But you have not explained why specified complexity cannot detect design.
I didn't say "cannot". I said "is not". There is a difference.
Nobody is using specified complexity to detect design.
When intelligent agents act they will produce specified complexity. That is because they will use choice directed towards intelligence as opposed to any possibility that is not. It is the ones that are directed towards intelligence that show ID.
We need to talk about the term "specified complexity" because it's being thrown around here with no real consideration for its meaning.
In ID circles it was Dembski who originally proposed trying to detect design via specified complexity. In Dembski's case he formulated a mathematical approach based on probability. In a nutshell, if one wants to detect design they would calculate the probability of a particular output and if that output exceeded a certain threshold one would then conclude design.
Unfortunately Dembski's ideas have not to my knowledge ever been empirically tested or verified as a means to detect design. Likewise I've never seen any examples of anyone using Dembski's approach to detect design.
However, the terminology involving words like "complexity" and "specificity" (along with "functional" and "information") have made their way into the ID lexicon. Thus when reading ID literature it is common to see references to some variation or combination of the above terms, often times used interchangeably. Stephen Meyer is particularly guilty of this in his own writings (which is where I suspect you picked up the term from).
Such usage tends to be colloquial rather than empirical. People talk about intelligent output as having some variation of the above terms, but it's never presented as a demonstrable, empirically verifiable property of the same and consequently never formalized in an approach for design detection.
That is why when you look at real examples of intelligent design detection, you won't find such terminology anywhere near it.
And those radio signals are recognized because they have been designed as opposed to natural signals.
Not quite. Those radio signals are
assumed to be the result of artificially manufactured transmitters because there is no known natural sources. That is why they are used for detection.
It's always possible that one day we discover a natural source of said radio signals.
there is a certain level of complexity. But when it is specified towards certain signifies of intelligence then this adds to the detection of ID.
Complexity is not a factor here. In fact, if you search the SETI web site you won't find complexity being discussed relative to the detection of signals.
The complexity of the signal is only relevant
after it is presumed to come from an intelligent source. Complexity itself is not an indication of whether it is from an intelligent source however.
I think Gates realizes this. He was saying it was like a computer program, comparing it to one.
Which is just an analogy. An analogy does not make an argument.