Contact with extra-terrestrial life?
Assuming there is advanced intelligent life on a planet around Alpha Centauri who have discovered signals from Earth, which action would be the most likely to succeed? Add motivation.
1) They come to visit us.
2) The send message back to us.
Update:The answer given by Alan Turing is wrong. There is a way to find the right answer.
Update 3:Wrong, wrong, absolutely wrong. Come on you people. It's all very logical. 
Some people just can't read.... ASSUMING there is advanced intelligent life ... That does NOT mean "Is there advanced intelligent life?"
Anyways, the correct answer is 1: They come to visit us is the most likely. Maybe I should have given a more distant solar system to make it more clear, but since most answers are clearly so far off I won't bother waiting for a correct explanation.
Here's the answer:
Alpha Centauri is "only" 4.37 light years away from us. That means we see AC where it was 4.37 years ago. And they would at this moment be receiving transmissions from 4.37 years ago. To be able to send an immediate reply, AC would first have to go through the following actions:
1) Locate us
2) Establish the distance
3) Establish our movement
4) Calculate where we will be 4.37 years from now, ergo: 8.74 years from the moment they send a message.
5) Send the message to us, hoping that changes or incorrect calculations won't cause the message to pass us by.
Answer 1 would be more like
Comments
Assuming is tooo easy.If our nearest neighbour Alpha Centauri has Earth-sized planets, we should be able to detect them with established techniques… right now, with the observatories we have today.But so far there is nothing to prove that there are habitable planets.
More ever you seems to know everything about A.C. You are looking for a particular answer which you are not getting!!!!
What makes you think they are soooooo advanced to travel to Earth?They may not have invented wheel yet.so sending message is 100s of years wait for them.Its toooo hypothetical!!!!
no 2.
More time for human to prepare for their arrival. to decide whether or not the public must know this info. To investigate, if it safe to let alien come to earth. To know their purpose, To inform them our terms and conditions on establishing a relationship.
If they choose no. 1, they will be in lot of trouble;
Misunderstanding, exploitation from certain human/ organization for their benefits, possible massive chaos from the human side, suitable environment for the alien to sustain life, lack of understanding of human culture which can produce culture shock and etc.
If the above risks are not to be considered,the advantage is, if the first visit is successful, and so are the other visits, we will take shorter time to establish a relationships.
that would all depend on what kind of extra-terrestrial life is out there...
what if there were dinosaurs, or something similar...I don't see t-rex or any other dinosaur being able to send messages back to us or even visit us...
if they were animals or marine creatures...same really.....
if they were human species like us, it would depend if they had the technology and know how, a cave man would find it hard to receive any kind of message from us.....
but if they were able to....it would probably be option 2 in my opinion, because they would need to know who we are and how to get here safely....:)
2) Would be more likely, since, unless they have technology and an understanding of physics far greater than us, it would take about 25,000 years to travel here at the fastest speeds our spacecraft are capable of traveling.
I just got a text message of them, they said they are lost and can i text them a postcode for their satnav.
We have no way of determining what they would do.