Board Thread:Movie Discussions/@comment-29923078-20160309035307/@comment-26850821-20160318014121

Godzilla's atomic breath color doesn't correlate to temperature in the same manner as real-world plasma. In fact, it behaves in the exact opposite manner. Red stars are cooler than blue stars, but Godzilla's atomic breath gets stronger and presumably hotter as it goes from blue to red. Just look at how much damage the red spiral breath did in the Heisei Godzilla movies compared to the normal blue breath. It was more than hot enough to burn away MechaGodzilla's diamond coating when the normal blue beam did no damage to the armor.

Even Godzilla 2000's orange beam is likely hotter than most other atomic breaths due to the way it just shredded through everything it touched.

The comparison involving Zilla Jr.'s green atomic breath and that one greenish Showa atomic breath doesn't hold, either. Green does NOT correspond to thermal emission.  Believe me, I recently looked for a plausible real-world explanation for green plasma because I was pondering the exact same question as the OP and anybody with a knowledge of plasma physics will tell you the same.

Red stars look red because most of their thermal radiation is in the infrared spectrum, which we can't see. The only part of their spectrum that we can see is in the red portion of the visible spectrum, hence the red color. Blue stars look blue because most of their radiation is in the ultraviolet spectrum, which we also can't see. The portion we can see is in the blue portion of the visible spectrum, hence the blue color.

Now, a star with its average thermal emission in the green portion of the visible spectrum will actually look white. This is because the star will emit not just green wavelengths, but wavelengths all across the visible light spectrum. All of these different wavelengths put together will look white to our eyes. This is why the sun looks white and why heating a metal rod sufficiently will make it glow white.

Now, interestingly enough, I actually did manage to find examples of green plasma in the real world, but they were green due to being injected with certain chemicals, not because of their heat. Here's one that was injected with microscopic copper powder to glow green, with the image on the left showing its original red/pink color. The same can be done with boron.  This video also seems to show a green plasma jet in action, assuming it isn't some kind of false coloring. I just thought these were all really cool.

GOJI-ATOMICO wrote: if godzilla has a purple atomic breath problaby can be the most hot of the atomic breath version The funny thing is he actually does have a purple atomic breath in one of the video games as a powered-up version of the atomic breath. It was either Destroy All Monster Melee or Save the Earth.