DC Wave Questions

Like I said before, Don, the big deal is people with nothing better to do than start internet arguments, all the while ignoring all the bits of knowledge that spill out during the course of same. Case in point.

That was never five minutes!?

No, but there's an awesome graph - did I mention something that I called "the Annoying Point" - in either another branch here or another thread that had also degenerated to a virtually amusing point. ;-) Oh, as a matter of fact, I'm almost sure that it's in another response to this very John F. x Floyd L.D. pissfest.

Anyways, if you go to the URL above, and just scroll down to below the first paragraph, which is a page in a teeny tiny monitor; there's a couple of awesome graphics. There are a whole bunch of points that could be construed as "The Triple Point", like, at 10^3 Pa - One kilopascal? at 273ish K, where water can freeze and boil simultaneously.

And if you look up in the "increasing pressure" direction, you'll see a kind of "crowded" or "busy" area. There's an enlargement of that area - where the "Triple- Point" _could_ be construed to be that little blue area labeled "III". But that _couldn't_ be the triple point, because there's no steam!

So, yeah, I have no idea what the triple-point of water is, other than that I'd heard where "the three states" all come together.

So, OK - I'm guessing about 273ish K at about one kilopascal. ;-)

(and the "lame" crack came about by your accolade of "Good one, J..." for merely expressing an invitation to do a web search that took me all of about four seconds. Sorry, I just didn't think that it was that great big a deal for a guy to say, "put your money where your mouth is." I since have, and nobody seems to have noticed that I've stumbled on a site that tells not only about the ten states of ice, but also, get this:

------ Enthalpy of Vaporization [61] 45.054 kJ mol-1 (0°C), 40.657 kJ mol-1 (100°C)

Enthalpy of Fusion 6.0095 kJ mol-1 (0°C, 101.325 kPa) [60] 6.354 kJ mol-1 (81.6°C, 2150 MPa, ice VI) [535]

Enthalpy of Sublimation 51.06 kJ mol-1 (0°C)

------ from amongst parameters that I didn't even know there were, at

Wait a minute! There's a picture of the triple-point!

Kewl! "(273.16 K "exactly ...) The triple point is the temperature and pressure at which three phases (here liquid water, hexagonal ice, and water vapor) coexist at equilibrium, and will transform phase with suitable but tiny changes in temperature or pressure."

So, now, I guess I do! :-D

Thanks! Rich

Confining comments to the topic makes newsgoups work better.

I believe that the "boiling point" is when the partial pressure of the liquid at the applied pressure and temperature is equal to the applied pressure. "Boiling" may be entirely apporpriate.

Bud--

Reading back through the thread I can see how John attributed the "tutorials" to "the Phantom", but the "tutorials" quote (in "the Phantom" post) was lifted from a post by Don Lancaster. I used square brackets as they are commonly used.

Bud--

OK, my final position:

Whoever said that DC cannot exist, shouldn't authoring tutorials.

and

Whoever posts stuff typed by others, without the > thingie first, is likely to confuse folks.

John

I see what happened.

In retrospect it is clear the "tutorial quote" came from one of Don Lancaster's posts. However, when the Phantom used it in his post, much of Don Lancaster's post was not attributed to him (Don): As with the Phantom's post, there were no attribution carrot(s) so it appeared to be part of the Phantom's post.

Subsequent posts were targeting what incorrectly appeared to be Phantom's tutorials.

All that aside, always in for a penny in for a pound, I now conclude that my remark was aimed at Don Lancaster's comment on DC.

Take your best shots.

Don (B)

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

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

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

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".

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

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,

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

daestrom