I think he means now.
Originally Posted by antoniseb
No, wait, not that now... this now... like, now.
Seriously, mathematically, and physically, present isn't the infinitessimal demarcation between past and future. Rather, it's a single instance of Planck time, which is 1/5.39x10-44 seconds in duration.
Supposedly, according quantum mechanics, it's the small divisible unit of time. However, I found the following intriguing:
"...according to news reports, analyses of Hubble Space Telescope Deep Field images in 2003 brought up a possible discrepancy. Images should have been blurry at very far distances, but the news articles stated that they were not, challenging the theory that Planck time is indeed the smallest measurable unit of time in the universe." - Quote from Wikipedia, and it's sources, below:
"Hubble Pictures Too Crisp, Challenging Theories of Time and Space". Space.com (2003-04-02).
Lieu, Richard; Hillman, Lloyd W. (2003-03-10). "The Phase Coherence of Light from Extragalactic Sources: Direct Evidence against First-Order Planck-Scale Fluctuations in Time and Space". The Astrophysical Journal 585: L77–L80.
Ng, Y. Jack; Christiansen, W. A.; van Dam H. (2003-07-10). "Probing Planck-Scale Physics with Extragalactic Sources?". The Astrophysical Journal Letters 591: L87–L89. The American Astronomical Society.
Perceptually, however, the "present" has a much broader scope, and generally includes whatever's on a person's mind at the time. Thus, even though you're in the here and now, if you're dwelling on past events, you're "reliving the past." Similarly, you could be thinking about the future. While you're doing either, to you, they're your present, or at least your present focus, rather than your focusing on the physical present, ie, what's going on around you.
A more normal viewpoint fixes the "present" as whatever's going on now. Like right now, there are several things in my "present." I'm typing. I'm chewing my spaghetti bolognesa, and thinking about posting it in the Post Your Dinner thread. I'm concentrating on making this make sense, so I'm real-time editing while I'm typing.
To me, all those things are my "present."