Every single year, the same ritual repeats. The longest day of the year is behind us. Summer changes into Autumn, the days slowly grow shorter, but we still have some long and warm nights.
Until, all of a sudden, it’s only 6 PM and the sun is already setting! Everyone mentions it. Some complain about it, as they expected to be able to do more that day, but it’s suddenly already dark. The same comments as always make the rounds: “It feels like just yesterday we could still walk outside at 8 PM. And now, in just a day or two, it’s suddenly dark!”
Although I refrain from joining this ritual, I do feel the same. Every year. As summer nears its end, you just assume that days will be “a bit shorter” but “it’ll still be light outside at 9 PM, right?” Then, even deep into Autumn, this feeling stays the same.
Until boom, skadeladoozie, it’s only 6:30 and the sun already sets.
Why does this keep happening? Why do we feel that way?
Why do our bodies or minds never learn? Why is it so hard to understand that yes, if the days get a little shorter every day, then at some point the days will be much shorter than during the summer. Why does this surprise us?
Well, because the assumption behind this is wrong!
Most people have the following basic understanding.
- From the longest day of the year (June 21st) to the shortest day of the year (December 21st) …
- The sun will set a little earlier every day …
- And this difference is, like, a few minutes (per day)
If you ask people, they can’t give a precise number, but they will give a number. Some think the sun sets 30 seconds earlier each day. Others say 5 minutes. It doesn’t matter, because all of it’s wrong.
Remember that the earth is round and rotates. It does so in an ellipse around the sun, yes, but that’s not relevant. It also rotates on its own slanted axis, and it tilts during the year. When winter approaches, the Earth is tilting away from the sun. Which means we’re exposed to sunlight for less time during each day, which is why the sun rises and sets earlier.
This is a gradual change in rotation. The position of your town, in relation to the sun, moves over an arc. A curve. A round path. Not a straight line.
In other words, the change in “daylight time” is not linear.
It’s not “2 minutes every day”. It’s not “the sun sets 64 seconds earlier each day until it perfectly reaches the shortest day”.
No, the difference in sunset time from day to day changes!
And now you can probably guess where this “feeling” (or “ritual”) in my introduction comes from.
- The first few months, this change moves from a few seconds to a few minutes.
- The second-longest day of the year is only a few seconds shorter. But by the time we reach September, the sun sets earlier every day by a few minutes (compared to the previous day).
- During October (roughly), the change is minimal. During just this period, the differences in sunset time are almost linear.
- It goes from 3:30 minutes to its maximum of around 4 minutes, then back to 3:30 minutes.
- The last few months, this change moves from a few minutes back to a few seconds.
- So yes, just before that shortest day of the year (~just before Christmas), the days are almost all equally long. The sunset time barely changes anymore.
For the first few months, we don’t “feel” the days grow shorter, because they barely do! Only once the end of September rolls around, has this difference (from day to day) changed from a few seconds to full minutes. And yes, then it quickly adds up, and we suddenly notice it’s already dark outside! And then, once we’re used to that, it slows down again and the length of the days barely changes until the shortest day.
So yes, people are actually right. It does suddenly get dark very quickly. Yes, it was just yesterday that the days were long and warm. All of August and most of September there is barely any change, until it suddenly adds up.
It’s actually a very acute observation that almost all humans have, but we just don’t know why, and we assume we’re wrong because we’ve taught ourselves that sunset times change linearly.
Why am I telling you this?
Firstly, because you might learn a thing or two. I don’t know, tell this to people at parties, use it in your next creative project, whatever. (“What if … we had a fantasy world where the change from longest-to-shortest day of the year happened instantly?”)
Secondly, to give a fun example that illustratues a bigger problem in how people “think”. So, so often people have these ingrained assumptions. These “I was taught things worked this way as a kid” or “when I first learned about this topic, I made assumption X, so I’m sticking to that the rest of my life”. Sometimes we do it consciously, sometimes it’s just a subconscious habit.
But then we build our other opinions or thoughts on such assumptions. We can be convinced we are right, because starting with assumption X, it is absolutely logical to arrive at argument Y. It’s extremely hard to change people’s mind when this is the case, even if all evidence points out they are wrong in practice.
The issue isn’t the chain of thought or the logical reasoning, it’s the very first assumption that started the reasoning in the first place.
I think you’ll find problems easier to solve and arguments easier to support once you realize this. Whenever you’re stuck, go over your input to your thoughts—go over your inherit assumptions and “I take this as self-evident”—and see if something fishy is going on there.
You’ll usually find something. Such as the assumption that daylight time changes linearly. Or, for example, the assumption that the sun directly heats our air. Which is not true. Sunlight heats the earth (our “ground”, if you want), which then emits that heat back to the air.
So much of what we’re taught in school, or by parents, or learned from our own first impressions, can be wrong. In small or huge ways. When we build our other thinking on top of it, it’s bound to end up in the wrong place, and we just don’t know why.
Train yourself to spot this. Help others spot this too, no matter how much they may resist. Whenever someone says something wacky, just ask them how they arrived at that conclusion. Ask them about their starting assumptions. What lies at the very start of their reasoning, which they assume to be self-evident, obvious, or proven?
It’s the fastest way to spot logical errors and reach the right conclusion. Additionally, it’s the nicest way of saying “you are talking bullshit right now, can you please explain yourself?” :p
But, you might say, weren’t people right about the sunset times? Yes! That’s why it’s such a good example.
I just explained how to think logically and make stronger logical arguments. But the world isn’t all logic, is it? Most people wouldn’t know how to form a logical argument to save their life, and those people might be very kind, or very smart, or have achieved a lot.
I’ve found that, if you just don’t close yourself off, our human sense and intuition are great. Not infallible, of course not. Sometimes not to be trusted, such as when you’re hungry, sick or sleep-deprived. Most of the time, though, when we feel something is off, then it is. We often arrive at a conclusion that is right and tangible—what our senses pick up—but then we sort of backtrack and find silly and wrong reasons to support that conclusion.
I once heard a statement about that in a talk about psychology and marketing. I’ve noticed it all around me ever since, and I hold it as one of the top five “Laws of Human Nature” people should know.
The statement was something like: “We think we’re logical beings, but we’re not. We’re just monkeys. Monkeys with a slight upgrade. So we first make a decision or reach a conclusion, and then afterward our slow intelligent brain comes in and makes up bullshit reasons for why we did that.”
It’s exactly that. People instantly feel or notice that the sun suddenly sets much earlier. Then, a few seconds later, their slower “deeper thought mode” arrives and comes up with all sorts of excuses and weird reasons for it. Then, to save face, we present that to our friends and family in reverse order, as if our feeling was the result of some wise deliberation :p
In other words,
- Keep your mind and body open. Trust your gut, lean on intuition, rely on your senses. They are often right about the reality of things. Of course they are! Our body and brain have evolved to survive as well as possible in reality. Especially if you need to make snapshot decisions, this is fine. You don’t need a reason; do what feels right.
- But catch yourself before you make up silly “arguments” and “reasons” later. Go over your assumptions, make sure they are actually valid, and then follow the assumptions logically. If, starting from the best possible input, you arrive at the same conclusion as your instinct, then it’s a great indicator you’re on the right track. If not, update your thoughts, and make a mental note to train your intuition in the right direction.
And now you can be more certain about your choices, maybe convince a few others who spout nonsense to learn logical thinking instead, or just show off your knowledge about sunset times at a party.
Those were my thoughts for today. Written after hearing that phrase “oh wow, it’s already dark at 6 PM! How did that happen? It really feels like the sun is setting earlier each your. Could it be climate change?” for the umpteenth time.
Until the next article in my series of Common Wrong Assumptions, where I explain how nobody actually knows how electricity travels through a wire and we’re just glad our power grids have worked out so far.
(Just kidding. Though it is true.)
Tiamo