User talk:Old wombat
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Talk:C (programming language)[edit]
Sorry, but I have removed your last two comments at Talk:C (programming language) because you interspersed your comments in a manner that was quite confusing, and you changed the previous person's comment, making it very hard to read what they had said. When a physical line of wikitext starts with a space, the line is rendered as a single display line, typically in a typewriter style font (you accidentally did that). I tried to refactor the comments to make everything legible, but it was too complex. So would you mind adding your comment again, under the last comment. This diff shows your two edits. Johnuniq (talk) 10:46, 28 April 2011 (UTC)
November 2011[edit]
Welcome to Wikipedia and thank you for your contributions. I am glad to see that you are discussing a topic. However, as a general rule, talk pages such as Talk:Common cold are for discussion related to improving the article, not general discussion about the topic. If you have specific questions about certain topics, consider visiting our reference desk and asking them there instead of on article talk pages. Thank you. SummerPhD (talk) 04:18, 24 November 2011 (UTC)
Recorder[edit]
Not covering 7 only makes a slight difference to the pitch, at school you could possibly get away with it. Why learn the wrong fingering though? Experienced players make use of alternate fingerings to assist with dynamics or fast passages, but for initial teaching the only way is to use the standard. As for not going above E: either the teacher didn't know how to play or else didn't know how to teach. Would I be right in assuming that this was whole class teaching?
If your 1963 recorder was a good instrument, then it will still be a good one. If it was cheap and off key when made, it will still be! The only way to tell is to play it and listen, or better ask a good player to play it and both listen. Martin of Sheffield (talk) 09:33, 8 December 2011 (UTC)
Thanx for your quick reply. Why did I learn the wrong fingering??? Hah !!!! Because I didn't know !!! I only learnt it was wrong as of about two hours ago!!!! For nearly forty years I have been sublimely ignorant of the fact!!!!! Moving forward, if the fingering in the Wiki article is the correct one then I shall certainly endeavour to use it.
As for not going above E: I don't know which of your two answers is the correct one. It was a long time ago, and I was only eight years old. And yes, it was whole-class teaching.
What I find confusing in all of this is that the notes DO sound shrill above E. Is that because: - They ARE shrill. - I don't know how to play them properly, because I was never taught. - My recorder is not that good. - Some combination of the above.
Anecdotally, I don't believe that my recorder can be totally dismissed as cheap and off key. It is wooden, not plastic, when even in 1963 plastic ones were available in Australia. It has a black keyhole-shaped insert, also of wood, in the "block". None of the recorders in any of the images in Wikipedia have that, although of course I have no idea whether that has any relevance to the quality. It has a sticker on it "Australian Made" at a time when the alternative, "Made in Japan", was seen as far inferior (wow that was a long time ago LOL LOL !!!).
I do enjoy playing it. My wife sings a solo hymn in chuch whilst the choir goes to communion, and occasionally we do a duet - her singing and me playing. It is very enjoyable and greatly satisfying. she sings the melody whilst I play the harmony, so ironically not being able to play above E has never been an issue !!! I make up my own harmony by trying to guess the answer to the question "What note would Mozart have played here?".
But look, again moving forward, you have inspired me. Even though we live in a small town, we have here a gentleman hear who plays the recorder extremely well - far far better than I do. I shall follow your advice and contact him, asking him to play my recorder and evaluate it. Maybe he can even teach me a little. I don't know how approachable he is - maybe he might be flattered to be asked.
Again, thanx for your input.
- Good to see all this. Fingering the higher notes requires a very small crescent opening in the thumb hole to get the note to 'strike' reliably. However a small hole does lead to shrill notes, so the thumb needs to open the hole slightly as the note is played. If you look at old wooden recorders you can often see wear aroung the thumb hole, there may be a real or fake ivory insert to combat this. Cutting the left thumb nail to the right length is essential for playing at the highest calibre.
- Historically the Teble (aka Alto) recorder was the upper solo instrument, the Tenor the lower one. Descant recorders were for playing the descant line, but since they are cheap and in C are the instrument of choice. Of the four standard recorders the descant is the hardest to play melodiously. Of course if you _really_ want to be heard at the back of the church, try the Sopranino or even Garklein. The latter certainly gets attention, but is a right pain to play well.
- In the 1960s in the UK (BTW I was seven in 1963), many primary teachers were simply told to get on with music teaching and may well have only been a chapter ahead of the class. The positive was that a lot of children learnt an instrument, the negative that the recorder was percieved as a toy and rarely played well. I would guess that something similar was happening in Australia. Martin of Sheffield (talk) 10:51, 8 December 2011 (UTC)
OK, Martin, thanx to this last comment I have made fantastic progress. I've been trying the correct F fingering and it does sound better. I've fairly rapidly got the hang of your "very small crescent opening" and have got the upper notes to 'strike' reliably, as you call it, right up to G, so I'm a full two tones higher than before. However, maybe simply because I'm not used to it, I don't really like the sound of those high notes. Probably nothing further to report until after Sunday. Old_Wombat (talk) 07:35, 9 December 2011 (UTC)
OK, got some more info. I have followed your suggestion: "The only way to tell is to play it and listen, or better ask a good player to play it and both listen." . I was finally able to corner the Reverend Dr David [surname suppressed], who despite living in our very small town is a well-known recorder virtuoso. He has seen and heard my recorder, and expressed the opinion that it was "very good", so much so, that apparently it (not my one, but that exact model) was used at a number of [Australian] state symphony orchestras. He asked me whether mine had a serial number; apparently, if it does, it is more valuable [than if it doesn't]. Alas, mine doesn't, but I do recall that when it was bought in 1964 or thereabouts it came with a typewritten document, now long lost, that I suspect MAY have had such a number. He also advised that since it is made of wood, it is most important to keep it dry, dry dry. That is not difficult - the climate of our town is, even by Australian standards, considered to be "semi desert"!
Answering another of your questions, there is no wear around the thumb hole at all, which is not surprising. Searching my memory, I think that my mother bought if from someone who bought it brand new and very shortly afterwards decided that they didn't want it. If that is indeed the case, then despite its near half century age, in terms of wear, I can say with a clear conscience that it is "near new", if you see what I mean, because I have not actually played it very much in that long long time. Old_Wombat (talk) 08:52, 12 January 2012 (UTC)
- Glad to have been of service. Mentioning humidity; as a lad I was given a plastic tenor which had cork joints. All was well until I took it on a canal holiday, the humidity (100% in the boat of course) caused the cork to swell and crack. I redid the joints with soft string and bedded them down with joint grease. That was 40-odd years ago and they've not been touched other than normal greasing, and work fine. Thank goodness it was only the cork that was damaged, not a wooden instrument - lesson learnt! Martin of Sheffield (talk) 10:16, 12 January 2012 (UTC)
Your recent edits[edit]
Hello. In case you didn't know, when you add content to talk pages and Wikipedia pages that have open discussion, you should sign your posts by typing four tildes ( ~~~~ ) at the end of your comment. You could also click on the signature button 
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located above the edit window. This will automatically insert a signature with your username or IP address and the time you posted the comment. This information is useful because other editors will be able to tell who said what, and when they said it. Thank you. --SineBot (talk) 10:15, 28 December 2011 (UTC)
I opened a discussion about a new bot that user 'Z' and I have been working on, it's not ready for big things yet, but it can do some small tasks and I've outlined them on Talk:Tiangong 1. I would very much like you to comment if you have time, I liked your recent edit there "Yes, and a whale looks like a big fish which looks like a submarine which looks like a torpedo" it made me smile, so I thought even if your not interested much in bots, it would be worth asking. Penyulap talk 11:25, 17 March 2012 (UTC)
MRI image[edit]
You mention that per the Radiology clinic the MRIs are your property? Do you have anything in writing which states that? Doc James (talk · contribs · email) (if I write on your page reply on mine) 00:24, 8 April 2013 (UTC)
Hyperfine structure -- your lab bench expt from 1970s[edit]
Old wombat, old boy, there is more physics here in what you wrote (Hyperfine structure, Talk page, 2011) than in anything I've read in quite a while. Can you revise it for article use? Perhaps it would be easiest for me to [highlight w/text in square braces] where mere mortals need some more help from you.
Relatively simple experiment to demonstrate hyperfine splitting. [1]
This was the most interesting Physics experiment in my entire brief stay at university. This was in 1975, so maybe my memory of it is a little rusty :)
We had a rubidium lamp with a deep red filter to select the appropriate emission line.
[Need an intro statement that hyperfine emissions from electron spin flips are inherently polaraized . . . how? Always circularly?] The light passed through a circularly polarising filter, which meant that the line was fine split - that is, the filter selected photons emitted from energy levels where the upper and lower energy levels had J-numbers that differed by one. From memory, either J=1/2 to J = 3/2, or the reverse, depending on the sense of rotation of the polarising filter wrt the magnetic field (described below)
The light then proceeded to a cell containing rubidium vapour which would selectively absorb the light.
Around the cell was an electromagnet [whoa. Can you word this so that, w/o needing to look at a diagram, we readers can picture how the flux lines ran with respect to the beam passing through the rubidium vapor cell? Linear flux lines straight across the beam?], powered by a very slow (from memory, about 1/5 Hertz; that is with a period of about 5 seconds) sawtooth voltage.
Perpendicular to the [Across light beam to either side?] light beam entering cell was an RF oscillator [were two antenna plates from an RF oscillator running at] at 50MHz. What is interesting about this is that at 50MHz, RF energy would normally be considered as a wave; but in the context of this experiment, it clearly demonstrated photon behaviour.
On the other side of the cell was a simple RF detector; I think nothing more than a piece of wire to an LC circuit with a diode and a resistor.
A feed from the sawtooth voltage and the output of the diode/resistor and were fed, respectively, to the X-Y plates of an oscilloscope.
As the light passed through the varying magnetic field it was hyperfine split. The varying magnetic field varied the [separation or energy difference between the hyperfine levels] hyperfine split energy levels. When the energy levels were integral multiples of the energy of the 50MHz photons, those photons were absorbed, creating a "dip" in the oscilloscope trace. (Don't you just love it!!)
Finally, if the amplitude of the RF oscillator was varied, an interesting effect was observed. If it was set reasonably "high", then transitions requiring absorptions of two RF photons "simultaneously" (that is, the F value of the transition went from F=0 to F=2) had a sufficiently high probability of occurring and thus being detected. If the amplitude was set to "low", then only transitions corresponding to a of a single change in hyperfine energy levels (that is from F=0 to F=1 or F=1 to F=2, but not the F=0 to F=2) would occur and be measured. Thus, at the high level, more dips in the oscilloscope trace could be seen.
[I'd like to be doubly sure you mean intensity not frequency. If yes, then this is a great place to cross-reference two-photon absorption confocal microscopy, a hot area and great tool in biology right now.]
A fabulous experiment !!!! Old_Wombat (talk) 12:38, 14 December 2011 (UTC)
OK, be of stout heart and good cheer. I understand you wrote this to share your pleasure in a fond memory, not to make work for yourself. But let's honor the prof who put it together for you, and share her/his accomplishment with the rest of the globe. It really does pull a lot of physics together in a concrete way that tempts others to think they can understand it. I suggest working on it here, and only putting a heads up note, if anything, on my own talk page. Let's see, to find a talk page, . . . https://en.wikipedia.org/wiki/User:Jerry-va capitalization Jerry-va matters. Jerry-VA (talk) 18:10, 29 September 2013 (UTC)