A Reflection on Reality, or Better Yet, Our Experience of It
“Do you think a fish knows it is living in a pond and that there is an ocean beyond it?”
“She is probably aware that there is air above the surface, I guess.”
“So do you think fish deep in the ocean know this as well?”
“No. They cannot perceive it.”
We were on a trip in Montenegro. It was around 6 p.m., dinner time, yet it was still hot outside.
I have always been a strong advocate of staying grounded in reality and seeking the truth, no matter what is happening, whether good or bad. Over time, however, it has become clear to me that my perception of reality is questionable. Perhaps what I call reality is actually just my experience of it.
This thought resurfaced when we started talking about the universe and our place within it.
As we sat there, we pulled out our phones and asked AI to explain the distances across the universe.
Have a look:
| Destination | Distance | Light Travel Time |
|---|---|---|
| Germany to the USA | 7,000 km | 23 milliseconds |
| Once around Earth | 40,000 km | 0.13 seconds |
| Moon | 384,400 km | 1.28 seconds |
| Sun | 149.6 million km | 8 minutes 20 seconds |
| Proxima Centauri | 4.24 light-years | 4.24 years |
| Andromeda Galaxy | 2.5 million light-years | 2.5 million years |
| Very distant galaxies | Billions of light-years | Billions of years |
The numbers were astonishing. The more we explored these distances, the more I realized how small our window into reality truly is.
Looking Into the Past
The most fascinating consequence is that whenever we look into space, we are also looking into the past.
We see the Moon as it was about 1.3 seconds ago, the Sun as it was more than eight minutes ago, Proxima Centauri as it was more than four years ago, and the Andromeda Galaxy as it was about 2.5 million years ago.
We also learned about an even more extreme example: the cosmic microwave background. The light we observe from it has been traveling for roughly 13.8 billion years. Because the universe has expanded during that time, the regions this light originally came from are now about 46 billion light-years away.
Like Fish in a Pond
When I think about millions and billions of years of light travel, I honestly struggle to comprehend it. The scale is simply beyond anything we encounter in everyday life.
It makes me feel as if we are fish in a pond, unable to comprehend the true magnitude of the universe and whatever may exist beyond what we can perceive.
A fish living in a pond may understand its immediate surroundings. It knows how to find food, avoid danger, and navigate its environment. Yet it has no concept of the vast ocean beyond its world, not because it lacks intelligence, but because it lacks the ability to perceive it.
Perhaps we are no different.
Although I love certainty, I often wonder whether one day I will discover that there was an ocean out there all along.
I also deeply hope to live another seventy years and witness what will be discovered with the technology we are developing today, because I have a feeling it will be absolutely mind-blowing.
