In most conditions, light doesn’t interact photon-to-photon. The field they flow in doesn’t engage the constituent particles this way. Photons are massless electro-magnetic force carriers for matter. If you have a million photons going around, they don’t care about each other directly, unless confined and given time to engage each other (which is a bizarre physical existence, such as in places we can never observe; namely, high mass stars and black holes). In this sense, we can say photons don’t occupy the same space or energy state … If photons land on an atom’s electrons, then they start doing things that could be overall viewed as interfering, but really it’s just an indirect effect. Photons can get matter to reverberate via it’s orbiting electrons to give an illusion of interference. This so called “interference” is a state of the electron(s)’ reaction to the photon. So, photons interfere with each other indirectly through matter, but not within the EM field they exist in unless in extreme (highly rare and misunderstood) states. The greater interference is just observational inaccuracy of what appears to be interference. Nothing interferes usually; it just becomes so chaotic we see jumbles due to our observational limits (physiological and engineering/analytical limits).
Photons are odd. They are beyond understanding. They are going the fastest possible (they’re unimpeded by cosmological speed-limits), they’re massless (unimpeded by energy/matter laws), and beyond physical time too (the lack of the previous two grant this). Yet, they ferociously engage matter and it’s force carriers; just to continue their massless madness through matter-induced space-time curvature.
To round it off, light doesn’t interfere with light on it’s own. But, it’s interaction with atom’s structure can cause observable patterns worthy of the label, “interference”. Anomalies allow photon-photon combination, but normality allows kinetic interference of matter states via photon effect.
The Broad Spectrum Life 
Lots going on! Sounds like your thoughts are traveling at the speed of light from one parallel universe to another!!! Love your writing!!!!! 🚀
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Absolutely true.
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I found myself being strangely fascinated by this discussion, despite knowing nothing about photons. How did we come to know as much as we do about them?
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I’ll admit I have faith more than know. It’s faith in the “standing on the shoulders of Giants” (i.e. science history/education culture) and combined or peer-reviewed science (i.e. contemporary science culture). This translates to conglomeration of engineered physical testing, based on theories (via mathematics and philosophy). The testing is further both observations of natural phenomenon (interpretations of detected things in nature) as well as contrived environments (experiments: contrived manipulations used to rule out causes of effects; in physics it’s usually highly sophisticated machines for just one focused purpose).
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I should add a hermeneutical (dense interpretation of information) analysis is used to understand what the detections mean whilst filtering both human bias and noise/error
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It’s a lot of faith for me too, since I don’t have much training in physics – although I thoroughly enjoyed the one physics class I took. I credit high school physics with softening my distaste for math, because it showed me how fun math can be.
Anyway, I feel more comfortable placing my faith in science than in other things. Science is far more transparent (if one takes the time to look) than other pursuits which require faith.
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the short answer: hundreds of years of observations, experiments, and inherent cooperation among highly skilled geniuses. All the long asking how they’re wrong rather than right and noting the results they cannot deny.
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“…inherent cooperation among highly skilled geniuses.” People working together? And even admitting that they’re wrong? That’s so 20th Century.
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