[dexy]

Not quite.

The actual reason is that we have invented radio technology only very recently. Because we are so new to the technology, odds are that our communication partner has had radio for much longer than we have (millions of years probably, given the age of the universe), and thus is far more advanced.

This logical step requires a few assumptions. First is that societies don't destroy themselves soon after the advent of nuclear weapons, which would limit them to a very short window of radio capability (measured in hundreds or thousands of years).

The second assumption is that other forms of intelligence progress their technology at a similar rate to that at which we progress ours.

If the former assumption is wrong, it's extremely unlikely that we will ever talk to any intelligence, even with relatively plentiful life in the universe, because it will kill itself too fast. The latter assumption could still be wrong though, particularly if the method used for interstellar radio communication was in any way evolutionarily derived.

This is my understanding of the topic at least.

[ars]

You missed my point - why do you assume they will talk to us before we talk to them?

We have zero data on any kinds of odds for how long anyone else might exist, or if the amount of time we have had radio is considered short or long.

[dexy]

This falls exactly into the scenarios I talked about...

Given how much randomness was involved in our creation as a species, let alone our technological ascendance, it is highly unlikely that other intelligence would develop in exactly the same amount of time elsewhere. It's astronomically unlikely. If they didn't develop at the same time as us, they're either still incapable of radio or have had radio for a long time. A long time in the life of the universe certainly doesn't mean 100 years, it means much longer. Even if it's only 1000 years, if they progress at anything like the rate we do, they'll be massively more advanced than we are.

If a species only has radio for a short period of time (like 200 years) and then disappears or loses it, the odds of overlapping with them are virtually nil (if they die out after getting this far, it says we're much more likely to die out soon too).

And I don't know if they would talk to us before we'd talk to them. Stephen Hawking has a lot to say about why trying to communicate with other civilizations is a bad idea, and they might be smart enough not to try.