Incredible as it may seem, in 1972 a physicist decided to use science to answer this question . In an article published anonymously in the specialized journal Applied Optics, the researcher presented the result, explaining that the calculations had been based on two passages from the Bible . To calculate the temperature of Heaven, the author turned to Isaiah 30,26, where he says: "And then will the light of the Moon be like the light of the Sun, and the light of the Sun seven times greater, like the light of seven days? ". The author deduces that the Sky receives as much radiation from the Moon as the Earth receives from the Sun and, in addition, 7 times more (49). That would give a temperature of 525ºC .
As for hell, in Revelation 21: 8 we can read: "… for idolaters and all liars, their inheritance will be the lake that burns with fire and brimstone." If a sulfur lake is molten, its temperature must be equal to or lower than the boiling point, which is 444.6 ºC . We then have that, the temperature of Heaven is 525 ºC and the temperature of Hell is lower than 445 ºC. Therefore, the article concluded, Heaven would be hotter than Hell .
However, there are other more recent interpretations that defend the opposite, arguing that the landscape of Isaías would refer to a single factor of 7, and that in that case the temperature of the Sky would be 231.5 ºC (more "cooler").
