John Cuthber

If metal on metal friction wasn't significant car engines wouldn't need oil.

Just because you don't like reality doesn't mean reality is wrong.

Crossed polarisers don't block IR very reliably. You can fry your eyes perfectly well with IR.

This sort of thing

http://cgi.ebay.co.uk/Telescope-Solar-Sun-Filter-425P1-fits-Meade-ETX-90_W0QQitemZ250253918145QQihZ015QQcategoryZ74923QQrdZ1QQssPageNameZWD2VQQcmdZViewItemQQ_trksidZp1638Q2em122

is quite common on ebay.

Has anyone seen any spare pairs of eyes for sale?

Did nobody warn our American cousins that the price of gasoline was going to rise as it becomes rare (or at least the easy stuff to get at becomes rare?).

If they had received such a warning I'm sure they would have invested in smaller cars etc.

Can someone let me know what the benefits of reducing biodiversity are for any species, our own included?

The word is illuminatus, ignoramus.

No it doesn't. Or at least, not at any measurable rate.

Well, I guess we just have to use the data we have got. Smoking less than doubles the dose of radiation received but the increased risk from smoking is much more than a factor of 2.

It looks to me as if there must be something else responsible for the rest of the excess cancer risk.

I maintain that it's all those nasty chemicals; particularly since they are present and known to cause cancer.

How much detail do you need about the spectrum?

Is this enough "UV spectrum of LAA in 0.1 M sulphuric acid gave two absorbance maxima at 235 and 260 nm, comparing favourably with nicotine"

It's from this reference

http://www.ijpsonline.com/article.asp?issn=0250-474X;year=2006;volume=68;issue=1;spage=88;epage=90;aulast=Mangathayaru

and it also gives details of where you might get more information.

Since that site is the first hit of a google search for nicotine uv spectrum I wonder just how hard you looked before you posted.

If you struggle through to the 5th hit you get this page

http://mic.sgmjournals.org/cgi/content/full/153/5/1556

which has a picture of the UV spectrum.

Nearly a month on. Have the EPA got back to you?

I can constuct a hypothetical perfluorate ion by analogy with perchlorate. I can put it on a list on a web page.

Is there any evidence of it really existing in macroscopic quantities?

Just a thought.

Perhaps they thought that fire was "magic" and heated their homes so they thought they would try this "magic" on their food.

Sounds preposterous doesn't it.

Now look at what they used to do with radioactive chemicals.

http://www.thebakken.org/artifacts/database/artifact.asp?type=category&category=L&id=1874

Incidentally, raw peanuts are perfectly edible but I prefer the taste afteer they are roasted.

OK, YT2095, perhaps you would like to explain how come it works better with the salt since you think the only reaction is with the acetic acid?

I may be mistaken, but I think the filter you need to get pictures of the sun is a nearly black one to discard the overwhelming bulk of the light. IIRC silvered mylar is often used.

A single line filter (very narrow bandwidth) can get some beautiful images but they are not cheap.

Also, contrast with the sky behind the sun isn't an issue. If you can see the sun properly then the sky will be black.

It's just as viable as science if I seek to falsify your hypothesis (that this stuff is harmful).

"I have a few questions as to how real world the studies are overall. In one reference a few homes were used as a study, I would say that can hardly account for the reality of the products use constantly all over the world. "

If you don't think studies of a few houses are valid (which may be a fair point) then you can take comfort from the fact that this stuff has (as you say) been in use for ages without much evidence of resistance.

In the long run there's every chance that some bugs will become resistant to triclosan.

So what?

It's not used directly in medicine; there are other products that do the same job; resistance to triclosan will not make the bugs better able to harm people (probably the reverse). The only losers will be the manufacturers.

Did it occur to you that we might agree with them?

They certainly have a couple of valid points- their product is based on triclosan which is relatively non specific in its actions so, to become resistant, a bacterium would have to simultaneously change a number of its metabolic pathways. This is unlikely as shown by the rarity of triclosan resistance noted even after many years of its use in a wide variety of products.

Secondly their produc seeks to maintain a high enough concentration of the active material that it kills things. Dead things can't evolve resistance.

One of the major contributions to resistance to antibiotics is the unreliabillity of people. They take the pills for too short at time, so there is a better chance of the bugs surviving and being able to develop resistance.

Until you can answer these points (as well as any others they may make) I think you are not on the scientificly justfied side of this debate.

Not all mass specs use a magnetic field (at least in a conventional sense). Quadrupole systems use an alternating elctric field and a static one to sort ions by mass.

http://en.wikipedia.org/wiki/Quadrupole_mass_analyzer

More to the point, time of flight spectrometers produce a pulse of ions (typically from a laser pulse hitting the sample). They then acclerate these ions through a known field and wait for them to arrive at a detector. The heavier they are the less they get accelerated and so the longer they take. With a bit of maths you can calibrate that and get a mass spectrum.

http://en.wikipedia.org/wiki/Time-of-flight_mass_spectrometry

Do perfluorates exist?

In principle you might get something like this

http://en.wikipedia.org/wiki/Iodine_clock_reaction

to work but 4 days would be a challenge.

Does this help?

http://en.wikipedia.org/wiki/Tetrathionate

the sulphurs at the ends are 6 valent.

You might want to look up the solubillity of MgSO4 in water and in alcohol.

I doubt anyone has tried. I guess that a ship with an electrical fire on it might have sunk in the sea- would that count?

Sorry, but it's never going to work.

Imagine you have a capacitor and a "signal generator" that can generate the signal you are after (about 10^19 Hz).

You connect the output of the generator to the capacitor and electricity flows into the capacitor. About 10^-19 seconds later the electric charge traveling at roughly the speed of light has traveled something like 10pm, about 1/100000 of the size of a typical nucleus. Then the signal generator changes polarity and starts to remove charge from the capacitor. Of ourse,most of the capacitor has yet to receive any indication of the charge coming in yet. In essense if the capacitor is bigger than the wavelength of the signal you are looking at then it stops working as a capacitor.

Similar problems occur with trying to make the antenna- it has to be vastly smaller than the nucleus of an atom to work as s simple dipole emitter.

Then there's the problem that no electronic device can switch anything like that fast, the best we can do is milimetre wave stuff and you want something like a million times faster.

If an elecron isn't real what leaves the tracks in a cloud chamber with a beta source in it?

Interesting stuff, and potentially very important to the world's ecconomy.

The idea of finding a small test engine is a good one too, perhaps a small diesel generator would be a good start.

There's one thing that puzzles me.

"the EtOH has to be 100% pure alcohol and the KOH has to be 100% dry also, any moisture and you will make Soap!"

That makes perfect sense but the lab grade KOH I have seen is always about 85% or 87%.

I always assumed the remainder was water. Anyone know what it is?

There are some people who get through life without learning to read or write. On the other hand, I can't help thinking that the litterate ones have a better time.

I guess the same is true for numeracy and an understanding of maths.

OK you don't expect the man in the street to know a lot of calculus (insert "blonde joke" here) but if he knew a bit more about statistics he wouldn't waste his money on the lottery. He wouldn't get taken in by pyramid marketing scams if he knew about the arithmetic (and understood that the world runs out of people before you get rich from one of these schemes).

Most people don't really need to know any maths at all, but that's no reason not to learn it.

Congratulations for going back to learn. The question of what do you need to knoew is dependent on what do you want it for?

I was diligently taught how to invert 3 by 3 (and higher) matricies as part of my chemistry course; in the subnsequent 20 years as a professional chemist I have never had cause to use this arcane piece of information. I will probably live out my years without ever needing it. However, it is useful for some things- that's why I was taught it.

It's very difficult to say what is going to be "useful" in much the same way as it's generally hard to predict the future.