The perpetual question that arises in the mind of anyone staring at the night sky, watching with awe at the millions of stars, is, "Is there life out there in this vastness, or are we all alone?" I have asked this exact same question countless of times and it is disheartening that we just don't have an answer.

Well, statistically speaking, there should be life out there. I mean, just think about the size of our universe. There are hundreds of billions of stars in a galaxy and now scientists estimate that there are about 2 trillion galaxies. The number of planets with the possibility of life is insanely huge.

I personally think that the universe is teeming with all sorts of life, be it microbial or intelligent life or something akin to plants and animals here on our planet.

But it is really difficult to detect lifeforms and so, we have not been able to find any despite our best efforts. There are a number of reasons for that but I find that two of them are at the top of the list.

Why So Difficult

The number one reason, which is really obvious is that of the distances involved. We may not realise it but even the distance between two neighbouring planets is too large to imagine in our heads. Take the average distance between Earth and Mars for example. It is a whopping 225 million kilometres.

The nearest solar system to us (Alpha Centauri) is a staggering 4.3 light years away. That means, even light, which is the fastest thing in the universe, takes 4.3 years to reach us from Alpha Centauri. As such it is really difficult to detect signs of life within our neighbourhood, let alone the rest of the universe.

The second reason is kind of derived from the first reason. Since light can take ages to reach us from different planets/stars/galaxies of the universe, we are essentially looking at their past. For example, light from the nearest major galaxy, the Andromeda Galaxy, takes 2.5 million years to reach us.

So, what that means is, we are looking at how Andromeda galaxy was 2.5 million years ago. Stop and think about that for a minute. In a way, the universe is kind of like a time machine.

Due to this reason, we have absolutely no idea what's going around in the galaxy at the current moment. Life may have evolved and there might be intelligent species looking right back at us and they would be seeing our past as well, with no idea that we exist.

And this is just for the nearest galaxy to us. There are some galaxies that are billions of light years away. Imagine how they might have evolved and if they might have life on them. It is so ironic that there could be different civilisations in the universe, all looking around at the right places, but oblivious of each other's presence.