If you google “what is a moment” or “how long is a moment”, you get a plethora of posts and answers. Nothing definitive.
It’s troubling because “moments” are something we all experience deeply, intimately. So, you’d think our understanding of this feature of time would be more fleshed out and less misty.
In medieval times, an hour wasn’t 3600 seconds. Rather, a “momentum” was about 90 seconds. 1/40th of an hour, the time it took for the shadow of the sun to pass over one segment of a sundial.
Science it seems, is settling on a very strict measurement of a moment - that being, the smallest unit of measurable time, a Plank. It is how long it takes light to travel 1 Plank length. 5.39 × 10 −44 seconds. It’s impossibly short, we can’t even fanthom it - it is the speed of thought itself. But it also makes one wonder about science itself, coming up with circular definitions like that …
In the early 90s, I did a poetry reading at the Globe Bookstore in Prague along with the Czech poet-doctor-scientist, Miroslav Holub. At the time, he was thinking deeply about this and do check out (if you can get your hand on it), his slender volume, Dimensions Of The Present Moment. Holub proposed that a moment was somehow musically entwinned. He finally decided on its definition as being “around” the time it takes to read one line of verse. 1 to 3 seconds. The length of a complete thought, a sentence.
Hindus tie our smallest unit of time to our bodily functions. They would say a moment is the time it takes to exhale and inhale a breath.
It’s a fascinating subject but ultimately very subjective. Like time itself. We define a moment mostly based on our own prejudices. In addition, we might also look at a moment in “memory time”. Is that a different length? Our conception of a moment outside of space/matter?
Ultimately, the question, “what is a moment”? is about mindfulness - how long “now” lasts. We know the past and the future are illusions, they don’t exist except as constructs (or do they? are you a fatalist?). But what about now, right now? How long is it? What is it? For example, you feel joy about something or other, how long does that moment of joy last? Of what is the material by which we experience and feel the world, made? How can we measure it?
Last question. There are many descriptions of how at the moment of “the dying of the light”, our moments of our life, pass and flash before us. But how long are these moments and which moments are chosen, who does the choosing?
What is a moment? Below find a PDF which is a good read on the subject.
What Is A Moment?