Before I begin, this focuses on a very specific example – so, if you have time, have a think about how it generalises. There are countless examples out there, in fiction especially, but where it bleeds over into real life we can run into serious problems.
Yes, it’s a post dedicated to Ken Ham, the dumbest person on the planet not named Ray Comfort, who recently said this in “celebration” of the same-sex marriage ruling in the United States:
Specifically, I want to look the part that says “Well, the president did not invent the rainbow; God invented it.” (emphasis added)
I’m sure many Christians out there think God is the de facto inventor of the rainbow by virtue of being the creator of the universe, but I’m not talking about that. That’s actually fairly self-consistent, and I can’t really fault it much. This is different. Remember: Ken Ham is a literal Biblical creationist.
He genuinely, literally believes the Bible is the historical book of record for all of history. And by extension, all of physics, too.
He honestly, really, genuinely doesn’t believe in any science that contradicts the Bible, never mind any historical fact that contradicts it.
He literally, actually, genuinely, really believes that the Book of Genesis is correct that the atmospheric phenomenon we call a “rainbow” is a sign from God, an apology for taking his anger management issues out on the entire population of the world in the single biggest act of genocide in “recorded” history.
Ken Ham literally, really, honestly, actually, literally, genuinely, properly, really, actually thinks that the rainbow was invented by God after the flood.
It didn’t, therefore, exist before the flood.
This is what Ken Ham actually believes – otherwise his entire world collapses in on itself faster than the rectal prolapse suffered by a homophobic televangelist after too much anal sex with gay hookers on speed.(That’s quite enough of that, Ed.)
Now to cut a long-winded pseudo-intellectual story short; we simply cannot build a universe where a rainbow cannot exist.
Well, we can, but we have to understand its wider effects. I’m perfectly okay with God Almightly clicking his non-corporeal fingers and altering physics in such a way that one moment there was no optical phenomenon in the sky and then suddenly there was… but we have to follow those changes to their logical conclusion. In stories, with their narratives, you can get away with changing one thing, but in real life you can’t.
There are three things you can change in order to stop a rainbow from being physically possible: the light, the principles of optics, and the source (I suppose one could call it the “material cause”?) of the refraction. Remove one of those components, and no rainbow is physically possible.
The details makes a fun and entertaining thought-experiment: what would happen if we stopped a rainbow from happening?
- Remove the light – No light, no rainbow. But then we can no longer see, either. Our vision requires light, so any antediluvian civilisation would be blind and incapable of sight. It doesn’t stop there, though. Without photons, chemical reactions that are sensitised by photons or that emit photons wouldn’t happen. Energy level changes at the quantum level would all have to take place non-radiatively. There would be no mechanism to masslessly transfer energy about the universe. Quantum mechanics breaks at the seams as it can’t shed energy around as photons. At the very least, the Earth would freeze solid as the sun was no longer capable of warming it from across the void of space with a massive influx of solar radiation.
- Remove the optical effects – Now we’re cooking! We can keep the light, but let’s kill the concept of refraction. Okay… now we can’t see either, since our (allegedly “intelligently” designed) eyes have to bend light twice in order to focus. Once through the main cornea and then through our squishier lens. Antediluvian civilisation is still blind. Light now travels at the same speed through all media, not slowing down or altering. Light is no longer interacting with matter in the way it should. Quantum mechanics as we know it again shatters into a thousand pieces, the universe dies of entropic heat death before it is even born.
- Remove the water – Okay… let’s keep all the physics behind the rainbow! The universe exists, light interacts with matter, let’s just kill the rainbow at its source – the condensed water droplets in the atmosphere. Immediately we all die of thirst and starvation as there’s no water, so let’s put the water back. Oh, wait, the hydrogen bonding between water molecules, as well as the mass of two hydrogen atoms and an oxygen atom give bulk water very specific properties such as its vapour pressure, and its melting/boiling points – that means if we put the water back we’ll have water vapour, and it’ll condense around any particulate matter in the atmosphere… back to the drawing board, let’s alter conditions so that water vapour can’t condense! Aha! Let’s lower the pressure of the atmosphere, that should keep it in the gas phase… oh, wait, now people can’t breathe because the partial pressure of oxygen is too low for haemoglobin to work properly. Let’s up the molar proportion of oxygen in the atmosphere so the partial pressure is still ca.0.2 atm as it is now…. oh great, now not enough nitrogen for nitrogen-fixing bacteria to work with and we all die of starvation and let’s not even start with what the lower pressure does to the boiling point of the oceans and the gases dissolved in them… okay, so let’s boost the temperature above the dew point of water… bah, we’re all dead again… quantum mechanics remains in tact, but chemistry explodes in fireball of icy self-contradicting death and destruction that renders the planet inhospitable to everything that isn’t a self-contained abstract concept.
That’s consistency for you. There isn’t a world where you can’t have a rainbow yet let it still work exactly as it does today. You can’t pick it apart from the rest of the universe and treat it as a narrative block, a piece of magic with its own separate rules. If you change one rule, it changes for everything.