Sending a signal to E.T.'s

Brian · 20th April 2004, 07:04 PM

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?

garys_2k · 20th April 2004, 07:25 PM

Many people suggest, and I agree, strings of prime numbers. Nothing in nature will create those.

DangerousBeliefs · 20th April 2004, 07:34 PM

You silly Earthlings and your primitive subspace transmissions!

The Gorlon of the planet Katow laugh at your "technology".

Hellbound · 20th April 2004, 07:57 PM

Quote:

Originally posted by DangerousBeliefs
You silly Earthlings and your primitive subspace transmissions!

The Gorlon of the planet Katow laugh at your "technology".

I'm warning you...I have a board! With a nail in it! Do not make me use this weapon of mass destruction!!!

Phil · 20th April 2004, 08:00 PM

Quote:

Originally posted by Brian
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?

Read "Contact" or rent the movie. There are some good ideas there.

Brian · 20th April 2004, 08:23 PM

Quote:

Originally posted by garys_2k
Many people suggest, and I agree, strings of prime numbers. Nothing in nature will create those.

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 · 20th April 2004, 08:27 PM

I think maybe transmitting something that sounds musical.

Brian · 20th April 2004, 08:39 PM

Quote:

Originally posted by T'ai Chi
I think maybe transmitting something that sounds musical.

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.

richardm · 21st April 2004, 03:24 AM

Quote:

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

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.

Peter Jenkins · 21st April 2004, 03:42 AM

Quote:

Originally posted by T'ai Chi
I think maybe transmitting something that sounds musical.

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

garys_2k · 21st April 2004, 05:09 AM

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

Quote:

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?

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.

Quote:

And I watched Contact, great flick.

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

Very, very unlikely.

Quote:

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".

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.

Bottle or the Gun · 21st April 2004, 05:37 AM

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.

garys_2k · 21st April 2004, 05:45 AM

Quote:

Originally posted by Bottle or the Gun
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.

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).

Peter Jenkins · 21st April 2004, 05:57 AM

Quote:

Originally posted by Bottle or the Gun
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.

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

wollery · 21st April 2004, 05:58 AM

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?

garys_2k · 21st April 2004, 06:01 AM

Quote:

Originally posted by Peter Jenkins

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

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.

garys_2k · 21st April 2004, 06:02 AM

Quote:

Originally posted by wollery
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?

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."

wollery · 21st April 2004, 06:07 AM

Quote:

Originally posted by garys_2k
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.

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?

garys_2k · 21st April 2004, 06:26 AM

Quote:

Originally posted by wollery
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.

Agreed. Base is meaningless if a pulse train is used.

Quote:

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?

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.

20th April 2004, 07:04 PM	#1
Brian Graduate Poster Join Date: Jul 2001 Posts: 1,780	Sending a signal to E.T.'s 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?
Brian Graduate Poster Join Date: Jul 2001 Posts: 1,780	__________________ O' beautiful, for spacious skies But now those skies are threatening They're beating plowshares into swords For this tired old man that we elected king Armchair warriors often fail And we've been poisoned by these fairy tales The lawyers clean up all details Since daddy had to lie -Don Henley

20th April 2004, 07:25 PM	#2
garys_2k Muse Join Date: Jan 2003 Posts: 756	Many people suggest, and I agree, strings of prime numbers. Nothing in nature will create those.
garys_2k Muse Join Date: Jan 2003 Posts: 756	__________________ - Gary

20th April 2004, 08:00 PM	#5
Phil Master Satyr Join Date: Jun 2003 Location: Society's underbelly Posts: 6,512	Re: Sending a signal to E.T.'s Quote: Originally posted by Brian 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? Read "Contact" or rent the movie. There are some good ideas there.

20th April 2004, 08:23 PM	#6
Brian Graduate Poster Join Date: Jul 2001 Posts: 1,780	Quote: Originally posted by garys_2k Many people suggest, and I agree, strings of prime numbers. Nothing in nature will create those. 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".
Brian Graduate Poster Join Date: Jul 2001 Posts: 1,780	__________________ O' beautiful, for spacious skies But now those skies are threatening They're beating plowshares into swords For this tired old man that we elected king Armchair warriors often fail And we've been poisoned by these fairy tales The lawyers clean up all details Since daddy had to lie -Don Henley

20th April 2004, 08:27 PM	#7
T'ai Chi Penultimate Amazing Join Date: May 2003 Posts: 11,235	I think maybe transmitting something that sounds musical.
	__________________ http://www.statisticool.com

20th April 2004, 07:34 PM	#3
DangerousBeliefs Graduate Poster Join Date: Aug 2003 Posts: 1,304	You silly Earthlings and your primitive subspace transmissions! The Gorlon of the planet Katow laugh at your "technology".

20th April 2004, 07:57 PM	#4
Hellbound Abiogenic Spongiform Join Date: Sep 2002 Location: In a handbasket Posts: 8,942	Quote: Originally posted by DangerousBeliefs You silly Earthlings and your primitive subspace transmissions! The Gorlon of the planet Katow laugh at your "technology". I'm warning you...I have a board! With a nail in it! Do not make me use this weapon of mass destruction!!!

20th April 2004, 08:39 PM	#8
Brian Graduate Poster Join Date: Jul 2001 Posts: 1,780	Quote: Originally posted by T'ai Chi I think maybe transmitting something that sounds musical. 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 Graduate Poster Join Date: Jul 2001 Posts: 1,780	__________________ O' beautiful, for spacious skies But now those skies are threatening They're beating plowshares into swords For this tired old man that we elected king Armchair warriors often fail And we've been poisoned by these fairy tales The lawyers clean up all details Since daddy had to lie -Don Henley

21st April 2004, 03:24 AM	#9
richardm Philosopher Join Date: Aug 2001 Posts: 9,270	Quote: Originally posted by Brian I also wonder, how likely is that an advanced species would or would not use base 10? 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.
richardm Philosopher Join Date: Aug 2001 Posts: 9,270	__________________ Rimmer: Look at her! Magnificent woman! Very prim, very proper, almost austere. Some people took her for cold, thought she was aloof. Not a bit of it. She just despised fools. Quite tragic, really, because otherwise I think we'd have got on famously.

21st April 2004, 03:42 AM	#10
Peter Jenkins Muse Join Date: Dec 2001 Posts: 561	Quote: Originally posted by T'ai Chi I think maybe transmitting something that sounds musical. 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
Peter Jenkins Muse Join Date: Dec 2001 Posts: 561

21st April 2004, 05:09 AM	#11
garys_2k Muse Join Date: Jan 2003 Posts: 756	Regarding sending strings of repetitive, base-2 numbers v. repetitive strings of prime numbers, Brian wrote: Quote: 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? 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. Quote: And I watched Contact, great flick. I also wonder, how likely is that an advanced species would or would not use base 10? Very, very unlikely. Quote: 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". 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.
garys_2k Muse Join Date: Jan 2003 Posts: 756	__________________ - Gary

21st April 2004, 05:37 AM	#12
Bottle or the Gun Muse Join Date: Jan 2004 Posts: 890	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 Muse Join Date: Jan 2004 Posts: 890	__________________ It's "Lather, rinse, repeat", not "Lather, rinse, then there is divine intervention" - Don Life is inevitable because matter is self-organizing. A deity isn't necessary for a chemical reaction. - Don That's the biz, sweetheart. - Remo Williams

21st April 2004, 05:45 AM	#13
garys_2k Muse Join Date: Jan 2003 Posts: 756	Quote: Originally posted by Bottle or the Gun 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. 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).
garys_2k Muse Join Date: Jan 2003 Posts: 756	__________________ - Gary

21st April 2004, 05:57 AM	#14
Peter Jenkins Muse Join Date: Dec 2001 Posts: 561	Quote: Originally posted by Bottle or the Gun 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. 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
Peter Jenkins Muse Join Date: Dec 2001 Posts: 561

21st April 2004, 05:58 AM	#15
wollery Protected by Samurai Hedgehogs! Join Date: Feb 2003 Location: Land of Eternal Hope Posts: 10,319	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?
	__________________ "You're a sick SOB. You know that, Wollery?" - Roadtoad "Just think how stupid the average person is, and then realize that half of them are even stupider!" --George Carlin

21st April 2004, 06:01 AM	#16
garys_2k Muse Join Date: Jan 2003 Posts: 756	Quote: Originally posted by Peter Jenkins 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 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.
garys_2k Muse Join Date: Jan 2003 Posts: 756	__________________ - Gary

21st April 2004, 06:02 AM	#17
garys_2k Muse Join Date: Jan 2003 Posts: 756	Quote: Originally posted by wollery 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? 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 Muse Join Date: Jan 2003 Posts: 756	__________________ - Gary

21st April 2004, 06:07 AM	#18
wollery Protected by Samurai Hedgehogs! Join Date: Feb 2003 Location: Land of Eternal Hope Posts: 10,319	Quote: Originally posted by garys_2k 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. 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?
	__________________ "You're a sick SOB. You know that, Wollery?" - Roadtoad "Just think how stupid the average person is, and then realize that half of them are even stupider!" --George Carlin

21st April 2004, 06:26 AM	#19
garys_2k Muse Join Date: Jan 2003 Posts: 756	Quote: Originally posted by wollery 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. Agreed. Base is meaningless if a pulse train is used. Quote: 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? 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.
garys_2k Muse Join Date: Jan 2003 Posts: 756	__________________ - Gary