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Paul Wally
2013-Jun-05, 09:32 PM
The search for extraterrestrial intelligence is currently looking for intelligent radio signals from any advanced civilizations that might be out
there. But what if a civilization a million years more advanced than us uses something completely different to communicate over vast distances. Suppose we don't have the technology to detect such a signal, and that such signals could be passing right through us without us noticing anything. What if we don't even have the physics that would allow us to design a detection instrument? I mean we get revolutions in scientific theory where old conceptions of reality are replaced by completely new ways of looking at the world, opening up new technological possibilities. A million years is a very long time. Who knows what we'll discover just in the next thousand years.

Take as an analogy the difference between sound wave communications and radio wave communications. What if the next step is analogous to this difference. Let's explore this analogy to see whether we could get any kind of understanding into the nature of the technological gap that might exist between us and advanced alien civilizations, millions of years ahead of us.

neilzero
2013-Jun-05, 10:41 PM
I agree, something much better than radio waves is likely in the next thousand years. For long distance they logically use a narrow beam, to reduce the amount of energy needed and/or increase the band width. Since both ends are moving, Earth is only in the beam briefly and not likely to repeat for years to centuries. Unless they can detect Earth, they can't keep the beam on Earth. Aiming at Jupiter would rarely cause a very narrow beam to fall on Earth. Neil

eburacum45
2013-Jun-05, 11:06 PM
That's right; a laser beam would have a small footprint at the destination system and use less energy than a radio transmission. The shorter the wavelength, the tighter the focus. Which short wavelength beams would be least absorbed by the interstellar medium?

Selfsim
2013-Jun-05, 11:16 PM
What if we don't even have the physics that would allow us to design a detection instrument? I mean we get revolutions in scientific theory where old conceptions of reality are replaced by completely new ways of looking at the world, opening up new technological possibilities. A million years is a very long time. Who knows what we'll discover just in the next thousand years.The speed of EM propagation in free space throughout the observable universe has not changed since its detection first became possible, ~13.8 Gya.

Why would millions of years of evolution of life have any effect on that Physics?

We already know how to detect EM propagation .. no new physics there ...

Selfsim
2013-Jun-06, 12:13 AM
As a baseline of current fact, I summarised SETI's current RF signal detection method here. (http://cosmoquest.org/forum/showthread.php?125623-Man-s-Radio-Sphere&p=1974195#post1974195)

They have recently altered their RF search strategy to search in the vicinity of the 8.66 GHz region. This corresponds to the quiet He3+ spin flip transition region, the idea being that ET would prefer this band for transmissions, in order to avoid polluting the Hydrogen transition band regions which it is assumed, ET would be studying. (This may be a good example of how thought paradigms may limit the scope of a particular exploration strategy(?) ).

Working forwards from this however, free-space optical comms is a different ball-game … Laser comms is limited by transmit power and receiver sensitivity.

N-slit interferometer techniques are in principle, capable of transitting large distances in free-space. See wiki: (http://en.wikipedia.org/wiki/Free-space_optical_communication#Usage_and_technologies )

It should be noted that, (without going into the details), these techniques require knowledge of how the information is encoded at the source in order to distinguish them as actually being transmitted by an intelligent source … which may present significant difficulties in guessing what "an advanced ET's" preferences for doing this might be, prior to human detection of such a signal. This problem, (I believe), is exacerbated when moving to optical over RF comms, because of the far greater searching and permutation space imposed on the detection end, which comes with the greater available messaging bandwidth available, for a given transmit power. The latter of which, presumably, ET would have selected this method for, in the first place(?)

TooMany
2013-Jun-06, 01:00 AM
It should be noted that, (without going into the details), these techniques require knowledge of how the information is encoded at the source in order to distinguish them as actually being transmitted by an intelligent source … which may present significant difficulties in guessing what "an advanced ET's" preferences for doing this might be, prior to human detection of such a signal.

That's really not true unless ET is attempting to hide his transmissions as noise using some sophistical encryption scheme.

If ET is transmitting in order to get the attention of other intelligences, there will be no problem detecting that the signal has an intelligent source, even if it takes a little effort to derive meaning from the signal. Pictures are worth a thousand words, it would be obvious to any intelligent ET that pictures can be transmitted as a raster scan, even three dimensional pictures. This is just as obvious to any intelligent receiver.

Selfsim
2013-Jun-06, 02:39 AM
That's really not true unless ET is attempting to hide his transmissions as noise using some sophistical encryption scheme. Hmm .. our own anthropic bias would steer us into looking at ET's motivations, I guess. I suppose they could also be split into two categories: (i) ET's own 'internal' comms and (ii) ET's calls outside(?)
Presumably, we'd be lookin' for anythin' we can get .. so if the techniques used at the source for purpose (i) and purpose (ii) are fundamentally different, then our chances of detection might depend on which one of (i) or (ii) above we intercept(?)


If ET is transmitting in order to get the attention of other intelligences, there will be no problem detecting that the signal has an intelligent source, even if it takes a little effort to derive meaning from the signal. Pictures are worth a thousand words, it would be obvious to any intelligent ET that pictures can be transmitted as a raster scan, even three dimensional pictures. This is just as obvious to any intelligent receiver.This is the Sagan 'Contact-style' of sci-fi thinking(?) The fundamental (and most difficult) problem was hidden by Sagan through the mysteriously and unrealistically talented character of Kent Clark (an inverse Superman?) who somehow 'heard' the encoded image pattern in the supposedly AM modulated sideband signal (which is total nonsense in the real world). The 'evil' SR Hadden sorted out the encoding problem (which was also more nonsense).

Thinking in some more depth however, about optical vs RF … there seems to be two fundamental drivers (for terrestrials):

i) our abilities to detect faint optical signals have advanced a lot recently, as has our cancellation of atmospheric optical interference, (as well as our abilities to get better telescopes into space). This is really about improving the signal-to-noise and narrowing detection apertures, avoiding the problem of having to build physically bigger antennas. Optical comms detectors scale more efficiently than RF antennas (noise vs signal). The efficiency of solid state optical detectors, far outweighs those of RF Low Noise Amplifier technologies, too.
and;
ii) More useful messaging information can be compressed into optically modulated signals, thus increasing the sourced information yield over greater distances, (courtesy of the greater efficiencies of concentrating energy into a more focused optical beam .. by using lasers).

As in RF, different modulation techniques in both the time and frequency domains can be used, but because there's a wider available spectrum range in the optical domain, the potential delivered information density is far greater in free space optical over a given transmission, than it is in RF. I think this extra flexibility would mean a lot more complexity for us terrestrials, to infer intelligence from a given optical detection(?) (It could even conceivably turn out to be not possible ..)

Paul Wally
2013-Jun-06, 03:19 PM
I agree, something much better than radio waves is likely in the next thousand years. For long distance they logically use a narrow beam, to reduce the amount of energy needed and/or increase the band width. Since both ends are moving, Earth is only in the beam briefly and not likely to repeat for years to centuries. Unless they can detect Earth, they can't keep the beam on Earth. Aiming at Jupiter would rarely cause a very narrow beam to fall on Earth. Neil

Those are really principle points; energy efficiency and bandwidth. I think that if alien scientists and engineers are rational, the drive would indeed be towards increased efficiency and bandwidth, irrespective of the actual medium used, whether radio, optical or other means that are still unknown to us. But doesn't this mean problems for us in detecting or intercepting their transmissions? Unless, there are also good reasons (for them) to make use of broadcasting type transmissions, e.g. beacons.

SkepticJ
2013-Jun-06, 04:12 PM
Bracewell probe.

TooMany
2013-Jun-06, 04:15 PM
This is the Sagan 'Contact-style' of sci-fi thinking(?)

No personage-related style needed, no sci-fi (implying nonsense?) thinking, just a blatantly obvious way to communicate without a shared language.

Paul Wally
2013-Jun-06, 09:03 PM
I guess where I'm heading with this is to look at alien communications (or the possibility thereof) in a broader framework of scientific change and technological change as it might occur over very long timescales. If alien scientists have developed their physical theory where they have discovered phenomena that we are yet to discover, then what are the chances that they will even make use of EM for communications? Maybe they are applying phenomena that we are yet to discover.

Selfsim
2013-Jun-06, 09:33 PM
No personage-related style needed, no sci-fi (implying nonsense?) thinking, just a blatantly obvious way to communicate without a shared language.What if they have no visual sensory organs? Does that 'possibility' exist in your speculation? (Or has it been ruled out .. if so, what is the specific exo-empirical basis basis for ruling out that 'possibility'?)

Selfsim
2013-Jun-06, 09:38 PM
… If alien scientists have developed their physical theory where they have discovered phenomena that we are yet to discover, then what are the chances that they will even make use of EM for communications? Maybe they are applying phenomena that we are yet to discover.If we haven't discovered it, how can we possibly envisage how to detect signals which make use of it?
Could you please explain exactly what you're after here(?)

TooMany
2013-Jun-06, 10:03 PM
What if they have no visual sensory organs? Does that 'possibility' exist in your speculation? (Or has it been ruled out .. if so, what is the specific exo-empirical basis basis for ruling out that 'possibility'?)

The stars that host planets radiate light. Light can be focused to produce an image thus providing an extraordinary sense organ that can examine the environment in great detail both near and far. Many different types of eyes have evolved right here on earth.

I would be very surprised if any life with our level of intelligence does not have eyes or some sort. While it's a possibility, there is no reason (that I'm aware of) to speculate it would be more than extremely rare.

Scientific speculation can produce a useful working hypothesis without direct evidence.

ASTRO BOY
2013-Jun-06, 10:05 PM
Hmm .. our own anthropic bias would steer us into looking at ET's motivations, I guess. I suppose they could also be split into two categories: (i) ET's own 'internal' comms and (ii) ET's calls outside(?)
Presumably, we'd be lookin' for anythin' we can get .. so if the techniques used at the source for purpose (i) and purpose (ii) are fundamentally different, then our chances of detection might depend on which one of (i) or (ii) above we intercept(?)



Your arguments seem to constantly deride any and all speculation concerning the overwhelming possibility of ETL and contacting them....That in itself appears as a bias, and afterall we all, you and me included have some bias at different times...not that there is anything wrong with that....Noting of course that some bias has lead to great scientific innovations and discoveries.
Carl Sagan's "bias" with respect to ETL did not stop him critically and sceptically analyzing reported UFO sightings.





This is the Sagan 'Contact-style' of sci-fi thinking(?) The fundamental (and most difficult) problem was hidden by Sagan through the mysteriously and unrealistically talented character of Kent Clark (an inverse Superman?) who somehow 'heard' the encoded image pattern in the supposedly AM modulated sideband signal (which is total nonsense in the real world). The 'evil' SR Hadden sorted out the encoding problem (which was also more nonsense).





Considering Carl was probably one of the greatest educators of our time, and considering he was at the forefront of such endeavours as searching for ETL and exploration in general, while at the same time critical and sceptical of UFO sightings and Alien contacts with individuals, his opinions demand great respect, certainly not derision.
His Imaginative idea of attempting possible Alien contact with the golden plaques aboard Voyager, remains a great testament to the man's wisdom and Innovation........and still a relevent means of contacting another Intelligent species out there somewhere.

Paul Wally
2013-Jun-07, 12:36 AM
If we haven't discovered it, how can we possibly envisage how to detect signals which make use of it?

I suppose we can't detect their signals, unless we make the same scientific discoveries that they did, but that's exactly my point. So what I'm trying to
look at is not the actual alien technology, but something analogous.


Could you please explain exactly what you're after here(?)

What I think would help is to look at historical examples of revolutionary scientific discoveries and compare the before and after scenarios in terms of their conceivable technological possibilities, e.g. Maxwell's EM theory predicting electromagnetic waves which were experimentally confirmed by Hertz. Now if we use that as an analogy: What if some future theory predicts an effect that makes some new communications technology conceivable? Then SETI will be saying the aliens must be using that, whatever that is, because it's so much more efficient etc.

Swift
2013-Jun-07, 01:18 PM
Your arguments seem to constantly deride any and all speculation concerning the overwhelming possibility of ETL and contacting them....
This is exactly the kind of comment that creates arguments in LiS and exactly the type I would like to see people stop making. You are making comments about another member's motivations and thought processes, not about the points they are raising.

Paul Wally
2013-Aug-14, 11:28 AM
The following was pulled in from the thread Why still there is no Alien contact (http://cosmoquest.org/forum/showthread.php?97916-Why-still-there-is-no-Alien-contact/page32).


The idea that we can extrapolate the differences in understanding of physics between two past historical events, into the future, is fundamentally invalid. (Eg: events such as the acceptance of Maxwell's EM Theories and then the widespread deployment of RF Communications, and then saying that this has some sustained implication into a somehow pre-destined future). Moore's law for technological development has its known limits of applicability, so does GR, as does QM. Such discontinuities at the limits of such theories, (for eg), is known to result in predictions not being feasible at the extremes of theoretical domains. Why would one then think there exists some pre-destined development rate across all of disparate theoretical physics, which would then facilitate the development of a specific type of finely-tuned technology (eg: comms).

Where discontinuities exist, uncertainties escalate, which renders predictions not feasible.

The problem here is one of human misperception .. not one based on what is known to enable accurate predictions by science, (within the domain of physics).

PS: To avoid any lengthy OT sidetracks, I recommend further discussions about this (if desired), be continued on Paul Wally's thread (as per his above link).

First of all, this is not intended to be about making predictions of the future, but rather, it is about attempting to imagine what it could mean if aliens are much more advanced than us in communications technology. Prediction of the development of technology is a different issue from what it would mean if such a technological gap exists.

The Maxwell-RF connection is intended as an analogy for understanding the relation that exists between any scientific theory and the technology it makes possible. A useful model to base further discussion on is Thomas Kuhn's theory of The structure of scientific revolutions (http://en.wikipedia.org/wiki/The_Structure_of_Scientific_Revolutions) . The discontinuities you're mentioning is exactly what we get during periods of scientific revolution; the shift from one scientific paradigm to another. The technological gap between humans and advanced aliens may very well be a case of two incommensurable paradigms.

Selfsim
2013-Aug-15, 09:42 AM
First of all, this is not intended to be about making predictions of the future, but rather, it is about attempting to imagine what it could mean if aliens are much more advanced than us in communications technology. Prediction of the development of technology is a different issue from what it would mean if such a technological gap exists.But in order to rationally discuss what 'the gap' would mean, one has to predict the existence of a particular type of 'advanced communications technology'. How can you possibly do this? Its clearly necessary as the communications technology becomes the critical factor on which to frame the discussion ...


The Maxwell-RF connection is intended as an analogy for understanding the relation that exists between any scientific theory and the technology it makes possible. A useful model to base further discussion on is Thomas Kuhn's theory of The structure of scientific revolutions (http://en.wikipedia.org/wiki/The_Structure_of_Scientific_Revolutions) . The discontinuities you're mentioning is exactly what we get during periods of scientific revolution; the shift from one scientific paradigm to another. The technological gap between humans and advanced aliens may very well be a case of two incommensurable paradigms.If they're incommensurable, then how can you possibly achieve your objective?

I'm sorry, but this just nonsense ..

Hlafordlaes
2013-Aug-15, 11:42 PM
Too bad there is no way to effect an initial spin on each member of an entangled pair sans measurement, and on top of that store them in matrices without causing decoherence. Then I could take a bunch of clockwise 'spinners' somewhere and read them in matrix order (so no clock needs to be synched) to see which have been changed by a distant buddy, and take each change as a '1' bit, each non-change as a '0' bit. And with two batches of the stuff, I could also have one for transmitting.

Oh, well. Barring stuff like that, though, I have a hard time imagining anything not using EM, or maybe gravity waves(?), unless things like neutrinos could be manipulated.

OTOH, and this is off-topic, the bigger question is whether one feels we have truly identified hard laws and limits, and scientific progress therefore does truly consist of progressively more accurate approximation to 'reality,' so no there can be no reason at all to speculate about, say, FTL or any form of energy outside, what, the four forces?
The problem is that such confidence in that the laws do truly hold, and will always hold, is also an implicit statement about other stuff we like to argue about philosophically from time to time.

Selfsim
2013-Aug-16, 12:01 AM
OTOH, and this is off-topic, the bigger question is whether one feels we have truly identified hard laws and limits, and scientific progress therefore does truly consist of progressively more accurate approximation to 'reality,' so no there can be no reason at all to speculate about, say, FTL or any form of energy outside, what, the four forces?
The problem is that such confidence in that the laws do truly hold, and will always hold, is also an implicit statement about other stuff we like to argue about philosophically from time to time.Point taken.

Going beyond those laws however, results in being plonked into more or less the same place as holding onto them without question.
So what's the point?

Our reality is the laws .. and we can't predict what comes next in science, using the past as a basis. There is no causal connection, especially when discontinuities exist.

Al we can do is query the visible boundaries, and see what pops up next.

Hlafordlaes
2013-Aug-16, 12:16 AM
Agreed.

ravens_cry
2013-Aug-16, 10:18 PM
As far as I know, wormholes aren't theoretically impossible. On the other hand, opening up a throat big enough to step through, let alone a starship, would take mind boggling amounts of energy. So . . .don't. Instead of sending people, just use it to send a laser pulse. Conceivably, a hell of a lot simpler. The downside if you have to send a wormhole the slow way, which could take hundreds or even thousands of years. But, on the plus side, apart from capturing one throat, there is no way, at least that I know of, of intercepting a sent message. How's that for security?

Selfsim
2013-Aug-16, 11:41 PM
As far as I know, wormholes aren't theoretically impossible. On the other hand, opening up a throat big enough to step through, let alone a starship, would take mind boggling amounts of energy. So . . .don't. Instead of sending people, just use it to send a laser pulse. Conceivably, a hell of a lot simpler. The downside if you have to send a wormhole the slow way, which could take hundreds or even thousands of years. But, on the plus side, apart from capturing one throat, there is no way, at least that I know of, of intercepting a sent message. How's that for security?This is currently being discussed in this thread. (http://cosmoquest.org/forum/showthread.php?145729-GR-vs-QFT-quot-Firewall-Paradox-quot-(maybe-not)&p=2151524#post2151524)

Hypothetical wormholes require very specific spacetimes and conditions. No serious theoretical scientist suggests their existence.
As hypothetical constructs (ER bridges), they cannot transport matter or messages. Typically the entrance shuts down, or their length grows too quickly to be useful. In hypothetical QM models, 'messages' sent from outside one end of a very specifically, hypothetically defined, QM entangled wormhole (EPR), by hypothetical manipulation of unconfirmed Hawking Radiation by a hypothetically absolutely humongously powerful quantum computer, may hypothetically be able to be received by an observer who has moved inside the Event Horizon at the other end .. and what would be the point, if the recipient is thermalised before they receive it, and cannot ever report that they received it to any outside observer? (The latter defeating the very definition of 'communications').

Hypothetical thought-capable aliens or not, hypothetical wormholes represent nothing more than a gedakenexperiment for exploring the extremes of theory .. nothing more.

eburacum45
2013-Aug-17, 09:19 AM
Hypothetical wormholes require very specific spacetimes and conditions. No serious theoretical scientist suggests their existence. There are some not-quite-so-serious theoretical scientists who are prepared to think about them, however.
John Cramer (http://www.npl.washington.edu/av/altvw69.html)
Michael Morris and Kip Thorne (http://www.physics.uofl.edu/wkomp/teaching/spring2006/589/final/wormholes.pdf) (pdf)
Matt Visser (http://arxiv.org/abs/gr-qc/9702043)
Greg Benford (http://edge.org/response-detail/11225)
Quantum-entangled black holes aren't likely to be much use, because of the event horizon. The trick is to have a traversable wormhole with no event horizon; this is probably not possible, however; see Fewster and Roman (http://arxiv.org/abs/gr-qc/0510079), for example.

It might be possible to create a traversable wormhole, but it would almost certainly be very, very difficult. Maybe a tiny wormhole just large enough to allow information through might be achievable- this could conceivably be the basis for a galactic or even intergalactic civilisation, communicating almost instantly via a wormhole modem. But such a civilisation could be entirely undetectable, and we might never know if it existed.

Selfsim
2013-Aug-17, 08:02 PM
… It might be possible to create a traversable wormhole, but it would almost certainly be very, very difficult. Could you please explain how this might be possible?

ravens_cry
2013-Aug-18, 04:58 AM
Negative energy and/or matter. Hypothetical, sure, but not impossible.



It might be possible to create a traversable wormhole, but it would almost certainly be very, very difficult. Maybe a tiny wormhole just large enough to allow information through might be achievable- this could conceivably be the basis for a galactic or even intergalactic civilisation, communicating almost instantly via a wormhole modem. But such a civilisation could be entirely undetectable, and we might never know if it existed.
The chief limitation is you still need to get one throat to the endzone. As for detecting these people, a civilisation that has developed the technology, but it is still too expensive in resources to have more than one or two per star system, would still need substantial light speed communication.

Selfsim
2013-Aug-18, 05:16 AM
Negative energy and/or matter. Hypothetical, sure, but not impossible.Let me understand this proposition in the context of the OP:

Take as an analogy the difference between sound wave communications and radio wave communications. Let's explore this analogy to see whether we could get any kind of understanding into the nature of the technological gap that might exist between us and advanced alien civilizations, millions of years ahead of us.OK, so the analogy we are now discussing is communications via hypothetical wormholes.
Now, in order to gain 'an understanding into the nature of the technological gap that might exist between us and advanced alien civilizations' making use of said wormholes, could someone please explain for me:

i) how a traversable wormhole is possible and;
ii) how negative energy and/or matter is possible.

Unless someone can first explain this, I cannot possibly see how an understanding of 'the nature of the technological gap' can then be explained?

Selfsim
2013-Aug-18, 05:22 AM
The chief limitation is you still need to get one throat to the endzone.Could you please explain why this is a limitation to making a traversable wormhole possible ?

Paul Wally
2013-Aug-18, 02:43 PM
But in order to rationally discuss what 'the gap' would mean, one has to predict the existence of a particular type of 'advanced communications technology'. How can you possibly do this? Its clearly necessary as the communications technology becomes the critical factor on which to frame the discussion ...

I'm approaching the subject from a more general perspective, so it's really not necessary to make predictions about actually existing and particular technologies. It's the more general idea of such a technological gap that I'm interested in, and there are plenty of examples of such gaps in history to draw from.


Too bad there is no way to effect an initial spin on each member of an entangled pair sans measurement, and on top of that store them in matrices without causing decoherence. Then I could take a bunch of clockwise 'spinners' somewhere and read them in matrix order (so no clock needs to be synched) to see which have been changed by a distant buddy, and take each change as a '1' bit, each non-change as a '0' bit. And with two batches of the stuff, I could also have one for transmitting.

This would then be an example of approaching the problem from within the current quantum paradigm, and it would appear that within this paradigm
it is not possible to send information faster than the speed of light. There is just no way around it, in this paradigm. But what if the aliens have a much more advanced understanding of how the universe works?



OTOH, and this is off-topic, the bigger question is whether one feels we have truly identified hard laws and limits, and scientific progress therefore does truly consist of progressively more accurate approximation to 'reality,' so no there can be no reason at all to speculate about, say, FTL or any form of energy outside, what, the four forces?
The problem is that such confidence in that the laws do truly hold, and will always hold, is also an implicit statement about other stuff we like to argue about philosophically from time to time.

I think you're quite on the topic here. I do have something to say about "progressively more accurate approximation to reality". I think science is progressive in that sense, but not necessarily in an asymptotic kind of way, as if we understand 90% today and 95% tomorrow but can never quite get to 100%. I don't think it's like that at all. It's more like we think we understand 90% but then there's a paradigm shift and then we realize we only understood 10% until we reach 90% again. Then there are always people who believe that we're really at 90% and that only a few loose ends need to be tied up, but then there's a new discovery that opens up a whole new world of possibilities and we're back at 10%. It's quite an optimistic view, but I think it's good for scientific progress.


As far as I know, wormholes aren't theoretically impossible. On the other hand, opening up a throat big enough to step through, let alone a starship, would take mind boggling amounts of energy. So . . .don't. Instead of sending people, just use it to send a laser pulse. Conceivably, a hell of a lot simpler. The downside if you have to send a wormhole the slow way, which could take hundreds or even thousands of years. But, on the plus side, apart from capturing one throat, there is no way, at least that I know of, of intercepting a sent message. How's that for security?

That's what I'm wondering too. Unless alien communication is of a broadcasting type, we may not be able to intercept their messages.


Let me understand this proposition in the context of the OP:
OK, so the analogy we are now discussing is communications via hypothetical wormholes.
Now, in order to gain 'an understanding into the nature of the technological gap that might exist between us and advanced alien civilizations' making use of said wormholes, could someone please explain for me:

i) how a traversable wormhole is possible and;
ii) how negative energy and/or matter is possible.

Unless someone can first explain this, I cannot possibly see how an understanding of 'the nature of the technological gap' can then be explained?

What you have to remember is that the alien scientific knowledge is much more advanced than ours. So they might know how to produce negative energy and we don't.

ravens_cry
2013-Aug-19, 12:25 AM
Could you please explain why this is a limitation to making a traversable wormhole possible ?
It isn't, but it is a limitation if you want to use them as a practical form of FTL communication, assuming you get the bugs worked out of actually making a set.

Selfsim
2013-Aug-19, 02:01 AM
I'm approaching the subject from a more general perspective, so it's really not necessary to make predictions about actually existing and particular technologies. It's the more general idea of such a technological gap that I'm interested in, and there are plenty of examples of such gaps in history to draw from. To draw what from, exactly?
This would then be an example of approaching the problem from within the current quantum paradigm, and it would appear that within this paradigm.
It is not possible to send information faster than the speed of light. There is just no way around it, in this paradigm. But what if the aliens have a much more advanced understanding of how the universe works? Advances in science don't result from discarding existing physical evidence.
'FTL anything', has no physical significance. There are no external reasons for why that will change, regardless of how many times the phrase 'much more advanced' is used. There is no physical significance associated with the phrase 'much more advanced', also.

I think you're quite on the topic here. I do have something to say about "progressively more accurate approximation to reality". I think science is progressive in that sense, but not necessarily in an asymptotic kind of way, as if we understand 90% today and 95% tomorrow but can never quite get to 100%. I don't think it's like that at all. It's more like we think we understand 90% but then there's a paradigm shift and then we realize we only understood 10% until we reach 90% again. Then there are always people who believe that we're really at 90% and that only a few loose ends need to be tied up, but then there's a new discovery that opens up a whole new world of possibilities and we're back at 10%. It's quite an optimistic view, but I think it's good for scientific progress. It also demonstrates the meaninglessness of thinking anything about the totality of what is not known. Attempting to realise the totality of what exists outside the paradigm of what is known, is more indicative of what exists 'inside the head', and precisely why it will always stay there, unrealised and of no significance in a physical universe.

What you have to remember is that the alien scientific knowledge is much more advanced than ours. So they might know how to produce negative energy and we don't.Take aliens out of the picture (they might be part of 'the musing', but they are superfluous to the issue).

The concepts of 'traversable wormholes', 'negative energy' and 'FTL' have no significance in the physical universe, particularly if the reasons for their 'possible existence' cannot be articulated. It doesn't matter how 'advanced' or how many aliens might exist, they won't be manipulating things which have non-physical significance. Even if paradigms change, physical significance doesn't. Paradigms only change because of physical significance.

Selfsim
2013-Aug-19, 02:06 AM
It isn't, but it is a limitation if you want to use them as a practical form of FTL communication, assuming you get the bugs worked out of actually making a set.Can you define: 'practical form of FTL communication'?
If FTL has no physical significance, how can such a thing result in 'practical communication'?

The chief limitation is you still need to get one throat to the endzone.Can you please define ‘throat’ and ‘endzone’ from outside of Paul Wally’s 'limiting paradigm’?
(.. I seem to be having difficulty in doing this).

eburacum45
2013-Aug-19, 07:42 PM
The concepts of 'traversable wormholes', 'negative energy' and 'FTL' have no significance in the physical universe, particularly if the reasons for their 'possible existence' cannot be articulated.I presume you have read the links I posted earlier? These things only have no significance in the physical universe if they are, in fact unphysical; this has not yet been demonstrated. I must admit I think they are, indeed, unphysical; but there is an outside chance that the conditions necessary for a traversable wormhole can be acheived, in which case we would have to deal with the consequences of multiply-connected spacetime.

Selfsim
2013-Aug-19, 10:13 PM
Speculation can be used to improve model effectiveness, but not at the expense of undermining the physical principles which gave rise to the concepts in the first place.

Suspending rationality might allow for the posited existence of these entities, but it also injects inexplicable (and unknown) inconsistencies, which dominate the rational exploration of consequences from thereon. The conversation then has no value to science, and becomes one about something else .. goodness knows, what ..

Hlafordlaes
2013-Aug-20, 01:20 AM
Sometimes I think that, given sub-light speed as a permanently limiting factor, that the only scenarios that are convincing for interstellar travel/expansion involve mostly machine intelligence. True, hibernation or artificial longevity are other possibilities for us bios, but I see motivation for the long trip as a problem there.

And if robots are to rule, where are they? If they are communicating, perhaps they are content with waiting decades or more for answers. And given that, what if they end up sticking to some old protocol, fearful the message may be lost among locally and disparately upgrading entities if no fixed code is used. "Study your XML, Junior, you'll need it at least once a century."