What Color Is Hellfire?
There has been much scholarly debate over the centuries about the physical properties of hellfire. It is generally known to be hotter than standard sources of terrestrial fire, and is often conceived of as being red or orange, like the typical fires known to humans in ancient times. This conception of hellfire is retained by modern cultures, and can be seen in such examples as the Hellfire card in the popular collectible card game, Magic: The Gathering:
But, is this conception of hellfire correct? To better analyze this, we turn toward Islamic sources of information about hellfire, as medieval and ancient Arabs were typically more adroit at quantification than contemporaneous Christians. From the Hadith we learn:
The (Hell) Fire has 69 parts more than the ordinary (worldly) fire, each part is as hot as this (worldly) fire.
In other words, hellfire is 70 times hotter than terrestrial fire. The consensus understanding is that this is in comparison to ordinary cooking fires which, centuries ago, were wood fires under full flame. While different types of wood certainly have different temperatures at which they combust, a fair approximation for the heat of a full-flame wood fire is about 500°F.
Of course, when dealing with temperatures in Fahrenheit, it is somewhat meaningless to discuss what temperature is N times as hot as what other temperature. Is 500°F five times as hot as 100°F? How many times hotter is 100°F than 0°F, or -1°F? Clearly, the Fahrenheit scale will not do for this, so we must first convert the temperature to Kelvin, which is the absolute temperature scale. 500°F, then, is equal to 533K.
Having established the temperature of worldly fire, and knowing the ratio of the temperature of hellfire to worldly fire, we can then determine that hellfire has a temperature of 533K x 70 = 37,310K. If we convert back to Fahrenheit, we find a temperature of 66,698°F. Something tells me that is very close to the right number.
So, how hot is this? When we think of hot stuff, the surface of the Sun comes to mind. A quick internet search reveals that the Sun is a paltry 5,778K, or only about 15% of the temperature of hellfire. What about a very hot star like Rigel? Rigel is a blue supergiant star in the constellation of Orion, and one of the brightest stars in the night sky. Rigel has a surface temperature of approximately 11,000K, or about 29% the temperature of hellfire.
Rigel is not, however, the hottest star. It is nowhere close. Many stars much bigger and hotter than Rigel are out there, such as the behemoth double star known as Eta Carinae, the hotter of which, Eta Carinae B, is estimated to have a temperature of approximately 37,200. In other words, Eta Carinae B is hot as Hell.
Having established the temperature of hellfire and, having found a celestial body with approximately the same temperature, we can turn to the business of determining the color of hellfire. Is it red? Is it orange? Or is it, perhaps, something else?
Wien’s displacement law is a tool used by astronomers and other scientists to determine the peak wavelength of emission of an object. As each wavelength in the visible light spectrum has a color, this can give a clue as to an object’s color as perceived by the human eye. This law can determine the peak wavelength of emission of all sorts of objects, from a wood fire, to the element of an incandescent bulb, to the heat radiated by the human body, to a star in deep space. If we assume hellfire is, indeed, a type of fire, then we should be able to use it to determine hellfire’s peak wavelength of emission and, as such, describe its color.
We know that the flames of typical terrestrial fire appear reddish-orange. We can also plainly see the color of our own Sun, and scientists have determined its peak wavelength of emission is about 500 nm, in the green range of visible light, which corresponds closely to the peak wavelength of sensitivity for the human eye, and, not by coincidence, the color of airport fire trucks.
We know from viewing the sky that other stars have colors that range in the visible spectrum from red to blue, with the red stars being cooler than the Sun and blue stars being hotter, such as the aforementioned Rigel. If we determine the peak wavelength of emission for a temperature of 37,310K, we find a value from Wien’s displacement law of approximately 80 nm. The visible spectrum runs from about 390 nm to 700 nm. Below that is the ultraviolet range; above that is the infrared range. 80 nm lies within the range of ultraviolet light, which runs from 10 nm to 390 nm.
Since we cannot perceive ultraviolet light with our eyes, we would not be able to witness the full brightness of hellfire, much as we cannot perceive the full brightness of the hottest stars in the night sky (though we would get a Hell of a sunburn). Animals that can perceive into the ultraviolet spectrum, however, would surely find hellfire blindingly bright. Incidentally, this is why some insects and moths can see so much better than humans at night, because they perceive the brightest stars at their peak wavelengths of emission, meaning those stars look even brighter to them, and the night doesn’t seem so dark.
The same stars moths can perceive in their full brightness appear blue to us, because the amount of radiation emitted by a source diminishes monotonically as it moves away from its peak emission wavelength. In other words, blue stars put out more green light than they do red light, and red stars put out more orange light than they do yellow light, and so on. This means that hellfire would appear to us as something along the lines of violet, indigo, or blue.
The aura surrounding this star gives us a good idea of how hellfire would appear to us. The intense heart of the flames, presumably fueled by the eternally-burning souls of the damned, would appear as a bright violet-hued white, fading to indigo and blue as the flames flicker away from the combusting souls.
