Transcript: Even if we accept the premise of SETI, that intelligent civilizations exist, and we accept the methodology of using radio waves to communicate across large distances of space and time, we are still left with a profound question. What should we say, and how should we say it? The idea of communication involves the idea of a message, but how do we encapsulate human intelligence and civilization in a message that can be coded and transmitted across regions of space? The danger,...

Transcript: Although traditional SETI is conducted in terms of radio waves and their communication, it’s worth considering the possibility of optical SETI, using light waves to communicate through interstellar space. This has become possible due to current and modern technologies. For example, we have lasers which in a pulsed mode can outshine the Sun by a factor of ten thousand, if only for a microsecond or less. If such lasers existed on planets around nearby stars and were being pulsed...

Transcript: Why has the SETI strategy focused so heavily on radio waves for communication? There are simple reasons to do with fundamental physics. Radio photons are preferred over optical photons because they have low energy and so are less costly to produce in energetic terms, and they travel unimpeded through space, being unaffected by dust and gas. Also, there are regions of the electromagnetic spectrum where there are minimum amount of cosmic noise from other energy sources, and the...

Transcript: Why has the SETI strategy focused so heavily on radio waves for communication? There are simple reasons to do with fundamental physics. Radio photons are preferred over optical photons because they have low energy and so are less costly to produce in energetic terms, and they travel unimpeded through space, being unaffected by dust and gas. Also, there are regions of the electromagnetic spectrum where there are minimum amount of cosmic noise from other energy sources, and the...