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trinitree88
2010-Oct-09, 04:26 PM
The LHC is optimized to answer six questions:
1 How do the elementary particles of the Standard Model acquire their masses?
2. What mechanism stabilizes the Higgs boson mass up to the next energy level at the Planck scale...~ 1016 orders above?
3.What weakly-interacting particle accounts for ~ one fourth the invisible universe...i.e. dark matter?
4. Why is there presently observed a matter/antimatter asymmetry in the universe.?..(a minor consideration since it explains why we exist at all)
5. Why are quarks unobtainable and confined to hadrons? ( the "free" quark problem...nobody has seen one...just one..)
6. What are the sources and compositions of the highest energy particles ever seen?...ultrahigh energy cosmic rays
The author , David d'Enterria , provides an overview. pete


http://arxiv.org/PS_cache/arxiv/pdf/1010/1010.1491v1.pdf

kevin1981
2010-Oct-09, 05:16 PM
When will we start seeing some fruitful answers to these questions? I have read that it will take around two years to go through the data before we start to see any, it is an exciting time but also frustrating that we have to wait that long.

Also, what do people here think we WILL find out, and how much of a possibility is there that we WONT find out some of the things, that we THINK we will?

Ken G
2010-Oct-09, 08:00 PM
Fundamentally new experimental regimes always seem to reveal something we didn't expect, or nothing at all, and the latter would certainly be a disaster.

HenrikOlsen
2010-Oct-10, 02:56 AM
If we find something new, that will tell us interesting things about the world, if we don't find anything new that will tell us interesting things about the world, that's the wonderful thing about science.
But the latter case won't make good newspaper headlines and requires actual knowledge from the science writers, so will likely be a PR headache.

trinitree88
2010-Oct-10, 06:32 PM
When will we start seeing some fruitful answers to these questions? I have read that it will take around two years to go through the data before we start to see any, it is an exciting time but also frustrating that we have to wait that long.

Also, what do people here think we WILL find out, and how much of a possibility is there that we WONT find out some of the things, that we THINK we will?

kevin1981 I'll take a shot, and try to confine it to physics so it's not ATM.

1. The origin of mass of the Standard Model's particles is also the origin of inertia, since by Einstein's decree they are inseperable. Should we learn that succinctly, we should be able to make starships that jump to absurdly high velocities without delivering killing impulses to their occupants, since we will control their inertias,simultaneously,too. Pay attention to any reports of such effects.
2. The Higg's will never be found , concluding a dead end.
3. Dark matter will be found as neutral hydrogen molecular clouds surrounding many galaxies with new satellites.
4. The asymmetry of matter over antimatter will yield not to experimental design this decade.
5 Free quarks will only show up mathematically in core collapse shock bounces, never in a detector.

trinitree88
2010-Oct-10, 06:48 PM
[QUOTE=trinitree88;1801842]kevin1981 I'll take a shot, and try to confine it to physics so it's not ATM.

1. The origin of mass of the Standard Model's particles is also the origin of inertia, since by Einstein's decree they are inseperable. Should we learn that succinctly, we should be able to make starships that jump to absurdly high velocities without delivering killing impulses to their occupants, since we will control their inertias,simultaneously,too. Pay attention to any reports of such effects.
2. The Higg's will never be found , concluding a physics dead end.
3. Dark matter will be found as neutral hydrogen molecular clouds surrounding many galaxies with new satellites equipped to look for it.
4. The asymmetry of matter over antimatter will not yield to experimental design this decade.
5 Free quarks will only show up mathematically in core collapse shock bounces, never in a detector.
6. The highest energy cosmic rays will be protons....garden variety protons...from supernovae shock fronts

jj_0001
2010-Oct-11, 08:46 PM
Fundamentally new experimental regimes always seem to reveal something we didn't expect, or nothing at all, and the latter would certainly be a disaster.

The experiments that you learn most from are the ones that don't work quite how you expected.

Nereid
2010-Oct-11, 09:25 PM
kevin1981 I'll take a shot, and try to confine it to physics so it's not ATM.

1. The origin of mass of the Standard Model's particles is also the origin of inertia, since by Einstein's decree they are inseperable. Should we learn that succinctly, we should be able to make starships that jump to absurdly high velocities without delivering killing impulses to their occupants, since we will control their inertias,simultaneously,too. Pay attention to any reports of such effects.
2. The Higg's will never be found , concluding a dead end.
3. Dark matter will be found as neutral hydrogen molecular clouds surrounding many galaxies with new satellites.
4. The asymmetry of matter over antimatter will yield not to experimental design this decade.
5 Free quarks will only show up mathematically in core collapse shock bounces, never in a detector.
3. Dark matter will be found as neutral hydrogen molecular clouds surrounding many galaxies with new satellites.

Whatever the LHC produces, in the way of new scientific discoveries, I doubt that there will be any way it could lead to this (speculative) conclusion! :razz:

trinitree88
2010-Oct-13, 04:25 PM
3. Dark matter will be found as neutral hydrogen molecular clouds surrounding many galaxies with new satellites.

Whatever the LHC produces, in the way of new scientific discoveries, I doubt that there will be any way it could lead to this (speculative) conclusion! :razz:

Nereid. My rationale is this: cosmic ray showers have had energies far in excess of the LHC to cough up a dark matter candidate since the turn of the previous century...~1900...in photographic emulsions stacked, and then various particle physics detectors, spark chambers, liquid hydrogen tanks, wire chambers, etc....and none has ever been seen. While it's true that the LHC is producing far more events at unique controllable energies with it's improved luminosity over the Tevatron, so far it's nix again. What has shown in recent decades is more of the same since the Z0, and the W+, and W- were found in the Eighties. More of the Standard Model.
Failure to find any of the dark matter candidates that have a reasonable rationale, can force the reconsideration of the mass/light arguments....that the luminosity of a galaxy traces it's mass faithfully.It's those arguments that led to the seemingly unexplainable non-Keplerian rotation curves. If the light does not trace the mass as suggested then the rotation curves can be Keplerian without invoking non-baryonic matter outside of the Standard Model. Much simpler Mr. Occam.
While atomic hydrogen traces with H-alpha, molecular is trickier to see. Carbon monoxide
entrained can help, but long term exposure to gamma ray bursts can photodissociate heavier nuclei in the periphery of a galaxy converting it to mostly hydrogen.
Some of the galaxy zoo images, and papers such as NGC3314's showed that the gas/dust lanes around superimposed galaxies extended much further out than was previously considered and the jump to a rather mundane explanation of a normal baryonic gaseous halo rather than a bizarre world of supersymmetric partners, axions, WIMPS, monopoles, tachyons or Bigfeet, never seen in a lab experiment seems pretty obvious. The speculators have been those proponents.
As usual, I will bet you a hot fudge sundae that the "missing" mass of Zwicky, Rubin et al turns up as normal baryonic matter within three years....and you can check with Antoniseb...I pay my bets. pete

Grey
2010-Oct-13, 04:54 PM
As usual, I will bet you a hot fudge sundae that the "missing" mass of Zwicky, Rubin et al turns up as normal baryonic matter within three years....and you can check with Antoniseb...I pay my bets. peteI'll take that bet. I pretty confident that at least a significant proportion of dark matter is nonbaryonic, and I'm even more confident that even if that's not the case, our views about it won't significantly change in three years. Mmm, hot fudge sundae. I might have to go buy the ingredients on my own time in the meantime, though, now that I'm thinking about it; I don't think I can wait that long. :)

Nereid
2010-Oct-13, 06:15 PM
Nereid. My rationale is this: cosmic ray showers have had energies far in excess of the LHC to cough up a dark matter candidate since the turn of the previous century...~1900...in photographic emulsions stacked, and then various particle physics detectors, spark chambers, liquid hydrogen tanks, wire chambers, etc....and none has ever been seen. While it's true that the LHC is producing far more events at unique controllable energies with it's improved luminosity over the Tevatron, so far it's nix again. What has shown in recent decades is more of the same since the Z0, and the W+, and W- were found in the Eighties. More of the Standard Model.
Failure to find any of the dark matter candidates that have a reasonable rationale, can force the reconsideration of the mass/light arguments....that the luminosity of a galaxy traces it's mass faithfully.It's those arguments that led to the seemingly unexplainable non-Keplerian rotation curves. If the light does not trace the mass as suggested then the rotation curves can be Keplerian without invoking non-baryonic matter outside of the Standard Model. Much simpler Mr. Occam.
While atomic hydrogen traces with H-alpha, molecular is trickier to see. Carbon monoxide
entrained can help, but long term exposure to gamma ray bursts can photodissociate heavier nuclei in the periphery of a galaxy converting it to mostly hydrogen.
Some of the galaxy zoo images, and papers such as NGC3314's showed that the gas/dust lanes around superimposed galaxies extended much further out than was previously considered and the jump to a rather mundane explanation of a normal baryonic gaseous halo rather than a bizarre world of supersymmetric partners, axions, WIMPS, monopoles, tachyons or Bigfeet, never seen in a lab experiment seems pretty obvious. The speculators have been those proponents.
As usual, I will bet you a hot fudge sundae that the "missing" mass of Zwicky, Rubin et al turns up as normal baryonic matter within three years....and you can check with Antoniseb...I pay my bets. pete

What if DM particles are like heavy, cold neutrinos? None would ever have turned up in any cosmic ray shower data, nor will they - if they are sufficiently massive - in the LHC. Even the solar neutrinos we already know flood us were incredibly difficult to detect, and no cosmic neutrinos have yet been detected, despite the fact that we know they're there, in vast numbers.

Your comments on galaxies - pace your reference to Zwicky - seems to suggest that you think most CDM is likely to reside in the halos of galaxies, as molecular H.

However, the first hint of CDM came from Zwicky, who studied the Coma cluster. Decades of research into clusters has shown that, first, most of the baryonic mass in rich clusters is not in the galaxies, and, second, that the estimated baryonic mass is only ~20% of the estimated total mass (a number arrived at by at least two independent lines of research).

Now molecular H cannot exist in any appreciable quantities in rich clusters[sup]1[sup] - do you know why?

Further, there are natural probes of halo molecular H: AGN jets, particularly as seen in DRAGNs. If there is molecular H in the halos of galaxies hosting DRAGNs, then it'd be lit up and made visible in no uncertain terms ... yet no such footprint exists (AFAIK); why not?

So I'll certainly take your bet, especially wrt Zwicky and WMAP! :razz:

[sup]1[sup] except possibly around the distant edges

trinitree88
2010-Oct-14, 04:33 PM
What if DM particles are like heavy, cold neutrinos? None would ever have turned up in any cosmic ray shower data, nor will they - if they are sufficiently massive - in the LHC. Even the solar neutrinos we already know flood us were incredibly difficult to detect, and no cosmic neutrinos have yet been detected, despite the fact that we know they're there, in vast numbers.

Your comments on galaxies - pace your reference to Zwicky - seems to suggest that you think most CDM is likely to reside in the halos of galaxies, as molecular H.

However, the first hint of CDM came from Zwicky, who studied the Coma cluster. Decades of research into clusters has shown that, first, most of the baryonic mass in rich clusters is not in the galaxies, and, second, that the estimated baryonic mass is only ~20% of the estimated total mass (a number arrived at by at least two independent lines of research).

Now molecular H cannot exist in any appreciable quantities in rich clusters[sup]1[sup] - do you know why?

Further, there are natural probes of halo molecular H: AGN jets, particularly as seen in DRAGNs. If there is molecular H in the halos of galaxies hosting DRAGNs, then it'd be lit up and made visible in no uncertain terms ... yet no such footprint exists (AFAIK); why not?

So I'll certainly take your bet, especially wrt Zwicky and WMAP! :razz:

[sup]1[sup] except possibly around the distant edges

Nereid, Grey. Bet's on. Please clue me in on the lack of molecular h in rich clusters, remember, I'm a chemist not an astronomer and still miss key points here and there. Thanks ,...pete

trinitree88
2010-Oct-14, 04:49 PM
Nereid, Grey. Bet's on. Please clue me in on the lack of molecular h in rich clusters, remember, I'm a chemist not an astronomer and still miss key points here and there. Thanks ,...pete

This is the paper I remember: see:http://home.pacbell.net/skeptica/H2.html

Nereid
2010-Oct-15, 02:17 AM
This is the paper I remember: see:http://home.pacbell.net/skeptica/H2.html
That's not a paper, merely a mention of one.

The paper is here (http://adsabs.harvard.edu/abs/1999ApJ...522L..29V); it's been cited some 46 times, according to ADS. Perhaps the most interesting is the most recent, Stacey et al. (2010) (http://adsabs.harvard.edu/abs/2010ApJ...721...59S); here's the abstract (I added some bold):


We have studied the molecular hydrogen energetics of the edge-on spiral galaxy NGC 891, using a 34 position map in the lowest three pure rotational H2 lines observed with the Spitzer Infrared Spectrograph. The S(0), S(1), and S(2) lines are bright with an extinction-corrected total luminosity of ~2.8 × 107 L sun, or 0.09% of the total-infrared luminosity of NGC 891. The H2 line ratios are nearly constant along the plane of the galaxy—we do not observe the previously reported strong drop-off in the S(1)/S(0) line intensity ratio in the outer regions of the galaxy, so we find no evidence for the very massive cold CO-free molecular clouds invoked to explain the past observations. The H2 level excitation temperatures increase monotonically indicating that there is more than one component to the emitting gas. More than 99% of the mass is in the lowest excitation (T ex ~ 125 K) "warm" component. In the inner galaxy, the warm H2 emitting gas is ~16% of the CO(1-0)-traced cool molecular gas, while in the outer regions the fraction is twice as high. This large mass of warm gas is heated by a combination of the far-UV photons from stars in photodissociation regions (PDRs) and the dissipation of turbulent kinetic energy. Including the observed far-infrared [O I] and [C II] fine-structure line emission and far-infrared continuum emission in a self-consistent manner to constrain the PDR models, we find essentially all of the S(0) and most (70%) of the S(1) line arise from low excitation PDRs, while most (80%) of the S(2) and the remainder of the S(1) line emission arise from low-velocity microturbulent dissipation.

Nereid
2010-Oct-15, 02:25 AM
Nereid, Grey. Bet's on. Please clue me in on the lack of molecular h in rich clusters, remember, I'm a chemist not an astronomer and still miss key points here and there. Thanks ,...pete
Please clue me in on the lack of molecular h in rich clusters

Sure thing.

Rich clusters of galaxies, such as Coma, are strong x-ray sources. The x-ray emission is diffuse, and, except in merging/colliding/interacting clusters, is centred on the cluster centre1. It is well-modelled by a hot, fully ionised gas (plasma). The estimated mass of this hot gas is many times that of the constituent galaxies.

Could massive clouds of molecular hydrogen exist in such a medium? Massive enough to account for the difference between the estimated mass of the cluster (from at least two independent sets of observations) and the estimated mass of the hot gas (a factor of ~5)?

I'd like to see someone try to make such a case! :razz:

1 Galaxies with AGNs are point x-ray sources within this diffuse glow, with one jet sometimes visible in x-rays too