What exactly is all this Dark matter anyway?
Discussion
Another thread about the latest thinking on Dark Matter, there'll be another about Dark Energy... you have been warned.
I am on call for a few days so may have to drop this, so it may appear in parts over that time.
The first thing to say is that DM is likely the most misunderstood thing about this Cosmos, it shares this elusive property with Dark Energy, they are not the same thing and describe totally different phenomena, but as always they may in the finality of things be related closely in ways we as yet not observed.
We need to get clear a few things about what we do know, first there appears to be quite a lot of it and it possesses some intriguing properties, the first is that although it is 'matter' it appears to be stable without the interaction of the full integer spin particles Quantum Field, these particles give matter its 'solidity', this means that unlike all the matter we encounter, it is not solid and it would pass straight through us and our planet without anything of note happening, unless it was a dense field of it and then that would be very different.
This is why its discovery didn't really change the Big Bang theory, it changes a bit, but nothing of consequence.
The natural question to ask is, 'If it is so elusive how do we really know it is there?' the answer is startlingly simple, it interacts through gravity and that is how we know of its presence.
It is as if the full integer field non-interaction was being compensated for with some sort of Gravitational Field, this is very challenging... because we don't have an account for there being a Gravitational Field, just the attribute of Gravitation.
This causes huge difficulties for the maths.
Quantum maths predicts something that is not too dissimilar to Dark Energy, but not really Dark Matter.
Other odd things we do know with a reasonable degree of certainty is that DM doesn't decay, it appears immune to the action of the weak force and everything else in the Cosmos that depletes all normal matter.
I think it is about the right time to tell you something that might be hard to take, but despite all you have ever read, the fundamental particles are not actually made of anything, they are not something at all, so all those models of a Nucleus and then a huge gap and a tiny electron circling it are even more strange, because you are regularly told that most of an atom is empty space, the reality is that it is all empty space.
I know, I know... it's hard to take, but I have been building up to this in previous posts and if you've tagged along so far you'll just about be able to accommodate this fact.
The well read and the well cosmologically versed will retort that there are tests that prove that wrong, the original experiment that 'proved' that atoms were mostly empty space is well known to those that take an interest, but it isn't the first time, nor will it be the last that what we think we see is not what really is.
You see there are perhaps 13 fields in the Cosmos, 11 pretty well defined and a couple that we have a less than perfect grip of, and it is those fields that create a 'state' a cosmological condition that produces things like Fermions and all the rest...
Now for the hard bit to grasp, despite each field having the name of the particle and is the progenitor of that particle, it is quite rare for that actual particle to appear in that field, so although the Cosmos is filled with a quark field, every quark produced needs to interact to become detectable, notice I didn't use the words 'become something', because it really isn't fundamentally something at all.
It is this constant interaction that gives all we see around us its identity as something.
Dark matter doesn't do this, well at least not fully.
I'll let you digest this before proceeding, I think there might be a few questions raised by this...
I am on call for a few days so may have to drop this, so it may appear in parts over that time.
The first thing to say is that DM is likely the most misunderstood thing about this Cosmos, it shares this elusive property with Dark Energy, they are not the same thing and describe totally different phenomena, but as always they may in the finality of things be related closely in ways we as yet not observed.
We need to get clear a few things about what we do know, first there appears to be quite a lot of it and it possesses some intriguing properties, the first is that although it is 'matter' it appears to be stable without the interaction of the full integer spin particles Quantum Field, these particles give matter its 'solidity', this means that unlike all the matter we encounter, it is not solid and it would pass straight through us and our planet without anything of note happening, unless it was a dense field of it and then that would be very different.
This is why its discovery didn't really change the Big Bang theory, it changes a bit, but nothing of consequence.
The natural question to ask is, 'If it is so elusive how do we really know it is there?' the answer is startlingly simple, it interacts through gravity and that is how we know of its presence.
It is as if the full integer field non-interaction was being compensated for with some sort of Gravitational Field, this is very challenging... because we don't have an account for there being a Gravitational Field, just the attribute of Gravitation.
This causes huge difficulties for the maths.
Quantum maths predicts something that is not too dissimilar to Dark Energy, but not really Dark Matter.
Other odd things we do know with a reasonable degree of certainty is that DM doesn't decay, it appears immune to the action of the weak force and everything else in the Cosmos that depletes all normal matter.
I think it is about the right time to tell you something that might be hard to take, but despite all you have ever read, the fundamental particles are not actually made of anything, they are not something at all, so all those models of a Nucleus and then a huge gap and a tiny electron circling it are even more strange, because you are regularly told that most of an atom is empty space, the reality is that it is all empty space.
I know, I know... it's hard to take, but I have been building up to this in previous posts and if you've tagged along so far you'll just about be able to accommodate this fact.
The well read and the well cosmologically versed will retort that there are tests that prove that wrong, the original experiment that 'proved' that atoms were mostly empty space is well known to those that take an interest, but it isn't the first time, nor will it be the last that what we think we see is not what really is.
You see there are perhaps 13 fields in the Cosmos, 11 pretty well defined and a couple that we have a less than perfect grip of, and it is those fields that create a 'state' a cosmological condition that produces things like Fermions and all the rest...
Now for the hard bit to grasp, despite each field having the name of the particle and is the progenitor of that particle, it is quite rare for that actual particle to appear in that field, so although the Cosmos is filled with a quark field, every quark produced needs to interact to become detectable, notice I didn't use the words 'become something', because it really isn't fundamentally something at all.
It is this constant interaction that gives all we see around us its identity as something.
Dark matter doesn't do this, well at least not fully.
I'll let you digest this before proceeding, I think there might be a few questions raised by this...
Edited by Gene Vincent on Saturday 21st July 17:14
Bedazzled said:
Another interesting post. Good stuff, although I'm a bit skeptical about such a literal interpretation of QFT, in terms of physical reality.
I think I can see what's being suggested though, if matter is just field perturbations, and DM doesn't interact with the electromagnetic field then it won't have any 'substance' because it won't repel other matter, and it will be invisible because it doesn't interact with photons; but it's still 'there' and interacting with gravity.
BUT... you could also interpret DM as a fudge to make existing theories fit with observation, nobody really knows what gravity is, apart from Einstein's theory about curved spacetime.
Looking forward to reading about dark energy...
You are right to be sceptical, but we are coming closer and closer to fully understanding that there really is no such thing as 'substance' at a quantum level and that only at the macro level we have things of substance and this has lead to some, me included, to consider that here-in lies the key to failure to compound both the Micro and Macro Cosmos.I think I can see what's being suggested though, if matter is just field perturbations, and DM doesn't interact with the electromagnetic field then it won't have any 'substance' because it won't repel other matter, and it will be invisible because it doesn't interact with photons; but it's still 'there' and interacting with gravity.
BUT... you could also interpret DM as a fudge to make existing theories fit with observation, nobody really knows what gravity is, apart from Einstein's theory about curved spacetime.
Looking forward to reading about dark energy...
It may be the path to a unified or unifying concept.
I can't detail anything of consequence here as I might be compromised, but by following this path there is, perhaps, a way to bring gravity in from the cold and truly understand it and define its core, but essentially gravity may just be the result of the cotermineity of the fields themselves, this works with Einsteins macro-view and does not interfere with the effect in the micro-view.
We are possibly looking at gravity making up the difference in the Dark Matter that is missing through a failure of interaction... it has deep ramifications if so.
Purposefully sketchy I'm afraid...
don4l said:
Gene Vincent said:
This is why its discovery didn't really change the Big Bang theory, it changes a bit, but nothing of consequence.
I was unaware that dark matter had been discovered.I thought that its existence was postulated - due to the fact that galaxies appear to be rotating faster than Einstein predicts.
Don
--
Not just rotating, but moving apart also.
The point you make is valid, but perhaps history shines a clear light on this, mathematicians have worked ceaselessly on the ramifications of the Higgs Mechanism for nearly 50 years, but only a few weeks ago it was 'discovered' and acclaimed as such.
I live in this day, if I were to wait for the Physicists to get to where I am, I'd be dead before they got to where I am on this day.
We may wait another 10/20 years before a 5 sigma on DM and perhaps 20/30 years for DE.
They won't even get there unless the mathematicians point the way to how to 'discover' it, to their satisfaction, in the first instance.
AJI said:
Gene Vincent said:
I think it is about the right time to tell you something that might be hard to take, but despite all you have ever read, the fundamental particles are not actually made of anything, they are not something at all, so all those models of a Nucleus and then a huge gap and a tiny electron circling it are even more strange, because you are regularly told that most of an atom is empty space, the reality is that it is all empty space.
I'm guessing you would have been expecting a question arising from the above quoted text... Edited by Gene Vincent on Saturday 21st July 17:14
When the likes of CERN collide particles and they are able to trace the resulting sub-particle paths, what are they actually tracing?
I know when I was there a number of weeks ago, the tour guide mentioned that they basically track the various energies (or forces produced within the detector fields), but I was taking this to be a method of tracking the particle itself. Is this not the case?
They don't track the particle at all, they track decay paths.
AJI said:
So where would be the boundary at which 'science' would start to say there is 'something' there?
I know you referred to the micro and macro levels, but is there a precise region at which 'nothing' becomes 'something'?
I do like this site, it forces me to clarify my thinking by tracking my path to here... and that is a really good question, in fact so good that I will at some point expand upon what I'll write now in a separate thread.I know you referred to the micro and macro levels, but is there a precise region at which 'nothing' becomes 'something'?
We have to attempt to see things in perspective, there are many ways to do this and the net is full of wonderful animations about scale, but the one I use often to bring some insight is this:-
We all know how big 1 millimetre is don't we... and we can just about equate how big the known Cosmos is in relation to that 1 millimetre... well... within that 1 millimetre the phenomenon we are looking for is so small that it would be like putting 8 complete Cosmos' along that 1 millimetre and finding the in those 8 Cosmos' another microdecimally equivalent 1 millimetre... and the Real single Cosmos we live in is filled with phenomena that small. What is more, it is filled (perhaps) 13 times over!
In this scale of things it appears that the manner and number of field interactions dictate when 'something' has material existence, so it is difficult to say when 'matter' appears along the scale, this is made even more difficult when and because we look at it in detail.
Our very action of looking changes things, now this has been given some sort of 'WOOOO' or mystical slant by many.
That is totally wrong.
The real reason is that we can only observe by adding to the interactions of the fields. so by looking we compound the interactions and matter appears, it isn't magic, it is because by looking we interfere or add to the process, this only happens when we look at a tiny portion of the Cosmos, out here, as I tap my keyboard and it has solidity and presence the interactions were set long ago and are so long established that I could put my keyboard into a melting pot and make a mouse from it, without it disappearing out of existence and no longer being matter!
It's not a good answer but it is accurate as far as it goes, and I will address this fully in another thread at some point.
Edited by Gene Vincent on Tuesday 24th July 15:36
mattnunn said:
This is metaphysics.
How often am I told philosophy has no place in this forum?
And yet this is a metaphysical discussion.
Gene, and his ilk, are trying to reinvent academia in there own image.
They are the Stones to Plato's Chuck Berry.
No, not at all.How often am I told philosophy has no place in this forum?
And yet this is a metaphysical discussion.
Gene, and his ilk, are trying to reinvent academia in there own image.
They are the Stones to Plato's Chuck Berry.
This is not fanciful or mystical, matter exists due to interaction of the numerous fields, but when we look we add fields through observation and matter appears to just 'happen', that is due to Human interaction, the maths tells us differently to what we observe and that is part (but by no means all) of why we have a problem with this transition from the Micro to the Macro.
You'd have to be purposefully ignorant not to appreciate this fact and instead attribute a metaphysical or mystical meaning to it.
It is, in reality, the very antithesis of such.
IainT said:
Gene Vincent said:
You'd have to be purposefully ignorant
Pretty good summation of his approach across these fora to scientific discussions.I wouldn't want mattnunn or anyone else feeling that they can't contribute to this sort of thread, I'd rather address the matter he raises and try to show where I believe he and his ilk are adding a further wrongful element or wilfully dismissing the 'core reale' for it.
He's not dumb, he has insight, it may not be the same on this, but intrinsically, he is another human being that I hope can persuaded to take a look from where I stand.
mattnunn said:
The fact you tie metaphysical to mystical is a pretty clear indication of your disjunct from your roots, if you wish to know where you're headed, best know where you've been?
You believe, have faith, that mathematics is discovered? You have chosen a side in this argument, Pythagoras did not describe the triangle, he discovered it - it has universal truth besides human measurement and interpretion - you have demostrated this is your point of view, you repeat "the maths tells us" - so why the inconsistency here?
If you're sure by observation we change reality then you're accepting an opposing point of view that inherent universal truth is not available to us, matter is perception, energy or fields are the language used. If a triangle not seen is not a if the process of measuring a triangle is what makes it so, Pythagoras didn't discover the triangle - he invented it and, helpfully, showed us how to invent them too.
If your way is true once we have discovered all we can we are still left with questions, how did the triangle get there, it could only be The One.
If my way is true then we can invent what we like, the limitations are only our imaginations, whatever we can conceive we can observe and then explain.
The trouble with modern metaphysics is that has been replaced and like all vagrant thought it lacks firmity, as a result the once noble metaphysics has become the domain of the vagrant mind, refusing to accept the foundation of physics that it once did, their fanciful ideas of the past were numerous and over time some proved to be a good lead, but that was a smuch to do with the number and frequency of the crackpot ideas that surfaced, we don't need metaphysics any more, it would for me be like choosing a broken down donkey to ride about on instead of the Ferrari F12 sitting on the driveway.You believe, have faith, that mathematics is discovered? You have chosen a side in this argument, Pythagoras did not describe the triangle, he discovered it - it has universal truth besides human measurement and interpretion - you have demostrated this is your point of view, you repeat "the maths tells us" - so why the inconsistency here?
If you're sure by observation we change reality then you're accepting an opposing point of view that inherent universal truth is not available to us, matter is perception, energy or fields are the language used. If a triangle not seen is not a if the process of measuring a triangle is what makes it so, Pythagoras didn't discover the triangle - he invented it and, helpfully, showed us how to invent them too.
If your way is true once we have discovered all we can we are still left with questions, how did the triangle get there, it could only be The One.
If my way is true then we can invent what we like, the limitations are only our imaginations, whatever we can conceive we can observe and then explain.
The donkey is amusing, you can feed the dumb thing the odd strawberry and boot it up the arse to hear it bray, but the F12... the real deal if I want to go anywhere.
Bedazzled said:
It is metaphysics, in that it takes underlying QFT, which has been around for 80 years, and embellishes it with one person's contemporary interpretation of "what is there, and what is it like?". But it's interesting all the same, and if it makes people stop and think and challenge some of the daft 'sci-fi' ideas that get bandied about, then GV is probably achieving what he set out to do.
Personally I find QFT helps me get my head around wave/particle duality and elementary particle interactions, but I'm not ready to make the mental leap that physical reality may itself exist only as a set of fields, because of the obvious questions it raises about the nature of the fields themselves, and because QFT doesn't account for the nature of gravity.
On the "observation changes reality" point, as I understand it quantum theory only describes the end result, it says nothing about the state of particles when they are not being observed or how they got there, or whether it's even the same particle from one observation to the next. The cat in the box, the EPR puzzle, Feynman's sum of histories, Wheeler's delayed choice experiment are all good examples. I don't see it as mystical, but it is mysterious!
All imho, as a layman!
Not metaphysics at all, I describe what is known and what is very likely only (unless I put in a proviso to the contrary) all that I say has both foundation and superstructure, bits fall off the superstructure regularly as it is replaced with stronger members, but the shape of it remains.Personally I find QFT helps me get my head around wave/particle duality and elementary particle interactions, but I'm not ready to make the mental leap that physical reality may itself exist only as a set of fields, because of the obvious questions it raises about the nature of the fields themselves, and because QFT doesn't account for the nature of gravity.
On the "observation changes reality" point, as I understand it quantum theory only describes the end result, it says nothing about the state of particles when they are not being observed or how they got there, or whether it's even the same particle from one observation to the next. The cat in the box, the EPR puzzle, Feynman's sum of histories, Wheeler's delayed choice experiment are all good examples. I don't see it as mystical, but it is mysterious!
All imho, as a layman!
You are right in that I am trying to kill the 'sci-fi', 'wooo' and 'ethereal' nature of what is none of those excuses for intellectual failure.
Field Theory is how this Cosmos works, it makes quantum theory work, it can incorporate Gravity, in fact it is the only way known that can, Einsteins answer works, but it was always incomplete, hugely so.
BTW, we know the nature of Gravity, that is what Einstein gave us, but we haven't until recently had a clue as to how it comes into being in nature, what part of Cosmological action/interaction generates its presence, that is not the case any longer.
For a long time now we have seen gravity as an attribute of other phenomena, soon, this will be spectacularly over-turned, it's not an attribute at all, it is not the result of anything, it is to a large extent the complete opposite. Einstein was wrong when he considered Gravity an attribute of the warping of spacetime, very wrong.
Quantum Theory can't do what you say because QT is resultant of a prior state, that prior state is the presence of Fields.
Bedazzled said:
Gene Vincent said:
For a long time now we have seen gravity as an attribute of other phenomena, soon, this will be spectacularly over-turned, it's not an attribute at all, it is not the result of anything, it is to a large extent the complete opposite. Einstein was wrong when he considered Gravity an attribute of the warping of spacetime, very wrong.
That bit sounds interesting, looking forward to reading about it in New Scientist etc when it filters down to the layman/luddite. 
Try this...
Part of Einsteins GT covered gravity and a fundamental part is that there must be Gravity waves... now as you know waves don't grab you and pull you, they just cause you to bob up and down, waves don't work... unless something holds you onto a leading edge and then you no longer bob up and down, you surf!
So there are two alternatives...
Does gravity somehow attach matter to a wave it itself generated or is there something else that can make you surf toward the shore?
I am working on the latter.
Domxe, interesting post and welcome back from the silence! Please continue to contribute, steel sharpens steel, and a good mind is never not worth the hearing.
My position is quite simple, in the past metaphysics was the realm (mostly) of persons well versed in the maths foundation or the physics foundation and they postulated on what was and what could be,
This honourable way to think is consigned to history, the questions have been asked, the answers sought, the subsequent questions that a long past Metaphysician would ask really can't be asked by one, the intricacy and complexity means that you have to be in the mix, you have to be a Mathematician.
I ask myself lots of questions and many would be seen as a metaphysical detour...
Metaphysicians could not have (and did not) come up with the Quantum Physics World, Dirac Anti-Matter, Yang-Mills NA Gauge Theory, QED, QCD... all could never be postulated by them, you had to be in there to even believe your own calcs!
I am trying to connect gravity to mass that fits with what we have observed, what Einstein got right and that conforms to the underlying QFT parameters and how far we can stretch them, additionally I have to gain a foothold on the underlying mechanism that allows what is simply a series of probability formulae to form a gradient so that gravity has a visible effect at the macro scale as to the micro... I'd have to have the patience of a Saint to not wish serious harm to someone who asked me... "yeah, but what's it like?"
But discourse, so long as it isn't too fanciful can help and even more helpful is to re-trace your steps and try to lay a path for others to ground you, that cannot be overvalued.
Some on here have made me stop short and think hard about the road map.
My position is quite simple, in the past metaphysics was the realm (mostly) of persons well versed in the maths foundation or the physics foundation and they postulated on what was and what could be,
This honourable way to think is consigned to history, the questions have been asked, the answers sought, the subsequent questions that a long past Metaphysician would ask really can't be asked by one, the intricacy and complexity means that you have to be in the mix, you have to be a Mathematician.
I ask myself lots of questions and many would be seen as a metaphysical detour...
Metaphysicians could not have (and did not) come up with the Quantum Physics World, Dirac Anti-Matter, Yang-Mills NA Gauge Theory, QED, QCD... all could never be postulated by them, you had to be in there to even believe your own calcs!
I am trying to connect gravity to mass that fits with what we have observed, what Einstein got right and that conforms to the underlying QFT parameters and how far we can stretch them, additionally I have to gain a foothold on the underlying mechanism that allows what is simply a series of probability formulae to form a gradient so that gravity has a visible effect at the macro scale as to the micro... I'd have to have the patience of a Saint to not wish serious harm to someone who asked me... "yeah, but what's it like?"
But discourse, so long as it isn't too fanciful can help and even more helpful is to re-trace your steps and try to lay a path for others to ground you, that cannot be overvalued.
Some on here have made me stop short and think hard about the road map.
The Black Flash said:
Are they curved and distorted like magnetic fields...
No, they are at Planck length magnitude and perhaps the best way to see them 'in your minds eye' is like a uniform gas cloud.The Black Flash said:
...and indeed like space-time is supposedly curved by gravity?
Space and time and all the interactions we call spacetime are an attribute of the uniform fields. Although garivity may be an attribute of a probability slope of all the fields interaction.The Black Flash said:
Although I guess that magnetic field lines are really just different strengths at different points in the field.
Yes and the inherent effect of a radiating energy from a single focal point.The Black Flash said:
Are the other fields similar?
All the Fields in this discussion are coterminous.The Black Flash said:
Gene Vincent said:
The Black Flash said:
Are they curved and distorted like magnetic fields...
No, they are at Planck length magnitude and perhaps the best way to see them 'in your minds eye' is like a uniform gas cloud.The fields are all uniform in placement, so from the centre of the sun to where you sit reading this, the fields are uniform in existence, any fluctuations are only that of probability, this probability is at root the fluctuation you are perhaps thinking of.
All the Fields themselves 'see' no differentiation in and of themselves, but in the first 380,000 years of the Cosmos, the conditions of heat and pressure caused interactions and formed what we call 'things' to appear.
Think of it as an infinitely long and wide piece of tarmac, the lumps on the surface are vehicles milling about (bits of mass, photons etc) and they have the potential to go anywhere on the tarmac but have to obey rules of movement (laws of physics) but the tarmac itself (the fields) just allows this to happen.
The Fields are of equal potential probability everywhere in the Cosmos.
Gassing Station | Science! | Top of Page | What's New | My Stuff