so if we been sending out signals for about a century, how far have they reached?
Since radio waves travel at the speed of light I would think that should put it at about 100 light years.
okay soooo is there any possible planets in that radius that seti think might have life?
Radio waves DON'T TRAVEL at the speed of light. What contact do you want to make with what type of signal?
i was just intersted to no how far in a the universe our furthers signal had reached 
QUOTE (midwestern+Jun 25 2008, 03:28 PM)
Radio waves DON'T TRAVEL at the speed of light. What contact do you want to make with what type of signal?
Nice lesson gmilam, but completely wrong. Wavelength has varied speeds and the speed of light is not one of them. Sorry for messing up the lesson. 
Gmilam, your confusing wave with wavelength. Waves DO travel at the speed of light. 
Then maybe you should inform everyone who publishes text books of their error. Maybe you should also inform the entire internet of the faulty info.
http://www.google.com/search?hl=en&q=speed+of+radio+waves
PS - you brought up wavelength - not me.
PPS - And that should be "you're" not "your".
http://www.google.com/search?hl=en&q=speed+of+radio+waves
PS - you brought up wavelength - not me.
PPS - And that should be "you're" not "your".
Lesson, indeed, saved. 
Everybody follow the simple thread. 
QUOTE (midwestern+Jun 25 2008, 08:41 PM)
Nice lesson gmilam, but completely wrong.
Wrong.
Wrong. Wavelengths don't have speeds. They have lengths.
Wrong. Wavelengths don't have speeds. They have lengths.
Waves DO travel at the speed of light.
Wrong. Sound waves. Water waves. Waves in flexible solids.
gmilam.
Wrong.
QUOTE
Wavelength has varied speeds and the speed of light is not one of them.
Wrong. Wavelengths don't have speeds. They have lengths.
QUOTE (->
| QUOTE |
| Wavelength has varied speeds and the speed of light is not one of them. |
Wrong. Wavelengths don't have speeds. They have lengths.
Waves DO travel at the speed of light.
Wrong. Sound waves. Water waves. Waves in flexible solids.
M pants, you only get point 1. The other two you went nuts on apply without the jargon being twisted.
QUOTE (midwestern+Jun 25 2008, 09:12 PM)
M pants, you only get point 1. The other two you went nuts on apply without the jargon being twisted.
Whatever the hell that means...
Whatever the hell that means...
We have good fun M Pants. 
QUOTE (midwestern+Jun 25 2008, 09:17 PM)
We have good fun M Pants.
How old are ya, son? Honestly, now...
How old are ya, son? Honestly, now...
Old enough to launch counters.
QUOTE (midwestern+Jun 25 2008, 08:41 PM)
Nice lesson gmilam, but completely wrong. Wavelength has varied speeds and the speed of light is not one of them. Sorry for messing up the lesson.
You are not confusing frequency speed with distance speed are you?
Or are you thinking of prisms which don't apply to this conversation.
Light is radio waves.
You are not confusing frequency speed with distance speed are you?
Or are you thinking of prisms which don't apply to this conversation.
Light is radio waves.
We resolved the problem buttershug. Wave and wavelength are totally different in interpretation.
QUOTE (midwestern+Jun 26 2008, 12:10 PM)
Old enough to launch counters.
You work behind a lunch counter?
You work behind a lunch counter?
gmilam.
Thank you, thank you! Two shows a night at 8 and 10.
Why am I not shocked that you loons believe in aliens?
Go to the alien thread and find out.
Sorry guys, radio waves are electromagnetic radiation, which does travel at the speed of light, regardless of wavelength (or frequency).
True wcelliott. http://imagine.gsfc.nasa.gov/docs/science/...emspectrum.html
Thanks for clarifying a twisted subject matter.
Thanks for clarifying a twisted subject matter.
okay so i guess our first radio signals have traveled 100 light years through space.
Q1. roughly how large is our universe in light years
Q2. do u think any e.t would be able to hear our radio signals?
Q1. roughly how large is our universe in light years
Q2. do u think any e.t would be able to hear our radio signals?
The first question answered is 'your guess is as good as mine' and the second one is a 'no'.
QUOTE (3388+Sep 16 2008, 02:52 PM)
offer you something special: www.cntradeshop.com
offer you something special: http://www.physforum.com/index.php?act=feedback&mid=42978
offer you something special: http://www.physforum.com/index.php?act=feedback&mid=42978
QUOTE (aarons+Jun 25 2008, 02:17 PM)
so if we been sending out signals for about a century, how far have they reached?
The signals we have sent are unintelligible beyond several light days because we aren't sending enough redundancy to overcome the SNR at that distance, even assuming the receiver knows the coding. Since this is a fundamental law of physics (information theory, to be exact), we can assume those "scientists" sending signals are doing it for the grant money, alone.
EDIT: I should point out that in theory a directional-enough antenna can pick up anything, but then to receive the sort of signals we have transmitted, the alien race must:
1. Be in the exact location that the beam is going to.
2. Know the exact coding of the signal
3. Know the frequency band of the signal
4. Build an antenna several thousand miles across (because antenna directivity is proportional to its size)
5. Know the precise location of Arecibo, Puerto Rico.
6. Develop a system that keeps the antenna pointed precisely at Arecibo, Puerto Rico.
In other words... grant money.
The signals we have sent are unintelligible beyond several light days because we aren't sending enough redundancy to overcome the SNR at that distance, even assuming the receiver knows the coding. Since this is a fundamental law of physics (information theory, to be exact), we can assume those "scientists" sending signals are doing it for the grant money, alone.
EDIT: I should point out that in theory a directional-enough antenna can pick up anything, but then to receive the sort of signals we have transmitted, the alien race must:
1. Be in the exact location that the beam is going to.
2. Know the exact coding of the signal
3. Know the frequency band of the signal
4. Build an antenna several thousand miles across (because antenna directivity is proportional to its size)
5. Know the precise location of Arecibo, Puerto Rico.
6. Develop a system that keeps the antenna pointed precisely at Arecibo, Puerto Rico.
In other words... grant money.
OK, this is interesting. I did a back-o-the-napkin calculation and got the following:
To pull in a heavily redundant signal (say each bit takes several seconds--much more than that and clock synchronization problems start to take their toll) transmitted with several tens of megawatts with Arecibo's gain at 14GHz, the alien receiver half-power beamwidth should have a diameter of about 200000 miles or tighter when it intersects the Earth. To get that beamwidth from Proxima Centauri, I figure you'd need a dish as big as a planet. Then you'd also need to know the Earth's location, have a system to point the antenna well, know the signal coding, etc. I figure if you're to a point that you can create such a receiver system and somehow psychically figure out the coding, etc., then you are also to a point that you can send a robot spacecraft with a star-drive to the Sol system in a matter of a decade or two. (Hey, we humans see on the horizon rocket engines with exhaust velocities in the tens of thousands of miles per second--i.e. a star drive that could send a robot to Proxima Centauri in a matter of decades).
To pull in a heavily redundant signal (say each bit takes several seconds--much more than that and clock synchronization problems start to take their toll) transmitted with several tens of megawatts with Arecibo's gain at 14GHz, the alien receiver half-power beamwidth should have a diameter of about 200000 miles or tighter when it intersects the Earth. To get that beamwidth from Proxima Centauri, I figure you'd need a dish as big as a planet. Then you'd also need to know the Earth's location, have a system to point the antenna well, know the signal coding, etc. I figure if you're to a point that you can create such a receiver system and somehow psychically figure out the coding, etc., then you are also to a point that you can send a robot spacecraft with a star-drive to the Sol system in a matter of a decade or two. (Hey, we humans see on the horizon rocket engines with exhaust velocities in the tens of thousands of miles per second--i.e. a star drive that could send a robot to Proxima Centauri in a matter of decades).
Your points about the difficulties in xmitting a detectable signal are good. However, you don't take into account any unknown technical means that a receiver might have at their disposal. It wasn't many years ago that a clear picture of anything in space wasn't possible for us because of the interference of the Earth's atmosphere. That isn't a problem for Astronomers anymore because of binocular telescopes and noise-canceling software.
Correctly decoding a signal may not even really be necessary to achieve a successful contact. Just the fact that a receiver can determine the direction and differentiate natural signals from technological signals should be enough for a "eureka" moment of their own. Still, much of that will depend (as you said) on how much power is used to xmit the signal.
Voyager uses a pretty low power signal and we can detect it easily (and I know in relative terms it isn't "that" far out there). Granted they use PLL so they can easily receive the signal but without PLL I'd think they could still communicate although it would be "hit and miss".
Listening holds more promise than sending in my book. Shostak believes that we'll know one way or another in the next 20 years whether our neighborhood (say 100 light years or so) has any technological civilizations. Regardless of whether SETI detects anything over the next couple of decades I believe it is a worthwhile effort.
But I believe we'll have a bigger more important "Wow" moment when we positively detect oxygen and water on a neighboring planet. That probably won't take 20 years to happen.
Correctly decoding a signal may not even really be necessary to achieve a successful contact. Just the fact that a receiver can determine the direction and differentiate natural signals from technological signals should be enough for a "eureka" moment of their own. Still, much of that will depend (as you said) on how much power is used to xmit the signal.
Voyager uses a pretty low power signal and we can detect it easily (and I know in relative terms it isn't "that" far out there). Granted they use PLL so they can easily receive the signal but without PLL I'd think they could still communicate although it would be "hit and miss".
Listening holds more promise than sending in my book. Shostak believes that we'll know one way or another in the next 20 years whether our neighborhood (say 100 light years or so) has any technological civilizations. Regardless of whether SETI detects anything over the next couple of decades I believe it is a worthwhile effort.
But I believe we'll have a bigger more important "Wow" moment when we positively detect oxygen and water on a neighboring planet. That probably won't take 20 years to happen.
QUOTE (BigFairy+Sep 30 2008, 03:22 AM)
IF I LEAVE MY WINDOW OPEN AT NIGHT I GET ABDUCTED AND ANALLY PROBED.
Insist on a condom. You never know what you'll get.
Insist on a condom. You never know what you'll get.
QUOTE (fleem+)
OK, this is interesting. I did a back-o-the-napkin calculation and got the following:
To pull in a heavily redundant signal (say each bit takes several seconds--much more than that and clock synchronization problems start to take their toll) transmitted with several tens of megawatts with Arecibo's gain at 14GHz, the alien receiver half-power beamwidth should have a diameter of about 200000 miles or tighter when it intersects the Earth. To get that beamwidth from Proxima Centauri, I figure you'd need a dish as big as a planet. Then you'd also need to know the Earth's location, have a system to point the antenna well, know the signal coding, etc. I figure if you're to a point that you can create such a receiver system and somehow psychically figure out the coding, etc., then you are also to a point that you can send a robot spacecraft with a star-drive to the Sol system in a matter of a decade or two. (Hey, we humans see on the horizon rocket engines with exhaust velocities in the tens of thousands of miles per second--i.e. a star drive that could send a robot to Proxima Centauri in a matter of decades).
So there's no way a backyard hobbyist can send an intelligible signal.
I mean it wouldn't have to be a complicated message in digital format. Just broadcast a LOUD electronic noise Morse code style; perhaps a series of prime numbers in base 1, where each radio pulse might last a second or two. The main idea would be to just send a signal that cannot be mistaken for a natural source. You make it sound as if communicating by radio is just about as hard as actual interstellar space travel. Not saying you're wrong by any means. It's just kind of a bummer to realize. . . .
To pull in a heavily redundant signal (say each bit takes several seconds--much more than that and clock synchronization problems start to take their toll) transmitted with several tens of megawatts with Arecibo's gain at 14GHz, the alien receiver half-power beamwidth should have a diameter of about 200000 miles or tighter when it intersects the Earth. To get that beamwidth from Proxima Centauri, I figure you'd need a dish as big as a planet. Then you'd also need to know the Earth's location, have a system to point the antenna well, know the signal coding, etc. I figure if you're to a point that you can create such a receiver system and somehow psychically figure out the coding, etc., then you are also to a point that you can send a robot spacecraft with a star-drive to the Sol system in a matter of a decade or two. (Hey, we humans see on the horizon rocket engines with exhaust velocities in the tens of thousands of miles per second--i.e. a star drive that could send a robot to Proxima Centauri in a matter of decades).
So there's no way a backyard hobbyist can send an intelligible signal.
I mean it wouldn't have to be a complicated message in digital format. Just broadcast a LOUD electronic noise Morse code style; perhaps a series of prime numbers in base 1, where each radio pulse might last a second or two. The main idea would be to just send a signal that cannot be mistaken for a natural source. You make it sound as if communicating by radio is just about as hard as actual interstellar space travel. Not saying you're wrong by any means. It's just kind of a bummer to realize. . . .
I never had a whole lot of confidence in current SETI methodology. We have been broadcasting in analog about a century, and with reasonable power since the late 1940's with HF radio and microwave radar. Less then a blink of the eye. It could be the equivalent to among the most advanced methods we used to communicate not that long ago, smoke signals. At least were now looking for optical transmissions as well, keeping in mind its nothing special, just a higher frequency of the same electromagnetic spectrum. But it still never hurts to listen.
But for the most part most of our EM transmissions have been analog (SETI has also begun searching using a digital filter along with analog). But the argument people have made about a potentially very narrow bandwidth, and time line being listened to and understood being a long shot couldn't be more correct. To know someone is transmitting artificial signals requires for us an identifiable pattern. The basis for code breaking is looking for patterns. We recognize our transmissions because we see a pattern, even if we don't know exactly is being said. Like watching a news broadcast in a language we don't understand. We still know their saying something.
You also have the distinct possibility a very intelligent ET may not be a technological species at all. Consider we know whales and dolphins are very intelligent, with mind numbing, complexity of language. After at least ten million years of evolution, it does not mean they will develop technology. Until recently, the oceans have been remarkably consistent in temperature varying only a few degrees across the globe. Not to mention consistency of chemistry, etc. We developed technology to help us survive. Sea living creatures don't have to build shelters or wear any thing to survive.
But for the most part most of our EM transmissions have been analog (SETI has also begun searching using a digital filter along with analog). But the argument people have made about a potentially very narrow bandwidth, and time line being listened to and understood being a long shot couldn't be more correct. To know someone is transmitting artificial signals requires for us an identifiable pattern. The basis for code breaking is looking for patterns. We recognize our transmissions because we see a pattern, even if we don't know exactly is being said. Like watching a news broadcast in a language we don't understand. We still know their saying something.
You also have the distinct possibility a very intelligent ET may not be a technological species at all. Consider we know whales and dolphins are very intelligent, with mind numbing, complexity of language. After at least ten million years of evolution, it does not mean they will develop technology. Until recently, the oceans have been remarkably consistent in temperature varying only a few degrees across the globe. Not to mention consistency of chemistry, etc. We developed technology to help us survive. Sea living creatures don't have to build shelters or wear any thing to survive.
Regarding ET. As someone who has taken part in disinformation applications, the gentle introduction of the idea aliens exist (never mind if their here or not) seems to have been introduced into the popular culture, and has been going on for decades. The methods applied have "disinformation" written all over it. No government would risk appearing powerless for any reason because its , historically the stability of a cultures social framework that must take precedence over all other considerations, or you have panic in the streets. Consider what has happened to almost every culture that has come into contact with a technologically superior ("superior here applies only to nuts and bolts) on Earth.
Sometimes a destruction of a culture may not be the result of war or disease, but in the presence of another civilizations almost god like powers sinks into insignificance. Overwhelmed by a fantastically advanced civilization, we may ask why do we bother to get up in the morning? Where's the challenge? No government would ever permit the complete release of all data on this subject. To unpredictable. I have often been asked why they don't just land on the White House lawn? Maybe they don't want our population fully aware of what might be very unpleasant. Any way, try landing on the White House lawn. and you will be shot.
Sometimes a destruction of a culture may not be the result of war or disease, but in the presence of another civilizations almost god like powers sinks into insignificance. Overwhelmed by a fantastically advanced civilization, we may ask why do we bother to get up in the morning? Where's the challenge? No government would ever permit the complete release of all data on this subject. To unpredictable. I have often been asked why they don't just land on the White House lawn? Maybe they don't want our population fully aware of what might be very unpleasant. Any way, try landing on the White House lawn. and you will be shot.
I think Star Trek Enterprise hits the nail right on the head.
Traveling in space is a very dangerous affair, with lots of aliens either being divisive or not so nice.
The way things are structured now, there is probably some hidden alien race that is already guiding Earthlings in their quest to explore space, as the Vulcans are on Star Trek Enterprise, but remain in the shadows for technical reasons.
You don’t think that men go to strip clubs, just because they like the music and to watch ladies dance?
Traveling in space is a very dangerous affair, with lots of aliens either being divisive or not so nice.
The way things are structured now, there is probably some hidden alien race that is already guiding Earthlings in their quest to explore space, as the Vulcans are on Star Trek Enterprise, but remain in the shadows for technical reasons.
You don’t think that men go to strip clubs, just because they like the music and to watch ladies dance?
Two other points about "ET" I want to add. "They" could be all around us, we just lack the; a) sensing ability to see them, except under unusual conditions. It's akin to us not being able to see x-rays or most forms of electromagnetic radiation. We know about the above only by detecting their effects indirectly. Or ; 
the one I lean in favor of is it's quite possible that a sufficiently advanced civilization operates under circumstances and with rules we don't yet have the ability to understand.
There are a lot of "UFO" reports, including contact reports (I should point out most are recalled without hypnosis) where the ET's are acting in a totally non-sensible way. Their behavior is reported to be more like grand theater then scientific investigation. I' vie heard it said "they can't be extraterrestrial beings/craft". The reason? WE wouldn't conduct research or observations that way. (perhaps THEY didn't read the manual...) Our folklore takes the shape of it's container. A technological culture, however in it's infancy, would have a tendency to see events through technological eyes. Preindustrial cultures would view them as elves, demons, etc. (which application is more representative of the "truth" may the worlds oldest "Jeopardy" question.)
As anti scientific as it sounds, and it is, "they" could be all around us, we just can't connect the dots that allow our limited brains to see a pattern. I imagine it could be the same for us as it is for my dog or cat being around TV/radio almost constantly. As we know animal sense's are very acute, they detect the output from the TV etc. But to them, its nonsensical, and not communication. For them as with us, it's just background noise.
the one I lean in favor of is it's quite possible that a sufficiently advanced civilization operates under circumstances and with rules we don't yet have the ability to understand. There are a lot of "UFO" reports, including contact reports (I should point out most are recalled without hypnosis) where the ET's are acting in a totally non-sensible way. Their behavior is reported to be more like grand theater then scientific investigation. I' vie heard it said "they can't be extraterrestrial beings/craft". The reason? WE wouldn't conduct research or observations that way. (perhaps THEY didn't read the manual...) Our folklore takes the shape of it's container. A technological culture, however in it's infancy, would have a tendency to see events through technological eyes. Preindustrial cultures would view them as elves, demons, etc. (which application is more representative of the "truth" may the worlds oldest "Jeopardy" question.)
As anti scientific as it sounds, and it is, "they" could be all around us, we just can't connect the dots that allow our limited brains to see a pattern. I imagine it could be the same for us as it is for my dog or cat being around TV/radio almost constantly. As we know animal sense's are very acute, they detect the output from the TV etc. But to them, its nonsensical, and not communication. For them as with us, it's just background noise.
QUOTE (BigFairy+Oct 3 2008, 05:09 PM)
HI IF U GO THOUGH ALL MY POSTS YOU WILL FIND A SECRET MESSAGE FROM E.T I WAS ABLE TO WRITE IT DOWN IN BETWEEN ANAL PROBES
Having the fillings in ones teeth bletch out "Avie maria" is a side effect of contact, not a message.
Having the fillings in ones teeth bletch out "Avie maria" is a side effect of contact, not a message.
ll
[QUOTE=Midwestern,Jun 25 2008, 02:28 PM]Radio waves DON'T TRAVEL at the speed of light. What contact do you want to make with what type of signal? [/QUOTE)
Radio waves do travel at the speed of light in a near vacuum. The so called vacuum of space is really awash with incredible energy. We only see a small fraction of "the truth". Radio signals can be distorted through a few methods we do not fully understand. According to theory radio and everything else across the EM spectrum THAT WE OBSERVE, is affected by intense gravity, as in a black hole. An EM signal must also convert the alien signals into a likable communication pattern we can pick apart. We have recently seen SETI scanning star systems with suns very unlike own, by optical and radio methods, which is short of "the greater impact on the gods". The viability of the speed of lights, despite belief to the contrary, may be influenced by what is called, among other things the "cosmic lighthouse". Laboratories can closely put two and two together. And like our military friends I would remind everyone; Don't believe every thing you read on the Internet. But plan for the worse, hope for the best. I am interested on why you think radio does does move from point "A" to point "B" through normal space time?
Sorry about the diatribe, to answer your question. I like the idea of the alien (or more likely more then one) in the same breath having as much success with taking to us as we can talk to a house plant.
I strongly believe the way "they" would or even could contact us is through a very slow psychological/scientific process of acclimation of our species to the reality of ET"s visiting us, on their terms no less. They may not see worth a second glance if they say I can assume if they saw humanity's slow, methodical nature, and would detect anything odd around them, it would be in our interest, the government to investigate and/or control I can't tell you the "right" signals to spot. But there is a real possibly aliens have been around on Earth for many thousands of years. This allows what most people at the moment can move about their daily lives and that of their kids, only to want a decent life for themselves. Two really good books on the ET subject and Jock Valie (forgive spelling) analysis of thousands of reports the 1968 book "Passport to Magnolia"', that exposure's modern and historical applications of folklore. Another good one is his book "Messengers of Deception". He does a good job of what purpose about around all this "grand theater". Sorry I don't have a date for "Messenger".
.
[/QUOTE)Radio waves do travel at the speed of light in a near vacuum. The so called vacuum of space is really awash with incredible energy. We only see a small fraction of "the truth". Radio signals can be distorted through a few methods we do not fully understand. According to theory radio and everything else across the EM spectrum THAT WE OBSERVE, is affected by intense gravity, as in a black hole. An EM signal must also convert the alien signals into a likable communication pattern we can pick apart. We have recently seen SETI scanning star systems with suns very unlike own, by optical and radio methods, which is short of "the greater impact on the gods". The viability of the speed of lights, despite belief to the contrary, may be influenced by what is called, among other things the "cosmic lighthouse". Laboratories can closely put two and two together. And like our military friends I would remind everyone; Don't believe every thing you read on the Internet. But plan for the worse, hope for the best. I am interested on why you think radio does does move from point "A" to point "B" through normal space time?
Sorry about the diatribe, to answer your question. I like the idea of the alien (or more likely more then one) in the same breath having as much success with taking to us as we can talk to a house plant.
I strongly believe the way "they" would or even could contact us is through a very slow psychological/scientific process of acclimation of our species to the reality of ET"s visiting us, on their terms no less. They may not see worth a second glance if they say I can assume if they saw humanity's slow, methodical nature, and would detect anything odd around them, it would be in our interest, the government to investigate and/or control I can't tell you the "right" signals to spot. But there is a real possibly aliens have been around on Earth for many thousands of years. This allows what most people at the moment can move about their daily lives and that of their kids, only to want a decent life for themselves. Two really good books on the ET subject and Jock Valie (forgive spelling) analysis of thousands of reports the 1968 book "Passport to Magnolia"', that exposure's modern and historical applications of folklore. Another good one is his book "Messengers of Deception". He does a good job of what purpose about around all this "grand theater". Sorry I don't have a date for "Messenger".
.
Re. Neocom: The US does not have a secret police in the traditional sense, but through a number of government agencies, we make up for that shortfall.
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