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epenguin
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tasp77 said:We are first.
Some people (i.e. this astronomer I heard in a meeting about 12 years ago) think we are last - we arrived when the party is nearly over.
tasp77 said:We are first.
I think this is a key point that is often forgotten in science fiction (unless you read hard-SF). Humans/the Homo genus evolved to the point where they could communicate and use tools to the sophistication we see today over the last few hundred-thousand to million years (depending on whether or not you consider the capabilities of other species of human). However we only started to organise into non-nomadic communities in the last ten-thousand years. There is little reason why a species with these attributes couldn't have evolved at any point since the Cambrian explosion but that is just how things have gone. It would seem an extraordinary coincidence if we were to identify an alien species whose history was the same length as us and who were at roughly an equal level of technology. More likely the separation would be measured in mega years.Wanderlust said:There are no civilizations active within a hundred thousand years in time, don't forget we are separated in time as much as space. There is only a 100,000 year window of detection after a civilizations stops broadcasting in one wavelength
No we don't. We simply recognize that, as an animal withTGlad said:4. That we are the peak and the future of evolution.
We arrogantly consider ourselves the 'best' animals,
TGlad said:I expect our discoveries in future will come mainly from simulations,
in which case we are not of slightest interest to them.
3. That signals would leak to earth.
If aliens were speaking to each other, broadcasts in all directions would be massively inefficient so wouldn't be used
Rasalhague said:The article Chronos mentioned in the thread I linked to has some interesting comments on high intensity narrowband radar, as the one kind of signal our civilisation makes which a civilisation of equivalent technological development could be reasonably expected to detect.
https://www.physicsforums.com/showpost.php?p=2564759&postcount=5
http://www.faqs.org/faqs/astronomy/faq/part6/section-12.html]
More than that looking at simple life would be intensely fascinating to any biologist, especially biochemists, microbiologists and any branch of evolutionary biology. If the ameoba were to use something other than water as a solvent and biochemistry not based on amino acids, nucleotides or carbohydrates (or even not based on carbon) that would be fantastically interesting.Wanderlust said:Ameobas are interesting. You don't realize that groups of people have specialists. I am not interested at all in a new species of slug in borneo, but some people are passionate about it. Some individuals in that society may have a keen interest in new sapient civlizations.
PacketMan said:The other question is how much of a sample have we really been able to take so far? We've been looking for what, 50 years? I saw an astrophysicist on some program on the Science Channel put it very well: If you dipped a glass of water in the ocean and looked it at, would you conclude that the ocean has no fish in it?
Firstly you are using the term dimension wrong here. Secondly no theory involving a multiverse involves the capability to transfer from one to the other. It's easier to keep it within the realm of known physics in the known universe.Radrook said:That's an excellent analogy which becomes even more compelling if we hypothetically add the possibilities of life inherent in the dimensional or multiple universes ideas that physicists are currently tossing around.
Ahem.Ryan_m_b said:Secondly no theory involving a multiverse involves the capability to transfer from one to the other.
No problem, you're dead right. I put it down to a slip of the tongue/hand.D H said:Let me correct that statement of yours, if you don't mind.
Ryan_m_b said:Firstly you are using the term dimension wrong here. Secondly no theory involving a multiverse involves the capability to transfer from one to the other. It's easier to keep it within the realm of known physics in the known universe.
Not that it wouldn't be interesting to view life under different physical laws but a bit moot.
Ryan_m_b said:Firstly you are using the term dimension wrong here.
Secondly no theory involving a multiverse involves the capability to transfer from one to the other.
It's easier to keep it within the realm of known physics in the known universe.
Not that it wouldn't be interesting to view life under different physical laws but a bit moot.
Brane cosmology
String theorists like Neil Turok, Burt Ovrut and Paul Steinhardt discuss the idea that there are no more or fewer than 11 dimensions. These structures, membranes, exist across all these dimensions. Presumably, the one dimension of time and other ten dimensions of spaces have always existed. The physicists suggest that our universe may have formed when two extra-dimensional membranes collided. On this conception, our universe may not be so special, since membrane collisions could cause big bangs all the time. The result is a sort of multiverse - with universes acting like bubbles that generally cannot interact with one another. These ideas have implications for Cosmogony.[1]
http://en.wikipedia.org/wiki/Brane_cosmology
No but the way you are using the term is wrong; only colloquially is dimension synonymous with universe.Radrook said:Really? How? Strange since I didn't go into a detailed definition of what I think the term dimension means.
I never suggested you did. My point was that talking about life in other universes is a pointless exercise because 1) we can't be sure that such universes exist and 2) even if they did we could never expect to hear from them anyway. As this thread is about detection bringing something to the conversation that cannot be detected won't get us anywhere.Radrook said:Please show me where I made that ridiculous claim.
Please show me where I said it wasn't.
Again only colloquially is dimension used to mean universe.Radrook said:Well, it might seem moot if we understand it in a certain irrelevant way and not as intended. The pint is that
life is life whether we can communicate with it or not and whether it is within our dimension or not.
Our claim that no extraterrestrial life doesn’t exist based on our meager attempts to detect it would be ludicrous. It would be even ludicrous when we consider the possibility of multiuniverses and extra dimensions where life might be present is taken into account. It is such a claim that I was commenting on as I clearly pointed out.
Popular science documentaries are not supportive evidence.Radrook said:Parallel Universes Videos...
Radrook said:Really? How? Strange since I didn't go into a detailed definition of what I think the term "dimension" means.
Ryan_m_b said:No but the way you are using the term is wrong; only colloquially is dimension synonymous with universe.
I never suggested you did. My point was that talking about life in other universes is a pointless exercise because 1) we can't be sure that such universes exist and 2) even if they did we could never expect to hear from them anyway. As this thread is about detection bringing something to the conversation that cannot be detected won't get us anywhere.
Again only colloquially is dimension used to mean universe.
Popular science documentaries are not supportive evidence.
Ryan_m_b said:No but the way you are using the term is wrong; only colloquially is dimension synonymous with universe.
I never suggested you did. My point was that talking about life in other universes is a pointless exercise because
1) we can't be sure that such universes exist
and 2) even if they did we could never expect to hear from them anyway.
thread is about detection bringing something to the conversation that cannot be detected won't get us anywhere.
Again only colloquially is dimension used to mean universe.
Popular science documentaries are not supportive evidence.
micromass said:The term dimension has nothing to do with parallel universes. We often see in science-fiction shows that "people have been transported to other dimensions", like tey have went to another universe where the laws of physics are different.
The term dimension has absolutely nothing to do with this. Dimension has a very precise mathematical meaning. A dimension actually is "the number of free variables possible in a system". For example, the plane has dimension 2 since you need 2 variables to specifically determine a point in the plane (indeed: you need an x and a y-variable). The space has dimension 3 since you need 3 variables.
So a dimension is not a parallel universe, it is simply a number!
In physics, a dimension has a related but different meaning. A dimension there can be used to signify whatever units we use. For example, accelaration has units [itex]m/s^2[/itex] and has a different dimension than velocity which has units [itex]m/s[/itex].
Again, there is no talk about parallel universes.
If you want to talk about parallel universes, you are welcome to do so: but do NOT use the term dimension.
micromass said:The term dimension has nothing to do with parallel universes.
We often see in science-fiction shows that "people have been transported to other dimensions", like they have went to another universe where the laws of physics are different.
The term dimension has absolutely nothing to do with this. Dimension has a very precise mathematical meaning. A dimension actually is "the number of free variables possible in a system". For example, the plane has dimension 2 since you need 2 variables to specifically determine a point in the plane (indeed: you need an x and a y-variable). The space has dimension 3 since you need 3 variables.
So a dimension is not a parallel universe,
it is simply a number!
In physics, a dimension has a related but different meaning. A dimension there can be used to signify whatever units we use. For example, acceleration has units [itex]m/s^2[/itex] and has a different dimension than velocity which has units [itex]m/s[/itex].
Again, there is no talk about parallel universes.
If you want to talk about parallel universes, you are welcome to do so: but do NOT use the term dimension.
In mathematics
In mathematics, the dimension of an object is an intrinsic property, independent of the space in which the object may happen to be embedded. For example: a point on the unit circle in the plane can be specified by two Cartesian coordinates but one can make do with a single coordinate (the polar coordinate angle), so the circle is 1-dimensional even though it exists in the 2-dimensional plane. This intrinsic notion of dimension is one of the chief ways in which the mathematical notion of dimension differs from its common usages
http://en.wikipedia.org/wiki/Dimension#Spatial_dimensions
Additional dimensions
Theories such as string theory and M-theory posit that physical space has 10 and 11 dimensions, respectively. These extra dimensions are said to be spatial. However, we perceive only three spatial dimensions and, to date, no experimental or observational evidence is available to confirm the existence of these extra dimensions. A possible explanation that has been suggested is that space acts as if it were "curled up" in the extra dimensions on a subatomic scale, possibly at the quark/string level of scale or below.
http://en.wikipedia.org/wiki/Dimension#Spatial_dimensions