[infurl]

https://www.livescience.com/proxima-centauri-mystery-radio-beam.html

Astronomers hunting for radio signals from alien civilizations have detected an "intriguing signal" from the direction of Proxima Centauri, the nearest star system to the sun.

This is the first potentially artificial radio signal that has been detected from another star system since 1977 when the WOW! signal was recorded by the Big Ear telescope at Ohio State University.

https://en.wikipedia.org/wiki/Wow!_signal

To become a candidate the signal had to pass numerous filters which are designed to ignore all the radio noise that is of human origin or emanating from natural sources such as stars and gas giants. There are a number of things that make it special. It is a single precise frequency down to the limit of measurement which is one hertz resolution; there are no known natural sources for such a pure signal. The frequency is 982.002 MHz which is not used for anything on Earth. The signal is a tight beam from Proxima Centauri and it has a doppler shift indicating that it originates from one of the planets known to orbit that star.

It was recorded between May and June last year and has been studied and analyzed for months. The news was leaked to the press last week and a peer reviewed paper is expected to be released soon. Interestingly, the data has not been released to the public yet although there is no indication that it contains any kind of message.

https://en.wikipedia.org/wiki/Breakthrough_Listen

https://en.wikipedia.org/wiki/BLC1

[HS]

Interesting. Proxima is just over 4 light years away, I wonder if Earth sent any signals in that direction around 9 years ago... Anyways I vote we don't reply to any signals until we become a multiplanetary species and get our space legs, at lest in the solar system, and asteroid belt.

[infurl]

https://en.wikipedia.org/wiki/Active_SETI#Transmissions

There haven't been any signals deliberately sent to Proxima Centauri so far.

Although the issue of sending messages is a contentious one I believe it is somewhat moot. We don't yet have the technology to detect random radio emissions from other planets; we can only detect something beamed directly at us which is what the two signals detected so far could be. However even our technology will soon be able to detect the presence of oxygen in the atmospheres of exoplanets and there is no surer sign of life than that.

[frankinstien]

Obviously, this thread reminds me of the sci-fi novel and movie "Contact" by Carl Sagan. However, I often felt that "Contact" wasn't approaching the idea of contacting an alien civilization(s) effectively.  For one the instructions for building an alien machine that can transport one person to the source of the signal wasn't effective at doing what contact is all about and that is introducing oneself!  So what would be a better approach? How about sending a message that is simply a "Linux" OS with all kinds of data, even an AI? The first reaction to this is: "But the recipients would need a CPU chip that could decode the instructions of the OS and that conclusion is correct.  But, let's not give up on our alien neighbor's sophistication yet.  If a civilization can detect the radio signal then they have at least developed electronic technologies to listen for radio. If you were to use a CPU like an x86 or x64 it has over 6000 instructions, but if you use an ARM its instructions set is about 170 or so. Now the challenge is how to teach the aliens the instruction set of an ARM processor! In the movie "Contact" the signal contained mathematical concepts that demonstrated through the use of a simple codification that could be figured out through patterns of zeros and ones, it was binary!  So if we focus on mathematical concepts of simple boolean operations and arithmetic we could send information in a signal that conveys binary computations that then can be related to the ARM instruction set. From the instruction set one can devise how to build the hardware, we don't need to teach the aliens how to build computers, we assume that they can. If the aliens have not developed computer technology yet or their computational technology is still in its infancy then the mission has somewhat succeeded in that the aliens know there is another intelligence in the universe! Once their technology has advanced enough they then can build hardware that can load the Linux OS and all the data files sent.

This approach allows for most of the signal sent to be decoded by a machine, and because of that, we can send much richer information like videos, music, virtual worlds, games, videos, models of our understanding of the universe, and an AI. The aliens would have a pretty good understanding of who we are and what we look like and how we think!

There is one more detail I have left out: Realize that the signal being set is graded for different levels of technological sophistication. If we also entangle the radio signal then we and our alien neighbors can connect in real-time, if they have the technological sophistication to do so! 

[infurl]

The biggest problem with "Contact" was the notion that you could detect a signal just by listening to the sound. In fact it is necessary to scan millions of frequencies simultaneously and that can only be done by a very sophisticated computing effort such as seti@home was. The next biggest problem is figuring out where to listen and where to beam the signal. We would have to be at least a Kardashev level 1 civilization before we could afford the energy to broadcast signals in all directions that were detectable at interstellar distances.

SETI is a science that has made considerable advances since the movie "Contact" was made and there are many more exciting new technologies within our reach. Nevertheless, it is likely to take centuries or even longer to establish effective communication and there is no guarantee that we or they would last that long.

Incidentally, if the signal from Proxima Centauri is artificial, it has some interesting implications. It is very unlikely that technological civilizations could be rare and two of them exist in adjacent star systems so it would mean that practically every star system would have to have a technological civilization.

The other interpretation is that since Proxima Centauri is a red dwarf, the space weather in that system would make it impossible for life to evolve there (as far as we know). That would mean that the technology arrived there from somewhere else. Given the projected energy cost of interstellar communication, it is possible that signals would be relayed from star system to star system in a galactic network. In other words, it could just be an interstellar cell tower.

[frankinstien]

Kardashev level 1 civilization before we could afford the energy to broadcast signals in all directions that were detectable at interstellar distances.

I don't think sending radio signals in all directions is a good approach. A true hunt for intelligent life would at least spot planets in the goldie locks zone and send a focused microwave or laser signal to that planet. Also, the Kardashev levels were invented in 1964. In 1964 there were still vacuum tube computers, transistors were power-hungry beasts and microchips were pretty much a joke at the time. It stands to reason the more sophisticated a civilization technologically the more efficient they become with energy...