DC Wave Questions

*Look* at the statement:

Water can "boil" at 0C too.

It is *correct*, as you've all been very hasty to demonstrate. It is not so precise as to say "at 0.010C", but certainly that value is well within the normal meaning of "0C" (what, -.5 to

+.5 C!).

And while sublimation might happen at that temperature too, as might just simple evaporation, the fact that it doesn't break into a full nucleate boiling state does *not* make what was stated wrong either.

But all of your squirming and name calling clearly does identify each of you! I don't need to call any of you names, because *you* are providing everyone who reads these articles with all they need to know, whether someone actually puts a label on it or not.

If course when *you* provide so many handy labels, you'll have to expect readers to use exactly those when they think of you.

I didn't do any thrashing - I went right for the answer:

------------------- Subject: Re: DC Wave Questi> On Wed, 15 Jun 2005 23:37:49 GMT, Tom MacIntyre

According to the graph at

, approx.

10^3 Pa, whatever the hell that means. Obviously, an atmosphere is up there near the "annoying point", ;-) , between 10^8 and 10^9 Pa.

------------------

But you might have missed it because it wasn't from "Pig Bladder". ;-)

And, admittedly, at that point in time I hadn't realized that that's called the "triple point", but that _was_ the point I was referring to.

Cheers! Rich

Either what I wrote did not come out how I intended, or you disagree that de's can be used to solve a circuit. You almost alluded to de's before so probably that's not it. So to Mr. Kelly, let me rephrase that to a more bland "Yes. Although I guess one could use time domain." Apologies.

And to you, too, Al. I'm sorry. Sorry you got fired from the cafeteria at Motorola. After 30 years "in electronics" that's a pretty hard break for the "Kitchen Man".

j

Huh? The issue is not whether water can be a gas at 0C, rather can it

*boil*. Since there is nowhere in the phase diagram that the water and gas phase touch each other at 0C, my guess is that it cannot boil at 0C, at *any* pressure. It's only a guess though. ;-)

What? Evaporation only occurs between the liquid and gas phases. I suppose you're proposing that it somehow "tunnels" through the solid phase at 0C? Me thinks you need to go back to high school physics.

Squirming? Try reading the phase diagram that has been put right in front of your nose. Water cannot "boil" at 0C. ...not possible.

"Handy" labels like "gas", "liquid", "solid", "boil", "melt", and "sublimate"? I guess you have a point. We're being *so* judgemental. ...hurt your feelings?

Did you even look at the charts? Did you read the many posts, all of which agreed that at 0.01C, water can be a solid, a liquid, or a gas.

Since what was specified was "0C", *not* 0.00C, arguing that 0.01 is different than 0C is silly. As noted, 0C covers anything from

-0.5 to +0.5C, because no decimal precison was specified.

Since at 0C it can be *any* of those... what's your point?

Learn to read. People cannot understand the statement 'Water can "boil" at 0C too.' have a problem with the English language. I you are going to claim you speak English as a second language, I'll listen, otherwise not.

All this pedantic nashing of teeth for people who can't even read common English syntax is amazing.

I have no problem reading. OTOH, you have a problem with high school physics. At no pressure, at 0C, is water both a liquid and a gas, therefor water *CANNOT BOIL* at 0C. It must become a solid when transitioning between a liquid and gas at 0C.

Correct physics is pedantic? Nice try, but perhaps you want to look at the phase diagram again.

Not writing what *you* want to read is hardly an error on *my* part.

The pressure is commonly known, was not the point, and your question was out of place and trivially ignored.

Which is to say, who cares if you asked a dumb question?

Learn to read. Your life won't be so filled with angst and bitterness.

What a lot of you are missing though is that the diagrams you are looking at are equilibrium states. Take a large quantitiy of liquid water at 0.05 C and let it stand. Now, have it in a chamber at something like 1 kPa. Next,

*rapidly* reduce the pressure on the surface (maybe suddenly open it to a large vacumn chamber). You can then get evaporation to cool the liquid and at the same time get some of the water to violently change phase to a gas (i.e. 'boil'). You will also get a far amount of ice formation as the latent heat of vaporization is supplied by fusing some of the water into ice.

Of course, this is only a transitory phenomenon, but it is 'boiling'

daestrom

No, it sounds to me like he knows his phase diagrams. Water can indeed be made to both boil and freeze (simultaneously) near 0C if the pressure is appropriately low. I don't recall the exact pressure, but it's a medium vacuum (1 Torr, 50 Microns,... ???) That combination of temperature and pressure is called the triple point of water because all 3 phases of water exist in equilibrium there. It is a fundamental property of water that can be used to calibrate thermometers.

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----------------------------------------------- Jim Adney snipped-for-privacy@vwtype3.org Madison, WI 53711 USA

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In fact, that's all you *ever* talk about.

Perfect example!

Spelling flames, John, just *do* become you perfectly!

This type of discussion is pointless and harmful. I've known brilliant people, some at Bell Labs, who had difficulty spelling. Some Engineers and Scientists had excellent command of the language (both English and English!), but weren't as "swift" as the ones with language usage or spelling problems. It's the luck of the draw either way.

It's quite difficult sometimes, but lets all try to be a bit nicer.

Awaiting flames.....

Don

Didn't get what you meant by "de's." It is now somewhat apparent that you mean "differential equations." So ok then, apologies all around.

Actually, I've never worked for Motorola. I didn't even know they had a cafeteria. They have some nice cafeterias at Microsoft, but I've never worked for them, either. You must have me confused with some other guy who's good in the kitchen *and* the garage. It happens.