Written by: Sakshyam Karna - 26013, Grade IX
Posted on: 16 June, 2022
While looking for aliens we normally look to the vast emptiness of space. But there is a bigger dimension that we are overlooking ‘Time’. There are chances that there were civilizations in the past other than us homo sapiens. Indigenous technological species that rose and died out with time. What does science have to say about this and what does this mean to us?
Life has existed on earth for 4.5 billion years, which consisted mostly of single celled organisms. 540 million years ago the Cambrian explosion heralded the age of animals, which is enough time for more than one human-like civilization to come into existence and die out. Right now we only have our civilization to look at to understand how civilization comes to existence and how it works.
We humans emerged about 300,000 years ago and lived as hunter gatherers. For most of our existence we made no progress until 10,000 years ago with the agricultural revolution which led to the industrial revolution which led to our modern society. We could say that our 300,000 years of existence has three phases. In the first phase we were hunter gatherers, farmers and industrialists.
So now we know that time is very vast. What we think of as a long time is nothing compared to the time from when earth came into existence. The oldest large-scale surface on earth is the Negev desert which is ‘only’ 1.8 million years old. Everything older has been crushed, turned around or is covered by ice or ocean. If there were aliens before us and they also went through these phases like we did then we would be able to figure out for how long their impact could be seen on earth.
Let's start with the first phase, the hunter gathers aliens. There might have been thousands of aliens of this category and we would never know about them because they dont leave any significant mark on earth. One of the most famous examples are the homo neanderthals who co-existed with homo sapiens when we were also hunter gatherers. But they died out while we survived. Other examples of such species are homo erectus, Homo ergaster etc.
Now the second phase, agriculture and empire aliens. Now looking back at modern humans, as many of us lived in that time there are more traces so it is easier to find. Many monuments we made when we were in that period still exist, like the coliseum in rome. These will exist for a few more thousands years. Some will exist as an outline on the surface but will be recognizable by future archeologists. Large monuments such as the pyramids will exist for a few hundred thousand years more than other monuments. And because of the large amount of humans that existed at that moment our artifacts and fossils will exist for at most 2.3 million years. But that's it. What will happen after that? You might say that fossils exist for longer periods of time. But fossils are very unlikely and over the course of millions of years only a handful of good fossils are formed. And even if they did form we wouldn't be able to identify if they were of an advanced civilization who knew how to do agriculture.
Now finally the third phase, the industrialists. We have made remarkable progress after we became an industrialist society. Our impacts on earth will be seen for millions of years. Our excessive use of fossil fuel will show an increase in carbon dioxide and this will be a big hint to the future archeologists. Our overuse of plastic will be seen in the ocean floor as small molecules for a few more hundred million years. Our monuments will survive for a longer time than that of the agricultural period. But how will a civilization so advanced perish. There are three ways that are possible, one with an asteroid like the one that hit earth when the dinosaurs went extinct. The second option is a huge volcano explosion. The third one is a nuclear war which has a higher chance to happen now than ever. But even if any of these happen the traces will stay for a few hundred million years. And if we are wiped out by a nuclear war the uranium in the soil will stay for billions of years preserving the layer under it.
So in the end we could say that there might have been a civilization that advanced to the most primitive level of agriculture. There might have been thousands of different types of aliens who lived as hunter gatherers and we would never know. And we can say the same for the agricultural aliens. These aliens rise and fall and their monuments and artifacts slowly persih to biological and later geological processes. But we can say for sure that there were no industrialist aliens before us as we haven't found any traces till now. ‘Cause that's what humans do, what they haven't seen does not exist.
