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Are we alone.... The answer is ''Yes''

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    #212
    Solair
    Closed Accounts Posts: 7,230 ✭✭✭Solair


    Without some idea of what a television was, you'd have absolutely no idea what that amplitude modulation of pulses meant though. They'd still be utterly meaningless.

    All you'd know is its a signal of some kind.

    They'd have to understand that it was controlling a display made of lines, that those lines represented a visual image.

    They may not even see the same way we do. Could be looking at different spectrum of radiation etc etc

    Digital signals would probably look even more obviously artificial than analogue ones did.


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    #213
    Senna
    Registered Users Posts: 8,800 ✭✭✭Senna


    Its pretty arrogant to think that radio waves are a universal form of communication, even if an alien race did use it once, it could have been thousands of years ago.
    If a carrier pigeon arrived on your window sill with a message, would you know what the hell was going on?


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    #214
    Capt'n Midnight
    Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 91,409 Mod ✭✭✭✭Capt'n Midnight


    Solair wrote: »
    Without some idea of what a television was, you'd have absolutely no idea what that amplitude modulation of pulses meant though. They'd still be utterly meaningless.

    All you'd know is its a signal of some kind.

    They'd have to understand that it was controlling a display made of lines, that those lines represented a visual image.
    like I said there are obvious line and frame pulses (and colour burst signals) in an analog signal
    Digital signals would probably look even more obviously artificial than analogue ones did.
    no, digital signals look like pink noise

    same as white noise but over a narrower set of frequencies.


    Have you ever heard the noise a modem makes on handshaking ?

    unless you know the demodulation it's just noise
    even if you know the demodulation it's just ones and zeros
    even if you can figure out the packets and streams it's still a lot of work


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    #215
    Duggys Housemate
    Closed Accounts Posts: 3,298 ✭✭✭Duggys Housemate


    Its pretty arrogant to think that radio waves are a universal form of communication, even if an alien race did use it once, it could have been thousands of years ago.
    If a carrier pigeon arrived on your window sill with a message, would you know what the hell was going on?

    Electromagnetic communication, rather than radio, is an all encompassing term meaning any signal attached to the the electromagnetic spectrum including light ( which we use to send information too). Sometimes technology comes against practical or theoretical limits. You can't go back in time to carrier pigeons, compare to now, and extrapolate forward. If you can think of something more exotic than the electromagnetic spectrum - you would need to prove it.

    Also SETI isn't looking for TV signals. The attenuation would be too high. It's looking for direct signals.


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    #216
    Capt'n Midnight
    Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 91,409 Mod ✭✭✭✭Capt'n Midnight


    Duggys Housemate wrote: »
    Also SETI isn't looking for TV signals. The attenuation would be too high. It's looking for direct signals.
    Radar

    possibly 50Hz / 60Hz mains - oddly enough this will actually get louder as more grids get synchronised together

    don't forget we are competing with the emissions from Jupiter and that big ball of plasma that keeps ejecting stuff , and I don't think anyone is planning on using x-rays for communication, and even if they did it would be for very low power point to point links


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    #217
    Solair
    Closed Accounts Posts: 7,230 ✭✭✭Solair


    Capt'n Midnight wrote: »
    Radar

    possibly 50Hz / 60Hz mains - oddly enough this will actually get louder as more grids get synchronised together

    don't forget we are competing with the emissions from Jupiter and that big ball of plasma that keeps ejecting stuff , and I don't think anyone is planning on using x-rays for communication, and even if they did it would be for very low power point to point links

    Actually due to HV-DC interconnectors that are becoming more common (eg out links to the UK), there's less need than ever before to synchronise grids.

    So, I'd say in 30 years you'll seen lots of 50Hz (or 60Hz) grids operating independently from each other.

    It's being made possible by massive improvements and cost reductions in solid state power technology.

    It seems the more technology progresses the less noise its likely to transmit into space.

    I would suspect though that we do give off a rather large 50Hz & 60Hz hum. I wonder how detectable it is.

    Power usage is certainly growing rapidly. I mean for example all of China's development must be producing lost of 50Hz buzzing!


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