Misplaced Pages

Revision as of 04:32, 12 August 2007

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You can leave messages here for me.
Greg L 17:33, 4 July 2006 (UTC)

Featured picture candidate

An animation uploaded by you has been promoted to featured picture status Your image, Image:Translational motion.gif, was nominated on Misplaced Pages:Featured picture candidates, gained a consensus of support, and has been promoted. If you would like to nominate an image, please do so at Misplaced Pages:Featured picture candidates. Thank you for your contribution! 28 January 2007 (UTC)

Hi Greg,

Just to let you know that the Featured Picture Image:Translational_motion.gif is due to make an appearance as Picture of the Day on May 14, 2007. If you get a chance, you can check and improve the caption at Template:POTD/2007-05-14. howcheng {chat} 18:42, 19 April 2007 (UTC)

Featured Picture Candidate

I nominated one of your animations (Image:Translational motion.gif) to be featured. See Misplaced Pages:Featured picture candidates/Translational Motion. —EdGl 02:05, 18 January 2007 (UTC)

Thanks. I wrote back on your personal discussion page. Greg L 20:45, 18 January 2007 (UTC)

(concerning your last post on my talk page) You should definitely speak out and state your case on the featured picture candidates page! —EdGl 21:27, 18 January 2007 (UTC)

I left a note on Antilived's talk page concerning his vote, directing him to my talk page. —EdGl 01:36, 19 January 2007 (UTC)

There are two users who voted neutral but clearly like it and lean support, voting neutral only because of minor issues. In this case it's not really a bad thing, since there are a few support votes and no oppose votes. Only a few more days left. —EdGl 04:47, 22 January 2007 (UTC)

That's the way I see it. Thanks. Greg L 05:13, 22 January 2007 (UTC)

Woohoo, the animation is now featured! →EdGl 00:26, 29 January 2007 (UTC)

It says on the picture-of-the-day page that "featured images are currently selected in the order they were promoted". So, it won't be on the main page in a while. They have already selected pics up to March 1st. →EdGl 01:00, 30 January 2007 (UTC)

• Of course, that's fine. I only picked Temperature because it was the first. Regards. Trebor 07:26, 31 January 2007 (UTC)

Elastic Collisions

I've been meaning to ask you - in the animation, are the atoms experiencing elastic collisions or inelastic collisions? In the animation it looks elastic, but apparently they should be inelastic. Now, I know making the collisions inelastic would be a lot harder, it's just that as an AP Physics student I pick up on these things ;) →EdGl 16:18, 27 January 2007 (UTC)

Very cool indeed! I think the inelastic collision article contradicts what you're saying, which is why I got confused there for a second. Maybe you can use your expertise to help along that article and any other relevant articles you may find. We can't have misinformation in an encyclopedia! →EdGl 16:59, 27 January 2007 (UTC)

I'm talking about this sentence: "Collisions between molecules of a gas or liquid may also be inelastic as they cause changes in vibrational and rotational energy levels." Hmm, I guess this is something you wouldn't be able to see in your animation, since the Helium is represented by circles rather than "atomic shapes". I'm guessing the helium atoms you are representing in the animation are diatomic molecules rather than single atoms, am I right? It could be that you are envisioning atom-to-atom collisions while I am thinking about molecule-to-molecule ones. I'm assuming there's a difference (?). →EdGl 17:30, 27 January 2007 (UTC)

This diff shows it was User:Numsgil who added this information. I left a not on his talk page saying I'll remove the info from the article. I'm not going to add anything to the article, but if you see something that could be added, you should; it's a rather poor-quality article (except for the animation lol). Hey, maybe you could put your soon-to-be-featured animation into the elastic collision article? I think that's a great idea! →EdGl 18:26, 27 January 2007 (UTC)

Kilogram

I edited your recent addition to the kilogram page and added a citation needed tag. I noticed that you labeled the source you got the information out of in the edit summary, but not in the article. Since I don't have that source, it would be great if you'd check and make sure I didn't introduce any errors in my edit, make sure that the information near the fact tag I added is all in the reference you were using, and add your new reference as a footnote. Thanks!Enuja 08:38, 8 March 2007 (UTC)

• Thanks so much! I'm a bit fan of the info you added; it's great to know what the prototype is made of and when it was made. I'm happy with the statement of ratification by the 1st CGPM; it doesn't read as repetitive any more. Enuja

Images

Sorry I didn't reply sooner - thanks for the offer, but I'm quite content with the images already on my page. They have amazing quality, by the way. :-) Mrug 21:10, 28 March 2007 (UTC)

Image:Z-machine480.jpg listed for deletion

An image or media file that you uploaded or altered, Image:Z-machine480.jpg, has been listed at Misplaced Pages:Images and media for deletion. Please look there to see why this is (you may have to search for the title of the image to find its entry), if you are interested in it not being deleted. Thank you. — Rebelguys2 17:58, 14 April 2007 (UTC)

So, what was the result? They seem to have decided to delete it, please correct me if I'm wrong. Mrug 10:47, 20 April 2007 (UTC)

So How About That?

Your animation will be on the main page! I'm excited, and I'm sure you are too. Congratulations. →EdGl 23:22, 19 April 2007 (UTC)

Sucralose

It has taken me a few days, but I've left a reply to your comments at Talk:Sucralose. Enjoy! --Ed (Edgar181) 20:37, 25 April 2007 (UTC)

HCP Close packing

Hello, I am an NYU student and an intern at the Mayo Clinic. For my computer program I need to create a lattice for a "closest packing" of same-size spheres. I was wondering if I could ask your help.

I have so far determined how to make each plane of my A-B-A-B-... HCP lattice but I dont know the z coordinates.

In otherwords I have the first plane, the balls that are resting on the z=0 plane, those balls all have their centers with a z coordinate of r, the radius. Then the balls are distributed correctly according to the HCP packing on the z=r plane. Then I have the next level on top of the first, those are all distributed according to A-B-A-B stacking but I don't know what the z coordinate is. It's clearly not z=2*r or z=3*r. So far my guess is z=r+SQRT(3)*r , but I have no geometric way to prove it.

Sorry if this was confusing. Thanks for any help. And thank you ginormously for your photos on the article. Mangledorf 21:39, 25 July 2007 (UTC)

So, I have a new guess. If the next ball on top of three balls forms a tetrahedron then the difference should be the height of the terahedron ( SQRT(6) *(a/3) ) where a is the length of the side and the length is 2*r so the height of the sec ond row would be r+SQRT(6) *(2*r/3). Is this correct?

See my response here on your talk page. Greg L (my talk) 23:01, 25 July 2007 (UTC)

Thanks for the links, the one had exactly what I needed. Turns out it is a tetrahedron even if I had to get out the tennis balls to prove it to myself.Mangledorf 20:49, 26 July 2007 (UTC)

The formula is the height of the tetrahedron formed by the centers of four spheres. Imagine three balls on the ground in a triangle (this arrangement tessalates into the entire plane) then place on ball in the middle. This forms a normal tetrahedron who's height is SQRT(6) *(2*r/3), and that'll be the difference in the z-direction for each stack. It's much easier to prove it with actuall object than on paper, but it matched the first paper you mentioned. Mangledorf 16:43, 27 July 2007 (UTC)

Mangledorf: I can confirm that your formula must be the correct one. I apparently forgot just how far I must have zoomed in with my CAD program when setting the z-axis but I managed to nail it amazingly close. The size of the balls in the Fig. 2 ray-tracing is Ø 10.16 mm (r = 5.08). Shown below is the results of your formula (top) and my CAD program (bottom):

8.295 605 262 225 696 492 561 47 mm
8.295 605 253

Are you going to add this formula to the Close packing article? Greg L (my talk) 17:12, 27 July 2007 (UTC)

I would like to add it. When I have it totally straightened out and a good reference source made out, I will. Thanks for the back up. I was actually surprised it wasn't on the site to begin with, but that's what we're all here to do, eh? Mangledorf 20:32, 27 July 2007 (UTC)

Greg L (my talk) 19:50, 29 July 2007 (UTC)

Thermodynamic Definitions at T=0 in a vacuum

Thanks for the interesting question on my talk page. I haven't contributed to Misplaced Pages lately and my opinion is definitely not authoritative, but I try. I think most people in thermo define internal energy or enthalpy based on what they reasonably think will cause a significant change in the system they are studying.

Imagine a box with a shaft sticking out of it in a vacuum at around T=0 with the shaft poking out of the vacuum chamber somehow. Something in the box makes the shaft turn for a while, and that motion does useful work or generates heat outside of the vacuum chamber.

Maybe there's some Casimir effect gizmo in the box utilizing electromagnetic force due to changes in zero point energy. Or maybe there's a weight falling within the box utilizing gravity due to changes in height. Or maybe there's some radioactive material in the box. But the energy inside the box is decreasing while work is being done or heat is being generated outside.

That energy inside the box is thermodynamic internal energy at T=0 in a vacuum. See the table of intensive and extensive variables in section 1.3 in Alberty's http://www.iupac.org/publications/pac/2001/pdf/7308x1349.pdf and the equations in section 1.4. So the answer to your question is no. U does not have to exclude zero point energy. U should include ZPE if its inclusion will significantly alter the system under consideration. But there's no need to include it as an additional "tally" that just remains constant during a process. Flying Jazz 05:52, 11 August 2007 (UTC)

I would not write At T=0, these crystals have minimal internal energy (retaining only that due to ZPE). I would either remove the word "only" or, better yet, remove the phrase in parentheses entirely. Alberty's paper (a publication of IUPAC so it should carry some weight for Misplaced Pages) makes it clear that internal energy may include or exclude many different terms. Flying Jazz 14:13, 11 August 2007 (UTC)

I cited the Alberty reference to answer a question you left on my talk page. All I meant to say is that thermodynamic potentials like internal energy and enthalpy are useful because the variables in the particular system under study determine whether the potentials include or exclude some terms. But Alberty only uses the word "temperature" a few times in that article, so I don't think a reference to Alberty is justified in the Thermodynamic temperature article. I hope you consider reducing the length of many of your Notes in this article. I've never seen such tangential Notes in Misplaced Pages. If the information is useful but tangential, it should be added to other articles and linked to instead of placed in a Note. I'd also consider removing the History section. We already have History_of_thermodynamics and Timeline_of_thermodynamics,_statistical_mechanics,_and_random_processes for historical information. Details about contributions should be included in the biographical articles. Sorry if I sound overly pushy, but the article as a whole is too long and cumbersome in my opinion. Flying Jazz 20:18, 11 August 2007 (UTC)

Featured image nominated for delisting

I saw the image above and was surprised to see it was a featured image of Misplaced Pages in spite of the fact that pressure and temperature values are given for a two dimensional representation. I've nominated the image for delisting. See Misplaced Pages:Featured_picture_candidates/delist/Translational_Motion to comment. Flying Jazz 00:17, 12 August 2007 (UTC)

What’s your problem? I wish I had never contacted you asking your opinion on a mathematics issue. People like you make editing Misplaced Pages so un-fun. That’s fine, I’ll play your petty game. Do you just go around in the world angry over something and take your frustrations out on others? Greg L (my talk) 03:41, 12 August 2007 (UTC)

P.S. Regarding deleting the above comment from your user page as a “personal attack”, unfortunately, it’s not; they’re all fair questions given the way you seem to operate. I suggest we part ways and you go find someone else to pester. Greg L (my talk) 04:32, 12 August 2007 (UTC)