Shouldn't we have heard alien radio signals by now? Why not?

  • #51
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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 wont get us anywhere.

Again only colloquially is dimension used to mean universe.

Popular science documentaries are not supportive evidence.


No but the way you are using the term is wrong; only colloquially is dimension synonymous with universe.

That is a mere unjustified inference. Even so, it is a totally unnecessary one since inferences derived from the written text should always be firmly based on context and this one isn‘t.. You see, textual context should indicate in this case that if indeed a universe is being spoken about it is a universe in the total sense of the word and not merely a detectable universe. Whether the usage is colloquial or not is totally irrelevant to the intended concept. In short, the colloquial objection is non-applicable and the premise which it represents is fallaciously skewed.





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

Inconsistency of policy. You aren’t sure if extraterrestrials exist but that doesn’t stop you from talking about it.


and 2) even if they did we could never expect to hear from them anyway.

Really? You know that for a fact? Some of the unexplained phenomenon has been hypothesized to be extra dimensionally derived. Electrons which disappear and reappear at unpredictable locations around atomic nuclei are thought to be flitting from dimension to dimension. Gravity itself is presently being hypothesized as extradimensional leakage into our dimension from anther where it is much more powerful. Physicists are even now attempting to explain the enigmatic Dark Energy and Dark Matters by factoring in extra dimensional mathematical equations. So a casual relegation of extradimensioality to the boondocks of the silly and irrelevant isn’t quite at the cutting edge of current scientific thinking to say the least.



thread is about detection bringing something to the conversation that cannot be detected wont get us anywhere.

Another baseless inference! I made no claim that it was intended to get us anywhere. Why? Well, because getting somewhere in relation to this subject means finding a definite answer to the thread’s topic which is presently impossible. In short, this whole thread is based on hypotheticals which can’t get anywhere unless by somewhere you mean additional hypothesizing that will get nowhere. Which is, BTW, exactly what I did..

Again only colloquially is dimension used to mean universe.
I never equated dimension with universe. LOL

Popular science documentaries are not supportive evidence.
It wasn’t offered as irrefutable supportive evidence. It was merely offered as an example that the idea is being seriously considered in scientific circles as the documentary points out. If indeed the physicist who is speaking in that documentary is lying, and you feel justified in brazenly and publicly accusing him of lying, then it is up to you to prove it since you are the one taking serious umbrage with what that physicist is claiming. Your mere personal opinion glibly posted on this forum does not in any way manner r form constitute irrefutable proof otherwise. It is merely an unsubstantiated OPINION.

As for popularity, your premise is completely off since popularity doesn’t invariably equate with the unscientific or with quackery. The Bib Bang Theory and the Dark Matter Dark Energy theories are also popular and they are not diminished by being so or by being shown on any documentary hosted by a physicist.

Of course if indeed this was a full-fledged debate I would present s doctoral dissertations and scientific articles submitted for peer review and ultimately accepted as reputable by the majority. But that would seriously deviate the thread and deviation of the thread wasn’t and still isn’t my intention. Neither does my very brief comment about the possibilities inherent in claiming that there is no life in space based on our inability to detect it derail it.

However, unnecessary quibbling with semantics and demanding extensive documentation for every statement based on personal interpretation concerning what the poster meant does seriously threaten to deviate the thread by attempting to turn it into a personal debate over a relevant albeit slightly side topic about another poster’s pertinent and excellent analogy which was definitely on topic,
 
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  • #52
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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.
The term dimension has nothing to do with parallel universes.
So now its suddenly a definition flaw thing? OK.
Show me where I defined dimensions as 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.
Show me where I spoke of teleporting between dimensions.



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.

1.I never claimed that dimensions cannot have precise mathematical meanings.

2.I never claimed that a plane has more than two dimensions and neither des anyone else.

3.I never claimed that the spatial dimension we humans exist in has more or less than three variables.


So a dimension is not a parallel universe,
Strawman



it is simply a number!!

It certainly can be limited to only a number. However, in reference to the subject matter your example proves otherwise. Obviously such coordinates taken in conjunction are spatially describing the place where we exist and the place where we exist isn’t simply a number.

If not then what are they describing if it isn’t length, height and depth?

BTW
Your premises is faulty: Reality does not preclude mathematical description..
That would necessitate that realities perceivable by the sense cannot ever be mathematically described. Which is obviously false.


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 the subject is parallel units accelerating why should there be? That’s equivocation.



BTW

Please note that your argument would be much more believable if there wasn’t so much evidence that physicists are treating the term "dimension" differently than you demand that it shuld be treated.


If you want to talk about parallel universes, you are welcome to do so: but do NOT use the term dimension.
I want to do what? Discuss dimensions and tag them all as universes ?


LOL
You are attempting to limit the concept as used by physicists to the following.


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
And ignoring this:

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

Btw
The use of straw man isn’t unconvincing, time-wasting and leads nowhere.

Please try to express only what I meant and not what you imagined I meant.
 
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  • #53
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