John Cuthber

You can't get FeI3 but you can get FeCl3 which is, I think, what the OP is asking about. The reason is that Fe(III) is a strong enough oxidant to oxidise (some of) the iodide ions to iodine. So if you could get FeI3 it would decompose like this. 2 FeI3 ---> 2 FeI2 +I2

If that's true then high powered vacuum cleaners are not banned. Problem solved. Of course, you would have to show that it's true. And that means you would have to do a better job than the manufacturers did of showing that it's true. Good luck. In the very real sense that you can read the power ratings on the back of them and find (in my case) that the monitor is rated for 144 Watts and the computer for 1200.

The magnification is undefined. Someone with reading glasses can't focus on a book without them. So you can't measure the size of the image at the retina wit, and without them in order to find the magnification ( the ratio of those two image sizes). The lenses move the "near point" they don't make the image bigger- because there isn't an image in the first place. They are "magnifying" lenses, in that they are converging. But they don't magnify. It is, of course, possible to use a positive lens (like these glasses) to produce a diminished image of an object. if you form an image of the sun with a "magnifying"glass, it's not bigger than the sun. Magnifying glasses don't always magnify.

Nope. No reference or origin needs to be specified because it's implied by the use of the word "too".. The reference is "just the right amount"- it has nothing to do with whatever the current background is. I have a lot of respect for people who can post stuff in their second language, but it's silly when they start arguing about English with not one, but two native speakers. Strange and I have both pointed out your error.. Arguing won't change that. Meanwhile, back at the topic. Since everything emits radiation unless it's at absolute zero, then no radiation would be plainly a bad thing- the cold would kill you, and so would the vacuum.

It is mildly amusing to consider that not only was the choice a convention, but it's arguably wrong. At the time, it was considered that the effect of electric charge was due to the presence of, or a deficit of some "fluid" . Well, there is a fluid of sorts, and it's practically always electrons. However they guessed wrong and ascribed a positive charge to things with a shortage of this fluid. They arbitrarily chose to take the case of glass rubbed with silk as their reference and they called the glass positive because they thought it had a surfeit of this "electric fluid". They were mistaken- it has a shortage. So, since conventional charge is based on a mistake, it's absurd to use it tas the basis for any spiritualist or similar mumbo-jumbo.

Swansont, given this "only things at a certain distance are in focus. (reading glasses are an exception to this — they magnify)" I'm assuming you don't wear reading glasses. Also, there are two reasons why telescopes use big mirrors (or, occasionally lenses). They gather more light and they improve angular resolution. The same goes for binoculars. Since most of the time, if you are using binoculars or a telescope the object you are watching is distant, you can pretty much assume it's at infinity and so the depth of field isn't much of a problem.

Yes, I read it. And, with respect I think there's a better chance that I understood it than that you did. Where you say "What does mean "too little radiation"?" I presume that you mean "What does 'too little radiation' mean?" And the answer to that is not enough radiation. The question is a bit vague because they don't specify what sort of radiation they mean. But the meaning of "too little" is clear

Pardon? Did you read the question properly?

So, you would enjoy lots of people dying. That's interesting. However the legislation won't stop powerful computers anyway.

They are life threatening so no, she does not make a good argument; she makes a false one.

Whatever you might do with the cornea, the lens is imperfect and so is the retina. There's also the stuff between them. The actual resolution of the eye isn't bad "The maximum angular resolution of the human eye at a distance of 1 km is typically 30 to 60 cm. This gives an angular resolution of between 0.02 to 0.03 degrees, " from http://en.wikipedia.org/wiki/Visual_acuity The theoretical limit is about 0.007 degrees from http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/raylei.html So it's within a factor of 10 of the best it could possibly be.

I don't know where Wiki got that definition, but classically, it was impossible to know if the water was bound directly to the cation or not. So the definition can not be right. All the water was counted as water of crystallisation.

The calculation I gave earlier in terms of distance fallen and stopping distance is derived directly from the conservation of energy. There's not a tot of opportunity to get round it. 3 g on a plane is quite a lot of force, but it's a big lump of metal so it's very strong.

Mostly the wings already stopped the plane falling. A plane might be doing a couple of hundred miles an hour when it lands, but nearly all of that speed is along the ground, rather than down. The wheels etc only have to absorb the impact from the vertical component of the speed. They then slow the plane down over many metres of runway. If you could fly, it would work for you too.

"The Probability of the Universe Being the Exact Way It Is" = 1 exactly, by observation.

It might clarify things to point out that the torque that spins a wheel is a vector along the axle. This might also help http://en.wikipedia.org/wiki/Torque

It's still the same problem. The strut would have to be absurdly long- tens of metres- so you wouldn't be able to pack one per passenger into a plane. It's considered a better idea to stop planes falling out of the sky in the first place. For the weight of all those struts, you could have a spare engine and that's probably a more sensible idea. On the other hand the flights would cost a little more, and the industry is lethally competitive.

Is there something complicated here, or could you just Google the heat capacities of the gases?

If all you want to do is heat a room or boil water to run a turbine then, in principle any fusion reactor produces a net amount of energy. Energy is released by fusion and it ends up heating the surroundings. I gather that with a good fusor and a kilowatt or so of input power, you can get something like a nanowatt of extra heat. Not terribly practical- but net energy production nonetheless.

(1) That happens a lot. ((2) You can run a fusor for minutes to hours. Over roughly how long do you think a fusion bomb "sustains" a nuclear reaction?

Classical physics couldn't interpret it in terms of E=hf because the idea of E=hf is one of the basic ideas of quantum physics.

According to this http://en.wikipedia.org/wiki/G-force#Human_tolerance_of_g-force You might be lucky and survive 100 g And the acceleration is inversely proportional to the stopping distance, not directly proportional. There is a way to survive much higher accelerations but it's neither morally acceptable not practical. A foetus will survive accelerations that kill the mother - mainly because it has no airspaces and it's well "padded".

H, He and Li were created in the big bang, the elements up to about iron were created in stars the heavier ones are created in supernovae (as Swansont pointed out) It's complicated and this explains it a lot better than I can. http://en.wikipedia.org/wiki/Nucleosynthesis You would be about 40 or 50 years too late for the patent. http://en.wikipedia.org/wiki/Fusor Typical acceleration voltages are 10 to 100 KV so the energies are in the region equivalent to temperatures of 100 million degrees (give or take a few zeroes). The pressure is typically something like 100 microns of mercury (feel free to turn that into SI units) which is a pretty good vacuum by engineering standards (though it's a very poor one compared to those used in surface chemistry research etc).

Essentially, all research is very expensive. Simplicity (and hence reliability) may be much more important that absolute efficiency.

The airbag slows the person's head to a stop over a distance of something like 10 cm. The steering wheel (or dashboard or whatever)would do so over about 1 cm or less. So the acceleration and hence the force is 10 times less. Also, and probably more significantly, that force is distributed over the whole of the persons face rather than just the bit that hits the wheel. So there's a lot less pressure acting on the person and it does a lot less damage.