Distance between stem growth affected by light?

Hello everyone, this is only my second post on this forum so please forgive my improper vocabulary usage in regards to the plant part identification...
I noticed the distance from the small round leaves on two of my new seedlings, are different from the next new set of actual leaves growing off the main stem (the internode?). Could this be because of the distance i keep my seedlings from my light? I am using a CFL system that i fabricated and the lights are currently about 3-5 inches from the plants. I am well aware of the heat issue but i can assure you that the plants will not burn unless you want to stand there for a long time and hold them by hand. Its extremely hot here all the time so the room temp is approx 79-84F.
My other inquire is about the IR signature of a CFL system. Would a grow setup with anywhere from 5-12 CFLs be as detectable as HPS or MH lights? The "ghetto bird" as we call it; flies all over the city and I wanna be sure that their FLIR camera wont pickup my IR signature using CFL setup. Would Panda pad lining work to reflect outside IR detection? or would it be too thick for such a hot place? I know there is always the mylar option.. Thanks for your help.

Your right, the distance of the light will affect the distance between the nodes. Get those CFL's as close as you can, if you have a fan blowing on them you could get within an inch of the lights easy.

IR sig from CFL is very very low, I rearlly wouldnt worry about the "Ghetto Bird". If your a bit paranoid about it, not a bad thing to be paranoid when your growing, then insulate from IR detection, just have good ventilation and your CFL's could never cook your babies. I dont know what Panda pad lining is but I do IR insulate with what we call astro foil, i'm in UK. Basically its bubble rap that has foil on both sides. Mylar is great for reflecting the light your babies love and is always a good idea to use but not sure if that on its own will IR shield.
Best of luck

Yup, but its not only the distance of the light but also the power of your light