct this. From visiting the forum as a guest, and reading multiple threads, I came to conclude that the average person visiting the political forum has no intention to have a discussion based on arguments. I have found that the majority of posts contain jokes or (not surprisingly) politically colored expressions of ideas. Most posts I just described are not backed up by links, references or explanations. Although it is true that there exist posts which would qualify imho as "a good start", those are followed immediately by a non-serious post containing a joke, funny movie or topic that is only related with a lot of imagination. And regarding the one post which was suggested to be scieitific (link provided in post #4) about gayness: It is a story based on what people belief. Although the theory sounds nice, it is not what I call scientific. On the first page of 10 posts, only post #4 provided a link to a page that linked to some scientific background. And this is no longer cherrypicking. I read posts on the science, tech. and health forum until I got blocked for reading too many threads without being a member (happens at 10?)... at some point, statistics can be used to make a valid conclusion that this forum gets a poor score in the field of science. I have seen enough posts that were completely unscientific (on the science tech. and health forum), and not enough posts that were in any way scientific. And from that I conclude that I think that I will have a problem communicating with the members of the political forum... which is why I'll spend my time here, on my favorite forum. I do agree that there is still a chance that I have simply missed all the quality posts. This is also scientific: you admit that there is a possible error in the measurements. The question is: how large is the error? I cannot say much about that, because I could not be bothered to do a statistical analysis about my measurements

I'm looking forward to read your next idea. Lemming powered skates? For everybody who is seriously considering rollerblades with engines: Please check the following things: 1. Jack ass. They tried rocket skates. It's on Youtube. It hurts. 2. The smallest engine that you can find for a bike/motorbike or any other transportation for people. Notice that it's quite big! The engine from your radio controlled car isn't gonna do it. 3. Any mechanism to connect the two rollerblades. If the power output is not exactly the same on the left and right, you're going to hurt yourself a lot. At 10 km/h (not fast), a 1% difference in speed means that your feet are moving 3 cm/s away from each other. That's more than half a meter in 20 seconds. I could come up with lots of other reasons why this is a bad idea... but somehow I get the feeling that a bunch of people fell in love with technology from a cartoon. People: Build a motorized skateboard! It has many advantages: Point 3 is no issue. And you can jump off it when it all goes bad.

To the second question: yes. Wind power and also solar will require less land area to generate the same amount of energy, although it's a different kind of energy (electric vs. chemical). Whether you can use that in a tractor depends on the size of the battery I guess. I've never heard of an electric tractor myself... but I do remember the previous thread that you started on the exact same topic (click here for link). So allow me to link to that, so that everybody is updated again with the previous discussion. Especially the last post seems to make sense.

The added value of the publishing company has been reduced as much as the added value of record labels. Previously both offered a physical product, one that you can touch (in one case, records and CD's, the other massive volumes of information in small letters). Especially the scientific journals are now practically 100% digital. A company such as Elsevier (the company behind Science Direct and other things) now only operate a search engine and a download server. They also make articles look good, I assume (removing too many empty lines, and reducing the font size to 8 or 10, so that it becomes just a bit harder to read)... In short, I do not see why they need to be paid as much as they are. It is true that the average article is downloaded perhaps 10-100 times, no more, but I also assume that no more than 1 hr is spent on it from the publishers' side... i.e. easy money. The part that annoys me the most is that you do not know the quality of the product before you buy it. (And after typing all this, I re-read the opening post, and I realize that I am quite off topic. It's nice to ramble though... time for coffee!).

Somehow I'd be surprised if anyone ever measured it. You want to know how fast the roots grow (in m/s? or kg/day or something?) of a mangrove forest that grows in salt water. And how would you express the fact that roots branch out? Do you want the speed of the tip of a root? The sum of all tips of a root? Does it include the thinnest parts, or only the bulky main roots? It's probably a nightmare to set up an experiment to measure this... because digging up the roots is likely influence the measurement. I wouldn't know of any other way to measure it - digging it up will be the only way I guess? (Any biologist who knows this perhaps?) I cannot answer it, but I'd say that there is no definite answer. Roots grow at very different speeds, depending on the soil, nutrients, temperature, etc. One day a root can grow not at all, the next day some animal urinates next to the tree, and the roots shoot out to absorb the new nutrients. Disclaimer: I am no expert, and I make things more simple than they are... and you should note that I use words such as "probably" and "likely", indicating some uncertainty.

I think that it's a miracle if you get the exact literature value. You're within 10%! Lesson #1 about measurements: there is always an error in the measurement. The question is how large is the error? You can reduce the error in the measurement by: 1. Calibration of the measurement devices (thermometers, pressure meters) 2. Doing multiple tests and taking the average (perhaps even after kicking out that experiment where you screwed something up). If you measure a temperature, you must take into account heat losses to the environment. If you do proper insulation (I have no clue about your setup), and the value is closer to the theoretical value, then you know you can blame the setup.

If you're gonna attract people from this forum to the politics forum, then the climate change forum probably is the topic where science and politics meet the most. But then again, I doubt that people here are interested in a discussion about the difference between climate and local weather. Nothing wrong with a post like that, if it comes from an 8 year old with a like for politics. But I do get worried when the 2nd post doesn't correct it. And when it actually goes off topic, and none of the posts after that get back on any topic at all, then I've seen enough. I think I'd rather stay here for my political talks. No offense, and I appreciate the intentions to get politics and science mixed, but I'll make the effort to explain basic science in real life, and I post on my favorite forum for fun. And indeed, we also have a politics forum with good discussions here .

This forum has female members?

I don't believe in any product with poor marketing. And I haven't heard of Thor for ages.

I'm never sure whether I know more about physics or chemistry. Chemical engineers kinda need both. And because this thread will be a giant complaint that there aren't enough options, allow me to say that "Engineering" should have been an option.

I don't think it's a good idea to attempt to control the weather. Weather systems are the size of a continent. Influence it locally, and somebody a few hundred or a few thousand kilometers away is going to be upset with you. You would disrupt the weather systems. We don't even completely understand the climate right now with only one major source of heating (sun). I can imagine that it would have a destabilizing effect if you increase the temperature locally (thereby also increasing vaporization). Of course it all depends on the scale of the project and the light intensity. But I would definitely advise against significantly shining more sunlight on earth. Check out Venus or Mercury to see the effects of that...