User talk:William M. Connolley/Old Talk 6

NOAA Pictures

• I've added sources to the pictures now. Sorry. They should be there if you go to the picture's page.

Warning

Please do not make personal remarks like this:

• you don't even understand what science is.

(William M. Connolley 18:12, 17 Nov 2004 (UTC)) I'm not aware of saying that. If you are referring to GWS, its not there that I can see. Could you possibly make an exception to your custom of never sourcing things and tell me where you got this from?

Glad to oblige:

• Endorsement of GWT - Ed degenerates into nonsense [1]

And it's not "nonsense". So take that back, you, you -- good golly, my keyboard refuses to let me insult you! Must be enchanted or something ;-) --user:Ed Poor (talk) 19:28, Nov 17, 2004 (UTC)

(William M. Connolley 21:57, 17 Nov 2004 (UTC)) Ah, thanks. I'll stand by the text of the edit: its not a personal insult, its a serious attempt to tell you what you don't know. Your statement, to which I was responding: To speak of the science of global warming is to assume that it has been proven *is* ... well, wrong certainly. Calling it nonsense in the edit comment was strong, but defensible. To try to restore civility, I *do* retract the word nonsense and replace it with "wrongness".

I suggest you review the following policy pages:

• Wikipedia:no personal attacks
• Wikipedia:avoid personal remarks

In view of our previous cordial relationship, I am reluctant to appeal to the authorities, but if you persist with attacks or other violations I may become impatient. --user:Ed Poor (talk) 18:01, Nov 17, 2004 (UTC)

Second Warning

Please do not make personal remarks such as the following:

• I do accuse you of disregard of scientific thinking.
• I do think your prejudices make you unable to objectively examine the science

Do you remember typing this, or has a gnome taken over your keyboard? --user:Ed Poor (talk) 19:19, Nov 17, 2004 (UTC)

(William M. Connolley 22:02, 17 Nov 2004 (UTC)) This is what I thought you meant the first time. I'll move my answer down into this section:

I do not regard my comments on t:GWS as a personal attack. I have no intention of repeating my comments on t:GWS: there is no need: I sensed ambiguity and resolved it.

Bias

I'd like your opinion at Wikipedia:Requests for arbitration. Thanks. Chameleon 12:05, 20 Nov 2004 (UTC)

(William M. Connolley 21:27, 20 Nov 2004 (UTC)) OK, I've had a look and added a comment. I'm late, because other editors have come in and fixed the page, to a casual glance, so this is now a minor issue (I don't think you can expect r-f-a for one small dispute over one page that is now fixed). But... if the sulphur wars ever recur, I may come and ask you.

Kyoto text

No problem; I'm happy to do it. - Evil saltine 13:22, 3 Dec 2004 (UTC)

Energy conservation in GR

Hi William,

I've added an answer to talk: big bang, and added a small article ADM energy. Quickly, the total energy is not conserved in general situations in GR, certainly not in cosmology. The energy conservation is via Noether's theorem associated with time-translation symmetry, but this is exactly what GR can avoid by making the rough shape of the Universe dependent on time drastically. The energy in GR is conserved if the spacetime is asymptotically flat - or asymptotically something else that is static - then the exactly conserved energy is the ADM energy. Anything can happen in the bulk, including colissions of fast black holes, but the ADM will be exactly conserved in these cases.

In cosmology, the total energy of dust is conserved; the total energy of radiation decreases like 1/R; the total energy from the cosmological constant goes like R^3, and so forth, where R is the typical "radius" of the Universe.

Best Lubos

(William M. Connolley 22:55, 6 Dec 2004 (UTC)) Thanks.

Recent amity

"Recent amity" is a very entertaining description. Such amity can be temporary, but honestly, it rarely returns back to the previous situations. Take Peter Woit - a well-known critic of string theory. We've had big battles, but he also wrote a letter for me recently. Some battles re-occured afterwards, but it's not quite the same thing as before. ;-) --Lumidek 23:22, 6 Dec 2004 (UTC)

Utilized/used

Haven't a clue whether it's a trans-Atlanticism. I grew up in British usage (and still use harbour, colour, spanner, etc), but now live in the US, so you can count me in either column! :-) Noel (talk) 11:35, 9 Dec 2004 (UTC)

PS: I don't usually check other User_talk: pages (so that I don't have to monitor a whole long list of User_Talk: pages - one for each person with whom I am having a "conversation"), so please leave any messages for me on my talk page (above); if you leave a message for me here I probably will not see it. I know not everyone uses this style (they would rather keep all the text of a thread in one place), but I simply can't monitor all the User_talk: pages I leave messages on. Thanks!

Article Licensing

Hi, I've started a drive to get users to multi-license all of their contributions that they've made to either (1) all U.S. state, county, and city articles or (2) all articles, using the Creative Commons Attribution-Share Alike (CC-by-sa) v1.0 and v2.0 Licenses or into the public domain if they prefer. The CC-by-sa license is a true free documentation license that is similar to Wikipedia's license, the GFDL, but it allows other projects, such as WikiTravel, to use our articles. Since you are among the top 1000 Wikipedians by edits, I was wondering if you would be willing to multi-license all of your contributions or at minimum those on the geographic articles. Over 90% of people asked have agreed. For More Information:

• Multi-Licensing FAQ - Lots of questions answered
• Multi-Licensing Guide
• Free the Rambot Articles Project

To allow us to track those users who muli-license their contributions, many users copy and paste the "{{DualLicenseWithCC-BySA-Dual}}" template into their user page, but there are other options at Template messages/User namespace. The following examples could also copied and pasted into your user page:

Option 1

I agree to [[Wikipedia:Multi-licensing|multi-license]] all my contributions, with the exception of my user pages, as described below:

{{DualLicenseWithCC-BySA-Dual}}

OR

Option 2

I agree to [[Wikipedia:Multi-licensing|multi-license]] all my contributions to any [[U.S. state]], county, or city article as described below:

{{DualLicenseWithCC-BySA-Dual}}

Or if you wanted to place your work into the public domain, you could replace "{{DualLicenseWithCC-BySA-Dual}}" with "{{MultiLicensePD}}". If you only prefer using the GFDL, I would like to know that too. Please let me know what you think at my talk page. It's important to know either way so no one keeps asking. -- Ram-Man (comment| talk)

Global warming

By "credible" models do you mean the definition of credible which is "capable of being believed"? And if so, do you really mean are there models which you would believe? For that I have no answer. However, I have placed the article into NPOV dispute, and outlined my reasoning and the corresponding facts and evidence for such on the article's talk page. These include reference to scientific theories from the article itself which do not predict significant human-caused global warming. — Cortonin | Talk 22:55, 16 Dec 2004 (UTC)

(William M. Connolley 23:08, 16 Dec 2004 (UTC)) I mean, can you produce any models which show cooling? It would seem not, since you haven't.

GW

Check on the nickname - I was just applying some gentle ribbing. To create a more convivial atmosphere. :P. As to the article, I've personally been in the former camp - I think you do a fine job and know the material much better than I could. Graft 21:38, 17 Dec 2004 (UTC)

fun question for you!

Hi. I was just wondering what would changes we could expect in the oceans if the winds all died, completely and did not return very soon. Thanks for your help. M.

That would depend on the mechanism that would be preventing the winds. Ocean temperature differences are communicated to the air masses above them, creating differences in temperature and moisture content. These differences in turn give rise to pressure differentials which put the air masses in motion. Winds and weather systems such as cyclones (typhoons and hurricanes) are a major energy transport mechanism that cools the equatorial and warms the polar regions.

Urhixidur 15:30, 2004 Dec 19 (UTC)

(William M. Connolley 22:06, 19 Dec 2004 (UTC)) Hmmm, not sure if this is a fun question or not... As U says, its hard to see *how* the winds would die. But, if you assumed that they had, then the absence of wind stress at the surface would have a major effect. You might look at Thermohaline circulation, too. OTOH no winds would make a major difference to the sea ice production too.

more info please

i am very interested in this subject and was wondering if you would mind elaborating on the subject relating to the two points you made. thanks. d.

Continental drift

Hey William, Happy New Year. Were you joking with the continental drift - it was a point that I remember best from your bizarre editing. Do you really think that the people who criticized Alfred Weneger were right?? Do you really think that it is fair to say that the other guys were correct if they said that it was impossible for the plates to "plow" through the rocks on the ocean basin? What do you think happened on Sunday in Asia? The "crust", the hard material, just "floats" on the "soft" material underneath, whatever the name of it is, and it "plows".

(William M. Connolley 22:32, 31 Dec 2004 (UTC)) Err, where do you think I go the info from? From plate tectonics of course.

Do you need to open plate tectonics to decide about basic questions connected to continental drift? I thought you were trained as a climate scientist, which I suppose absolutely requires to know something about Earth. Do you know that Sahara used to have an arctic climate - well because it was on the Southern pole? Do you think that it is irrelevant for climate whether you are on the equator or the Southern pole? Do you think that one can have an idea about the climate in the longer scale without understanding other basic things about Earth and physics? Those comments that "he was not quite right with plowing" were invented by his former critics once they switched sides, just as a personal defense of their past errors. Of course that he was right. If you told the critics about seafloor spreading or plate tectonics, they would have also told you that you were nuts. These details are irrelevant. They just believed it was impossible for the continents to move. --Lumidek 23:20, 31 Dec 2004 (UTC)

(William M. Connolley 21:21, 1 Jan 2005 (UTC)) He wasn't "not quite right", he was wrong.

More importantly, it really seems that you believe that consensus is an argument in science.

(William M. Connolley 22:32, 31 Dec 2004 (UTC)) Not sure where you get that from. Read what I wrote about IPCC. IPCC *is* the consensus because that is how they built it: from the extant scientific papers.

(William M. Connolley 21:21, 1 Jan 2005 (UTC)) So you can argue from the IPCC consensus, because you are then arguing from the weight of sci papers. In doing this, one is arguing from something that *is* scientific consensus, but not using the fact as an argument. Come on: this distinction is *not* too subtle for you.

... --Lumidek 03:02, 31 Dec 2004 (UTC)

Incidentally, you should read about his life [2] - it's fascinating, although I am sure that you will be nervous how extremely similar this story is to various stories today about the climate. --Lumidek 03:45, 31 Dec 2004 (UTC)

You are hereby warned about no personal attacks

(--Lumidek 00:04, 2 Jan 2005 (UTC)) You are hereby warned about no personal attacks, wrt the MC article. Cool down, behave nicely.

(William M. Connolley 20:23, 2 Jan 2005 (UTC)) I don't see why you think this will help you. I have indulged in no personal attacks, unlike you.

Ozone Layer page

Hello William. I came across the Ozone Layer page recently, and wasn't very happy with it (in constrast to the Ozone Depletion page which IMO is very good.) I revised some statements that were downright wrong (e.g. the description of the latitude dependence of the layer thickness was exactly backwards), but I think the page could use a more substantial rewrite. I'm willing to do this but thought I should drop a note here first, since you're the only contributor to that page who I recognize.

One thing I'd suggest is that the page focus on the basic physics and chemistry of the ozone layer, with only a brief mention of ozone depletion (including a link to the dedicated page.)

--Rparson 21:58, 7 Jan 2005 (UTC)

(William M. Connolley 23:01, 7 Jan 2005 (UTC)) I've added a note to your talk page. In essence: yes, go ahead and improve it, and thanks.

Pic of the Day

Hi William,

Just to let you know that your photograph of Nice is coming up for Pic of the Day again on the 19th Jan. I've reused the description from last time, but you can check Wikipedia:Picture of the day/January 19, 2005 if you want to make any changes. -- Solipsist 09:30, 15 Jan 2005 (UTC)

(William M. Connolley 10:25, 15 Jan 2005 (UTC)) THanks for letting me know, I'm honoured. I'll check.

volcanic activity

Hey WMC - a question for you. An acquaintance of mine mentioned a theory that global warming was resulting in increasing volcanic activity and earthquakes (citing mostly one Tom Chalko, I believe). Chalko appears to be a loon - but are you aware of anyone else who seriously espouses this theory? It IS just bunkum, right? Graft 19:26, 19 Jan 2005 (UTC)

POTD - Wikipedia:POTD/January 26, 2005

Hi William,

Just to let you know that your animation of Pentakis dodecahedron is up for Pic of the Day again on the 26th Jan. Once again, I've reused the previous description, but you might want to check the caption at Wikipedia:POTD/January 26, 2005. -- 22:06, 21 Jan 2005 (UTC)

(William M. Connolley 12:00, 22 Jan 2005 (UTC)) Thanks for the note re POTD Pentakis dodecahedron but... its not mine guv! From the history it looks like Cyp's :-)

What was I thinking?!? I obviously can't read for toffee. Oh, I see the trouble, it was wrongly attributed in the [of the day Archive]. Thanks for pointing that out. -- Solipsist 13:31, 22 Jan 2005 (UTC)

Climate models - did they make much progress?

Hi William, I am not editing climate models, but I used the page to argue what sort of factors are neglected by the current models, and used the page climate models as a user. Some people complained that the models described on that page are too primitive and much better models are used in reality, and that Wikipedia is rubbish, and I'm not sure whom to believe especially because I think that Wikipedia in average is pretty good. All the best, Lubos

(William M. Connolley 14:52, 23 Jan 2005 (UTC)) Ah, I see. By "current models" you're on the GCMs section. Some of the other models described there *are* primitive of course... I hope its clear though that only GCMs are really used for future prediction, with occaisional process-studies by radiative-convective models. The page as a whole seems fair enough to me. What is there is correct, though is room for much more. There are links to the IPCC report for anyone who wants the gory details of model evaluation. Tell your friends to complain on the climate models talk page...

Arbitration Committee case opening

You have been named as a disputant in the recently opened Charles Darwin/Lincoln dispute case brought before the Arbitration Committee. You may wish to add evidence to Wikipedia:Requests for arbitration/Charles Darwin/Lincoln dispute/Evidence to support your case. -- Grunt 🇪🇺 03:32, 2005 Jan 25 (UTC)

The underpinnings of general relativity

Hi William,

you wrote: "In GR, all (local) coordinate systems are equivalent for describing physics (...) Being able to measure absolute rotation, locally, would destroy the underpinning of GR." William M. Connolley 21:39, 21 Jan 2005 (UTC)

I'd like to comment on that. In the years up to 1915, Einstein explored the consequences of comparing points on a rotating disk with points in a gravitational field. An observer moving about on the disk will be in a different Lorentz frame for every distance r to the center of rotation. (In the limit of infinitisimally small spacetime intervals, all Lorents frames with equal distence r to the center of rotation are assumed to be equivalent).

Einstein figured: moving over the disk, the observer is moving through regions with different time dilation and space contraction. Therefore, if the space-time around a gravitating mass is altered in such a way that it has different time dilation and space contraction for every distance r to the center of gravity it is indistinguishable from the gradient of time dilation and space contraction observed on a rotating disk.

It seems to me that this geometrical assumption, together with special relativity, is the logical underpinning of general relativity, and that no further assumption is required. Cleon Teunissen 17:02, 25 Jan 2005 (UTC)

(William M. Connolley 22:34, 25 Jan 2005 (UTC)) I'm a bit busy around now (see Wikipedia:Requests for comment/William M. Connolley) so I'll get back to you on this in a few days. Remind me if necessary.

OK, I will remind you if necessery. If there is something I can do in the request for comment affaire, tell me. Cleon Teunissen 01:25, 26 Jan 2005 (UTC)

External link: Probe B experiment to measure frame dragging.

Internal link: gyrocompass A device that finds geographic north. To find North, it compares the Earth-rotation with a more steady reference.

(William M. Connolley 14:17, 26 Jan 2005 (UTC)) You've signed up, and thats what I need at the moment. Thanks.

Hi William, I have written a new version of the article on fictitious force. It's standard textbook physics, and it's pretty far out. It's Hofstadters law of strangeness: 'Nature is stranger than you think, even if you take Hofstadters law of strangeness into account' Cleon Teunissen 09:54, 29 Jan 2005 (UTC)

Hi William, I know I tend to write convoluted prose, so here I'll try to be brief. Do you agree that gyroscopes display a property that has significance: Take a gymbal mounted gyroscope. Before the gyroscope is spun up it can revolve in its gymbal mounting in any plane of rotation, at any rate of revolution. As the gyroscope is spun up, it spontaneously ceases to revolve. If the suspension of the gyroscope is sufficiently frictionless, the axis of spinning motion will stay pointing at the same star, the star it happened to be pointing at when it ceased to revolve in its mounting. When a gyroscope on Earth is spun up, it never adopts Earth rotation. Cleon Teunissen 08:16, 30 Jan 2005 (UTC)

(William M. Connolley 12:33, 30 Jan 2005 (UTC)) Oh yes, I agree with that property (with the frame-dragging exceptions from GR of course). What I'm rather less sure about is its significance.

Well, the next question is: how do the gyroscopes know? The observer doesn't prepare the gyroscopes, he just starts them spinning. Even if the observer would try, he can't mess them up. As soon as the gyroscope has spun up it ceases all revolving in its mounting and only the spinning around its gyro-axis remains (if the suspension is frictionless in all planes of rotation). Then the gyroscopes all show to the observer the sidereal revolution period of the Earth (if the experiment is conducted on Earth) 23 hours, 56 minutes etc. etc. So how can the gyroscopes show something that is not supplied by the observer? How can they show something that can only be verified by astronomical observation? Where does that information come from? Cleon Teunissen 14:27, 30 Jan 2005 (UTC)

MM

Dear William,

if you want to enjoy the last few days in which the paper by MM is not published, feel free to enjoy them. I will return the formulation once the issue of the Geoletters is published. (William M. Connolley 20:24, 30 Jan 2005 (UTC) this message has been partially censored to retain civility).

Best wishes Lubos

Hey William - you're being remarkably coy about this subject, considering you've already crawled through some Fortran code over it and written about it. Why not just answer the paper on its merits? Graft 15:29, 30 Jan 2005 (UTC)

(William M. Connolley 19:50, 30 Jan 2005 (UTC)) Sorry, I didn't realise that. I'd rather wait till its published - I haven't read it yet. I think you can tell, though, from comments like Lubos's above, that the chances of a reasoned debate on the matter are slight. From the work I've done (and the numerous errors that Tim Lambert has publicised about M&M's work) I don't think MM05 will be of any great importance, scientifically, though they are doing their best to talk it up.

Sorry - maybe I'm misunderstanding which paper is being talked about, here - this is the one due to be published in Geophysical Research Letters about artifacts resulting from Mann et al's normalization procedure? You haven't read it? I'm assuming the version they've made available is the same one that will be published. Graft 20:11, 30 Jan 2005 (UTC)

(William M. Connolley 20:22, 30 Jan 2005 (UTC)) No, I haven't read it. I probably will, eventually (in fact I'll probably be forced to, because the skeptics will misquote it...). But... really, its not that important (and I'm not saying that to minimise the fallout: I'm still pretty sure MBH are right). This is an issue focussed on by the skeptics for their own agenda not because of its scientific importance; there are other records than MBH which show much the same thing; Rutherford et al show that if you take out the "disputed" procedure you get much the same thing... etc etc. And the skeptics grossly over emphasise the degree to which the attribution analysis depends on MBH: read http://www.realclimate.org/index.php?p=114 for some good stuff. Also good is Tim Lamberts http://www.cse.unsw.edu.au/~lambert/parody/tcs/.

Wow, that's amazing. You, William, one of the people on realclimate.org, have not read MM05 yet? I can't believe it. --Lumidek 00:30, 31 Jan 2005 (UTC)

(William M. Connolley 09:31, 31 Jan 2005 (UTC)) Just goes to show how little you know :-)

What is a real force?

It is common to see the Coriolis force described as "making it look like a force is acting upon the object, but actually there is no real force acting on the object". This prompts the question, "what is a real force"? --Wiiliam M Connolley

Hi William, I think (given the context) that that question can be rephrased as follows:"what is the difference between inertia manifesting itself, and a real force?"
Again and again, people repeat: "Its not a force, it's inertia!"
So what on earth is inertia?

The more I think about inertia, the more it baffles me. Inertia tends to resist change of velocity, but it depends on change of velocity in order to manifest itself. When considering a current circuit with a coil with self-inductance in it, it makes sense to say the change in current induces a field that induces an electromotive force that opposes the driving electromotive force.
When an electric car designed to convert energy on decelerating is switched to braking, the manifestation of inertia is doing work, and the car's battery system is recharged.
Inertia, when it manifests itself, is always doing work. Forces do work. Forces cause change, inertia opposes change.
Cleon Teunissen 19:55, 4 Feb 2005 (UTC)

(William M. Connolley 20:54, 4 Feb 2005 (UTC)) The trouble is, there is no (local) way to distinguish gravity from acceleration. I insist upon my original question. If you don't know what a real force is, how can you know what a fictitious one is? I still don't think that there is any sign of it being a useful concept.

Cleon Teunissen 06:47, 5 Feb 2005 (UTC) Let me contrast two situations, in order to check whether I follow your line of thought.
Situation (1): Suppose a rotating disk and an observer is allowed to move around an accelerometer over the surface of the disk. He will find that concentric rings on the disk are lines of equal accelerometer reading, and he can also set up events that will bring out coriolis effects. The grand total of these measurements gives the observer amply sufficient clues to infer the disk is rotating; that particular distribution of accelerometer readings is consistent with a rotating disk only.

Situation (2): Suppose the observer is only allowed to position the accelerometer on a single spot, just the one measurement. Then he cannot deduce anything.

I gather that you are talking about situation 2, I gather you feel that situation 2 should be the stage to discuss questions like: "What is a real force?"

I choose to adopt situations like situation 1 as the stage to discuss questions like: "What is a real force?" I will go over many patches of space, and I will assemble them into a larger perspective, allowing inferences to be made. Cleon Teunissen 06:47, 5 Feb 2005 (UTC)

Back to the basics

Cleon Teunissen 11:47, 5 Feb 2005 (UTC) Hi William, I do agree with you that in physics the question 'what is a real force?' is very valid indeed. Unlike mathematicians, physicists tend to use "quick 'n dirty" definitions. I do believe that current physics can be axiomatized, much as Newton axiomatized his dynamics in the Principia. I doubt it has ever been attempted for modern physics. Here are some remarks, going back to basics.

When two electrically charged objects are floating in space, they will either attract or repel each other, causing acceleration with respect to each other. The common center of mass of these objects is the symmetrical choice to use as zero point of a reference frame. When two charged objects are moving towards each other but not on a collision course, they will interact in a direction-of-motion altering way; they will exchange momentum, after the interaction they are moving in a different direction from the direction they were moving before the interaction.

Electrostatic force is not mediated with infinite speed, it is mediated with the speed of light. This implies that the mediator of the electrostatic interaction must be able to carry momentum independently. With this ability, there is no violation of energy conservation. In quantum mechanics, the mediator of electromagnetic interactions is described as the exchange of massless, momentum-carrying particles.

When two objects with negligable electric charge move towards each other, not on a collision course, their interaction will be gravitatonal interaction only, and they will transfer momentum, and move away from each other again. In the case of gravity, the mediator of the transfer is a deformation of space-time geometry.
In general relativity, the gravitatonal interaction is mediated with the speed of light. The mediator of gravitational interaction is part of the world of physical entities, it carries momentum independently.

In classical dynamics, the predicted trajectories arising from electrostatic interaction and from gravitational interaction have exactly the same shape, since both the coulombforce and gravitational interaction are described by an inverse square law.

In general relativity the predicted trajectory for gravitational interaction is slightly different, and at non-relativistic speeds the difference is negligably small.

In the preceding paragraphs I have emphasized the similarities between electrostatic interaction and gravitational interaction. Very often, when the nature of gravitational interaction is introduced, it is emphasized how different gravitational interaction is, sometimes even to the extend that is is denied that gravitational interaction is a force. That is regrettable, it causes confusion.

As seen from the largest possible perspective, the four fundamental interactions of nature: Gravity, Electromagnetism, the Weak nuclear force, the Strong nuclear force, are categorized as forces, in the sense that they are interactions, they are what make the universe move.

When two electrically charged objects accelerate towards each other, potential energy is converted to kinetic energy. The tricky part is: what is the repository of that potential energy? One assumption is that the field is the repository of that energy. In that case, it is hypothesized that as an object is electrically charged, the increasing fieldstrength is expanding into space. By analogy, it can be hypothesized that the deformation of space-time geometry is a repository of potential energy. As matter condenses to a sun or a planet, space-time around it is deformed, and as the accumulation of mass in one location increases, the gravitational deformation expands, increasing the potency for transferring momentum to objects moving through that space.

Slingshot technique
Gravitational interaction transfers momentum. Take for example the space explorations by the Voyager space probes. Each flyby close to the planet visited had a carefully calculated slingshot effect. Angular momentum was transferred, and given the orbital dynamics that had the effect of boosting the space probe to a much higher velocity, velocity that was essential in order to climb out of the Sun's gravity well. In the calculation of the interaction during the flyby, the calculation can be simplified to a two-body problem. In that two-body treatment, Voyager flew past Jupiter along a hyperbolic trajectory, with the two exchanging momentum, moving with respect to a common center of mass. In the three body treatment, some of Jupiters angular momentum with respect to the Sun was transferred to Voyages angular momentum with respect to the Sun. Cleon Teunissen 11:47, 5 Feb 2005 (UTC)

Photo of Didcot

Hello — I was about to add your photo of Didcot Railway Centre to Wikipedia:List of images/Places/Europe/United Kingdom/Counties/Oxfordshire, but there are no copyright details. Does it count as free (and if so, could you add a copyright template to it, so that I'm justified in adding it)?

(William M. Connolley 11:23, 6 Feb 2005 (UTC)) Oops, all mine are GFDL, sometimes I forget.

Thanks, I'll add it then. Mel Etitis (Μελ Ετητης) 11:41, 6 Feb 2005 (UTC)

By the way, when were you at Teddy Hall? My first College Lectureship was there (1989-90), and I still do some tutoring for them most terms (for Stephen Blamey, if you knew him). Mel Etitis (Μελ Ετητης) 23:59, 5 Feb 2005 (UTC)

(William M. Connolley 11:23, 6 Feb 2005 (UTC)) Undergrad 83-86 then D Phil till 90 I think - so we overlapped a bit. But I stuck strictly to the maths-type circles.

To be honest I was so busy teaching and organising (and trying to get on with my D.Phil.) that I wasn't around much. Stephen Blamey might have turned up after your time; he's a logician and philosopher of maths, and (I'd have said) unforgettable. Mel Etitis (Μελ Ετητης) 11:41, 6 Feb 2005 (UTC)