(02-17-2023, 09:38 PM)mikesez Wrote: As for life on other planets, there probably is or was life on other planets, but, like cat bells said, we will never detect it.  Even if we send a machine out to look for it, that's a one way trip.  Once the machine is about a light year away, we will not be able to receive its signals anymore. That machine would have to send another machine with mass back to us, back into our radio range, for us to get communication about what it saw.    So even communication between worlds that are 50 light years away or less will take hundreds of years each way. 
So it doesn't matter either way
Unless
There is another intelligent species that lives long enough or has a social memory long enough for those kinds of centuries long incommunicado trips to be sensible.  But such a species would see no threat from us and leave us alone, most likely.

We will detect life on other planets when their mechanical representatives arrive here.  

Biologically based organisms like ours have almost no chance of making the incredibly long (millions of years) trip to find other planets with intelligent life.  We have to eat, and drink, and we have a life span.  But a machine can withstand that trip.  A machine can turn itself off for long periods of time and wake up periodically to scan the local area for signs of intelligent life.  And if it doesn't find any, go back to sleep and continue traveling.   And this is why I say, when aliens arrive on earth from outer space, they will be machines.  And they will say, 

"Hello, we represent the civilization on such and such a planet in such and such an area of the galaxy.  This space craft has traveled millions of years to find you, and while we cannot communicate directly, or even assure you that we still exist, we want you to know that we were out there, and might still be there."  And they might include some messages or give us some technology or something.  

And that will be the most mind-blowing thing ever.

There are 400 billion stars in the galaxy.

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