I put this category in as a potential problem as we need to consider what we are doing with all our attempts to communicate with other civilisations on other planets or around other stars. This is being done blindly on the assumption that anybody who hears will be more advanced and happy to let us continue the way we are.
There are a number of options.
- Nobody will hear. This is the likeliest option. Voyager 1 is about 14.5 billion light years away, and knowing exactly where it is we can concentrate a world-wide deep space network in its direction. It knows where we are so points its communications, which is a 23W transmitter and dish in our direction. When it reaches us it’s somewhere near a billionth of a billionth of a watt, so a decrease of 20 trillion times, so 1/20 trillionth every 15 billion miles. The nearest star is about 4.2 light years away, so about 1700 times as far. A random transmission may dissipate as much as 20 trillion to the power of 1700, so you may be lucky to get a single photon of energy. Add to this everything transmitting is spinning, so it’s like a lawn sprinkler in action on the top of a merry go round, on a fast moving train turntable, all rotating at different speeds and different directions.
- Somebody will hear, but unable to do anything about it. It’s only recently that we have the facility to return or transmit any large power after about 50 years of being able to receive such a signal. If they did happen to hear us it would take a lot of detective work to find out where it came from unless they understood our message. We have only been able to work things out like that for maybe 50 years out of a 300,000 year human history, so the timing would need to be exactly right.
- Somebody hears us, but is more cautious. Just because a may be prey animal shouts out its existence it doesn’t mean that any other similar creature who thinks of the risk will do the same.
- Somebody hears us and thinks communication is a good idea. If they decide there aren’t predators on the lookout for prey they might return the call. Locating where it came from and returning an intelligible message to us may prove a problem though. We have a system called mathematics, but there may be other systems that are incompatible, even if by an odd circumstance that our moral and social view may be. They are likely to be completely different.
- Somebody hears us and thinks we can take what they have. If they can make it this far they would likely be far more advanced technically than us, and they probably would have as little a problem with conquering us as we do a sloth when we are armed with a shotgun.
- Somebody hears us and thinks we are a threat. So they send something that wipes us out, choose any option from the list.
Humans have developed in a certain way with certain morals and objectives. We live in a dog eat dog world of evolutionary competition where we have found that cooperation works better than conflict. So, our mental processes are geared towards social cohesion, and we have many benefits of peace, although conflict still happens.
If they exist, what would other civilisations be like. We don’t know. We only know what works here and under our environments. Things like democracy where everybody has a decision is not necessarily the most efficient way of doing things. The most efficient is people who have knowledge telling the people who don’t how to do things and making sure they are done that way. Some of the fastest growing civilisations of the past have been a master-slave, or elite-drone type affair, so if a civilisation has advanced this way and it needs resources it may seek to impose these principles on a society that has those resources.
By necessity a civilisation that can travel through space will be more advanced technologically than one that hasn’t. Earth is still in the learning to walk and talk line in this respect, or shout out its presence, and through this its wealth of resources.
Luckily we have distance on our side, the nearest star being around 4.2 light years away, so 8.4 light years away if faster than light travel is not possible. The chance that the closest star would harbour advanced life is quite small, but there may be somebody travelling through that system who can hear. In rough likelihood is that such a civilisation would be around 100 light years away, so our first communications would not reach them until maybe 2030 and if they were very space able may mean they could not reply or get back until maybe 2130.
If they have faster than light drive they could be back within days, so the fastest may be in 10 years time.
Will they be friendly, nobody knows, the assumption is that all advanced life will be, but based on no knowledge at all, certainly not earth where a potential for abuse is usually taken.