Good to hear that the build-down fix appears to work, though it seems to only have received minor mention.
Well of course. You're not going to get a "it doesn't work at all" bug at this point because it's something he could easily test on command. Possibly some situational thing he'd have to track down but that wouldn't necessarily reveal itself this quick.
i vote you speak, after all wasn't a challenge thrown down to get this thread's page count from 236 to 1000? we need all the posts we can get.
I'm just not feeling it.
But to give it a shot anyway. Black body radiation is how any hot solid or dense gas gives off light (cold gasses will just absorb certain frequencies.) The hotter it gets the more light it gives off but what we're really concerned with right now is that as it gets hotter the light it gives off is mainly shorter wavelengths.
To make that easy to grasp we've all seen how a human basically looks like it's on fire through infrared goggles. There's not the flickering and such because the air isn't so hot that it wants to move up very fast but it's clear that we're giving off lots of light being as warm as we are. With a flame you've gone up quite a lot in temperature so we're once again seeing something hot giving off light but this time it's in a frequency our eyes can see and being that the air's really hot it shoots up from the cooler air around it.
(I've skipped details about what makes a flame the color it is. If anyone wants to elaborate to make this explanation more correct I won't mind.)
On the other hand plasma as a state of matter is more of an electrical thing, or magnetics, whatever. Point is it's about ions. What this means is that plasma interacts with magnetic fields and carries current and so on. It's possible to make fires that are hot enough to produce plasma but standard fire is nowhere near that and I doubt and flame we can comfortably look at without eye protection really reaches that threshold.
I thought that flame was plasma; ex. methane (CH4) would interact with oxygen (O2) by a mechanism similar to:
CH4+O2->CO-2 + H2O + H2 +2e+
H2+O2-> H2O + O2- + 2e+
CO-2 +2e+ -> CO
O2- + 2e+ -> O
O + H2-> H2O
CO + O2 -> CO2 + O
CO + O -> CO2
Net: CH4+2O2-> CO2+2H2O
I probably got some numbers wrong, but the important concept is that combustion produces short-lived gas ions, and that the light released in flame comes from the ions regaining electrons.
My experience with flame welding and cutting backs that up- The hottest portion of an acetelyne flame is not in the middle of the brightest light, as it would if the light were blackbody, but at the tip of the cone.
On topic: I do NOT envy the 'testing' responsibility. I would love to have even an unstable, not-fully-working new version. I would even deal with all of the random crashes, and not bother the author unless I found a reproducible bug.
Please?
Close, with flame color. It's not ions regaining electrons, but excited molecules giving off a photon to lower the energy state of a valance electron. But, there is also visible radiation-effected color, such as your standard wood fire where the burning off of volatiles in the wood cause the characteristic orange flames. Going with the wood flame, you'll notice that it eventually becomes invisible: wood burns for quite a while once the volatiles are purged, appearing as red glowing embers.
If you don't have a Bunsen burner handy, your everyday butane lighter can show the effect quite well. At the very base, against the metal, you have a premixing zone that doesn't burn. Directly above that, you'll see a (likely very small) blue chemiluminescent zone. This zone is fuel-rich, meaning not enough oxygen to fully combust all the butane, and produces a lot of carbon soot. As you go further up the flame, the stoiciometric profile will go from ful-rich to fuel lean, increasing heat and causing the soot to burn. Once the soot is burning, it gives off visible radiation, overpowering the blue flame with its orange, hence being the color that would most likely first come to your mind when thinking of a lit lighter.
As for the acetylene torch, you're looking at an entirely different beast. I would assume you have an oxygen line, so you have a premixed flame instead of a diffusion flame. When the mix is proper--most likely at stoiciometric conditions, though not necessarily--your flame color should be based only on chemiluminescence. The temperature, however, has more to do with flame quenching than anything else. If you have the metal too far up the flame, it will absorb the energy of the flame before it can be used to complete the combustion of the unburned gases, leading to a cooler flame.