Since I'm likely the only Vort who has actually made a limelight, allow me to make a few observations. First, limelight isn't lime colored or even slightly greenish, a common misconception on account of the name I guess. It has a very aggreable color compared to the blue-white of the carbon arc, however. It doesn't take much imagination to think that commercial suppliers might have added a few secret ingredients to their lime cylinders to give their light a more pleasing color.
Looking at the limelight with a spectroscope, even a simple one, reveals what must be the major source of the emitted light besides incandescence. Candoluminescence is ill-defined and seems to be mostly an archaic word for fluorescence. But easily seen in a spectroscope are the characteristic bright narrow band spectra of ionized calcium overlayed on the continuous incandescent spectrum. Town gas, a mixture of hydrogen and carbon monoxide, would probably not work as the CO would tend temporarily to form calcium carbonate thereby poisoning the cycle I think occurs in the limelight. My guess is that under the relatively high temperature of the oxy-hydrogen torch the calcium is ionized after having been reduced to elemental calcium by the hydrogen. The combustion finally re-oxides the calcium and returns it to the lime surface. I did this a very long time ago in my father's instrument repair shop where he had welding equipment including both oxy-acetylene and oxy-hydrogen torches. You can direct the torch at a pile of lime of the type available at hardware stores, but it's hard to do this without melting whatever you put the lime on. I imagine the cylinders of lime were made for the purpose by compression. My cylinder was a piece of chalk which starts out as calcium carbonate, but quickly becomes calcium oxide under the intense heat. In this form it's easily broken apart, but it holds it's shape well enough for this purpose. Although it is plenty hot enough, the oxy-acetylene torch doesn't work nearly as well as the hydrogen torch. With a welder's mask you can see that there is actually a darker area where the acetylene torch flame first touches the lime. With the hydrogen torch there is a brighter spot where the torch flame contacts the lime, and the overall brilliance is much greater. How this might relate to possible O/U or supra-chemical reactions I have no idea, but you might find it interesting. M. --- On Sat, 6/7/08, Jones Beene <[EMAIL PROTECTED]> wrote: > From: Jones Beene <[EMAIL PROTECTED]> > Subject: [Vo]:In the Limelight > To: "vortex" <vortex-l@eskimo.com> > Date: Saturday, June 7, 2008, 8:32 AM > Lights, camera, action. In the 'nothing new under the > sun' department: > > You have probably heard the word "limelight" > before, > but may not be aware of the actual method of operation > of the stage-lighting device, going back nearly 200 > years before grid electricity became available. > > http://en.wikipedia.org/wiki/Limelight > > "Limelight is a type of stage lighting once used in > theaters and music halls. An intense illumination is > created when an oxyhydrogen flame is directed at a > cylinder of calcium oxide ... which can be raised to > white heat without melting. The light is produced by a > combination of incandescence and candoluminescence." > > "Although it has long since been replaced by electric > lighting, the term has nonetheless survived, as > someone in the public eye is still said to be "in the > limelight". END of WIki quote > > Some interesting historical things about this device- > looking back from the modern context- are first that > hydrogen was once readily available (extracted from > "town gas" for instance or other ways) whereas > electricity was not. > > And secondly that: given the theater could have used > straight town-gas for lighting - but instead, they > went to what seems like extreme limits. Was this a > cost cutting step to maximize the lighting effect and > intensity per unit of gas, or simply to get the > white-greenish 'lime' color, or both? > > Since theaters immediately switched over to electric > arc lighting (which is glaringly white) as soon as > that became available ... which was both a cost > cutting measure as well as for fire-safety - then it > is fair to suggest that cost must have been a major > issue in the original use of calcium oxide all along, > as opposed to the artistic quality of light. > "Impresarios" are noted for caring both for > profit as > well as art ;-) > > How could a cylinder of calcium oxide placed in the > oxyhydrogen flame have been an actual way to greatly > increase the net photonic output in the visible range, > per unit of town gas? That does not sound too probable > at first, but it is a close call since incandescence > and candoluminescence while not gainful, do benefit > from being able to employ a much higher temperature > than town gas can deliver, but hydrogen can. > > OTOH - Calcium oxide has been mentioned many times in > connection with LENR, most recently by Horace Heffner > and Michel Jullian in regards to several schemes for > cold fusion. Plus - Calcium and oxygen ions are BOTH > hydrino catalysts, mentioned in the original CQM (as > opposed to the recent shoe-horning of anything and > everything). Don't forget Louis Kervan. > > IOW-there are modern suggestions that point to more > than "incandescence". > > Could the original limelight have been an actual > energy anomaly to some degree ? ... there is ZERO > suggestion of that now, nor it was ever said to be > efficient AFAIK except by looking at what it replaced > (this is mainly because there was so little to compare > it with at the time)... > > ...but nevertheless, it is tantlaizing to suggest that > the original Limelight "M.O." may have benefited > to a > small degree, from supra-chemical reactions which are > only now, 182 years later- beginning to be understood. > > Which might some day make a nice chain of events for a > future episode of BBC "Connections." (Last > episode > 1997 now 21 years old, but LENR could be the impetus > for a new run, James ;-) > > Jones
