CaptainPanic

Option 1: Because it's a 4 hectare sheet of newspaper covered in super glue, and they're on the far edges of it? Option 2: It is because they're printed on the same page.

"Gas" is a state. "Liquid" is also a state. "Solid" is also a state. I post this just in case the word "state" was confusing you. We say for example that water at 20 degrees C is in the "liquid state", and for example steel is at 20 degrees C in its "solid state". In an answer to this very much related other thread, I believe that some people consider plasma another state of matter. http://en.wikipedia.org/wiki/State_of_matter So, basically you've already answered the question in your opening post.

Solar insolation I know a decent site: http://www.apricus.com/html/insolation_levels_europe.htm For the other topics I'm afraid I have no decent source myself (I'd have to google just like anyone else).

I have no clue what this thread is about (our thread starter is not making a lot of sense to me), but I'd like to say 1 thing about posts that I fail to understand: they're not necessarily wrong. I am certain that if you just follow school, you do get brainwashed on the level of problem-solving and basic concepts. I have the feeling that kids have such overwhelming creativity that they would be able (some of them) to find a different way of describing many problems, and possibly would arrive with a different solution. Some kids will just fool around, but some might derive a new description of old things. And we cannot say that this (eventually) cannot arrive at a solution which combines classical physics and quantum mechanics. This does not remove the fact that main stream science is an almost perfect description of the observations that we make every day, and there seems no reason to re-invent it. But once someone claims to have done it we should try to see if it makes any sense, rather than flame it on the basis that we don't understand it. You can only say someone is wrong when you can point out the mistake. If you don't understand a concept doesn't mean it's wrong. There is merely a (large) communication problem.

Solving these kinds of equations are just good bookkeeping. If you find it convenient to add extra + and (), then go ahead. It is just not true that [math] b + 4(c^5) + 8 [/math] is less correct than [math]b + 4c^5 + 8[/math]. They are mathematically identical, and therefore equally good. Write whatever you find convenient. If you are getting confused, that is actually a terribly good reason to include the (). I'm also a good example of somebody who adds a lot of extra symbols just to avoid mistakes. I know I am always making a mess... I know the rules, but I make stupid small mistakes. You can spend minutes or even hours solving something, but it only takes 1 second to make a mistake. Good bookkeeping is the key here (and knowing the maths of course).

If you take 1 metal atom, you have a nucleus (which is positively charged: all the protons are in it, as well as the neutrons) and a bunch of electrons circling around the nucleus. The amount of electrons is the same as the amount of protons. In a metal, the atoms are arranged in an orderly structure. The thing that distinguishes metals from other materials is that the outer orbitals overlap (the electrons that circle the furthest from the nucleus have overlapping orbits) . This means that an electron in this orbital can do half a circle around one nucleus, then continue around the next, and the next, and the next etc. And it can go through all the length of a wire... which means it is conducting.

The whole argument about whether McCain is likely to die or not is totally irrelevant. Part of the job description of a Vice-President is to be the backup plan is the President dies. And the choice of the person should be based on that job description... I get the feeling some people are saying "It doesn't matter that Palin is merely a corrupt hockeymom from the middle of nowhere in Alaska, because she'll never become president anyway - McCain is not likely to die". That's a very odd reasoning. I for one would be scared as hell if Palin ever becomes president. From what I've read and heard, I am slowly starting to think that it can be even worse than Bush (which I considered unthinkable until not long ago).

A good first start is to look at the "predator prey model", which is a really simple model for a system where there are just 2 animals: a predator and a prey. Modeling an ecosystem can be as complicated as you want. I've just given you the name of the most simple one. But obviously, if you plan on including 1000 species, and make geology part of your model, and perhaps include bacteria and the odd virus, you're gonna need a lot of time.

Sure! Post it I am not sure if this forum keeps a record on an average activity for the different days in the week, but I am sure mine has a spike on Friday.

Microbes would loooove a washing machine! It's just that normal machines have: 1. nasty detergent which they do not like - but I'm sure there are some microbes who will eat it. 2. a much too short residence time (meaning you refresh the water much too fast). But the mixing, the 30-40 deg C temperature and the fact that oxygen is present would be perfect. What's your secret plan to remove the microbes from your clothing once they're permanently settled in there? And how do you plan on making the microbes eat the siliconoxide (SiO2) part of the dirt on your clothes? As for the gene selection: have a look at anaerobic digesters (used in waste water cleaning, and bio-gas production). There you just dump some microbes into the feedstock, and wait. The ones that like the feedstock the most will multiply the fastest. This is called "adaptation". It can take up to several months to do this. Probably best to do the adaptation using synthetic clothes, so you don't select the cotton-eating bugs.

Nice illustration of the problem with non-SI units. You end up with a silly constant in your formula. You can defend it whatever you want. But using SI units, all you need to do is derive the formula using only the symbols, and then fill it in using the SI units. Done. Never any discussion or mistake. Totally fool proof.

Just to put things into perspective: Over 1 billion people are discussing the fact that some dude called someone else a pig with lipstick. Because this is discussed a lot outside the US too. Weird, isn't it?

Funny that you call it the People's Republic, when People's Kingdom would be more accurate. But I'm afraid the old socialist days of the 70's are over, and we're now copying the "success" of the American economy. We've privatized a lot of things, and that includes insurances, energy and healthcare. Of course, they only got more expensive, but hey, it's the market that does that! But all in all, my government has a lot more to say about my life (financially) than the US gov. about the average US citizen. And people seem to trust our government financially too.

I think it might be an old field telephone, like used in WWI. The handle on the left is the thin that will power the phone. The rest isn't really visible. you can estimate its size by the two screws (I think they're screws) close to the corner of the device. http://www.myinsulators.com/commokid/telephones/ww2_phones.htm - other examples (pictures!) Hope we're right so you can win.

The reason I called the units silly is that I would need a few minutes perhaps to work out what the units are of the constant with the value 5252 in the formula: HP=torque*RPM/5252 Especially if you would not have given the examples later, I would have been clueless which units to use for the torque. If I would have used the standard SI units (N m), I would not get the right answer. The units of the constant will be lb*ft*RPM/HP... which is a bit of a mess to be honest. the main problem shows up with converting the Torque. In SI, the units are (N m), which is (kg*m/s2) * m. The Imperial version is in lb*ft... which would convert to kg*m. Somewhere the gravitational constant (m/s2) has gone missing. It could also be lbf*ft (poundforce*feet)... but I haven't been able to doublecheck that (because I cannot be bothered, silly units). In addition: There have been a number of different "pounds" in the past, but the common definition I guess is 1 lb = 0.45359237kg. You should note that there exists also a pound-force, which is 0.45359237 kg × 9.80665 m/s² Then 1 ft = 0.30480 m. Then we have the horsepowers according to wikipedia: 1 HP =745.6999 W There are some more variations though: Mechanical horsepower = 745.6999 W Metric horsepower = 735.49875 W (exactly) Electrical horsepower = 746 W Boiler horsepower = 9809.5 W So, let's just use the 1st one: 1 HP = 745.6999 W Using the torque in lb*ft (and not lbf*ft). Then we can derive that 5252 lb*ft*RPM/HP = 5252 * 0.45359237 * 0.30480 * (1/60) / 745.6999 = 0.0162 s2/m. but I might be wrong, as I said before... the torque is just puzzling me. If the torque is in pound-force: 5252 lb*ft*RPM/HP = 5252 * (0.45359237 * 9.80665) * 0.30480 * (1/60) / 745.6999 = 0.16 [dimensionless]. I haven't done a lot of research into the formula itself. If I needed this for work, some background might give me a clue what is going on. But I hope I have shown the problems challenges that an engineer faces daily. You're right about the RPM. In addition, adding the s would be confusing as people might take it for "second". I don't see how I was (completely) wrong though when I said: "Two identical objects accelerating (ideally) at different accelerations up to a similar speed (or: velocity) will both need exactly the same energy input, and will have the same kinetic energy when finished accelerating. Power is "energy per time" (J/s, or W), and energy input, as far as I am concerned, is the amount of energy you put into it (energy, in J (Joule)). I agree that the power is different, the energy is not... unless we're adding stuff like friction into the equation, which we shouldn't for now.

Reason: "[Francium... ] is the second rarest naturally occurring element (after astatine). That's already a good reason, but to top it off: "Francium is a highly radioactive metal that decays into astatine, radium, and radon". Two very good reasons not to play with Francium in your bath tub. [edit] There should be a YT-is-already-answering-this-post-warning in this forum.

What I mean is that journalism as a whole, individual journalists, and entire news papers, are fighting a dog-eat-dog fight to get the attention of the people. There is soooo much info out there, that we just cannot digest it all. And it turned out that good old commercials get the most attention after all... So: news has become one-liners as well. We're all being dumbed down by the media because it's the only way that they can get our attention. I am assuming that the majority of the people on SFN are actually part of the minority who go out there to read backgrounds and search for facts. You wouldn't be on this forum if you didn't. [disclaimer: this is a thesis, not a fact, and I have no sources for it]

I don't think so. I think we would have to make carbonates which would totally screw up the pH of the entire planet. All other storages depend on some matrix in which the CO2 will fit, and the costs are just enormous. Normal underground storage is also no option by the way: The carbon we combust is either from natural gas, crude oil or coal. For each molecule of natural gas (methane), we produce a molecule of CO2, which we can store in exactly the same gas field as where we found the methane. That will not go for coal and oil. Even if we would be able to use empty oil fields, we can store a maximum of about 440 g/l of carbon: the density of solid CO2 is 1600 g/l, and CO2 consists of 12/44 of carbon (and 32/44 of oxygen). Both coal and gas contain a higher concentration of carbon, so we need more space to store the produced CO2 than we created by extracting the oil and coal. Then we could use other fields too perhaps (empty salt mines or something), but I think that the only place that is proven to be closed off completely from the surface is an empty gas field... Everything else is just dangerous. It will not be possible to store all the CO2. My plan to save the world is simple: clean sustainable energy. Remove the whole CO2 issue altogether. We already have the technology, we only need a little (a lot of) initiative.

Two identical objects accelerating (ideally) at different accelerations up to a similar speed (or: velocity) will both need exactly the same energy input, and will have the same kinetic energy when finished accelerating: [math]E = 0.5 * m * v^2[/math] Where efficiency comes into play is indeed in things like torque and an engine's RPMs. p.s. I must object to the use of nice rules of thumb like traveler has posted, because they are using silly units. Please use SI units whenever possible, it will avoid mistakes.

While the entropy might be reduced locally, the light will come from a source. In some cases entropy will be increased in that source (the sun for example) or at a distant power generator (like a coal powered plant or nuclear installation). In any case, the entropy of the whole thing will increase, reflective mirror or not.

Ok, here is another scheme, which has proven itself in the past, and will be a lot less controversial: It was called the "Marshall plan" and was executed right after WWII in Europe. Europe was in ruins, but the US wanted to have it back up and running, and with a reason: it's a huge market, and it would be an ally against the evil commies. What did the USA do? They gave Europe money, lots of it, and also resources. The agreement was: "Pay it back, yes please, but no interest". This enabled Europe to get back in business in less than no time. The US did not exactly annex us (although we can debate that) or keep a military presence (although we can also debate that). Do the same to the carribean: really help them without trying to make a profit... and they'll gladly become allies and you'll increase your market. p.s. Europe is sort of doing the same in East Europe now (new EU members). Non-profit economic help in lots of countries.

LOL! :D :D You Americans are just weird. I'd be more than a little uncomfortable with a large (profit making) company owning that much private debt. (At least a government isn't making profit, and at least it is, supposed to be, elected by you and the rest of the people). Tsk. I guess I'll never truly understand capitalist thinking.

The sad thing is, given the 2 options for the democrats: 1. The winning strategy. Throwing mud is what the masses understand. Oneliners catch more attention than good arguments. This is why washing powder commercials don't explain how the powder works. 2. Probably also a good idea, as long as they use oneliners, and avoid using words such as "because" and "therefore" because that will suggest a reasoning and will cause many people to switch the channel. The saddest of it all is: This is showing that democracy is not working in a time of youtube videos and 1 minute news articles. Nobody reads a whole page of a newspaper anymore, so good arguments have close to zero audience while a good headline (mud) gets all attention without even having to show any evidence or proof. But I have no alternative to our democracy (believe me (<-- now there's a good argument!), Netherlands is rapidly catching up with the crappy level of US politics).

My point is that if you generate 1 kWh of nuclear derived electricity, you have 2 options to use it: 1. Put it on the grid for consumers to use it. This means that some dirty coal powered plant should generate 1 kWh less. 2. Use it to bring up a little CO2, which means that the coal powered plant will also have to generate the 1 kWh because consumers will still need it. In addition, the space elevator will not be able to bring up all the CO2 produced by that coal powered plant. This scheme will only be useful if: 1. We have 100% sustainable energy, and a bit more (we have too much clean energy). 2. We really need to remove CO2 from the earth (and storage or conversion into C + O2 is no solution for some weird reason). We should do this only if both criteria are met, and while we can discuss about the 2nd case, the first one most certainly is not happening yet. And even if it could be an energy free transportation: ...the construction of a space elevator would be a little too costly to lift something silly as CO2. You should realize that in order to make any difference on the earth, the amount of CO2 we remove from earth should be in the same order of magnitude as our production... which happens to be something like nearly 10 billion tons of CO2 per year. That is over 300 tons per second. That's quite a space elevator. But, yes, it is not impossible. It's merely a giant engineering problem challenge.

Is there any proof (from measurements) for dark matter and its properties (like the angular momentum)? I've always understood that "dark matter" exists only in our minds to fill in a very large gap in the models we have of the universe. also, all its properties were derived from the gaps in the model, because if it wouldn't have these kind of properties, the universe shouldn't behave as it does. But I admit that this is not my field, and my post here should be seen as a question, not as an answer to a question.