After seeing the movie 'Contact', I am now sure that there are no space aliens. As the movie starts, we see the opening sequence, when after traveling a few light years, there is 'radio silence'. And it lasts an awful long time. Thats when my 'light' came on; if our planet has been a radio beacon for over a hundred years, with thousands of radio & television stations beaming signals out in every direction, (usually for 24 hours a day at large urban stations). All this as we have hurled millions of miles since we 'winked on', this as we rotate simultaneously in four directions: around the earth's axis, around the sun, with our galaxy, and with the expanding universe. These movements I call E.S.G.U.- for earth, sun, galaxy & universe. So if life is common in the universe, then in 15 billion years there should have arisen millions of alien species, all at various stages of development. There should be some similarities between evolved species,, therefor species that develop technology, will, like humans leave electromagnetic noise. Therefor anywhere that a radio telescope is pointed, an alien signal will be found. So then, where are all the other beacons? They all can't be transmitting on special sub-space signals. Because at one point in their technological development, they would be placing audio &/or video onto carrier waves. Why would we or they be special or different? I would assume that any species capable of communicating with others of its kind, would have some sort of sense organs to see and hear the world around them. And they would invent some sort of mass communication system, like our radio or TV stations. Why would we or they be special or different? We have left a hundred year trail, of ever expanding radio noise. And I assume that other species have also, at least for a hundred years or so before they develop some sort of sub-space radio. We have been trailing and crossing the paths of probably millions of star systems since we 'winked on'. Everywhere you point a radiotelescope you should be able to find a signal that has traveled millions of miles with the next episode of a Boolean soap opera, or a daily Mobius newscast,or the latest Cartesian music video. So were are these signals? Are we the only ones sending 'I love Lucy' into the outer reaches of space? Radio silence, an apt image for a vast, wonderful universe. That only has one speck of life in all its vastness. I hope you can prove me wrong. --------------------------------------------- !! ET, phone our home!!!
Why on earth would you think that any other evolved lifeform would still be using EM propogation for a communications medium ? If, as you suggest, others have been around for millions of years, they may have actually moved on from it. What's to say they didn't bother with EM and went straight to another type of wave theory. Basing your conclusions after seeing a hollywood glitzer on the subject is a scarey enough announcement, but don't close the door automatically just because Jodi Fosters search touched you.......
My conclusion didn't come from the movie, but my idea came to me while watching it. When an idea comes to you, does it matter what sparked it? Is there validity only to those ideas that come in 'special' places or times? My whole point is that if there is life out there, it should have left electronic evidence. If there are millions of advanced lifeforms out there, why did they all invent undetectable communications? Why did they all skip the stage we are in? Are they all special or do we not fit the norm? Did we miss something so obvious to all other species? Where are those sub-space channels? Come on you inventers! We're lagging behind! Think! Think! Invent!
Randolfo, There are a number of problems with your proposal. Our radio signals have only travelled out to less than 60 lightyears (they were not powerful enough to escape through the atmosphere before about 1940s). In comparison, our galaxy alone has a radius of about 75,000 light years, just to give you a sense of scale. Yet, it is well known that intensity of a signal drops off as square of distance. That means our signals are incredibly diluted by the time they get out to large distances. As they were pitifully weak to begin with, by the time they reach even the nearest stars, our signals are undetectable with all but futuristically hyper-advanced technologies (which the aliens in Contact are assumed to possess). Think about this: suppose a radiostation is broadcasting at 50,000 watts. That's a lot of energy. But, take that energy and stretch it out evenly to cover the surface of a sphere with 100 light year radius. How much energy do you get per square yard? Let's see: 1 ly = 365days*24hrs/day*60min/hr*60sec/min*~300,000,000 yd/sec =~ 9.5E15 yd. That means the sphere's surface is 4*PI*(100 ly)^2 = 1.1E37 yd^2. This means, 100 light years out we get on the order of 4.4E-33 Wt/yd^2. That's on the order of one millionth of a billionth of a billionth of a billionth of a watt per square yard! Next to the blinding electromagnetic noise emitted by the Sun and the rest of the cosmos, such a signal will be basically undetectable. And that's only 100 light years out. So naturally, even if the universe is teaming with civilizations which all use radio communications, we wouldn't be able to hear them. What SETI, for example, is looking for is not a stray radio signal, but a deliberate, focused, powerful radio beam precisely directed at the solar system -- a beam far more powerful than even the most powerful transmitter in existence today can output. Edit: I must've been pretty stoned that day. I was off by a factor of a million in the signal power... ------------------ I am; therefore I think. [This message has been edited by Boris (edited October 11, 1999).]
Years ago I remember reading in the paper that NASA was sending control signals to one of its probes on Mars, of only 10-watts. I don't remember whether any band was mentioned, but my guess is that the ionoshere doesn't trap 100% of every AM signal? Or does it? There has to be some ham operators & others out there that would know? Also, my theory assumes that we would not be the very first technological species, but that others should have come before us. Therefor we should be constantly passing through somebodies electronic noise. I may be wrong but aren't the only times that the sun has a disruptive effect on our signals, is when there are powerful solar flares? Otherwise how are we sending all those commands to our spacecraft & then receiving back info from them? How can Voyager still have sent us info from the outer reaches of our solar system? If to send us that info, it had to aim its signal toward us? And the sun? Since anything aiming toward us, would have to be disrupted by the sun's energy output?
I believe sunspots will affect radio waves as well as solar flares. Sunspots are predictable, I believe, on a 22-year scale (I may be wrong about the period). Between here and Mars, or even here and the edge of the solar system, we don't need that much power. One of the deep-space probes of the 70's, if I recall, was still readable at .5 watts when NASA stopped tracking it two years ago. Do we have any orbital radio telescopes? I know ground dishes will lose weaker signals incoming, which might explain why humans would have missed a brief radio era of a relatively local life forms. Also, if we can hear deep-space objects via radio, how big and "polluting", as such, are those signals? I think I'm starting to restate the questions, so I'll stop now. thx, Tiassa ------------------ "Let us not launch the boat until the ground is wet." (Khaavren of Castlerock)
It's one thing to detect a space probe that is still in the solar system. Voyager 1 is still only about 10 light-hours from the Sun (roughly 75 AUs). Compare that to 4.5 light-<u>years</u> to Alpha Centauri, the closest star. Voyager 1's antenna is indeed pointed at Earth. It is a parabolic dish, so it focuses all its energy into a narrow beam. This helps us detect the extremely weak signal -- though people have to use massive networks of large dishes to pick the signal up even at such a close distance. And consider the dissipation law: as Voyager 1 gets two times farther, its signal will fade by a factor of 4 (even if its generators continue to function as they do today.) It is difficult to do, but one really has to consider the sheer vastness of space. A light-year might sound small thanks to the latest sci-fi shows and movies, but in reality it is an almost unimaginable distance. ------------------ I am; therefore I think.
I'm trying to think on logical terms here. But as for first contact may seem pretty unlikely in a radio manner, why wouldn't they just formally present themselves in a manner that would be noticeable towards us humans? I mean, Star Trek is no where near the truth, but it only seems logical that they would do that. Not so far off as the movie assumes, but in the near future, within the next few years. Even though they are already here, I think they may be planning a formal presentation of themselves to the humans.
Dolphins are fairly intellegent. For arughments sake lets say they were every bit as intellegent as us humans. I dont think it would be possable for them to create a radio or anything. They're just physically incapable . Also, assuming life evolves throughout the universe on planets similiar to earth, isn't it more likely intellegant life would evolve inside oceans rather than dry land. That in itself would create yet more complications. ------------------ "I hope you all find what you need in whatever hole you peer down, whatever cloud you peek behind, let the disaster dukes masticate on the green grass of hope and love. this year is the most joyous and happy, mournful and sad year I have ever known. life is good bleats the bleating heart, and keeps bleating like an 808. never ever forever tommorow comes, new dawns blister, new songs to be sung. the aeroplane flies high, turns left, looks right. the aeroplane knows you know, sings the song of truth, of redemption, of sorrow, look no further than your dirty feet."____Billy Corgan
I beg to differ. Dolphins, for example, are mammals. They (and all caetacians) originate from land creatures that re-adapted themselves to water. There may be a reason why all the more intelligent species on Earth evolved on land -- a dry environment may simply be more challenging to survival than a wet one. Of course, there are some (semi-)intelligent creatures indigent to the sea. The octopus comes to mind, for example. But it is not at all clear that on planets with both water pools and dry land, the high intelligence should more likely emerge in water. Either way, it doesn't matter where you are from. If you have discovered electro-magnetism, you would surely employ it for fast communication -- whether it be within a gas or within a fluid. And once you venture into space, radio is very likely to be your link back. And from then on, you might start guessing about aliens... All of which is still beside the point, since as I've argued, radio noise from extraterrestrial intelligent civilizations could never reach us at detectable levels. All we can hope for is a deliberate high-powered collimated signal (like a laser, maser, or whatever beam you like), deliberately targeting the Sun and meant for easy detection -- a highly overt and very premeditated greeting card. Which I doubt anyone has sent, since they probably still don't know about existence of intelligent life here. First, we have to make enough noise for them to detect; next, their message must have enough time to reach us back. The first has yet to happen... Either that, or they already know about us, which means that they were extremely close to the Sun when they first learnt about us, which means they are already here. Which means there's no need for radio signals, as they can just walk onto our lawn any day they please. Which I seriously doubt is going to happen in the foreseeable future, one way or another. ------------------ I am; therefore I think. [This message has been edited by Boris (edited October 29, 1999).]
