An interesting proposal for interstellar communication

You will need:

1. A Cepheid variable star. Getting your hands on one of these might be tricky - the nearest ones are Polaris (which seems to have various oddities which might make it unsuitable for this kind of thing) at 400 light years and Delta Cephei at 900 light years. Since yellow supergiants are probably not good candidates for hosting habitable planets, some interstellar travel capability is probably required.
   
2. A really powerful neutrino beam emitter.

Instructions:

1. Park your neutrino beam machine in orbit somewhere around your Cepheid variable, aiming it at the star.
   
2. Wait until the Cepheid is getting to the end of a variability cycle.
   
3. FIRE!!!
   
4. The neutrinos dump energy into the core of the Cepheid, which should trigger an instability causing the next variability cycle to begin early. This would allow you to modulate the Cepheid's variability in order to transmit messages, and simultaneously really irritate any astronomers in neighbouring civilisations who are still trying to get the cosmic distance scale figured out.
   
5. Repeat as necessary

arXiv: The Cepheid Galactic Internet

Whoa! Trying to use a decently luminous Cepheid would take years to whip out the phrase : "Mr. Watson - Come here - I want to see you."

Juramike wrote:Whoa! Trying to use a decently luminous Cepheid would take years to whip out the phrase : "Mr. Watson - Come here - I want to see you."

Not to mention the length of time needed for him to complete said task.

Woah something just hit me...

Lazarus wrote:You will need: ... A Cepheid variable star. Getting your hands on one of these might be tricky - the nearest ones are Polaris (which seems to have various oddities which might make it unsuitable for this kind of thing) at 400 light years...

Lazarus wrote:This would allow you to modulate the Cepheid's variability in order to transmit messages, and simultaneously really irritate any astronomers in neighbouring civilisations who are still trying to get the cosmic distance scale figured out.

Of course! Lazarus, I think you might have inadvertently discovered the cause of Polaris' oddities

More seriously though. I'm sure any civilisation with this capability would have figured out more efficient ways of communicating.