What is the Present?

Live in the moment, stay focused on the present, exist in real time.

These are philosophical concepts. You might have heard one of these coming from a coach, teacher, yogi, Pilates instructor, maybe a parent. What does it mean? They all want you to stay focused on your tasks, your goals, your or your team’s mission. Sure, staying focused on your tasks helps you reach goals and eventually the mission. But the present, the moment, and real time are only concepts, not reality.

Reality is, due to the physical limits of the speed of light, we always live in the future. The farther away something is, the farther in the past we experience it. Oh, and the farther in the past we appear to it too. Is that weird? So, it would appear everything that experiences the universe experiences it as it was, not as it is. Even having a conversation with someone close is experiencing them as they were milliseconds or nanoseconds ago. That might not cause you to lose sleep, unless you are someone who stresses over the small stuff.

It’s the big picture that illustrates just how limiting the speed of light is. When we look at the nearest star to us (other than the Sun), Proxima Centauri, we see it as it was about 4.2 years ago in our timeframe. A little closer to home, when I observe Neptune, I see it as it was about 4 hours ago. The photons of sunlight reflected from Neptune take that long to reach Earth. At the speed of light!

Even real time clocks are living outside the “now” as they have to execute functions that take nano or femtoseconds. OK, I know, that is irrelevant in our lives. We live comfortably in our time delayed world, but what does that imply for the concept of time?

Time doesn’t stand still. Duh!

There are implications for our understanding of spacetime however, as time is the 4th dimension and linked to space intimately. Gravity and mass are attached at the hip too, and affect spacetime by warping it, affecting the apparent passage of time. In a stronger gravitational field time appears to pass more slowly than in a weaker gravitational field. Clocks on Global Positioning Satellites, in weaker gravity, run faster than those on the ground, so a correction has to be implemented.

Time doesn’t stand still, or does it? Photons propagate at the speed of light and do not experience time so time for them is standing still – so I suppose photons themselves exist in real time. For photons, it’s always now.

So, are photons eternal? Maybe. If photons truly have no mass, it appears they are eternal. But eternity, like infinity, gives astrophysicists the creeps. Like a black hole’s singularity.

I’m not going to worry about it.

What’s in the Sky?

June 30; before sunrise; southwest: Southern Delta Aquariid meteor shower – a bright Moon interferes.

August 01; Full Moon, aka Sturgeon Moon. It’s at perigee (closest to Earth) meaning it’s also a supermoon.

August 03; before sunrise; southwest: A nearly full Moon and Saturn grace the sky.