And now, Dark Matter Planets!

[CraigS]

Love to start this thread with Robh's gem from a few days ago ..

Originally Posted by Robh

But just how much more complicated are things going to get? If dark energy exists, its nature is going to be even more elusive than dark matter.

and now comes Dark Matter planets !! …
Dark matter could provide heat for starless planets

In a resent paper posted at arXiv.org and submitted to Astrophysical Journal, Dan Hooper and Jason Steffen, physicists at Fermilab in Illinois, present the theory that cold and dark planets, not heated by a star, could be heated by dark matter. In theory, this dark matter could produce habitable planets outside of what is known as a habitable zone.
…
Hooper and Steffen suggest that should this dark matter be trapped within a planet’s gravity, the bursts of energy could produce enough to warm the planet. When it comes to Earth, the energy that could be produced is low, but in areas of space where there are high densities of black matter; Hooper and Steffen believe there is the possibility of finding planets that could be warmed in this way.

And so … do we really know what we're looking for .. and where ?
What is a habitable zone ?

Cheers

[CraigS]

So this is a fairly new way to think of DM:

These WIMPs interact with regular matter by a weak nuclear force and gravity, but they are also antiparticles. When two WIMPs come together, they work to annihilate each other and cause a burst of energy.

The paper they've written says:

In many models, dark matter particles can elastically scatter with nuclei in planets, causing those particles to become gravitationally bound.

While the energy expected to be released through the subsequent annihilations of dark matter particles in the interior of the Earth is negligibly small (a few megawatts in the most optimistic models), larger planets that reside in regions with higher densities of slow moving dark matter could plausibly capture and annihilate dark matter at a rate high enough to maintain liquid water on their surfaces, even in the absence of additional energy from starlight or other sources.

On these rare planets, it may be dark matter rather than light from a host star that makes it possible for life to emerge, evolve, and survive.

Creative thinking going on here, methinks …

Cheers

[CraigS]

So, so far we know the following can alter the surface temperatures of a planet:

- Proximity to host star;
- Chemical cycles;
- Greenhouse Effect;
- Decay of radioactive elements;
- Geothermal (or volcanic) energy;
- Dense atmosphere;
- Tidal (gravitational) flexing;

and now;
- annihilation of Dark Matter particles.

If the list length increases over time and into the future, 'Habitability' will include much more of the superset of known exo-planet 'candidates'.

'Habitability' of course, may represent completely different conditions from those causing the emergence of life. We still don't know what conditions actually cause life to emerge.

Diverging the possibilities, (as this paper seems to do), serves to defocus and dilute scientific investigation.

So I'm left wondering why they've brought all this up?

Cheers

[mswhin63 (Malcolm)]

Don't forget, it also states that they assume something and know we will never find it in the near future. Seems like a complete waste of funding.

we really should be trying to find things first for making assumptions are other things.

[CraigS]

Originally Posted by mswhin63

Don't forget, it also states that they assume something and know we will never find it in the near future. Seems like a complete waste of funding.

we really should be trying to find things first for making assumptions are other things.

In theoretical studies, one isn't limited by what isn't possible in the present.

Theoretical research also uses very little funding.

Conjoining the search to understand the nature of DM with the hunt for habitable exo-planets and exploring the overlap, is also an attractive proposition.

From memory, these two areas are very close to the number one, and number two, top priorities for research funding in the US Government's priority listings (announced last year).

This paper lands smack bang in the middle of those top priorities.
Fermi labs has also had project closures (due to the LHC work underway).

Interesting.

Cheers

[Robh (Rob)]

Hi Craig,

Interesting hypothesis and in theory it appears feasible.
How about life evolving on a planet without a Sun? They would have great dark vision and permanent night skies. An astronomer's dream.

From the article ...
"While no one knows exactly what dark matter is, it is believed to make up about 83 percent of the universe."

And final comment ...
"Hooper and Steffen admit that they currently do not see a way of detecting any of these possible dark matter planets in the near future, but that in theory, it is possible."

There are so many new hypotheses. When are we going to be able to pin something down?

Regards, Rob

[CraigS]

Originally Posted by Robh

Hi Craig,

Interesting hypothesis and in theory it appears feasible.
How about life evolving on a planet without a Sun? They would have great dark vision and permanent night skies. An astronomer's dream.

There was an episode of Star Trek: Enterprise where they found a rogue planet with permanent darkness. There were creatures living there who could change shape .. and a bunch of hunters from a nearby planet considered them prime game.
Perhaps these guys saw the same episode and wrote a paper to make it real.

Originally Posted by Robh

From the article ...
"While no one knows exactly what dark matter is, it is believed to make up about 83 percent of the universe."

And final comment ...
"Hooper and Steffen admit that they currently do not see a way of detecting any of these possible dark matter planets in the near future, but that in theory, it is possible."

There are so many new hypotheses. When are we going to be able to pin something down?

Personally, I think the IceCube project (neutrino detectors) has the best chance of making something of it all (if it exists).
There's a lot of big funding about to be injected into it all this year. We'll be seeing heaps more about it in the media this year, methinks.

Patience, grasshopper, patience !


Cheers

[xelasnave]

Thanks for the post Craig.

I like how you post things that interest me... I have said what I have said about dark matter but I can not resist to say it all again and here would seem appropriate.


I find the speculation about dark matter extraordinary.


It is not science in my view to dwell upon the prospect of something invented to shore up our view of gravity..when observations strongly suggest we are wrong.

Why does no one question the speculation that is dark matter...and it is mere speculation.....why does no scientist say..the observations we make demonstrate our formula e in respect of gravity do not serve us unless we present the existence of hypothetical "dark matter" such that it will allow our belief that attraction is the force behind gravity.... clearly the observations of the pioneer craft slowing offers an observation that does no fit the current science..(and I suggest there we have an observation that clearly tells us we are wrong)....is its behavior due to dark matter???? or again I ask does the determination to fit our belief in the force of attraction into a universe that does not recognize such a force need to be addressed....

Science must proceed in a step by step process I am told but the first step in establishing the force of attraction was never taken..there is no experiment to establish the force of attraction and so it could be that every assumption made that there is such a force has led us to applying incorrect analysis to our observations....

Does it not worry science that dark matter makes up so much of the universe but it has no footprint of electromagnetic radiation...to me that would suggest there is more probability that there is no dark matter than to offer any case for a reasonable assumption that indeed dark matter exists in the extraordinary abundance needed to explain the inconsistent observations such as Pioneer and the outer velocity of stars in host galaxies not doing what our sums tell them they must...unless of course we aid our sums with the introduction of a mythical dark matter....

The first trace I can find of it was when Vera Ruben introduced it and I found it extraordinary that the idea was entertained then but more extraordinary that it got up and now considered "good" science but the nonsense it doth now proliferate must demand a rethink.

I know we call things we know little about "dark" which is OK but if they are such why do so many carry on with the speculations such as the above article suggests... it seems little elevated to the dark magic we despise in lesser cultures...

AND while we enjoy the prospect of dark matter I do wonder how it interacts with the Higgs field
alex

[CraigS]

Oh boy … I suppose the 'spin' I gave this thread was somewhat sceptical, but I do have my limits !

Alex .. DM is hypothetical .. no one argues that point.

The reason it exists in scientific circle discussions, is because it is predicted by theories based on empirical evidence. It is not therefore, pure 'speculation'.

No one has said that the Pioneer anomaly has no physical explanations. This is still under analysis, based on empirical data.

I have never seen any scientist say that 'attraction is the force behind gravity'.

And isn't it great that scientists can still maintain the 'mystery' of DM by publishing these kinds of papers ! It shows they have maintained an 'even keel' and are well balanced individuals !

Cheers

[marki]

Craig I see these things as just another nail in the coffin of scientific credibility. I mean we freely slang off at astrologers, witch doctors etc but what are we really offering here? I get questions about dark matter, dark energy, noodle theory and so on all the time by my students and am finding it increasingly more difficult to say physicists know what they are doing and their studies are legitamate. I don't mean to hijack this thread but this stuff is really getting to me.

Mark

[CraigS]

Originally Posted by marki

Craig I see these things as just another nail in the coffin of scientific credibility. I mean we freely slang off at astrologers, witch doctors etc but what are we really offering here? I get questions about dark matter, dark energy, noodle theory and so on all the time by my students and am finding it increasingly more difficult to say physicists know what they are doing and their studies are legitamate. I don't mean to hijack this thread but this stuff is really getting to me.

Mark

Mark;
I really think the difficulty people have is in 'getting' this concept.
And it is probably due to their own lack of knowledge in the theoretical areas underpinning the hypothesis.

Dark matter and dark energy evolved from observation.

The theoretical aspects are derived from mainstream theory and were not invented.

This approach is exactly the same approach used in predicting the existence of Neptune (which can stand in as an analogy for dark matter). Scientists took an existing theory (Newtonian gravitational theory) and applied it as a perturbation to the orbit of Uranus. There was no need to alter the theory.

The same type of reasoning applies to explaining galaxy rotational curves, through the presence of dark matter.

Dark energy also has it's origins in quantum field theory. It attempts to explain the cosmological constant as a vacuum energy fluctuation.
The point is that neither dark matter or dark energy involves "new" physics or "magic". It's an increasing crossover of QFT into cosmology and celestial mechanics.

The fundamental problem with dark matter is that if it does exist, it will impact on the Standard Model in particle physics. If dark matter turns out to be ordinary matter observed at a different wavelength, then no such problem exists.

I urge those who question scientists and the science underpinning the concept of DM, to learn up more, rather than make accusations that other people don't know what they're talking about.

A lack of understanding is a very probable cause of not understanding something.

If you're a teacher, I'd expect you would appreciate this aspect.

Cheers

[CraigS]

Just a follow on from my previous post (and as a demonstration of my trying to view this fairly), I find Robh's comment, to be quite a valid point of view.

Robh for instance, is purely questioning how complex will it all get ? (Presumably, for the common man, or us amateurs).

In the light of having to understand Quantum Field Theory before 'getting' how DE arises from it, I also share this question, and point of view.

In the light of not having this detailed knowledge, I am prepared to give scientists the benefit of any doubts I may have.

Ask yourselves … are you ?
(I'm not directing this question at anyone specific .. please don't take it this way, or personally. It is not intended this way).

Cheers & Rgds

[xelasnave]

Craig I agree that dark matter is hypothetical..

That was and has been my point for many years....

But the fact is it is hypothetical and yet it is clear that most who write upon its existence do not treat it in such a manner as it is no longer hypothetical but a fact...yes a fact.. this is undeniable it is treated as more than hypothetical and to say otherwisw does not embrace what is going on ...man just read up..and tell me again folk see dark matter as merely hypothetical...they dont.

Dark matter is fact because our sums say it must be so...

Reliance upon math can be dangerous like many things humans say they use with skill it only does what it does..it is the human who corrupts..a gun is a gun and only kills when a human uses it so. I dont blame the gun or the math for an unacceptable outcome.

I see no problem with the math but when humans apply it to things they can and do get it wrong on occasion..not the fault of math but the fault is in its application..... and I recall how those dumb Greeks figured that the Earth was the center and the planets revolved in circular fashion about it...the math proof said it was irrefutably so ..but the math although correct did not show the reality ..the math proved the reality those Greeks had worked out but they had worked out the incorrect reality.. OK those Greeks were ignorant fools who have nothing of the sophistication humans have today but I suggest that a similar problem exists in so far as our math can support the unsupportable and deny a correct view of reality.....

there is no doubt in my mind that for most dark matter is a fact beyond doubt and not regarded as a mere hypothetical proposition..

It is not correct to say it is only hypothetical because dark matter is not embraced in such a manner ..since Vera Ruben put it out there it has only existed as a hypothetical I think not... who out there sees it as hypothetical...only you and me I suggest...really it is nice to say that it is all it is but for most it is now a fact..most folk do not see it as hypothetical as for them it is real..if it is not real then our science as to gravity is simply wrong is it not???.. read the articles and ask yourself..do these folk call dark matter hypothetical..clearly they do not and so there are only a few of us who see dark matter as hypothetical because science has absolutely embraced it..as science must if they are to support the current views of gravity.
If hypothetical why do they have those vats of cleaning fluid in mines ..to find hypothetical dark matter?

Dark matter is more than hypothetical and that is the danger for alternatives will never be presented..

AND so I say my concerns, that dark matter is treated as an acceptable answer to the observations that do not fit our sums, are valid...WE have a hypothetical view carrying the weight of sciences endorsement.

ANYWAYS science should not for one moment entertain such rampant speculation upon one single matter to the exclusion of any alternative if it is indeed merely hypothetical...we chat about hy[potheticals but leaqve it before experiment I would think...we cant have a hypothetical given such a degree of respect such that all other than it is eliminated.... and so I ask what alternatives do we have to dark matter...none you say or will say and such a answer proves that there is a determination to have only one result and that result is the one that supports all we have supported to date..irrespective that many observations simply cut away the ground under the theory (dark matter) stand upon...I presume although hypothetical dark matter is nevertheless treated as a theory..a very high level of reality be that to those keen to limit science to hypothesis, observation, prediction, theory and sample testing to establish trends etc.

I disagree that the observations support the concept of dark matter....the interpretations of the observations is another matter.

The pioneer is set aside on the basis that we are right on gravity so there must be something else going wrong because certainly our views as to how gravity works is not wrong....

An observation is used by folk to establish as a fact what they already believe in my view.

I heard about some aborigines who believe that winter occurs because a certain flower blooms. AND clearly when the flower blooms winter does follow...now they have an observation and a prediction of sorts which strangely all fit..and yet one feels they may have missed what is really going on..I suggest that what has been going on when attempts are made to fit the unpleasant observations with our current sums is similar...Could it be that reality is missed by those who must fit what they observe into a universe they have in effect laid plans to well before their observations...it does seem to me that there is a desire to prove what we know is right even when the observations have various opportunity of interpretation... to limit an observation to one set of outcomes seems to do no more than those aboriginals who attribute the coming of winter to the appearance of a specific bloom...why can we look at these folk as being ignorant of reality when we do much similar in our interpretation of our observations...

The big bang takes an observation of an apparent expansion of the universe with glee as it offers support for the theory..is any other outcome considered..no of course not ..is this any different to our aboriginal interpretation of the blooms that bring winter?

I do think that as we specialize we do lose the ability to consider alternatives and I find that the absence of an alternative to dark matter laughable in the extreme....

Folk say I have an approach that is not scientific and yet I would suggest that I at least do not get carried away by a single concept and single possible interpretation of how the universe may work and do not present a hypothetical as an answer only to say it is only hypothetical if questioned....

AND I ask..what more should one "learn up" as to dark matter.
Is it that we dont understand the math? Dark matter is there to explain the unexplainable in that the universe is not obeying our sums..dam universe..

what more does one have to "learn up" to find an uneasiness with a proposition that suggests of all that is out there we can not observe the bulk of it and that this "dark matter" only shows itself by gravitational influences ..is it not us who have determined in advance what these gravitational influence must be....is it all so neat and nice now we have dark matter cause the sums now work ... what more does one have to "learn up" to find the concept that gravity is a weak force because much of its power "leaks" into another dimension or universe..there must be a big universe draining off the gravity when it comes to dark matter I guess....AND although these concepts may be supportable in math I do think that observation and testing is still where science finds its strength and that speculation upon things we can not see and can never see (or observe) is the strength of witch craft and superstition.

I have no time to edit so I hope grammar etc is ok

alex

[CraigS]

Originally Posted by xelasnave

I have no time to edit so I hope grammar etc is ok

alex

I do wish you would use more full stops to distinguish single sentences (and thoughts).

Cheers

[xelasnave]

Originally Posted by CraigS

I do wish you would use more full stops to distinguish single sentences (and thoughts).

Cheers

I do also.. but.. I get into this qualifying of various points... and the sentence grows.. but.. I forget the stops... add to that verbosity and I can see notwithstanding my use of "small" words meaning could be elusive nevertheless.

Thanks for even trying to understand what I was trying to say.

alex

[CraigS]

Originally Posted by xelasnave

I do also.. but.. I get into this qualifying of various points... and the sentence grows.. but.. I forget the stops... add to that verbosity and I can see notwithstanding my use of "small" words meaning could be elusive nevertheless.

Thanks for even trying to understand what I was trying to say.

alex

Alex;

You've said all of it zillions of times over, since I've been around.

And .. its been pointed out that you are blatantly wrong in your interpretations of how science operates; about how maths is used in science, how observations are made, how theories and hypotheses are formed and how science keeps empirical evidence separated from theory.

I don't know what else can be done …

For me, its like going 'round and 'round in a washing machine !

I do enjoy our conversations, but why do you belabour the same point, over and over ? I'm not in charge of how things work, nor do I understand lots of the technical sides of some of the in-depth theories in science.

Perhaps you are looking for a consensus view which aligns with yours and .. there bang .. Alex gets to be right …

If that's what its about then .. Alex you are 100% right ! There ya go.

Has this made any difference to the world of science, amateur astronomy or the way the real world works ????

I don't want to seem nasty .. perhaps I'm just not in the mood for it today.

Cheers & Rgds

[xelasnave]

Originally Posted by CraigS

Alex;

You've said all of it zillions of times over, since I've been around.

And .. its been pointed out that you are blatantly wrong in your interpretations of how science operates; about how maths is used in science, how observations are made, how theories and hypotheses are formed and how science keeps empirical evidence separated from theory.

I don't know what else can be done …

For me, its like going 'round and 'round in a washing machine !

I do enjoy our conversations, but why do you belabour the same point, over and over ? I'm not in charge of how things work, nor do I understand lots of the technical sides of some of the in-depth theories in science.

Perhaps you are looking for a consensus view which aligns with yours and .. there bang .. Alex gets to be right …

If that's what its about then .. Alex you are 100% right ! There ya go.

Has this made any difference to the world of science, amateur astronomy or the way the real world works ????

I don't want to seem nasty .. perhaps I'm just not in the mood for it today.

Cheers & Rgds

I am sorry to cause you grief Craig and I greatly enjoy your work.

It is not about me being right. Your observation in this regard is uninformed and based on observation of a character you have never met and never had opportunity to work out with the benefit of a personal chat.

I do not enjoy the same determination to be right as those in many other camps... I am outside it all making what I see a reasonable observation upon the single mindedness of some approaches.


I dont say I am right it is others who claim they are right to the exclusion of reasonable alternatives who say they are always right you could well focus upon.

As to your belief that I do not understand how science works I say I have a fair idea... I understand for example string theory is not a scientific theory but only a hypothesis for if a theory it would have little things in support like observation, experiment and sample results etc.. I say it is others, who drop the notion of scientific method when delighting in a math extrapolation with none of the usual requirements,( that in my humble and blatantly wrong estimation of the requirement of scientific method suggests should be present), may well deserve rebuke.

Anyways you have heard it all before and I have no more to say.

At least I understand the requirement of scientific method.... and say scientific method is abandoned when we say we have dark matter to shore up our sums on the one hand and yet on the other say it is merely a hypothetical...science is not about hypothetical matter that we can not observe...is it science to suggest that gravity is weak because it leaks into another dimension... I have never taken the wild steps in even a speculative manner that dark matter folk happily suggest is beyond doubt.
AND I know its not all your fault you always present as fair minded and do not represent the complaints department of science.
Hope you feel better and I apologize for laboring the same point such that it becomes so intolerable.


alex

[snas (Stuart)]

And so … do we really know what we're looking for .. and where ?
What is a habitable zone ?

Craig, this is an excellent question. It has been suggested that we are living in a narrow zone called the habitable zone. And yet it has also been suggested that some of the moons of Jupiter and Saturn may be candidates to harbour life. We may live in a narrow habitable zone for the life forms we see on Earth, but microscopic life may (or may not) exist far out in the solar system where we could clearly not survive.

So it may be that in our own solar system or in another star's system that there are more than one habitable zones, one for us, and one or more closer in to the star, or further out than we (or similar life forms?) are.

Stuart

[CraigS]

Originally Posted by snas

Craig, this is an excellent question. It has been suggested that we are living in a narrow zone called the habitable zone. And yet it has also been suggested that some of the moons of Jupiter and Saturn may be candidates to harbour life. We may live in a narrow habitable zone for the life forms we see on Earth, but microscopic life may (or may not) exist far out in the solar system where we could clearly not survive.

So it may be that in our own solar system or in another star's system that there are more than one habitable zones, one for us, and one or more closer in to the star, or further out than we (or similar life forms?) are.

Stuart

So Stuart;

We really have no non-Earthly-based ideas about where to confine our searches for exo-life ?

And yet there is a need to discuss the probabilities for finding it.

This whole 'there must be exo-life argument' is just as silly as the 'there must be no exo-life' argument.

There is no scientific data other than that based on our own instance of life on Earth (which is all inter-related). Extremophiles, in my view demonstrate only that life which finds its way into 'extreme' environments can adapt to that environment. This does not mean that it can emerge from that environment.

Cheers

[renormalised (Carl)]

Originally Posted by marki

Craig I see these things as just another nail in the coffin of scientific credibility. I mean we freely slang off at astrologers, witch doctors etc but what are we really offering here? I get questions about dark matter, dark energy, noodle theory and so on all the time by my students and am finding it increasingly more difficult to say physicists know what they are doing and their studies are legitamate. I don't mean to hijack this thread but this stuff is really getting to me.

Mark

Dark "anything" in physics means this = "we actually don't know what we've found, we're just speculating as to what it is and we really don't have a clue as to what we're on about", in spite of what they maybe telling you to the contrary. In all honesty, they don't know what they're really finding or looking at. If they did, there wouldn't be so much speculation being bandied about and they'd have a better theoretical handle on what's there (or not there, as the case may be).