How Long Is Now?
Imagine this: The neutron star named “PSR J1748-2446ad” has a radius of 16 kilometers—which gives it, roughly, a diameter of 20 miles—while weighing in at about twice the tonnage of our sun—a very compact ball, in other words.
And it spins. Fast. Very fast.
It is in fact the fastest spinning pulsar known to astronomy at 716 Hz, which is how the nerdy way of saying that this pulsar spins 716 revolutions per second (or that each spin is just over a millisecond—0.0013959548 seconds—long).
As a culinary frame of reference, a regular kitchen blender spins at between 250-500 revolutions per second; but, of course, the kitchen blender blade does not have a diameter of 20 miles.
Try to picture this.
Here is a globe, twenty miles across, weighing in at twice our sun, spinning at twice the speed of a kitchen blender. Dizzy yet?
Then let’s assume that each revolution constitutes one now, one moment, one single slice of presentness.
But that is probably wrong. This very, very now is probably a lot shorter, the razorblade edge of the present moment a lot thinner, than that.
To human perception the now stretches eternally: here it is, now it’s gone into the past, while the future (the new now) takes its place; seamlessly ad infinitum. One long seamless stream of much-finer-than-a-razor’s-edge nows.
As seamless a stream as any movie we’ve seen.
Of course, when we step back and take a look at what a movie really is we see that it is 24 frames per second, each frame a frozen bit of time that when run through a projector at just the right speed (i.e., 24 frames per second) will seem as seamlessly progressive a stream of occurrence as any sequence of moments we live through.
Movie-wise, each now is a 24th of a second long.
But life-wise, how long is the now?
The shortest perceivable time division—sensory psychologists call it the fusion threshold—is between 2 and 30 milliseconds (thousands of a second) long, depending on sensory modality.
Two sounds, for example, seem to fuse into one acoustic sensation if they are separated by less than 2 to 5 milliseconds. Two successive touches merge if they occur within about 10 milliseconds of one another, while two sights (say two flashes of light) blur together if they are separated by less than about 20 to 30 milliseconds.
So, does this mean that, humanly speaking, the now, the present moment, is 2 milliseconds long? That would make for about five hundred nows per second.
In one Pali Canon sutra, the Buddha—some 2,500 years ago—said that there are thousands of moments (e.g. nows) during the raising of your arm.
Well, come to think of it, that could translate to 2 milliseconds per moment as well, could it not?
In another Pali Canon sutra, the Buddha said that there are three thousand moments in the blink of an eye. That would make the now a little shorter, say 1/5th of a millisecond; or even 1/10th, the blink of an eye is, after all, pretty short.
As an aside, I find it utterly amazing that the Buddha Gotama, over two and a half thousand years ago, observed and voiced something psychologists today are just beginning to fathom—the perceived now.
Scientists, on the other hand, take a mathematical view of now: seeing it more like a concept than a physical reality. In fact, the now, mathematically, is viewed as an infinitesimal length of time similar to the mathematical point: a concept, or a location, not really a thing at all.
Mathematically speaking the point does not have physical size, nor does it have shape. Rather, it is simply a location without dimension.
Just a concept.
Back to the pulsar. If it can spin 716 times in a second, that’s a little more than a spin every 2 milliseconds.
So, perhaps the now is 2 milliseconds long—or 1/20th of that, if the Buddha’s second statement holds true. But, of course, there’s no way to prove that.
And here’s the problem.
Remember the old philosophical/geometrical proof that if you drop a penny, it will actually, theoretically, never reach the floor.
For, first, it has to fall half the distance to the floor, then, it has to fall half of the remaining distance, then the half of that, and—you can see where this is going—you can always halve the remaining distance, ad infinitum. It will always have half the remaining distance to fall and so will never actually complete its fall. There’s always one half of the remainder remaining.
In real life, it takes less than a second to hit the floor. So much for theoretical proof.
To me, the same seems true about time. If we can measure it, surely we can halve that measure, and then halve the remainder. It will become infinitesimal indeed, constantly approaching (as we keep halving the remainder) zero—but never reaching zero.
So how long is the now?
I think the truth about this lies in a different direction. I think that the true now is actually independent of time, that it lies beyond time, that it cannot be measured by time.
That it can’t even be thought of as time.
For the true now includes all the past there has ever been, and it includes all the future there will ever be, for there is—in truth—neither past nor future, just the thing we refer to as the present, the now, which, when all is said and done, simply is (here and now), un-measurable in physical terms.
Is what I think.