If aliens make contact with us, will we even recognize it or them? Presumably, as in movies such as Contact, a simple form of math will be the key to unlocking the communication if it is possible.
But the problem is, if they have figured out a way to visit us, they are far more sophisticated and advanced than we are now. And if we receive a communication, how long has it taken to get here and how long will it take to send a message back. Will their civilization even still exist when we send a return message?
Think about our history. We began the stone age about 2.5 million years ago. It took until 5,500 years ago to begin to move to the bronze age. Then the iron age about 3,000 years ago. Then the first steam engine was invented about 300 years ago. The first electric motor was created about 150 years ago.
The first train and the first car were just after 1800. The first plane flew in 1903. We landed on the moon in 1969. So it only took 66 years from the first time we were able to figure out how to have powered flight to landing on the moon. One lifetime!
The first general purpose computer was built in 1945 (ENIAC) and the first integrated circuit was in 1958.
The speed of knowledge accumulation seemed for the longest time like it was on a straight line. But the last several hundred years have shown that it was just the beginning of an exponential curve. Could people from 200 years ago understand today’s technology? It would be difficult. A lot of people living today don’t understand today’s technology.
In another 200 years at the present rate of increase, where will we be? Most of this change has happened over 5,000 years and the bulk of the change has happened over the last 200 years. When compared to geological times scales, this is less than a blink of an eye. So if another civilization on another planet in another solar system got started 10,000 years before us, which is essentially at exactly the same time in geological terms when you look at the age of the universe, galaxy and solar system, there is little chance we would understand anything that was 10,000 years more advanced than where we are now.
Is it more likely that as knowledge accumulates that it will be an S curve and start slowing down with time? Or is it likely to keep rapidly expanding. If it is an S curve, we have a chance of catching up enough to understand. If not, which is more likely, they might consider us as pets the way we treat dogs and cats. Or at least as curiosities. Any real communication might be difficult or impossible. Do we really want to have contact with aliens considering the likely technological differences?