Aliasing is a phenomenon you’re probably most familiar with in old movies, where the wagon wheels appeared to go backwards, or perhaps you’ve seen the stunning artwork of John Edmark and his BLOOM creations.
Perhaps now you’re being hypnotised by the video and can read no further, but that’s ok. I can wait.
The phenomenon of aliasing is basically just removing a whole bunch of information to see whether it makes the story better or makes other stories become possible. For example, the two sinusoids which fit with the aliased signal in the geeky graph below: the red is “truth” but we only get to “see” it at the black dots. The result is that we think the blue line is what is really going on.
When you look at a wagon wheel going backwards, the movement of the wheel between the shutters of the video camera is not seen. Same for the video above: it’s done under a strobe light so that most of the movement of the sculpture happens in the dark, and we only see tiny, tiny slivers of information from which our brains construct the new story. Importantly, the key to a beautifully aliased effect is to remove enough of the information; if there were other frames shown in any of these situations, the movie would become jerky, fragmented and awkward. In other words, it’s only nice to look at because you’re not seeing all the information.
I was really surprised to read that the same aliasing effect has also been seen under continuous illumination, in real life, not the movies, and without the use of strobe lights. How could this happen? No-one is really certain, but there are thoughts that it could be because our visual processing is more discrete (that is, distinct, disconnected) than we’d imagined, or not, or that the sensors in our eyes and brain which are tuned in to motion are also tuned in to the reverse motion too, and sometimes that’s just what our brains go with (there’s a review paper here, but you’ll need to be able to login to see it). All in all, just seeing something relies on our own interpretation to quite a large extent. Which is a good thing in a lot of ways; otherwise the works of Oleg Shupliak, Maurits Escher, the incredible world of Mitsumasa Anno, and many many more would not be quite as delightful as they are, and the world would be poorer for it.
Why does this matter? Is there more here than weird and wonderful artwork? I think it’s good to understand aliasing because it gives us a glimpse of something important, and that’s just how much we don’t see, and even when we do see, how much we really don’t, if you see.
Let me give you a non-visual example. I live near Geneva and the main language here is French, which I am trying to learn, but struggling. At the front of our apartment building is a bakery where I go to get bread for breakfast, and the other day (you may recall we had friends staying) I bought two loaves of lovely bread. More recently I went in to get bread, asked for a loaf and pointed out the one I wanted. The lady put it in a paper bag, then asked, “Two?”. I was quite surprised at her memory – clearly, she remembered not just me, but that last time I’d bought two loaves of that same bread. I was quite impressed! I said, “No, no,” with that deprecating hand gesture we all use, but she looked confused. She said again, “Say two?“.
At this stage you need to know that although I try my best to speak French in shops, most of the time the shopkeepers try their best to be kind and reply in English. But I still reply in French, so I said “Non, merci,” and she still looked confused. “Seulement le pain complet, s’il vous plait.” Ok, that seemed to settle it, or at least enough for me to pay for my one loaf of grainy bread and leave the shop. Only on the way back home did it occur to me that “Say two?” was really “C’est tout?” or “Is that everything?” … soooo … she didn’t remember me, she wasn’t speaking English, and it was no wonder she was confused by my replies and actions. Anyway, the bread was lovely.
In a third language, I was in Canada watching a German woman try – not very successfully – to get her dog to obey verbal commands. My first thought was, “Oh, silly woman, dogs don’t speak German.” Yeah. Anyway.
It’s scary the amazing speed at which misunderstandings happen. In a French-speaking shop, having a conversation in French with a stranger, my first interpretation – which persisted – was that she had performed an incredible feat of memory whilst speaking a different language. And also that dogs speak English. The trouble with first interpretations is that, at the time they’re happening, they’re just what’s happening. We don’t think of them as first and we certainly don’t think of them as only impressions; they’re our truth in that moment. It’s only later on when we learn – when we are willing to learn – more that we relegate them to the box of first interpretations or impressions.
This is why I think aliasing is important to understand. Because however much we think we see – whether in films or in life – or think we know, or understand, it’s never the whole picture or the whole story; it’s something fragmented and aliased, and there are huge amounts happening in the darkness. What we take from it is just our best guess at truth at that moment. And, very often, what we understand isn’t even our best guess; it’s just the first one that kinda makes some kind of sense (though that particular threshold seems to be quite low, in my case). C’est tout? Non! Is it everything? No!
And all of it colours how we react to the world and its people. We don’t know what’s happening in someone else’s mind or heart or life. We don’t have all the pieces, and even if we did, what we saw would still require the interpretation and processing of our own minds. And, as we’ve seen, our minds usually stop searching for meaning once they’ve found the first viable solution, unless we’re willing to prompt ourselves to keep our minds open a little longer, so that a bit more of the real story can come in.
So here’s my challenge for you. See a situation, and challenge yourself to find different explanations for it. Your co-worker is grumpy. Your child doesn’t want to go to school. Your wife has a headache. Your husband gave you chocolate. The lady on the train smiled at you. Remind yourself that the answer to C’est tout? should probably be Non, except when buying bread.