Looking at the Stars is Like Looking into the Past

Wonders of the Night

The night seems to bring out a side of us we don’t usually see during the day. Our hearts and minds tend to open up during twilight hours; making us feel and think about things we don’t usually feel and think about during the day. There is something mystical about the night time, the moonlight, and the stars sparkling in the sky. It makes us think about all that was, all that is, and all that could be.

You could say that it’s always nighttime in space, so I found myself feeling rather introspective pretty often when I was aboard the Arrow of Light. Once you’ve spent enough time out there and you’ve gotten used to living on a spaceship, it becomes commonplace to find yourself wondering and dreaming about all sorts of things whenever you're not busy. At multiple points in our journey I had some breakdowns, and so did everyone else on board. I remember one time I was asking myself what I was doing in the middle of space, away from everyone and everything I’ve ever known. Thoughts were racing and emotions were brewing. Once I calmed myself, I suddenly remembered something I read when I was younger, and how it played a huge role in me becoming more interested in the wonders of the cosmos.

It was something like: When you look at a star, you are seeing the past.

“How could that be?” younger me wondered.

In a way, it turned out to be true. Let me tell you how…

Space and Light

The universe we exist in is unimaginably huge. The space between planets, let alone stars and galaxies, is something we just can't fully wrap our minds around because we are so physically small in comparison to it. The average human would find 100 km to be quite a lot to walk all in one day. Flying 10,000 km in a standard commercial airliner from Tokyo to Toronto takes nearly a whole day. Compare that distance to an approximate 150,000,000 km between the sun and Earth. At the speed of a standard airplane (assuming it could travel in a straight line at a constant speed) it would take around 18 years to get to the sun.

Our universe is huge and light is fast in the perspective of organisms such as ourselves. When you switch a light on, you don’t perceive any delay. It seemingly goes from light to dark in an instant, because a few meters or a few thousand kilometres is nothing for photons. Now, remember the sun 150 million kilometres away? It takes light about 8 minutes to make it from there to here. So if the sun stopped shining for a second, we wouldn’t experience that second of darkness until 8 minutes later. That's still really fast in comparison to 18 years of flying there by airplane.

Most stars we see are around the size of the sun or bigger (like way way bigger.) Yet, they look like tiny speckles in the sky because of how far away they are. Which means light is going to need a bit more time to travel that length of space. The nearest star system, Alpha Centauri, is about 4 light-years away - meaning it takes 4 years for light to travel that distance. For the ones that are further away and more difficult to see with the naked eye, it can take their light hundreds... thousands... even millions of years to make it across. Which means that the light, which is only now reaching your eyes, was emitted from those stars possibly before you were even born. That “star” you “see” right "now" might have bursted into a supernova just a moment ago and you wouldn’t be be able to tell since you’d only be seeing that star as it was x years ago. This is specifically the case for stationary observes like you and I at the moment. For something moving very fast, it’s a little different.

Perspective

When the crew and I were flying at nearly the speed of light towards Epsilon Eridani, we were gradually seeing the star closer and closer to its actual state. When further away, we saw it at a younger/earlier stage; and as we got closer, we watched it get older and older until we reached it and saw it as it actually was at the time. It was almost like time travel. Conversely, the delay between us and all the bodies we were moving away from was getting longer. And since we were moving so fast, light from behind us could barely catch up. Only when we slowed down would we start seeing things in all directions again, rather than just what was in our trajectory. Nevertheless, just because we couldn’t see anything behind us when we were moving at maximum speed, didn’t mean there wasn’t anything there. As we got further away, we would start seeing the stars behind us at earlier stages in their history ( their light needed more time to reach us since we moved further away.) Very much like peering into the past.

From whatever position we are in, everything we see is a delayed and filtered image of the real thing (with varying degrees of inaccuracy depending on various factors such as relative position, speed, direction of movement, etc.) Even with that seemingly instant illumination of the room at the flick of a switch, there is technically a micro delay that is imperceptible to beings like us. That delay doesn’t make any difference in our daily terrestrial lives, but it’s enthralling to think about.

The reality is that we never actually see anything as it happens or as it really is. That’s because, on the most fundamental level, “seeing” is the passive formation of after-images that are based on whatever visible light has bounced off the objects around us. Although our eyes are pretty reliable most of the time, we can’t always confirm with utmost certainty that something is there in the shape and form we optically observe it to be in. Things really aren’t always as they seem, because the way they seem to be is dependent on your subjective perspective and the surrounding conditions. Optical illusions and mirages are just a couple of examples that prove we can’t always rely on our eyes to tell us what’s there and what’s happening. Good thing we have a bunch of other senses to help us figure it out.

Later I’ll explain to you how it’s possible to leave Earth for nearly a century and return having aged just a few years. When people ask me how old I am, sometimes I'm not sure how to respond.

To be continued...