|
Post by Progenitor A on Nov 19, 2015 18:05:13 GMT 1
"For example you have already stated that space has a boundary " Please show where I said that.
|
|
|
Post by fascinating on Nov 19, 2015 18:18:15 GMT 1
Right so I DIDN'T state that space has a boundary.
|
|
|
Post by Progenitor A on Nov 20, 2015 9:18:59 GMT 1
Right so I DIDN'T state that space has a boundary. Of course you did! If Space is not 'nothing', and is expanding into 'nothing' then there is a boundary between 'space' and 'nothing' You have difficulty with English it seems
|
|
|
Post by fascinating on Nov 20, 2015 18:50:26 GMT 1
Your reasoning is flawed; the definition of a boundary is "a line which marks the limits of an area; a dividing line." A nothing has no area.
Cosmic inflation assumes that space itself expands; at every point of space there is something, ie space. In that space more space is created, making the distance between large objects greater.
If space is finite then it presumably has a boundary. I think your mind will turn to thinking that outside of finite space there is an infinite area which you call "nothing", and you imagine that it is bound by the same boundary as space, but that is wrong. In reality, there just isn't anything, outside of space, and "it" (though it isn't even an "it") doesn't have a boundary.
|
|
|
Post by Progenitor A on Nov 20, 2015 20:19:21 GMT 1
Your reasoning is flawed; the definition of a boundary is "a line which marks the limits of an area; a dividing line." A nothing has no area. Cosmic inflation assumes that space itself expands; at every point of space there is something, ie space. In that space more space is created, making the distance between large objects greater. If space is finite then it presumably has a boundary. I think your mind will turn to thinking that outside of finite space there is an infinite area which you call "nothing", and you imagine that it is bound by the same boundary as space, but that is wrong. In reality, there just isn't anything, outside of space, and "it" (though it isn't even an "it") doesn't have a boundary. Gobbldygook Bye
|
|
|
Post by fascinating on Nov 21, 2015 8:52:13 GMT 1
You can't give any reason why you think it is gobbldygook, you are incapable of putting forward a rational arguement regarding this matter.
|
|
|
Post by mrsonde on Dec 8, 2015 23:45:32 GMT 1
The observation that the galaxies are moving apart from each other is believed to be due to space expanding in between them. No, not really. It was always a popular expositional metaphor - expounded first by Eddington, I think, then repeated by Jeans and Dingle, in a trio of popular science books attempting to explain GR to a general audience in the 1920s and 30s. It was never part of a serious physical hypothesis, that I'm aware of - in any event, it is in no way implied by the theory of GR. The "expansion of the universe" had not even been suggested when that was formulated: it's a derivation from Hubble, not Einstein. "Space" is the distance between objects. "It" doesn't do anything.
|
|
|
Post by mrsonde on Dec 8, 2015 23:50:01 GMT 1
I don't think you have a clue. As usual, I agree with you Nay. How did Physics become usurped by the mathematicians from the Engineers?! What a disaster.
|
|
|
Post by mrsonde on Dec 8, 2015 23:56:04 GMT 1
Your reasoning is flawed; the definition of a boundary is "a line which marks the limits of an area; a dividing line." A nothing has no area. A space does, however. Nope. There is and can be no discernible difference between this proposition and a proposition that the matter in the universe expands its distribution. Tell me: what observation could differentiate the two? There is not even a theoretical construct that differentiates the two, as a matter of fact. It's purely an expositional device for the popular imagination that you seem to have taken too literally.
|
|
|
Post by fascinating on Dec 9, 2015 9:13:45 GMT 1
Well I had heard of this idea of cosmic inflation, which (I thought) was specifically the creation of space. OK then, do you know what the correct explanation is for the expansion of the Universe? Whole galaxies, in fact clusters of them, which have quite a lot of mass (!) are somehow being driven apart from each other, such that distant galaxies are receding from us at close to the speed of light. And I recently heard a professor talking who said that the Universe is likely to be much larger than our visual horizon, so that beyond that the galaxies are receding from us faster than the speed of light.
|
|
|
Post by mrsonde on Dec 10, 2015 0:42:08 GMT 1
Well I had heard of this idea of cosmic inflation, which (I thought) was specifically the creation of space. Errr...no. No. It's certainly plausible that all the matter in the universe is spreading apart through time from an intial point origin. But it's not the only explanation. Another explanation is that the interval between quantum vibrations is expanding through time, for example - there's very persuasive evidence from the spectral records to substantiate that, though it;s never ever discussed. The answer to your question is: I don't know. I'm happy with that state of being: it's the people who pretend otherwise that I'm unhappy with. Maybe. That's one interpretation of the spectral evidence. Just one. There is no other corroborative evidence - is there? One interpretation. Well, of course. Unless you believe there's something special about our little location in the grand scheme of things? So - tell me. If that is true, as it almost certainly is, even within the confines of the theory that's generated it, what wieght do you now give to these so-called "measurements" of the "mass of the universe"?!
|
|
|
Post by fascinating on Dec 10, 2015 14:26:51 GMT 1
Do you know, then, how the fact that objects are pushed apart at faster than the speed of light, is explained?
I just don't know, and anyway I don't think my opinion on the matter has any relevance. I am just struggling to understand what cosmologists are saying, taking it as a given that they know at least something about the subject.
|
|
|
Post by mrsonde on Dec 11, 2015 5:54:37 GMT 1
Do you know, then, how the fact that objects are pushed apart at faster than the speed of light, is explained? Well, they're not. Your implied force is not required. If they were accelerating in that separation, as has been recently strongly suggested, then it might be - but the proposed explanation for that (if indeed it's valid, which I strongly doubt) is nothing to do with the Big Bang or Inflation or "expanding space" but something mysterious to do with something mysterious called Something Mysterious - or Dark Energy, take your pick. These days cosmologists are like economists - take your pick. What matters I think is what observations have been made - what measurements? The rest, the theories, the hypothetical factors, the mathematical models, is interesting, often entertaining, sometimes even quite possibly correct - more often of course it's not. Cosmology and Theoretical Physics generally have now reached such a mathematically dominated stage that this obvious logical and indisuptable historical truth has very largely been forgotten.
|
|
|
Post by mrsonde on Dec 11, 2015 6:03:04 GMT 1
And by the way, if that were really true those objects attaining those speeds would have infinite mass, time would have stopped, space would have become infinite, and the whole universe would be one enormous black hole.
|
|
|
Post by mrsonde on Dec 11, 2015 8:46:08 GMT 1
This is not a fact, incidentally - or if you're using the term in a physical rather than a logical sense, it's only one if it's true, and we don't know that. As it stands, it's a hypothesis, attempting to explain the red-shifts observed in galactic light spectra. There is no independent corroborative evidence for this hypothesis. And as I've said, there are alternative explanations for those observations. Consider this startling fact: those red-shifts are quantised. That is, the lines in the spectra are moved towards the red, and the extent to which this is so seems - again, somewhat hypothetically - to correlate with distance, but the shift is not continuous, but occurs in discrete steps. This is one of those awkward anomalous observations that, as usually happens in science until a new theory replaces the existing consensus, has been completely ignored. It means of course that space-time, and hence speed, is quantised. That being so - and theoretically it's unexceptionable - then we have to ask: what reason is there to suppose that the size of the spatio-temporal quanta have remained unchanged throughout the history of the universe? Or, for that matter, across its expanse? Maybe the further you look, in space and time, the smaller that quantum becomes; and this would be apparent, proportionately with distance, in the spectral lines received from those objects superimposed on the spectra as produced here, now. In other words, you'd have a red-shift, correlated with distance, even though those observed objects are not moving relative to us at all: not a Doppler shift, merely a stretching through time of the metric. Another consequence would be the speed of light itself would be different, changed proportionately with distance in time or space: doubtless another way of saying the same thing. Nay reported a few years ago measurements that strongly suggested just such a phenomenon.
|
|