John Cuthber

I don't know the terminal velocity of a pebble, but it can't be that different from a hail stone of the same size.

Assume, for the sake of doing a rough calculation, that the meteorite is 9 times denser than ice (not a bad guess if it's iron).

I'm pretty sure that the viscous drag rises as the square of the velocity and, for an object 9 times denser, the force would be 9 times greater so the velocity would be 3 times greater.

A bit of searching gave me this data

"Research has found that a hailstone's terminal velocity is roughly proportional to the square root of its diameter, with a diameter of 1 cm corresponding to a terminal velocity of 50 km/h (Munich Re, 1984)."

so I gues about 150Km/Hr or 100 mph is the right ballpark as ophiolite said. (or rather less if it's not as dense as iron)

"Why is the "simplest" explanation a non-Biological one? What is so "complicated" about "hey, man, Martian microbes make Methane" ?"

Because rocks are much more simple than life forms.

Was that meant to be a serious question?

We're walking on a fallacious minefield here. We first need to figure out if there's another way methane is produced other than biological processes.

The reaction of hot iron (like a meteor) with carbonates will generate iron carbides. Reaction of these with water will generate a truly awful yeild of methane.

Other metals might well give a better yield but I don't care. I only have to make a bit of methane abiotically to prove the point.

If you generate carbon in the super hot conditions of a star thenn let the star cool that carbon will react with leftover hydrogen to produce methane.

That's another possible, reasonable, explanation.

Of course, it might be that the gas board laid a really long pipeline out into the distant universe in a bid to sell gas to ET, but that's a bit speculative.

Also I can only presume that widdekind is deliberatlely missing the point again.

I was pointing out that extrapolating from one local observation to the whole universe is so bizarely unscientific as to be funny.

What is the point of this thread?

Ask Kleinwolf, he started it.

BTW, is it jusy me or could you ssay that about quite a lot of his threads?

A solution of copper chloride in water will plate a thin layer of copper onto a clean piece of steel placed in it (the "traditional" item is a knife blade or scalpel blade.

Chromium chloride won't.

Long ago the details of a lot of chemistry were worked out with lab equipment not much better than you can find in a school.

I'm pretty sure that, at the temperatures needed to reduce phosphates to phosphorus, the glass would melt. Also phosphoric acid is known to atack glass at high temperatures I think this mixture might do the same.

The cinnamon might help to cover the smell of rotted urine.

It makes a lot more sense to look at the threads that already cover this sort of thing rather than starting a new one.

Would someone like to close this thread?

That is going to be a difficult thing to do if, because of the actual performance characteristics of each vehicle, they actually DO need to buy gas guzzlers.

 

I was being ironic.

Anyway, 200 years ago there were no gas guzzlers but humanity got by. There was no need for them then.

I contend that there is no need for them now.

It's easy to replace the SUV; we just need to explain to buyers that they don't need to buy gas guzzlers.

"What is this thread about?"

Ask Kleinwolf; he started it.

BTW, is it just my imagination or might that exchange occur in other threads?

Much as I value the importance of accuracy; does it really matter what you would die from without your mast cells?

There are two sorts of medicine; the stuff that works and the alternative.

Before the thalidomide tragedy nobody though about teratogenicity testing. It was widely (though naively) believed that the placenta acted as a barrier to toxins. It doesn't make sense to use it as an example of "failed" testing because it wasn't tested.

The medical establishment is well aware that some problems only show up after clinical trials.

That's what sites like this

http://yellowcard.mhra.gov.uk/

are for.

Herbal medicine is, at least in some cases, not really "alternative". Morphine is still derived from poppies because it's easier and cheaper than synthesising it. The fact that you can't patent it hasn't stopped it being used.

You mean solve using elementary functions?

 

Otherwise you always have a solution, it is defined by the differential equations you have. This is also different to a numerical solution where you use some numerical algorithm.

I mean so that you actually get the right answer.

Saying that the differential equations are a solution is like saying that, in general,

the solution to f(x) = 0 is easy because it's the value of x that makes f(x) = 0.

That's not a solution, that's a restatement of the question.

Once the relativistic and quantum non determinacy aspect of the 3 body problem are considered, I understand that the problem isn't analytically soluble.

If there's really a solution please let me know where I can find it- just the simple case of a helium nucleus and two electrons would do.

Incidentally I'm not talking about chem. eng.; that's knowing more engineering than a chemist and more chemistry than an engineer without needing to know much about either.

"Are Diamagnetism and Paramagnetism classical or quantum mechanics phenomena?"

Yes.

Can I claim the prize please?

What- you want a better answer?

OK how about

Diamagnetism is certainly not classical; it lets you violate Earnshaw's theorem which relies on moving electric (or magnetic) fields emiting energy.

I think paramagnetism is quantum too.

An electron "orbiting round a nucleus" shouldn't be stable, nor should a "spinning" charged particle.

Feel free to give the cash to charity.

By analogy with Widdekind's post;

On the basis of one extensively studied case*, everyone is a 43 year old bloke with a beard.

*That's me, by the way, and I have checked.

Some of the ideas put forward here are really so funny there should be a comedy section.

Since Mr Maxwell calculated the speed of em radiation from the known, measured, values of e0 and mu0 it must have been possible to measure them all those years ago.

It still is.

He then found that the speed he got tallied with the speed of light.

On the other hand, since c and mu0 are fixed by definition, there's no point in measuring them or e0 because it can be calculated.

The measurement of e0 is a high school experiment.

Chemistry is what you get when you realise that those lovely equations that the physicists come up with are impossible to solve so you make a few aproximations.

(3 body problem anyone?)

Please provide a link that supports this assertion.

"We can already make computer programs that can pass the Turing Test. "

(except of course for the trivial cases like a machine that can emulate a person perfectly; assuming the person to be asleep, mute, unable to type...)

I always thought it was to let you know when someone telephoned your fax/ modem line.

Quite a lot of things are difficult to explain in classical physics (ie without QM).

The spectra of atoms and molecules, black body radiation, superfluidity and superconductivity spring to mind, but there are plenty of other examples.

I'd like to see a solution to Maxwell's equations for an oscilating dipole that doesn't emit EM radiation.

As far as I can see this thread should be in the "speculation" section of the site.

Has anyone checked that people can reliably pass the Turing test?

To get back to something like the original question. Bad guys would have no qualms about shooting these "robocops" on sight. The crime would only be property damage even if they were caught, and most of the time they wouldn't get caught. Then you would have to spend resources repairing the robots.

I think that there are better ways of spending the tax payer's ££$$.

Let's see them prove this assertion about (holy zarquon!) singing fish "Most ichthyologists—scientists who specialize in sea kitten biology—agree that this is just about the cutest thing ever."

Don't forget to account for radioactive heating.

Anyway, if the sound is loud enough to cause the glass to deform significantly it might induce (or speed up) devitrification.

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

But I think you would need to be nearly breaking the glass before this was a significant effect.

I would like to point out, that iron is not a product of blast furnaces. Smelting only extracts previously existing Iron from rocks.

 

An apt, and accurate, analogy would be:

 

Iron is produced by

Big Stars

, and distributed by

Supernovae

. The presence of Iron implies the past presence of

Big Stars

, and

Supernovae

.

 

I'm sure, however, that there are Industrial Byproducts specific to Smelting & Blast Furnaces. And, the presence of those specific "Smelting signature compounds" (as it were) would, in fact, imply the presence of Heavy Industry on our hypothetical planet, yes?

 

I am glad everybody found this discussion stimulating. Logically, the link between Methane & Biology, coupled with the ubiquity of the former, suggests the possible ubiquity of the latter.

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Merged post follows:

Consecutive posts merged

 

 

Are Molecular Clouds, where most Methane is apparently observed, Reducing Environments ?

Ho hum.

I guess I should have made it clear that I was talking about metalic iron rather than the iron nucleus (without reguard for oxidations state).

Oh! hang on a minute, I did. Unless you think that blast furnaces are nuclear reactors.

If it helps to destroy the strawman please insert the word "metalic" in front of the word iron wherever it apears in my original post.