The uselesness of SETI

Discussion in 'Astronomy, Exobiology, & Cosmology' started by Avatar, May 10, 2003.

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  1. Avatar

    Avatar smoking revolver Valued Senior Member

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    my sister talked me into trying SETI@home again.
    watching at that small window which is showing analysys of some radio wave stream (at least I think so) I come to think of the uselessness of it all.

    1. Radio signals move at the speed of light. The radius of our galaxy is about 300 000 light years long -> diameter 600 000 l.y.
    a simple communication exceeding any distances more than 100 ly is non productive.

    2. ok - so we listen to radio, but what says that aliens use the same technology
    If they have invented FTL travel then they surely don't use radio technology to communicate, because it would be too slow and thus eliminate any coordinated action, if they don't use it, then we are just wasting our time

    our only chance is that the civilization is as close as 100 (ok make it 200) light years away, is technologically advanced to our level and also isn't too advanced (*note: if they would be too advanced would we have anything to talk abut except for begging technology?)

    that is close to being a miracle
    are we so lucky and will the benefits overexceed the potential bad effects (I don't know - aliens declaring war to us maybe - we have such a beautiful planet and if they are running scarse of raw resources (which would be if they are more advanced than us) or just want another planet to dwell on)

    btw- I think it would be wonderful if we discover a civilization that is more primitive than us, because they would supposedly be no threat to us and would also be an amazing thing to study.
     
    Last edited: May 10, 2003
    Avatar, May 10, 2003
    #1

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  3. sargentlard

    sargentlard Save the whales motherfucker Valued Senior Member

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    Why would they be a threat to us though i do agree they would be a amazing study, also who says that there are any advance species out there maybe the idea of us being the only at our level crazy enough to be true....the rest of them are just at primitive stages or even bacterial stages, well in our own galaxy atleast......i would not however turn down the notion of advanced beings out there in another galaxies....but they are also bound by the laws of physics and have not found a efficient way to travel the universe. Or it could be the exact opposite of what i said...sadly we may never know what was or is out there beyond the realm of science.
     
    sargentlard, May 10, 2003
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  5. Avatar

    Avatar smoking revolver Valued Senior Member

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    I'm sorry- it's late at night
    what I meant is that they would supposedly be NO threat to us
     
    Avatar, May 10, 2003
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  7. Fraggle Rocker

    Fraggle Rocker Staff Member

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    It presumes that civilizations never die.

    As I suggested in another thread, the problem with SETI is that it presumes that the source and receiving civilizations are at the same level of technology at the same time, offset by the time required for the radio waves to traverse the distance.

    If high-tech civilizations rise and fall just like low-tech, it's quite possible that by the time the radio waves from Planet X reach Earth, we will already have bombed ourselves back into the Stone Age, or Even the Bronze Age, which would still leave us without radio.

    Or Planet X may have put zillions of dollars into interstellar radio broadcasts for five thousand years, and then they had their own World War III and bombed themselves back into their Stone Age. That might have happened fifty thousand years ago, and their radio waves went right past us while we were trying to light a fire.

    Now if you want to talk about FTL technology, that changes things. As we learned on Enterprise last Wednesday, you can send a "subspace" message all the way from the Alpha Quadrant to the Delta Quadrant (which I assume is pretty near the entire diameter of the galaxy from the way they describe it) in just 200 years. This doesn't really change the basic problem, you've still got to have civilizations lasting long enough to be around when each other's messages arrive. But at least in the Star Trek scenario, if you do pick up a message, it's only a couple of centuries old, so the chances are pretty good that the civilization that sent it is still standing.

    Um... well that's only "good" if the civilization we're talking about is not the Borg, which it unfortunately is this week.
     
    Fraggle Rocker, May 10, 2003
    #4
  8. sargentlard

    sargentlard Save the whales motherfucker Valued Senior Member

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    I guess they do it on the off chance that all this requirements go through an they do find something out of nowhere....no hurt in trying i guess

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    sargentlard, May 10, 2003
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  9. Avatar

    Avatar smoking revolver Valued Senior Member

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    Fraggle Rocker:

    exactly
    so should the SETI project continue?
     
    Avatar, May 10, 2003
    #6
  10. sargentlard

    sargentlard Save the whales motherfucker Valued Senior Member

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    Well that depends...is taxpayer money being used to fund SETI????
     
    sargentlard, May 11, 2003
    #7
  11. Prosoothus

    Prosoothus Registered Senior Member

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    Fraggle Rocker,

    Well, I guess if you heard it on "Enterprise", then it must be true.

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    Seriously, if advanced civilizations do exist, then it is likely that they're communicating via quantum entanglement. That way, the communication would be instantaneous (and you wouldn't be able to eavesdrop

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    Tom
     
    Prosoothus, May 11, 2003
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  12. Avatar

    Avatar smoking revolver Valued Senior Member

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    quantum entanglement?
     
    Avatar, May 11, 2003
    #9
  13. Prosoothus

    Prosoothus Registered Senior Member

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    Avatar,

    Yes. Let's say you have two entangled photons, A and B. If you seperate them with a great distance, you can tell what the spin of photon B is by measuring the spin of photon A, and vice versa. So for example, if the spin of photon B changes, the spin of photon A will change instantly as well, regardless of the distance between them.

    Back in the old days, when you measured the spin of one photon, the entanglement would be lost (you could only make one measurement). Recently, scientists have found ways to keep the photons entangled even after measurements.

    Tom
     
    Prosoothus, May 11, 2003
    #10
  14. Fraggle Rocker

    Fraggle Rocker Staff Member

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    And this explains why SETI is worthless. These signals are not "broadcast", no energy radiating out in every direction to be intercepted by every civilization with a radio receiver.

    But wait a minute. If you don't have FTL travel, then how do you deliver the entangled photon to the planet where the other civilization lives? I suppose once you actually deliver it you've got FTL communication for all eternity. But the size of your network of civilizations participating in the QE community can only grow at sub-light speed. If our photon-delivery drones don't encounter civiliations packed together closely, we won't have a lot of people to talk to, even after centuries or millennia of photon-planting.

    Do the photon pairs have a nice long useful life? There won't exactly be a maintenance crew patrolling the galaxy replacing burned out photons. And is there really no practical limit to the distance between the two entangled photons?
     
    Fraggle Rocker, May 11, 2003
    #11
  15. Frencheneesz

    Frencheneesz Amazing Member Registered Senior Member

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    I think the point of SETI is just to prove that aliens do exist. Communicating with them would be very very important and cool, but nevertheless secondary.
     
    Frencheneesz, May 11, 2003
    #12
  16. dickbaby

    dickbaby Banned Banned

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    I first played around with the SETI stuff a few years ago, but soon stopped (partly due to a slow, naff machine).

    However, it does seem to me that with all the evidence around of other life, and the sheer mind-bending size of the universe out there, then there must, must be other civilizations about. But, the chances are they won't use the same technologies, as has been stated already. And why do we consider ourselves so imortant that we will be contacted?

    Isn't the SETI project a bit like running around in your back garden frantically searching for something you have a fair idea is on the next continent?

    Just want to keep this thread going a bit...
     
    dickbaby, May 11, 2003
    #13
  17. Prosoothus

    Prosoothus Registered Senior Member

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    Fraggle Rocker,

    First, let me say that atoms, ions, and molecules can be entangled just like photons. Even a chamber full of gas can be entangled. Unfortunately, the entanglement doesn't last that long. However, physicists are making quantum entanglement last longer, and longer, in their experiments. In the future, entanglement will probably be permanent.

    Yes. It is believed that two particles can be in different galaxies, and if the spin of one changes, the other one will "know" instantly.

    Tom
     
    Prosoothus, May 11, 2003
    #14
  18. Avatar

    Avatar smoking revolver Valued Senior Member

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    how is the information about the change "transmitted" to the other particle? how does the particle know about the change FTL?
     
    Avatar, May 11, 2003
    #15
  19. Prosoothus

    Prosoothus Registered Senior Member

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    Prosoothus, May 11, 2003
    #16
  20. Fraggle Rocker

    Fraggle Rocker Staff Member

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    Postulating non-Euclidean space?

    I read your original posting that started that thread, and kept going until my brain started to hurt. It’s interesting, well stated, and scholarly. Shame on the guy who thought it belonged in the UFO room.

    However, I have the same problem with it that I have with all extra-dimensions, other-universes models that are used to explain the “illusion” of FTL (or in this case downright instantaneous) travel in “our” universe.

    Regardless of how many dimensions the “true”, “unknowable” hyper-universe may have, the basic rules of Euclidean geometry still apply. The distance between two points is a vector whose linear measure is the root-mean-square of the individual distances as measured on each of the one-dimensional axes that the multi-dimensional universe has to offer. This distance can NEVER be smaller than the LARGEST of the distance measured on all the axes.

    An example in our “perceived” three dimensional universe. You have two points which happen to both lie on the X axis. The distance between them on that axis is one light-year. The Y and Z components of the distance between those points is zero because they both lie on the X axis. Despite the fact that we are free to travel in three dimensions to traverse the distance between the two points, that distance can never be less than one light-year.

    The same will hold true whether the hyper-universe has six dimensions, or 11 or 14, both of which have been suggested recently. The distance between two points can never be less than the largest distance measured in any one dimension.

    Now I did say “Euclidean geometry.” If the hyper-universe is non-Euclidean in its properties, all bets are off. The trivial real-life example is our perception of living on a plane when it is in fact the surface of a sphere. It looks to us like the distance between the North and South Poles is about 20,000 km because that’s what the odometer on our car says after we’ve driven it. But we know that if we want to go to the trouble of boring a hole along the Earth’s axis, the distance between the poles can be reduced to about 12,000 km.

    We can imagine other non-Euclidean surfaces that might reduce the distance between two points to almost zero if we could free ourselves from the constraints of surface life.

    But now we’re getting into wormholes and all the stuff of SF. Everything I have read about the theories of multi-dimensional universes, which are used to explain how waves really are particles and particles really can only occupy a discrete number of points in the perceivable universe rather than an infinite locus, sticks to Euclidean geometry. You’ve surely read more of this than I have. Is there any reason to speculate that the greater universe that we can’t see is non-Euclidean, other than wishful thinking?
     
    Fraggle Rocker, May 11, 2003
    #17
  21. Prosoothus

    Prosoothus Registered Senior Member

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    Fraggle Rocker,

    Thanks for pointing out the major error in my theory. You're right, according to Euclidean geometry, two multidimensional particles can't interact unless all of their dimensions are identical. If only three dimensions were identical, it wouldn't be sufficient for an interaction.

    It appears that in order to make theory valid, I would have to introduce three dimensional particles into my theory, as well as the original six dimensional particles. So for example, an electron would be a six dimensional particle, while a virtual photon (that makes up an electric field) would be a three dimensional particle.

    I wonder if there are two, or one dimensional particles?

    Tom
     
    Prosoothus, May 12, 2003
    #18
  22. zerp

    zerp Registered Member

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    P2P Philanthropy

    A far more worthy recipient of your unused and idle CPU time would be to sign up for one of United Devices' CURE programs. Designed to search for something that is way more likely to benefit mankind sooner than the search for extra-terrestrials will.

    Download the United Devices software here.
     
    zerp, May 12, 2003
    #19
  23. Pollux V

    Pollux V Ra Bless America Registered Senior Member

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    Photon spinning...heady stuff.

    But back to SETI--I remember seeing somewhere the problem that the various SETI antennae can't cover all that they'd like to, and by simply installing recievers on everyone's homes they'd be able to turn the earth into one big radio dish. Anyone know what I'm talking about?
     
    Pollux V, May 12, 2003
    #20
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