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Sending a signal to E.T.'s

Brian

Graduate Poster
B
Joined
Jul 27, 2001
Messages
1,776
If we were going to pulse, say radio waves, into space to see if anybody gets them and signals back, what would we use that any advanced species would understand and not think it was random?

I was thinking the concept of "1,2,3..." would be inescapable.
How about:
1 pulse, pause
2 pulses, pause
4 pulses, pause
8 pulses, pause

Every time 15 times we complete that cycle, take a longer pause and:
15 pulses

Repeat.

Think that would do it?

Idle thought in traffic today.

Any other ideas?
 
Many people suggest, and I agree, strings of prime numbers. Nothing in nature will create those.
 
You silly Earthlings and your primitive subspace transmissions!

The Gorlon of the planet Katow laugh at your "technology".
 
Brian said:
If we were going to pulse, say radio waves, into space to see if anybody gets them and signals back, what would we use that any advanced species would understand and not think it was random?

I was thinking the concept of "1,2,3..." would be inescapable.
How about:
1 pulse, pause
2 pulses, pause
4 pulses, pause
8 pulses, pause

Every time 15 times we complete that cycle, take a longer pause and:
15 pulses

Repeat.

Think that would do it?

Idle thought in traffic today.

Any other ideas?
Click to expand...

Read "Contact" or rent the movie. There are some good ideas there.
 
garys_2k said:
Many people suggest, and I agree, strings of prime numbers. Nothing in nature will create those.
Click to expand...
That "nothing in nature will create those" fascinates me as a math dummy. I think my message is simpler though. Although I wonder, is simpler better?


And I watched Contact, great flick.

I also wonder, how likely is that an advanced species would or would not use base 10?

Anyone want to conjecture what we'd send after communication was established to advance the dialog?
Like, how do you go from "1,2,4,8,10" to "Take me to your leader".
 
T'ai Chi said:
I think maybe transmitting something that sounds musical.
Click to expand...
I don't know about that one. Ever listen to Middle Eastern music? They seem to follow different rules and scales and such.
An alien race may never invent music and it may invent an art form that has no parallel to anything we have on Earth. Which is pretty cool.
 
Brian said:
I also wonder, how likely is that an advanced species would or would not use base 10?
Click to expand...

Quite unlikely, I'd have thought. I don't think it would necessarily be more convenient than other bases, and probably would never have been thought of here if people had had six digits on each hand.

In fact, the UK used really weird arithmetic for financial matters up until the 1970s, with no problems whatsoever. The USA still does for weights and measures.
 
T'ai Chi said:
I think maybe transmitting something that sounds musical.
Click to expand...
Audio (music) waves are in the (generally quoted) range 20 hz - 20 khz. That would not be an efficient range to propogate as radio waves

Music radio is, generally, either Frequency Modulated or Amplitude Modulated on a carrier frequency. It needs some understanding of the propogation method to 'decode' the signal.

To contact an alien intelligence we would need, in the first instance, to send a Simple signal that could not have come from a natural source

Binary would be the most obvious way to send a signal, and Carrier Wave Modulation (carrier on/ carrier off) would be the simplest way to transmit it

P
 
Regarding sending strings of repetitive, base-2 numbers v. repetitive strings of prime numbers, Brian wrote:

That "nothing in nature will create those" fascinates me as a math dummy. I think my message is simpler though. Although I wonder, is simpler better?
Click to expand...
But who says a string of base-2 numbers would be that recognizable? What if no mathematical base was used? Sending on-off pulses as groups of prime numbers, 1-2-3-5-7-11-13-17-19-23 and on, maybe up to a hundred or so, wouldn't depend on ANY base.
And I watched Contact, great flick.

I also wonder, how likely is that an advanced species would or would not use base 10?
Click to expand...
Very, very unlikely.

Anyone want to conjecture what we'd send after communication was established to advance the dialog?
Like, how do you go from "1,2,4,8,10" to "Take me to your leader".
Click to expand...
Hmmm, probably go from simple strings of numbers to basic addition/subtraction problems. In any case we'd have plenty of time to think about how to do that, as we'd wait a long time between transmitting a signal and receiving an answer.
 
How come we or aliens can't just talk and be recognized as a signal from an intelligent and not natural source?

I mean, unless every broadcast word in an alien language is "SSSSSSSSSSSSSSS" I think we could recognize somebody saying hello. Could any alien species mistake Ricky Ricardo saying "Lucy, you're in a lot of trouble" for the noise from a quasar?

It would be ironic if there were aliens everywhere transmitting like crazy but only spoke Universal Background Static.
 
Bottle or the Gun said:
How come we or aliens can't just talk and be recognized as a signal from an intelligent and not natural source?

I mean, unless every broadcast word in an alien language is "SSSSSSSSSSSSSSS" I think we could recognize somebody saying hello. Could any alien species mistake Ricky Ricardo saying "Lucy, you're in a lot of trouble" for the noise from a quasar?

It would be ironic if there were aliens everywhere transmitting like crazy but only spoke Universal Background Static.
Click to expand...
As long as their communications were statistically different than random noise we should be able to tell the difference, supposing that those differences existed over short enough time intervals. But so far we haven't seen any such differences (and increasing the time interval long enough to make our searches inefficient would suppose a very low bandwidth communication).
 
Bottle or the Gun said:
How come we or aliens can't just talk and be recognized as a signal from an intelligent and not natural source?

I mean, unless every broadcast word in an alien language is "SSSSSSSSSSSSSSS" I think we could recognize somebody saying hello. Could any alien species mistake Ricky Ricardo saying "Lucy, you're in a lot of trouble" for the noise from a quasar?

It would be ironic if there were aliens everywhere transmitting like crazy but only spoke Universal Background Static.
Click to expand...

Lucy could very easily be missed by the aliens.
TV signal = FM audio + am video. Decode it though a simple am decoder listen through a loudspeaker and you get - SssSsSSsSsSsSs - or, at least,something very difficult to distinguish from static. You have to use the very simplest form of signal, or it could easily get missed in the static
P
 
For a simple pulse count it actually doesn't matter what base you use. A geometric series is a geometric series regardless, and maths works the same in base 2 as it does in base 10 or base 15. Bases are simply ways of representing numbers in a convenient shorthand. Any advanced civilization would recognize a geometric series for what it was. After all, we can happily move from one base system to another, so why wouldn't they be able to?
 
Peter Jenkins said:


Lucy could very easily be missed by the aliens.
TV signal = FM audio + am video. Decode it though a simple am decoder listen through a loudspeaker and you get - SssSsSSsSsSsSs - or, at least,something very difficult to distinguish from static. You have to use the very simplest form of signal, or it could easily get missed in the static
P
Click to expand...
Television signals decoded through an AM detector are quite non-random, with the video blanking interval showing a strong signal at the basic frame rate. Even the FM audio can be detected with an AM demodulator via slope demodulation.
 
wollery said:
For a simple pulse count it actually doesn't matter what base you use. A geometric series is a geometric series regardless, and maths works the same in base 2 as it does in base 10 or base 15. Bases are simply ways of representing numbers in a convenient shorthand. Any advanced civilization would recognize a geometric series for what it was. After all, we can happily move from one base system to another, so why wouldn't they be able to?
Click to expand...
Too many natural phenomena, such as orbital synchronicity, could cause a signal to mimic at least a simple geometric progression. Prime number chains won't happen over and over due to repetitive natural events.

Edit, changed the earlier mistaken "random" to "prime."
 
garys_2k said:
Too many natural phenomena, such as orbital synchronicity, could cause a signal to mimic at least a simple geometric progression. Random number chains won't happen over and over due to repetitive natural events.
Click to expand...
I'm not suggesting that the geometric series be really simplistic and mistakable for a natural phenomenon, I'm just making the point that we don't have to worry about which base we use.

And are you really suggesting that there's a natural phenomenon that could replicate the series 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024 broadcast as a repeating pulse count?
 
wollery said:
I'm not suggesting that the geometric series be really simplistic and mistakable for a natural phenomenon, I'm just making the point that we don't have to worry about which base we use.
Click to expand...
Agreed. Base is meaningless if a pulse train is used.

And are you really suggesting that there's a natural phenomenon that could replicate the series 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024 broadcast as a repeating pulse count?
Click to expand...
Not necessarily (but I won't rule it out), but it does imply a base-2 prediliction. Prime numbers, otoh, MUST have been generated by intelligent life.

Edit: Also, if your chain missed some bits in broadcast the true progression may be missed in some of the steps. It's likely that SOME of the bits in the 512 and 1024 steams may be missed. Smaller prime numbers, repeated more often, would have a lower error rate.
 
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