A realistic SETI attack would need to transmit a very large quantity of information broadcast over very large distances, where the cost is quadratic with distance.
With a physical attack the ‘energy’ payload can be very dense and targeted, and it can use adaptive computations to decompress based on local information, harness energy from the local star, do physical manipulations, etc.
There is related analysis showing that sending particles or physical objects at high speeds can beat photons for interstellar communication in terms of energy efficiency.
With a physical attack the ‘energy’ payload can be very dense and targeted, and it can use adaptive computations to decompress based on local information, harness energy from the local star, do physical manipulations, etc.
This is an interesting point. However, while it is true that a physical attack can be precisely targeted, it is also true that it must be precisely targeted. One of the advantages of a SETI type attack is that it can be launched with no specific target in mind at all. The quadratic drop-off in signal strength that you allude to comes with a corresponding cubic increase in coverage space/volume, provided you run the signal continuously.
There is related analysis showing that sending particles or physical objects at high speeds can beat photons for interstellar communication in terms of energy efficiency.
This is an interesting point. However it would seem to apply to a targeted, point-to-point communication whereas a signal would not need to be precisely targeted.
One of the advantages of a SETI type attack is that it can be launched with no specific target in mind at all.
That isn’t a practical advantage—by the time the attack civ is capable of launching a SETI attack they will know where the other stars are located, and they will probably also know which ones are likely habitable. More elder civs may exist in the interstellar medium or elsewhere, but that hardly matters because they are immune anyway.
A realistic SETI attack would need to transmit a very large quantity of information broadcast over very large distances, where the cost is quadratic with distance.
With a physical attack the ‘energy’ payload can be very dense and targeted, and it can use adaptive computations to decompress based on local information, harness energy from the local star, do physical manipulations, etc.
There is related analysis showing that sending particles or physical objects at high speeds can beat photons for interstellar communication in terms of energy efficiency.
This is an interesting point. However, while it is true that a physical attack can be precisely targeted, it is also true that it must be precisely targeted. One of the advantages of a SETI type attack is that it can be launched with no specific target in mind at all. The quadratic drop-off in signal strength that you allude to comes with a corresponding cubic increase in coverage space/volume, provided you run the signal continuously.
This is an interesting point. However it would seem to apply to a targeted, point-to-point communication whereas a signal would not need to be precisely targeted.
That isn’t a practical advantage—by the time the attack civ is capable of launching a SETI attack they will know where the other stars are located, and they will probably also know which ones are likely habitable. More elder civs may exist in the interstellar medium or elsewhere, but that hardly matters because they are immune anyway.