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philippeb8
2015-Jul-21, 12:32 AM
So we hear a lot about research at CERN, Snolab, etc. for dark matter and dark energy entering phase 2 lasting for another 10 years because phase 1 failed to detect it.

How many phases are there going to be before they give up? Those experiments are starting to be expensive.

Thanks in advance and that's all I wanted to know.

ShinAce
2015-Jul-21, 12:53 AM
What do you consider expensive?

Compare that to the total cost of AIDS cure research, etc... and it might not seem so expensive. Was the cost of discovering the Americas expensive? Sure it was, but difficult discoveries are typically expensive.

They'll give up when:
a) theorists explain away dark energy. Entropic gravity, the causal entropic principle, and many others do not posit dark energy as directly 'detectable'.
b) they find it
c) they run out of money

Dark matter, on the other hand, has a good chance of being a particle. When you know there's a particle out there, you try everything you can to find it. I can't imagine we'll ever give up looking for dark matter. After all, what good scientist can resist the urge to discover something that's 10 times more massive than all the known matter?

philippeb8
2015-Jul-21, 01:02 AM
What do you consider expensive?

Compare that to the total cost of AIDS cure research, etc... and it might not seem so expensive. Was the cost of discovering the Americas expensive? Sure it was, but difficult discoveries are typically expensive.

They'll give up when:
a) theorists explain away dark energy. Entropic gravity, the causal entropic principle, and many others do not posit dark energy as directly 'detectable'.
b) they find it
c) they run out of money

Dark matter, on the other hand, has a good chance of being a particle. When you know there's a particle out there, you try everything you can to find it. I can't imagine we'll ever give up looking for dark matter. After all, what good scientist can resist the urge to discover something that's 10 times more massive than all the known matter?

It depends which theory you're using but I am not here to talk about that.

So you're saying there will be ongoing searches for dark matter forever and ever?

Thanks a lot that answers my question.

Noclevername
2015-Jul-21, 02:26 AM
It depends which theory you're using but I am not here to talk about that.

So you're saying there will be ongoing searches for dark matter forever and ever?

Thanks a lot that answers my question.

Or when we figure out what the dark matter is made of. Once we find them, the research will shift to finding out about dark energy and dark matter. That's how science works.

Also, while they're looking at/for those things, CERN et al are also doing a lot of other things at the same time, and gathering lots of valuable information about the physics of particles in the process.

Cougar
2015-Jul-21, 03:05 AM
How many phases are there going to be before they give up?

Give up? Scientists don't "give up." Over 2,000 years ago, the ancient Greeks figured light was a beam that traveled outward from the eye. Of course, there wasn't exactly what we would call modern science back then. Nevertheless, despite Lucretius's more accurate description, it took a full millenium for the idea of the eye-beam to really change. Around 1020 CE, Alhazen got it essentially right - six centuries before Kepler and Descartes, who both still thought light traveled with infinite speed. Then there was the light particle vs. wave debate that started in Newton's time, with Newton on the particle side, and Hooke, Huygens, and later Euler on the wave side. There are no set deadlines for uncovering the mysteries of the universe!

The effect of what we call dark matter is observed. Are we off on the wrong track in thinking it's a weakly interacting particle with some small mass? Apparently not, since there have been observations in the last decade that are supportive of this standard view of dark matter. They haven't come from CERN, but rather from weak lensing studies of colliding galaxy clusters. Yes, additional independent supportive observations would be nice. It's tough, though, when you don't know exactly what you're looking for. History would suggest patience.

philippeb8
2015-Jul-21, 03:22 AM
The effect of what we call dark matter is observed.

I think you meant: [...] dark matter is predicted by General Relativity.

Once again thank you all.

Noclevername
2015-Jul-21, 03:28 AM
I think you meant: [...] dark matter is predicted by General Relativity.


No, dark matter's gravitational interaction with the matter in galaxies is a well established observation. We may not know what it's made of, but what it does is clearly detectable.

philippeb8
2015-Jul-21, 03:36 AM
No, dark matter's gravitational interaction with the matter in galaxies is a well established observation. We may not know what it's made of, but what it does is clearly detectable.

Dark matter is implied, predicted or observed if you use General Relativity as a mathematical model.

Noclevername
2015-Jul-21, 03:37 AM
Dark matter is implied, predicted or observed if you use General Relativity as a mathematical model.

Do you mean Dark Energy? The unknown stuff that accelerates expansion?

Noclevername
2015-Jul-21, 03:39 AM
Dark matter is observed if you look at the rotations of galaxies. It takes no mathematical models to observe stars moving in curves. Interpreting the observations does, but the effects themselves are common to all observers.

philippeb8
2015-Jul-21, 03:42 AM
Do you mean Dark Energy? The unknown stuff that accelerates expansion?

I'm talking about both; they are implied, predicted or observed if you use General Relativity as a mathematical model.

(I wish I could talk about this live)

Noclevername
2015-Jul-21, 03:52 AM
I'm talking about both; they are implied, predicted or observed if you use General Relativity as a mathematical model.

(I wish I could talk about this live)

Implied, predicted, and observed are three totally different things.

How does GR predict dark matter?

philippeb8
2015-Jul-21, 03:52 AM
Dark matter is observed if you look at the rotations of galaxies. It takes no mathematical models to observe stars moving in curves. Interpreting the observations does, but the effects themselves are common to all observers.

Well I'm sorry but I can't talk about other theories here.

Jens
2015-Jul-21, 03:52 AM
I'm talking about both; they are implied, predicted or observed if you use General Relativity as a mathematical model.


No, I think that dark matter would be necessary even under Newtonian gravity. The fact that stars appear to orbit at the same velocity even as they get further from the center of a galaxy would be a problem in Newtonian as well as relativity-based calculations.

Jens
2015-Jul-21, 03:54 AM
How many phases are there going to be before they give up? Those experiments are starting to be expensive.


I think they are already expensive. :)

And I don't think anybody will give us until some way is found to explain the rotation curves of galaxies.

philippeb8
2015-Jul-21, 04:03 AM
Implied, predicted, and observed are three totally different things.

How does GR predict dark matter?

It is implied (induction).

Noclevername
2015-Jul-21, 04:06 AM
It is implied (induction).

Can you describe how? I have never heard of GR being used in that way, can you tell me what GR says about dark matter?

Shaula
2015-Jul-21, 04:06 AM
Worth noting that pretty much all of the expensive or large experiments which could shed light on dark matter also provide us with excellent data on a range of other things. They are not one trick ponies. So the LHC, well that should be obvious. Snolab does great neutrino physics. Most of the underground facilities are doing great weak sector work generally. Many of the indirect detection instruments are doing gamma ray astronomy.

philippeb8
2015-Jul-21, 04:08 AM
It is implied (induction).

Even is there is a halo of dark matter over a galaxy, how can it affect the speed of outer stars without affecting the speed of inner ones?

If the speed of outer stars is speeded up by the halo of dark matter then inner stars should go even faster as well.

Jens
2015-Jul-21, 04:12 AM
Even is there is a halo of dark matter over a galaxy, how can it affect the speed of outer stars without affecting the speed of inner ones? If the speed of outer stars is speeded up by the halo of dark matter then inner stars should go even faster as well.

The people who made those theories took that into account of course. The computer models show how it can be clumped in a way that that doesn't happen. Otherwise it wouldn't be a very good theory, would it.

Shaula
2015-Jul-21, 04:14 AM
Even is there is a halo of dark matter over a galaxy, how can it affect the speed of outer stars without affecting the speed of inner ones?

If the speed of outer stars is speeded up by the halo of dark matter then inner stars should go even faster as well.
The rotation curves of all the stars are affected by the amount of matter (visible + dark) found inside their orbits. It is only noticeable in further out stars because the amount of visible matter enclosed by them drops off fairly fast whereas their orbital speeds plateau, which would imply that the actual matter density is not dropping of so fast al all. A dark matter halo with a density profile of the Navarro–Frenk–White type or Einasto type fits the data pretty well.

philippeb8
2015-Jul-21, 04:15 AM
Can you describe how? I have never heard of GR being used in that way, can you tell me what GR says about dark matter?

GR was made to explain the solar system so it doesn't say anything about greater scales. But when it is used at greater scales then we must have dark matter / dark energy somewhere.

Noclevername
2015-Jul-21, 04:19 AM
GR was made to explain the solar system so it doesn't say anything about greater scales. But when it is used at greater scales then we must have dark matter / dark energy somewhere.

Dark matter is not dark energy.

philippeb8
2015-Jul-21, 04:28 AM
The rotation curves of all the stars are affected by the amount of matter (visible + dark) found inside their orbits. It is only noticeable in further out stars because the amount of visible matter enclosed by them drops off fairly fast whereas their orbital speeds plateau, which would imply that the actual matter density is not dropping of so fast al all. A dark matter halo with a density profile of the Navarro–Frenk–White type or Einasto type fits the data pretty well.

Why dark matter aren't forming dark stars then?
\Why is normal matter not colliding with dark matter?
What is attracting dark matter exactly?

Noclevername
2015-Jul-21, 04:39 AM
Why dark matter aren't forming dark stars then?
\Why is normal matter not colliding with dark matter?
What is attracting dark matter exactly?

DM weakly interacts with gravity; that's how we know it exists. But the interaction is so weak that the DM is scattered over wide regions compared to the denser, more gravitationally interactive baryonic matter (IE, us). As for why it does not "collide" with our kind of matter, that depends on what kind of particle it is, which we don't know yet.

Shaula
2015-Jul-21, 04:40 AM
Why dark matter aren't forming dark stars then?
\Why is normal matter not colliding with dark matter?
What is attracting dark matter exactly?
This has been dealt with many times on the board. The short form answers are:
Why dark matter aren't forming dark stars then?
Dark matter is required to interact at most gravitationally and via the weak force. This seriously limits its ability to clump - it cannot lose energy via EM interactions like normal matter can and so it forms far larger and looser structures. As for stars - fusion is primarily to do with the strong force. You may as well ask why we don't see neutrinos forming stars.

Why is normal matter not colliding with dark matter?
Colliding is an imprecise term. Collisions are interactions, and are usually down to one of the fundamental forces. DM is possibly able to interact with matter via the weak force, just like neutrinos, which would make these interactions very hard to spot. The search for them is ongoing, however (Snolab etc)

What is attracting dark matter exactly?
Gravity. That is all that is needed. You can model DM very well as a fluid only interacting via gravity. For normal matter you also have to include EM interactions to model it well.

philippeb8
2015-Jul-21, 04:57 AM
This has been dealt with many times on the board. The short form answers are:
Why dark matter aren't forming dark stars then?
Dark matter is required to interact at most gravitationally and via the weak force. This seriously limits its ability to clump - it cannot lose energy via EM interactions like normal matter can and so it forms far larger and looser structures. As for stars - fusion is primarily to do with the strong force. You may as well ask why we don't see neutrinos forming stars.

Why is normal matter not colliding with dark matter?
Colliding is an imprecise term. Collisions are interactions, and are usually down to one of the fundamental forces. DM is possibly able to interact with matter via the weak force, just like neutrinos, which would make these interactions very hard to spot. The search for them is ongoing, however (Snolab etc)

What is attracting dark matter exactly?
Gravity. That is all that is needed. You can model DM very well as a fluid only interacting via gravity. For normal matter you also have to include EM interactions to model it well.

So dark matter is like "dust" with no speed and not necessarily glued to the galactic bulge but distributed away from the center of the galaxy.

Not all galaxies can explain it unfortunately:
http://www.dailygalaxy.com/my_weblog/2013/10/dwarf-galaxies-condradict-dark-matter-predictions.html

Shaula
2015-Jul-21, 05:12 AM
So dark matter is like "dust" with no speed and not necessarily glued to the galactic bulge but distributed away from the center of the galaxy.
No, dark matter is modelled to be like a roughly spherical distribution of particles of an unknown type and size. It is concentrated in the centre of the galaxy to a degree and the density of it tapers off with distance. See the plots at https://en.wikipedia.org/wiki/Einasto_profile


Not all galaxies can explain it unfortunately: http://www.dailygalaxy.com/my_weblog/2013/10/dwarf-galaxies-condradict-dark-matter-predictions.html
And by studying these kinds of exceptions we learn more. Not sure what your point is, all this article says is that either the proportion of cold dark matter is different for these galaxies or that their formation phase is not as simple as we had modelled. With an outside chance that these observations were incorrectly interpreted, as the article says they are hard measurements to make.

Cougar
2015-Jul-21, 12:52 PM
Not all galaxies can explain it unfortunately:
http://www.dailygalaxy.com/my_weblog/2013/10/dwarf-galaxies-condradict-dark-matter-predictions.html

I disagree with a number of things in that article. Perhaps the author misunderstood what the researchers were telling him. For example....



Most astronomers assume that dark matter consists of "cold" (i.e. slow-moving) exotic particles that clump together gravitationally.

No! They don't clump. They can't. Except for gravitationally, they do not interact with normal matter, nor do they interact with themselves (except gravitationally, and possibly a very rare DM-DM annihilation). They orbit gravitationally, but there's nothing in the center to stop them - they zing right through and out the other side. (The central black hole is relatively so small, they rarely hit it.)


Cosmologists use powerful computers to simulate this process. Their simulations show that dark matter should be densely packed in the centers of galaxies.

As Shaula said, there is more dark matter in the center, but it's not hugely more dense there, otherwise the speed of stellar orbits would be slower with increasing radius. Which they're not. The article is apparently talking about the longstanding cuspy halo problem. (https://en.wikipedia.org/wiki/Cuspy_halo_problem) Simulations predict a much higher density toward the center, which is not seen. The simulations seem to be missing something....


Instead, new measurements of two dwarf galaxies show that they contain a smooth distribution of dark matter. This suggests that the standard cosmological model may be wrong.

Standard pop-sci sensationalism. Dwarf galaxies are possibly the result of tidal forces from long ago galaxy interactions. One would think such an interaction would have an effect on the DM distribution, spreading it out, "smoothing" it. Due to its nature, it would not settle back into a tight structure, even over large spans of time. We observe galaxies and dwarfs in a singular snapshot in time, but we know little of their 13 billion year-long long history of formation, which continues today.

mkline55
2015-Jul-21, 01:35 PM
I interpret the question to be a general frustration with a science that spends a great deal of time, effort and money compared to what an individual has available personally on what appears to a layman to be no more than a fool's errand. In other words, if all that money was spent on ME, I'd like it better. Besides, what does dark matter have to do with my personal comfort? At least that is where I think the question comes from. That is not my own opinion of the science.

There is also the layman view that if current theories are correct, and DM is actually 5 times more prevalent than normal matter, why is it so hard to find? If there are five times as many black cars as all other cars, I should be able to see more black cars than any other color. If you told me I cannot see the black cars because they are invisible, and you are going to spend 1000 times my lifetime income looking for the ubiquitous black car, I'd scoff at that, too. But if you showed me traffic patterns that proved there were five times more cars on the road than I could see, then I'd agree that either 1) my eyes are deceiving me, 2) the traffic patterns are wrong, or 3) there is some kind of black car,. When it comes to DM, I believe 1) and 2) have been investigated extensively, and maybe still are being investigated, but 3) requires more effort.

Jeff Root
2015-Jul-21, 04:06 PM
DM weakly interacts with gravity; that's how we know
it exists. But the interaction is so weak that the DM is
scattered over wide regions compared to the denser,
more gravitationally interactive baryonic matter (IE, us).
You made it sound as if gravitation of dark matter is
weaker than gravitation of ordinary matter. They are
expected to be identical in that respect. Gravity is
weak compared to electromagnetic forces, but not
weaker for DM than for baryonic matter.




Most astronomers assume that dark matter consists of
"cold" (i.e. slow-moving) exotic particles that clump
together gravitationally.
No! They don't clump. They can't. Except for gravitationally,
they do not interact with normal matter, nor do they interact
with themselves (except gravitationally, and possibly a very
rare DM-DM annihilation). They orbit gravitationally, but
there's nothing in the center to stop them - they zing right
through and out the other side.
I agree with your description of what does and doesn't
happen, but not with the assertion that your description
describes a lack of clumping. I think the sentence from
the article is correct. Dark matter clumps gravitationally.
Since it doesn't interact in any other way, the clumping is
very "loose". It is much like a low-density globular cluster,
where stars are moving in random directions, with only a
slight increase in density toward the center, but the stars
are all gravitationally bound to the cluster and never go
very far away.

-- Jeff, in Minneapolis

philippeb8
2015-Jul-22, 12:04 AM
I interpret the question to be a general frustration with a science that spends a great deal of time, effort and money compared to what an individual has available personally on what appears to a layman to be no more than a fool's errand. In other words, if all that money was spent on ME, I'd like it better. Besides, what does dark matter have to do with my personal comfort? At least that is where I think the question comes from. That is not my own opinion of the science.

As I understand the resources for research for dark matter are infinite.

I think there should be 0.01% of these resources spent on different theories. For an individual, renting a supercomputer is $1,000 per year which is possible but performing an minor experiment is quite expensive and starts at $90k (in my case).

So I don't know but Stephen Hawking said himself we need to find a way to civilize extrasolar systems or else it is highly possible we self destruct.

Thus hopefully we can work on other theories in parallel given GR doesn't work well at great scales.

Reality Check
2015-Jul-22, 12:04 AM
I'm talking about both; they are implied, predicted or observed if you use General Relativity as a mathematical model.

The words implied and observed are obviously wrong, philippeb8. Theories predict.
General Relativity predicts that a positive cosmological constant corresponds to a negative pressure that increases the rate of expansion of an expanding universe.
General Relativity predicts nothing about dark matter.
If you use General Relativity as part of a cosmological model (https://en.wikipedia.org/wiki/Lambda-CDM_model#Parameters) and fit that to CMB data then you find that the matter density is 0.30890.0062, dark energy density is 0.69110.0062, etc. The total mass–energy of the known universe contains 4.9% ordinary matter, 26.8% dark matter and 68.3% dark energy.

Observations about dark matter are about matter missing from Newtonian calculations. GR gets involved when calculating masses from gravitational lensing.

Reality Check
2015-Jul-22, 12:16 AM
As I understand the resources for research for dark matter are infinite.

That understanding is wrong, philippeb8. We do no have an infinite amount of money, people, etc. on Earth :D!
What will happen in practice for experiments to directly detect dark matter is that

an experiment will directly detect dark matter or
the experiments will become too expensive to run and stop or
the experiments will cover all of the possible dark matter candidates that they could detect and stop.
In that case the strong evidence that dark matter exists leaves the dark matter candidates that cannot be directly detected in current experiments here on Earth.

philippeb8
2015-Jul-22, 12:20 AM
That understanding is wrong, philippeb8. We do no have an infinite amount of money, people, etc. on Earth :D!

Well they are infinite given the time factor.

Swift
2015-Jul-22, 02:22 AM
I think there should be 0.01% of these resources spent on different theories. For an individual, renting a supercomputer is $1,000 per year which is possible but performing an minor experiment is quite expensive and starts at $90k (in my case).

philippeb8,

You do not seem to be asking a question with a straightforward, generally accepted answer. In fact, you don't really seem to be asking a question, you seem to be advocating a position about the funding of science and research on dark matter in particular. As we have said many times about Q&A:

This section of the forum is for astronomy and space exploration questions with straightforward, generally accepted answers.

Questions that are likely to lead to extended discussion about the correct answer, or that have no clearcut correct answer, should be posted in the forum most appropriate to the topic of the question.
I am moving the entire thread from Q&A to Astronomy, at the moment.

It also seems that you may be using this thread to advocate against theories about dark matter. If you use this thread to advocate a non-mainstream position, you will be infracted and this thread will be moved to ATM or closed.

WayneFrancis
2015-Jul-22, 04:01 AM
Well they are infinite given the time factor.

philippeb8 there are a few problems here that you are basing your argument on and I'm going to list, at least, some of them (note if my understanding of any of these concepts are wrong people will correct me I'm sure)

1) Your understanding of GR seems flawed.
While GR does predict the cosmological constant which would cause the universe to be non-static in size it does not predict dark matter.
What you might be thinking of is that for a given observation, that we observe the universe to be flat, the visible universe should contain a certain energy density. Based on observation we could only account for a very small amount of mass/energy required to produce what the model predicted. Scientist did not just plug in DM and DE to fill the gap. DM was and is observed and based on observations DM is determined to be comprised of about 5x the total mass of ordinary mass/energy. A number of candidates have been proposed, many of them involve just hard to see objects like black holes but they've all failed in that they do not match what is observed. We've narrowed DM down to Weakly Interacting Massive Particles (WIMPs) and by their nature, of being Weakly Interacting, they are hard to observe. Effectively they are invisible because even photons will hardly ever directly interact with them. There are predictions, given the current mainstream models, that guide us on how we could look for signs of these WIMPs but since they are so elusive detection is hard. An analogy is if you ever saw the movie Karate Kid there is a plot through the movie where they try to catch a fly with chop sticks. The master has been doing this his entire life and has never caught one. For our analogy the fly is like DM. We can "see" its affects but we have yet to be able to "touch" it.
After DM was discovered scientists still had this large amount of missing energy from the universe to produce what we observed. Again the scientists did NOT just label this as Dark Energy. What happened is observations, by 2 separate teams were looking to see how the expansion of the universe was slowing down with time. Instead what they observed was that the universe was the rate the universe is expanding is increasing. When calculated the observations of that energy matched the amount of energy to produce the flat universe we observe.

No were did GR directly predict them. GR predicted a given energy density to produce the visible universe we observe. There was a problem about "missing" energy for a long time but until observations where made that detected that missing energy it was left as "We don't know". Now we've got ideas of how to investigate these newly discovered mass/energies.


Even is there is a halo of dark matter over a galaxy, how can it affect the speed of outer stars without affecting the speed of inner ones?

If the speed of outer stars is speeded up by the halo of dark matter then inner stars should go even faster as well.
No because the mass from DM further out does not affect stars inside. This is a Newtonian concept called the shell theorem. This is one of the reasons it is called a halo because it isn't just a concentration of DM at the centre of galaxies but a larger cloud that envelopes entire galaxies.


GR was made to explain the solar system so it doesn't say anything about greater scales. But when it is used at greater scales then we must have dark matter / dark energy somewhere.
No GR was developed to explain how mass/energy distorts space time. That space and time are one entity. It did make predictions within our solar system like the precession of Mercury but it wasn't developed to just explain it and the orbits of celestial bodies within our solar system. The Einstein field equations are much more broad then just describing local phenomena.

2) You seem to be setting up a false dichotomy that research into dark matter stops other research.

This is not true. If we follow your reasoning through then shouldn't the whole world only focus on 1 problem at a time and fix it as fast as possible or dump in and move on to the next. The reality is different people have different interests. Different methods of investigating things. You can only throw so many people at a problem before it quickly becomes very inefficient. There are a host of reasons why research is done in areas many people think are useless. Young Earth Creationists think it is useless to investigate the early universe, the evolution of species, plate tectonics, global warming and a host of other things. So what. Should scientists worry about what they think? Why should scientist worry that your misunderstanding of the science in question leads you to think that their investigation is a waste of time?

The LHC is a great example of lots of science being able to be done. While investigating other areas they may make discoveries they where not expecting or may add confirmation to the validity of existing models.

3) You are executing a "begging the question" fallacy by making a conclusion, based off a very flawed understanding of a topic, that research into the topic is useless.

Scientist don't generally just look for stuff at random. They look for stuff that they can reasonably expect if a given model works and it fits within the model. Even better if the model suggests something should be there. Not always but often. Some times chance discoveries in 1 area ends up as an observation for some other model.


Well they are infinite given the time factor.

The research into dark matter and dark is relatively young compared to other things in science. The Higgs boson was predicted over 50 years ago. Should they have given up on that idea? The standard model was adopted over 40 years ago and we are still making discoveries on it. Evidence of proton decay has been looked for for over 25 years with no result but given the models predict a half life of at least 1x1033 years it isn't surprising that even the huge experiments that have been running haven't seen any evidence for it. Doesn't mean it doesn't happen. Just that it is VERY hard to detect. At some point most of the scientists working on it may decide that it doesn't happen and stop major research on it. Some may continue the research. Some team might make a huge discovery. This is the nature of science.

Shaula
2015-Jul-22, 05:02 AM
Well they are infinite given the time factor.
As I pointed out dark matter experiments are almost always multi-use instruments. You have fastened on to one thing that these facilities can do and are arguing that their entire cost therefore reflects the cost of that one thing.

Hlafordlaes
2015-Jul-22, 10:49 AM
DM and DE are placeholders in science that signify that there are observations that require solutions. Highly unlikely science would ever give up; that is exactly the kind of challenge that will put a spring in the step of theoreticians and experimentalists. Irresistible. What the definitions, theories and further observations turn out to be may go under other names, different models, or a change in other models, but concepts like DM and DE are what make science a blast, and a worthwhile endeavor.

DM has already been pointed out as having a 'suspect' particle, and seems on-track more or less 'as is'. Personally, in speculative mode, I think DE will be a real eye-opener when cracked (I'm betting on some sort of pressure from virtual particles in empty space, but my bets are made as a layman, with payoffs in popcorn.)

philippeb8
2015-Jul-22, 01:31 PM
As I pointed out dark matter experiments are almost always multi-use instruments. You have fastened on to one thing that these facilities can do and are arguing that their entire cost therefore reflects the cost of that one thing.

Ok thanks for the info.

swampyankee
2015-Jul-22, 05:39 PM
So we hear a lot about research at CERN, Snolab, etc. for dark matter and dark energy entering phase 2 lasting for another 10 years because phase 1 failed to detect it.

How many phases are there going to be before they give up? Those experiments are starting to be expensive.

Thanks in advance and that's all I wanted to know.

They'll keep looking for dark matter until they find it or until they have an acceptable hypothesis to explain the orbital dynamics of galaxies without it. For dark energy, the answer is similar: until the find it or until they have an acceptable hypothesis that explains the accelerating rate of expansion of the Universe without it.

Jerry
2015-Jul-26, 11:58 PM
Removed from thread - inappropriate transition.