[neilep (OP)]

If Dark Matter constitutes the majority of mass in the Universe...then...could it be that we ....and all that we know of the Universe are in fact the weird stuff in a dark matter Universe ?

Perhaps it is us who are the anomalies !

whajafink ?.....sense or nonsense ?

[DoctorBeaver]

If the matter from which we are made is in the minority, then we are, indeed, the anomaly. I think we should start a support group! Get EEC funding!!

[another_someone]

It sounds more a question of semantics to me, but I would regard an anomoly as nh a matter of democracy as a question of what fits the model we have and what does not fit the model we have.

Since the model we have created is a model of what the bright matter does, then it follows that the dark matter must be the anomaly within that model.  Maybe some dark matter intelligence has formed a dark matter model of the universe, and for them it is the bright matter that is an anomaly to their model, and maybe they and we should get together and compare models; but to our model, it is the dark matter that remains the anomaly.

[lightarrow]

It sounds more a question of semantics to me, but I would regard an anomoly as nh a matter of democracy as a question of what fits the model we have and what does not fit the model we have.

Since the model we have created is a model of what the bright matter does, then it follows that the dark matter must be the anomaly within that model.  Maybe some dark matter intelligence has formed a dark matter model of the universe, and for them it is the bright matter that is an anomaly to their model, and maybe they and we should get together and compare models; but to our model, it is the dark matter that remains the anomaly.

Yes. But the problem is: if we (minority) consider them (majority) as the anomaly and they consider us the anomaly, who would win in a global referendum?   []

[neilep (OP)]

THANK YOU ALL for your replies....when i posted it at 5:10 this morning....my head was filled with something...it certainly wasn't  'matter ' !

I was just speculating that perhaps there's a whole community of dark matter worlds and beings out there who are trying to figure what all this light matter is !

[DoctorBeaver]

I can't imagine such things as inhabited dark matter worlds exist.

Conjectured dark particles such as WIMPS & neutrinos could not form atoms. Dark gas clouds are a non-starter & other forms of dark matter - brown dwarf stars, itinerant planets etc - would not be able to support life.

[neilep (OP)]

I can't imagine such things as inhabited dark matter worlds exist.

Conjectured dark particles such as WIMPS & neutrinos could not form atoms. Dark gas clouds are a non-starter & other forms of dark matter - brown dwarf stars, itinerant planets etc - would not be able to support life.

It's that ' think outside the box ' time again !!..we don't really know what dark Matter is..(or do we ?)...but our definition ,if we do know, is the definition obtained from our perspective !

There may be life...just not (Spock Mode)...life as we know it !

[DoctorBeaver]

Well, anything's possible.

[another_someone]

Yes. But the problem is: if we (minority) consider them (majority) as the anomaly and they consider us the anomaly, who would win in a global referendum?   []

Who is to say they are the majority?

If you have 2 blue whales, and 20 human beings, who represents the majority? The Blue Whales may be heavier, but there are fewer of them.

Does the fact that I weight 19st mean that I should have twice as many votes as someone who only weighs 9st?

[Soul Surfer]

The answer to the original question is no.  The reason is simple.  Dark matter only interacts through gravity to form weak agglomerations that do not appear to hold together very densely and therefore has virtually no possibility of creating complex structures.  Ordinary matter interacts using the strong and weak nuclear forces to produce a range of different nucleii and the electromagnetic force to produce atoms.  These atoms in turn are attracted to form much denser agglomerations by gravity and enter into nuclear reactions to produce stars and where it is cool enough chemical reactions to produce planets and life if conditions allow.

[Soul Surfer]

After posting my original reply I think I need to explain a bit more about the way dark matter particles interact by gravity. Unlike the particles that we know well they almost never collide with each other so if they attract each other by gravity (and even this is very rare) they approch each the whip round in a quick parabolic orbit and go their way unchanged.  they never stick together.  this means that the dark matter universe is a very boring place with lots of large galaxy and larger sized clumps in it and not much else.

[another_someone]

Do we actually know that dark matter does not create structures, or is it merely that we have not observed structures on the scales we have been looking at (could they perhaps have structures on the super-large (far larger than a galaxy), or ultra-small scale)?

[Soul Surfer]

We observe dark matter structures on the super large scale ie clusters of galaxies and the cosmic microwave background.  It is in fact the behaviour of dark matter that affects quite strongly the structures of galaxies and clusters of galaxies.  Structures on the scale of stars and planets do not appear to exist in any great numbers because a great deal of effort is being put into observing the gravitational microlensing of stars to find solitary quiet black holes and planetary sized bodies in our galaxy.  So far, only a few of these events have been seen.  This is consistent with the number of normal matter bodies that are expected.  If dark matter formed bodies like this to any great extent (which is not predicted by modelling of the expected dark matter interactions)there would be a great many more.

As to the very small sacale this would be somewhere between the plank length and the size of an atomic nucleus.  I have never seen this discussed by others but I do expect there will be quantum mechanically gravitationally bound states of dark matter but I expect that there will be very few of them, most probably the number will be equal to the number of lepton generations ie three  electron muon tau and their respective neutrinos.  This also reflects in the number of  quark generation up/down  strange/charm  top/bottom.  So there is no opportunity for complexity here.

This is what you would expect from gravitational theory  Two isolated gravitating bodies can form very long term stable gravitational states but only with the help of a third  (or an energy loss process like a collision or radiation of energy).  It is very difficult but possible to form stable configurations of three bodies  and more than three bodies are almost always unstable.  Please note that this is true for all large bodies including planetary systems which can only be considered to be metastable.

It is electromagnetism and its offshoots in the form of the strong and weak forces that create the interesting complexity in our universe.

[another_someone]

It is electromagnetism and its offshoots in the form of the strong and weak forces that create the interesting complexity in our universe.

This is true for the visible universe.  I was not really thinking of small scale interactions between dark matter and bright matter, but rather small scale interactions between dark matter than has no influence of bright matter (small scale gravitational effects are not normally observable, and at present, as far as I am aware, the only interaction between dark matter and bright matter that is observable is mediated by gravity).

[Soul Surfer]

I was talking abouut the observable small scale gravitiational interactions of dark matter

If for example there were another set of "dark electromagnetic" interactions that our electromagnetic interections could not detect and there was a complete complex "dark electromagnetic universe" with galaxies stars planets and life in parallel with ours we would be able to detect them by their gravitiational interactions notably there would be a significant excess of microlensing events associated with the locations of the dark electromagnetic stars and planets.  OK the jury is still out on microlensing but we should have much more siginificant statistical results in a few years.

I the "dark electromagnetic" galaxies would largely be colocated with our galaxies but that would be largely undetectable  because individual stars in a galaxy very rarely interact and one would have to observe a real star interacting gravitiationally with a dark star to know that such a star existed.

An interesting thought but on the whole I think that it is improbable

mathematically one might visualise the process as the universe having both extended real and extended imaginary dimensions

[another_someone]

I was talking abouut the observable small scale gravitiational interactions of dark matter

If for example there were another set of "dark electromagnetic" interactions that our electromagnetic interections could not detect and there was a complete complex "dark electromagnetic universe" with galaxies stars planets and life in parallel with ours we would be able to detect them by their gravitiational interactions notably there would be a significant excess of microlensing events associated with the locations of the dark electromagnetic stars and planets.  OK the jury is still out on microlensing but we should have much more siginificant statistical results in a few years.

But is it inevitable that if a "dark electromagnetic" or "dark strong" force existed (not necessarily both, or some other force that does not map onto either bright force), does it follow that the granularity of the ensuing dark universe would be similar to that of the bright universe?  Could it be that the dark universe could not easily create stellar sized objects, but could still retain a microstructure?

[lyner]

The original post, from neilep said

Perhaps it is us who are the anomalies !

It made me think of the old newspaper headline
"Fog in channel, continent isolated."
It depends where you're looking from as to which is more important. Perhaps everyone's out of step but us.

[Soul Surfer]

When I said  "dark electromagnetic" and "dark strong" I implied any force that could create fine structure in the dark matter so you could have almost any sort of structured universe that you like but remember you must not have structure that would significantly effect the behaviour of our universe with its gravitiational anomalies. Gravitiational anomalies need to be kept within the limits of the uncertanty principle