The Line Between Possible and Impossible

How did we go from this:

(source: https://owlcation.com/humanities/prehistoric-man)

To this:

(source: https://events.unsw.edu.au/event/earth-conservation-x-space-exploration)

Well, that's a perfect question to illustrate what i will be discussing in this topic. Human civilization has been around for much longer than you could imagine. For a significant period, humans roamed the earth, exploring from place to place, leaving traces, and most importantly, learning and advancing. But for me, the fact that we are already in the phase of being capable of exploring space makes me wonder if our ancestors ever thought that we would be this far. 

In the first picture, we can see a snapshot of human life during pre-historic times. Not a real "snapshot" surely, but enough for us to get the idea. Pre-historic times dominated the horizon of overall human civilization. I will not go with the detail of lifespan or era to era, but let's just consider pre-historic era is everything before the industrial revolution and modern era is everything after. There are a lot of things humans have discovered or invented—from fire and elements to machinery and tools—all of those have complemented and advanced one another over time. Many of these innovations were unimaginable to earlier generations of humans. Just like the picture on the top of this writing. Those men who warming themselves in front of the fire probably couldn't have imagined that we would end up in space and exploring it. But where exactly is the line between what we can possibly invent or discover, and what's beyond our reach?

https://www.washingtonpost.com/news/wonk/wp/2015/10/04/what-people-in-1900-thought-the-year-2000-would-look-like/

Before moving further, kindly skim the article above. There are things that our ancestors predicted that turned out to be true, and there are things that did not. In the article, some of the things mentioned are flying machines, battle cars, and whale buses. People in that era predicted these things not without a reason. Possibly at that time there were cars, buses, machine, but they could only imagine them being more advanced. Well, we do have battle cars and flying machines now, even though it might not exactly the same as they imagined. On top of that, we have invented something wayyy more valuable and advanced compared to those things: Internet.

Internet is surely a miraculous invention. As a person who grew up in the internet development era, i can confidently confirm that it has provided me with a lot of benefits. But returning to our previous article,  none of them predicted something similar to the internet. What they could imagine at that time was something already present but in a more advanced version. That's why i mentioned that internet is a miraculous invention, because people who lived centuries ago might have thought that something like internet today is impossible—something that can connect people from South Pole to North Pole, make communication as easy as pie, and advance people's live in unimaginable ways. But this makes me wonder again, is there any line between something that is possible to achieve and something impossible? Because if there is, i would definitely put internet outside this line, considering none of the people predicted it would be invented. However, what this line exaclty is, under what conditions determine this line, and what falls inside and outside this line are yet to be known.

For me, one thing that can determine this line is science. If i were asked what is something we currently cannot do but might be able to do in 100 years, i would answer: smelling scents through a screen. I have always wondered about this since i was a kid, but as i grew up, i understood that this is scientifically impossible. But even with science, the parameter of "impossible" that i have in mind and that people in 100 years will have could be different. Humans always find a way to break the impossible. People in early history would not have thought something called a lamp would replace fire, or something called a machine would replace their herds, etc. So, in the future, could we do teleportation? Or live on Mars? Or become immortal? No one knows, no one can guarantee; it's better to draw your own line.

Note: There could also be an invention restriction made by government or powerful entities that prevent us from achieving certain things in certain sectors, such as finding cancer cure or developing a substitute for crude oil (not proven yet).