This is why we might be alone at least in the near visible universe.<br>If we get to live for say 10 million years there is just no way that it would not be blatantly obvoius to any other civilization in a near galaxy that we are here!<br>If we get to live for say 10k, or even 1k years the same goes for any other civilization within the milky way.<br>These are all incredibly short time frames on a cosmic scale.