On 2017 May 13, John Sotos commented:

Although interesting, this paper is hurt by the narrow possibilities it examines, and by prior work on interstellar communications it overlooks.

Specifically, it does not consider communication methods that require almost no energy from a civilization, but instead use the energy of the civilization's star. For example, page 127 of Stephen Webb's excellent book, "If the Universe is Teeming with Aliens... Where is Everybody?", mentions: (1) Frank Drake's realization that unusual chemical elements, e.g. praseodymium, could be launched into a star to change its spectrum, causing a signal and (2) Philip Morrison's suggestion that matter be placed in orbit around the star so it periodically obscures the star's light output. Both methods would be detectable at long distances, and could be modulated to give clear evidence of life (e.g. modulating in a prime number pattern). Certainly, the success of the Kepler probe proves that Morrison modulation can be detected over interstellar distances.

Thus, Rose and Wright don't ask the right question. Instead of seeking the lowest-energy insterstellar communication method, they should have been seeking the method that demands the lowest energy from a civilization. The best answer to that question seems to be modulation of stellar electromagnetic emissions. Realizing this, our civilization could launch a program called "Stellar Oscillations To Observe Sentience."

On 2017 May 13, John Sotos commented:

Although interesting, this paper is hurt by the narrow possibilities it examines, and by prior work on interstellar communications it overlooks.

Specifically, it does not consider communication methods that require almost no energy from a civilization, but instead use the energy of the civilization's star. For example, page 127 of Stephen Webb's excellent book, "If the Universe is Teeming with Aliens... Where is Everybody?", mentions: (1) Frank Drake's realization that unusual chemical elements, e.g. praseodymium, could be launched into a star to change its spectrum, causing a signal and (2) Philip Morrison's suggestion that matter be placed in orbit around the star so it periodically obscures the star's light output. Both methods would be detectable at long distances, and could be modulated to give clear evidence of life (e.g. modulating in a prime number pattern). Certainly, the success of the Kepler probe proves that Morrison modulation can be detected over interstellar distances.

Thus, Rose and Wright don't ask the right question. Instead of seeking the lowest-energy insterstellar communication method, they should have been seeking the method that demands the lowest energy from a civilization. The best answer to that question seems to be modulation of stellar electromagnetic emissions. Realizing this, our civilization could launch a program called "Stellar Oscillations To Observe Sentience."