User talk:Sbharris/archive8

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Archive #8 All messages from July, 2008 though the end of 2009.

Mass/Energy

My thinking on this is as follows: the issue for people learning this thing is that they don't understand the physics. The idea of E=mc2 is that energy and mass are the same thing. Once you understand that, you can redefine mass to be the length of the energy momentum vector, but not before. There is no need to think of E=mc2 as a special case of anything, it is a physical identification between mass and energy. This physics is the subtle point, and the relativistic dispersion relation is just trivial nonsense compared to that.Likebox (talk) 15:56, 4 July 2009 (UTC)

My thinking is opposite. I have no problem with the idea that rest/invariant mass and rest/invariant energy "are the same thing." But this statement is just wrong for relativistic energy where there is some momentum component involved, because it forces a new definition of "mass" which isn't anything like the mass we're all used to. So why should I be required to call it "mass" just so it we have something we can call "m" that still satisfies E/c^2 even for non-invariant E's?

Example: a particle moves by me with considerable kinetic energy-- enough to double its E. Does it double its "mass"? No, not really. Some components(!) of its inertia and momentum get larger, but they vary in direction. Its gravitational field with regard to me isn't even definable without picking a coordinate system, but it's clearly not larger by all measures, because no matter how fast the thing goes, it will never become a black hole in the view of any observer, including me. So why am I supposed to call its new attributes (whatever they are) "mass"? Just to satisfy people who continue to want to use E=c^2 for everything, which means people who want to insist that "energy" (of any kind) is just the same as "mass" (of some kind). I don't find that useful. I don't see anything in it that is physical. "Relativistic mass" is made up by people who can't stand not to have one rule for everything, even when it doesn't work very well. It's like insisting that all Japanese peole are short, and when confronted by a 7 foot tall Japanese man, insisting on a special definition of "Japanese shortness" which will allow Japanese to be short by definition. What's the point?SBHarris 18:16, 4 July 2009 (UTC)

I get your point, but there is no way to discuss this without writing down formulas which will scare off the readers. The relation "E=mc2" can be understood two ways:

1. as a way of changing units between units of mass and units of energy
2. as the zero momentum limit of E^2 - p^2 = m^2

Point 1 is 90% of the physics. Point 2 is defining "m" as the length of a vector whose time component is the energy. So if you take the view of point 2, you make the distiction between "mass" and "energy" look very important, when it is no more deep than the distinction between "speed" and "velocity".

While it is useful and important to not waste the word mass, and use it to mean "rest mass", point 1 is nearly all the physics, and this is what lay people get confused about. Point 2 is not confusing. Really. I never got confused about point 2, and anyone who understands the concepts involved won't get confused either.

On the other hand, point 1 causes endless confusion. This is essential, because the content of point 1 includes the following:

• Hot coffee weighs more than cold coffee
• when a pitcher throws a baseball, he is slightly lighter at the end than at the beginning.
• Heavy stuff can be thrown into a black hole to do work, and the heavier the stuff the more the work.

About "relativistic mass", you are overstating what this is supposed to be. The "relativistic mass" is just the energy, interpreted in mass units, which is legitimate, by point 1. There is also the "x-relativistic-mass" which is the mass value of the x-compoenent of momentum, but it's harder to interpret these as masses because they don't weigh so easily.Likebox (talk) 18:29, 4 July 2009 (UTC)

Hot coffee weighing more than cold is not point 1 above, but point 2. It's a zero momentum limit. It's the invariant mass of the coffee you're weighing, because you're in the coffee's COM frame. Same for your example 3 (how would you even calculate this without going to the COM frame?). I don't know what you mean to say by example #2. Of course he's lighter-- he's missing the baseball (no energy involved, just mass). If you examine the system of ball+player, that's another zero-momentum problem, point 2 (and the COM frame system is NOT lighter; it has the same invariant mass always before and after the throw). Frankly, I don't know ANYTHING that is made easier by your point 1, alone. The reason particle physicists calculate invariant masses (which is equivalent to moving to the COM frame, thus your second point), is that using point 1 does nothing for anything. It's just not very useful as a general statement, outside the COM frame and zero momentum limit. SBHarris 19:01, 4 July 2009 (UTC)

What I meant was that if a pitcher throws baseball slowly, then he ends up a little heavier than if the pitcher throws the same baseball quickly. The length of his energy momentum vector is slightly shorter.

The mass carried away from the pitcher by the baseball is just the total energy of the baseball, converted to mass units. It's not an invariant concept, but so what? It's just a different system of units for energy that makes mass-energy equivalence transparent. It is only used pedagogically, because frankly, once you understand what's going on, there are no more confusions about anything.Likebox (talk) 19:11, 4 July 2009 (UTC)

Let me say it a different way: The equation E=mc2 is a tautology in natural units, it says that E=m. Therefore it can correctly be thought of as a tautology in any units. As a tautology, it is just saying that you can rename "energy" "mass" and "mass" "energy" with no confusion.

I will not give in on this, because I have had the miserable unfortunate experience of having to explain this point a thousand times to ignorant people, most recently in the conversation you contributed to where the point was that the solar system is lighter than the individual planets and atoms that make it up. The only way to get this across and make it stick is to use mass units for the total energy. It's not wrong. It just is not an invariant quantity associated to a particle. Don't get hung up on invariance. The "kinetic energy" is not invariant either, nor is the "gravitational field" or "vector potential". That's not a problem at all. Covariant quantities are just as physical as invariant quantities.Likebox (talk) 19:16, 4 July 2009 (UTC)

(deindent) About your black hole example: when the particle is ultra-ultra relativistic, you won't be able to tell if it's a black hole or not, because a highly boosted black hole will have exactly the same gravitational field. You will only be able to tell it isn't collapsed by physically chasing the particle until you are near it's rest frame. If you try and make a measurement of the particle with stationary instruments, you will cause it to collapse into a black hole immediately.Likebox (talk) 19:18, 4 July 2009 (UTC)

Further comment on your fast moving particle: a particle whizzing by you very fast will pull you gravitationally by an amount proportional to its relativistic mass. The faster it goes, the more deflection. This is not ambiguous or arguable, but it is slightly tricky to calculate well because you need to boost the gravitational field.Likebox (talk) 19:29, 4 July 2009 (UTC)

(Outdent) Yes, the fast moving particle will pull you transversely harder, but that is because its grav field is pancaked by space contraction (same thing happens with a charge). In the forward direction, its field is actually weaker. Overall, I'm not sure there's any change (there isn't for a charge, and for a relativistic particle, I'm not sure how you'd integrate "overall").

Nevertheless, there is certainly a difference between a untrarelativistic particle and a black hole, no matter how pancaked they are by relative motion. One is spitting out Hawking radiation, and if it's just the right size to blow up as it passes you, you'll see that. An extremely boosted particle of that same mass will not evaporate, radiate, blow up-- you don't need an instrument. It can't do anything it doesn't do in its rest frame. A rest-frame black hole is active-- it doesn't just sit there. It has an infinite metric-curvature somewhere which no boost will ever give.

I'm not sure what you mean by covariant quantities. Lorentz covariant quantities are what I MEAN by "invariant"-- they are the familiar 4-vectors. Yes, kinetic energy is not one of those. No, I don't think kinetic energy is as "real" as invariant energy (or invariant mass). Nothing that everybody in all frames "sees" is as "real" as something that goes away and doesn't exist in some frames. I think that's part of what nature is trying to tell you by allowing you to make black holes with enough invariant mass, but no amount of "relativistic mass". Or you can make particles out of enough "invariant energy" but no amount of relativistic energy will do, because in a sense it's not real. This is one reason why a single photon will never turn into any other particle-- all the energy it has is in the eye of the beholder, and that's not enough juice for nature to say "okay, I can make electrons and positrons with this." Nor the kinetic energy of a single particle, without another interacting with it. You can blame this on momentum, but notice the same is true of an evaporating black hole. Nature's trying to tell you the same thing-- you can't cash a promise, or just one observer's (unverifiable) opinion. And nature won't either.

The baseball is instructive. The energy carried away by the moving baseball (nonzero p) actually cannot be calculated straightforwardly in any manner as you suggest, because it's frame dependent. It has no "answer". It's a slightly different quantity as viewed from the pitcher, than as seen from the COM frame where he recoils (put him in a spacesuit in space), and carries some kinetic energy with him (more than than he sees himself take in HIS frame, where he gets NONE). The only "real" quantity is the total energy (the ball+player's invariant mass) which doesn't change no matter what frame you choose (even the ball's, in which IT takes NO energy except its rest mass, and all kinetic energy goes to the pitcher). In neither the pitcher nor ball's frame is energy conserved across the throw, because you have to change frames to follow each one, and changing frames results in non-conservation of "relativistic mass." However, since it doesn't matter if you change frames for invariant mass, it is conserved for the system, and you can calculate it from any frame, ball or pitcher, before or after the throw. Thus you see my regard for it. That which is conserved is more real than that which is not. You have to keep your frame rigidly fixed through the throw to conserve relativistic mass, and even then it's for the system, and even then, different observers will not agree on what its value is. As for how much energy the baseball "gets," forget it in any type of calculation. It's not "real." It's an illusion to think it is.

As for not giving up on E = mc^2 for nonzero momentum situations, why do you insist on keeping it, when the equation was never built for it? The correct equation is E^2 = m^2 + p^2, not E = m. If you insist on E = m for situations in which there is indeed a net p, all it does is result in a bastard type of m which is observer-dependent, which causes student confusion by making photons massive, and which is generally not very useful.

Why do you need the thing to explain why bound systems are less massive? A bound system often has no net p, so E = m. Bound systems are less massive simply because you've removed the binding energy E, and thus have removed some m with it. That is all. SBHarris 21:01, 4 July 2009 (UTC)

In response to your comments:

1. The integrated gravitational field for a fast moving particle will give you the relativistic mass of the particle, not the rest mass. The reason is that the simultaneity slice on which you integrate the field is boosted. The easiest way to verify this is to imagine that the fast moving particle is going around in circles in a small magnetic field, and then the total momentum of the system particle+magnetic field is zero over long times, but assuming the field has negligible mass contribution, the gravitational field of the particle will be according to its instantaneous relativistic mass, not by its rest mass.
2. The Hawking radiation from a fast moving black hole is frozen by time dilation, and doesn't get emitted. When the black hole is forming in a boosted frame, you can't tell that it is collapsing because the collapse time is stretched by time dilation, and the question of the singularity or the horizon is impossible to resolve because of the ultra-relativistic motion. If you try to probe the ultra-relativistic particle in a way that is detailed enough to reveal the horizon, the horizon will form.
3. Both energy and mass are conserved for isolated systems, so both are "physical" in the sense that you want (although there are physical quantities like Entropy which are not conserved, and other physical quantities like the direction of the angular momentum which are never frame independent).
4. The pitcher/baseball question is not ambiguous. A pitcher stands on a mound and throws a baseball at 10 mph, vs. same pitcher throws baseball at 90mph. What's the difference in mass between the end-state of the two pitchers? It's exactly the difference relativistic mass of the baseball.

I agree with you completely that students get confused. The question is: what is it that they are confused by? I am 100% sure that what they are confused about is not the distinction between rest energy and energy. What they are confused by is the philosophical identification of mass and energy that is required to even understand the energy momentum vector physically.Likebox (talk) 18:33, 5 July 2009 (UTC)

Request for advice

Hi Steven:

I have been trying for some time to add some material to Wavelength which regardless of content, wording or sources is reverted by Srleffler and Dicklyon. The reasons given for these reversions varies greatly, and is generally not specific to particular phrasing or facts but applied in blanket form to erase figures, paragraphs and sections. Counterargument or additional sources have no effect. My reaction to all this after considerable effort is simply that these two editors will revert any contribution made to this article by myself, regardless of the merits.

What I would like from you is some help identifying whether there is any recourse to such behavior on Wikipedia. I have tried a RfC in one instance, and these editors simply deleted the entire section for which RfC was made.

Maybe you have some suggestions? Brews ohare (talk) 22:12, 5 July 2009 (UTC)

Barnstar awarded, and another proposed

		The E=mc² Barnstar
		For massive contributions to scientific articles, particularly articles involving chemistry, physics and mind-bending mathematics, I award thee this barnstar. Preston McConkie (talk • contribs) 16:36, 8 July 2009 (UTC)

Now, I also like your notions on Wiki editors using aliases. I also use my actual identity and make my email available. I'd like to encourage others in this direction by creating a barnstar or service badge for editors who use their real names. Perhaps the non-paranoid barnstar? The service badge of personal pride? What think ye? I suck with graphics and maybe you could help, if interested. --Preston McConkie ^{(talk • contribs)} 16:36, 8 July 2009 (UTC)

Why thank you kindly. I like your other idea also. One of these days I'm going to finish the Wikichickens essay and get it on meta. Meanwhile the barnstar should have something like a busted or dropped mask-- opera mask, Lone Ranger mask. I'm no better with graphics but know some people who might help. A universal sign of a masked dude with a circle-and-slash (no masks) might be fun. SBHarris 19:39, 8 July 2009 (UTC)

I like the mask idea. And please let me know when you get that essay posted; in fact, if you didn't mind sharing what you have so far, it'd be much appreciated. As a reporter I am sensitive to sharing personal work before the embargo date, so if not that's cool, but I'm bedbound from a back injury and appreciate any intellectual stimulation. There's an email link on my userpage.

Incidentally, yesterday I saw a guy get busted for posting material he'd written himself into the Calvin and Hobbes article. The only reason he didn't get away with it was because he edits under his real name. A Florida professor trying to insert some of his academic writing into a subsection he'd created on "Academic response." Still, I congratulated him for using his own identity. Cheers. --Preston McConkie ^{(talk • contribs)} 19:05, 14 July 2009 (UTC)

My mistake

SBHarris naming you as a sock (Johntex too) was a mistake on my part and I am sorry to you for that. I quickly got a list of names and just wanted to get it to an admin so any harassment would stop. I am a pretty new Wiki user and don’t know all the ins and outs. I am still learning and I should have checked better before making assumptions and should not have jumped to conclusions. I just wanted any contact from one user to stop. Please let me know if there is anything I need to do on my part on any other part of Wiki or for you to rectify my mistake. I feel bad for dragging your name into this. I don’t know exactly what you are saying by “real McCoy” but if you are thinking I am Houston McCoy I am not nor have I ever met the man just know his story and have done a lot of research on it. Once again sorry for my mistake. Carrt81 (talk) 22:21, 13 July 2009 (UTC)

Thanks. Happy editing! SBHarris 22:26, 13 July 2009 (UTC)

Diagram in 'Gold'

I have deleted the offending diagram. Let us see what happens next. Martin Hogbin (talk) 22:21, 19 July 2009 (UTC)

Indeed. Thanks. SBHarris 22:37, 19 July 2009 (UTC)

Gold/nucleogenesis

Hey Mon, Coolest message I've gotten in ages! Thanks so much for your personal reply to my query about the interstellar origins of gold. Way nice. In cheerful solidarity, Smilo --Smilo Don (talk) 17:56, 22 July 2009 (UTC)

You're welcome. Just hit me that your username is a familiar one from the tarpits here in L.A. Maybe we can clone DNA from the dang things. Coolest cat ever, for sure. SBHarris 22:16, 22 July 2009 (UTC)

Re: Are you sure that page is right?

That chem formatting is used on many pages; it saves spaces and looks a bit neater (if visible :) than usual sub+sup. I see it nicely on Win XP/Vista, IE or Firefox. I understand this is important that you don't and would ask technical help, specifying all your PC details (OS, browser, etc.). Regards. Materialscientist (talk) 03:45, 24 July 2009 (UTC)

by the historian Bernard from The Netherlands

Dear writer,

As a historian from The Netherlands I like to change your version of the story. With new research on the role of de Morhenschildt and the Kennedy assassination your story is not the correct version.

Read the new memoires of Willem Oltmans, he stood in close contact with de Morhenschildt.

Regards,

Drs Bernard

Historian The Netherlands —Preceding unsigned comment added by 77.251.53.75 (talk) 10:13, 30 July 2009 (UTC)

ummm...not sure if i'm doing this right!

Sbharris, I hope this is like the wikipedia version of sending you an email, if not I apologize. I just wanted to thank you for updating the spelling of "Fly's" on the Gunfight at The OK Corral page. As I said, I have no clue how wikipedia works, but it wouldn't let me edit the spelling and somehow you did! Thank you so much. It was one of those little things that irked me :) Thanks again! Heather —Preceding unsigned comment added by 75.111.34.123 (talk) 04:57, 16 August 2009 (UTC)

This is, and you did it right (as you see, I've fixed it already). YOu can change nearly anything you see on wikipedia, but some things are changable only by "nameusers". You pick out a name and a password (you need an email account to send to) and in 4 days and after 10 edits, you'll be a "nameuser". Then you can edit semi-protected pages. That said, the file you were looking at: http://en.wikipedia.org/wiki/File:Tombstone1908OKm.JPG can be edited by anybody, in just the way you added a section. Just hit the edit button, fix the spelling, and hit "save." Try it! Welcome to Wikipedia! SBHarris 09:42, 16 August 2009 (UTC)

Nitrogen narcosis at GAC

Hi Steve, I know this is a long shot, but in Nitrogen narcosis I'm trying to find a source for the statement

An early effect may be loss of near-visual accommodation, causing increased difficulty in close-accommodation reading of small numbers in middle-aged or older divers who already have any degree of presbyopia

which you added with this edit back in June 2007. Do you recall any source that verifies it? I know it's true, because it happens to me! but I can't find anything in the literature that confirms it. Best regards and thanks in advance for any help you can give. --RexxS (talk) 10:36, 17 August 2009 (UTC)

I'm afraid it's original research, as it happens to me and every other middle-aged diver I know. But I can't find a source, either. We should try the more extensive literature in nitrous oxide and other anesthetic gases. Otherwise we'll have to take it out. Bummer, since I'm sure I'm right. The problem with the Navy divers is they're all too young presbyopia, and thus for this problem to bother them. SBHarris 03:47, 18 August 2009 (UTC)

I wondered about looking for loss of accomodation with anesthesia, but we'd fall foul of WP:SYNTH, since the mechanism of nitrogen narcosis is not absolutely proven to be the same as that of an anesthetic. I've taken it out for the moment, but I'll keep trying to get a source. As Gene Hobbs says, there's absolutely no funding for research into diving medicine, so the only thing I can think of is to see if an acknowledged expert (like Peter Bennett) has made any pronouncements that we could quote. I'll bug Gene when he's less busy to see if he can come up with some conference papers on the subject. Thanks anyway, and dive safe! --RexxS (talk) 09:41, 18 August 2009 (UTC)

Wikichickens?

Greetings, Dr. Harris. I too edit with my real name, Norm Reitzel. I came across your comments in an article on Lithium, and was surprised, but not too much, to find you here. Congrats on your 10Kth edit. Norm Reitzel (talk) 14:42, 26 August 2009 (UTC)

Thanks, Norm. I think the place would be vastly improved if everybody was connected to their real-life identity and rep, here. There's be a lot less need for WP:CIVIL and far fewer edit wars. And a lot less wasting of time while anonymous people tried to sniff out each other's academic credentials or knowledge (or lack thereof).

Was the article on lithium the one here on Wikipedia, or someplace else? That IS your bar of ultrapure fuelrod zirconium which still sits proudly on my display shelf, right? Anyway, hi. I really am going to have to finish the Wikichickens essay, just for the benefit of the many people who are using the specter of being stalked as an admin, not to come out from behind the mask. In the history of Wikipedia, it is a fact that all the very worst administrators have been anonymous ones, and my own education here started with my being blocked by Essjay. We don't let judges, policemen (and policewomen) or politicians remain anonymous in the real world. When we do allow this (as in the CIA's interrogation of prisoners) we wish we hadn't. Supreme Court Justice Louis Brandeis said, “Sunlight is the best disinfectant.” SBHarris 01:35, 27 August 2009 (UTC)

Tc isotopes

Hm. I guess you are correct about 98Tc. But clear as day, the CRC handbook (87th ed) shows ~6.6 MYA. I'll clean-up the rest of my mess. --mav (talk) 01:58, 12 October 2009 (UTC)

Edition 2002, eh? The CRC has notorious nuclide table printing errors. In the 1970's they got the natural isotopic abundance of K-40 wrong for 4 or 5 years straight. It's too bad, since the thing was the Bible before the internet. Those people who learned chemistry more than 10-15 years ago still feel that way about it. SBHarris 02:46, 13 October 2009 (UTC)

Isotopes of xenon

We keep coming to you with isotopes :-D .. There is a question whether or not WP should state 6 (7) or 9 stable isotopes of xenon. It is again about those long-lived one. I couldn't find a clear answer, and got a reply at "From Mye Flatley, on Xenon stability" (at the bottom of my talk page). Your opinion? Regards. Materialscientist (talk) 22:34, 25 November 2009 (UTC)

Steven, thanks. I understand the part on what and how to count stable - the problem was that some sources apparently do WP:OR :-D and substitute >xxx yrs by =xxx yrs; I wasn't sure I read the right ones. Actually a recent CRC which looked in lists 9 rather than 6. Interestingly, physics.nist.gov relies on the book of Emsley, which sounds ridiculous. I am quite convinced at 9 for the moment. Materialscientist (talk) 23:21, 25 November 2009 (UTC)

Yeah, let's do it that way. Anytime somebody comes up with an "=" half-life and cite as to how it was measured, we can stand ready to remove a nuclide from the list in stable nuclide, as we did for Bi. But we say explicitly how we count these, in that Wiki: Many isotopes that are presumed to be stable (i.e. no radioactivity has been observed for them) are predicted to be radioactive with extremely long half-lives (sometimes as high as 10^18 years or more). If the predicted half-life falls into an experimentally accessible range, such isotopes have a chance to move from the list of stable nuclides to the radioactive category, once their activity is observed. Good examples are bismuth-209 and tungsten-180 which were formerly classed as stable, but have been recently (2003) found to be alpha-active. There are other ways, but this is the only one I could think of which approximates what you see in texts, and isn't ridiculously short. SBHarris 00:46, 26 November 2009 (UTC)

Abuse Response

Greetings! Thank you for filing an Abuse Report for abusive behavior originating from 194.73.190.53. Unfortunately, there was a problem with your filing and it has been rejected. Please see Wikipedia:Abuse response/194.73.190.53 for details on why the filing was rejected. You may also review filing criteria for abuse reports filings. GrooveDog FOREVER 23:35, 28 November 2009 (UTC)

BLP semi-protection petition

Is here: http://en.wikipedia.org/wiki/Wikipedia:BLP_semiprotection_petition

Please consider the arguments there. I hope you will sign. Thanks. SBHarris 03:16, 18 December 2009 (UTC)

Magnet therapy

I've always been under the distinct impression that magnet therapy was a pseudoscience; a sham idea used to sell useless devices to the sick and elderly. But our article on this seems to indicate that is no longer the case. Has the literature changed direction? Could you take a look? I ask b/c there may be pressure to include mentions of magnet therapy as a valid application in corresponding element articles. Already some mention about this at Talk:Titanium#Aqua Titanium and Health Benefits?. --mav (please help review urgent FAC and FARs) 20:45, 21 December 2009 (UTC)

Point of order

Here http://en.wikipedia.org/w/index.php?title=Commodity_money&diff=prev&oldid=225340613 you wrote "...pennies (mostly zinc) and the metal in nickels (mostly copper)..." Is that order reversed. Pennies seem to have more copper! dvdrtrgn (talk) 23:16, 23 December 2009 (UTC)

They seem to, but nowadays do not. Since 1982, US pennies have been almost entirely zinc, with a thin cladding of copper. See Penny (United States coin). And US nickels have more copper than nickel (except for the wartime nickels, they are 75% copper, 25% nickel). I have it right. SBHarris 01:27, 24 December 2009 (UTC)

Dagnabbit! You're right. I thought I'd just trust my fool-eyes on that one... Your new edits make that counter-intuitive truth more clear. Thanks! —Preceding unsigned comment added by Dvdrtrgn (talk • contribs) 23:13, 27 December 2009 (UTC)

This is an archive of past discussions. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page.