The speed of light is far too slow for any potential alien to know we are even here. An alien 50 light years out that detected Hitler’s Olympic address (send in 1936 one of the first strong signals, intentional sending didn’t come until latter) still hasn’t got their response back to us yet! Even if there are aliens, there are only around 2000 stars at that distance and so odds are against them being that closer.
that is before we start talking about how signals lose strength of distance. Most of the stars we see in the sky are in the same sub-arm of the spiral arm of the milky way that we are in - even stars don’t have enough energy to reach earth from farther out! (telescopes of course can detect a lot more, but still we are talking about star level energy here). I don’t know what the limits of detecting life on earth are, but I doubt even the most sensitive possible systems could have detected dinosaurs from the nearest star to us (excluding our sun). TV (that is strong signals but not directed) is detectable farther out, but even still we don’t gets much farther. As the world moves to low power digital communications there is less to detect. There are of course intentional “we are here” messages sent via directional radio telescope - but they are rely on our best guess of where aliens might be and so could miss a lot, and still those only reach so far - and have not gone very far.
The speed of light is far too slow for any potential alien to know we are even here. An alien 50 light years out that detected Hitler’s Olympic address (send in 1936 one of the first strong signals, intentional sending didn’t come until latter) still hasn’t got their response back to us yet! Even if there are aliens, there are only around 2000 stars at that distance and so odds are against them being that closer.
that is before we start talking about how signals lose strength of distance. Most of the stars we see in the sky are in the same sub-arm of the spiral arm of the milky way that we are in - even stars don’t have enough energy to reach earth from farther out! (telescopes of course can detect a lot more, but still we are talking about star level energy here). I don’t know what the limits of detecting life on earth are, but I doubt even the most sensitive possible systems could have detected dinosaurs from the nearest star to us (excluding our sun). TV (that is strong signals but not directed) is detectable farther out, but even still we don’t gets much farther. As the world moves to low power digital communications there is less to detect. There are of course intentional “we are here” messages sent via directional radio telescope - but they are rely on our best guess of where aliens might be and so could miss a lot, and still those only reach so far - and have not gone very far.
Then there’s the whole Dark Forest hypothesis.