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Feb 12, 2012

CERN’s annual Chamonix-meeting to fix LHC schedules (Feb. 6–10 2012): Increasing energies. No external and multi-disciplinary risk assessment so far. Future plans targeting at Mega-LHC.

Posted by in categories: cosmology, engineering, ethics, events, existential risks, particle physics, physics, scientific freedom, sustainability, transparency

Info on the outcomes of CERN’s annual meeting in Chamonix this week (Feb. 6–10 2012):

In 2012 LHC collision energies should be increased from 3.5 to 4 TeV per beam and the luminosity is planned to be highly increased. This means much more particle collisions at higher energies.

CERN plans to shut down the LHC in 2013 for about 20 months to do a very costly upgrade (CHF 1 Billion?) to run the LHC at 7 TeV per beam afterwards.

Future plans: A High-Luminosity LHC (HL-LHC) is planned, “tentatively scheduled to start operating around 2022” — with a beam energy increased from 7 to 16.5 TeV(!).

One might really ask where this should lead to – sooner or later – without the risks being properly investigated.

For comparison: The AMS experiment for directly measuring cosmic rays in the atmosphere operates on a scale around 1.5 TeV. Very high energetic cosmic rays have only been measured indirectly (their impulse). Sort, velocity, mass and origin of these particles are unknown. In any way, the number of collisions under the extreme and unprecedented artificial conditions at the LHC is of astronomical magnitudes higher than anywhere else in the nearer cosmos.

There were many talks on machine safety at the Chamonix meeting. The safety of humans and environment obviously were not an official topic. No reaction on the recent claim for a really neutral, external and multi-disciplinary risk assessment by now.


Official reports from the LHC performance workshop by CERN Bulletin:

http://cdsweb.cern.ch/journal/CERNBulletin/2012/06/News%20Articles/?ln=de

LHC Performance Workshop — Chamonix 2012:

https://indico.cern.ch/conferenceOtherViews.py?view=standard&confId=164089


Feb 10 2012: COMMUNICATION directed to CERN for a neutral and multidisciplinary risk assessment to be done before any LHC upgrade:

http://lhc-concern.info/?page_id=139


More info at LHC-Kritik / LHC-Critique: Network for Safety at experimental sub-nuclear Reactors:

www.LHC-concern.info

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Comments — comments are now closed.

  • Niccolò Tottoli on February 12, 2012 11:12 am

    High-Luminosity LHC (HL-LHC):
    http://hilumilhc.web.cern.ch/HiLumiLHC/

    sLHC:
    http://en.wikipedia.org/wiki/Super_Large_Hadron_Collider
    sLHC upgrade projects:
    http://project-slhc.web.cern.ch/project-slhc/

    VLHC:
    http://en.wikipedia.org/wiki/Very_Large_Hadron_Collider

    (See table 2 for parameters).
    http://cdsweb.cern.ch/record/1403041

    VLHCI:
    20TeV !

    VLHCII:
    87.5TeV !!!

    All just to give jobs?

    At these energies no cosmic ray argument will work anymore, no matter how wrong it would be told and no matter whether the differences between natural collisions and collisions at the LHC would be concealed. But anyway there was probably never a cosmic ray collision with two equally fast protons or lead ions with LHC-design energy on Earth since its existence.

  • Niccolò Tottoli on February 12, 2012 11:32 am

    Dear people
    Much work for the critics for many years too, depending on when or whether we will be blown up…! What about to employ more people for an independent(!) safety assessment? So many people work for CERN but only a handful CERNies for a safety paper? According to surveys most (ca.3/4) of the people in Switzerland would sign for an open discussion between CERN and the international scientists referring to risks, for better controlled experiments and for an independent safety review.
    Best wishes to all.

  • Niccolò Tottoli on February 12, 2012 11:57 am

    Dear all

    Just an idea: Various international scientists could build an independent “collider safety assessment group” and perhaps ask Switzerland or someone for an employment?

    Sincerely yours,

    N. Tottoli

  • Niccolò Tottoli on February 12, 2012 12:58 pm

    I think the false cosmic ray argument has been varied about 12 or 14 times in the LSAG-report.
    In case of 10 x the luminosity of the LHC they would have to repeat and vary it about 120 to 140 times. Still to be suggestive.

  • Peter Conant on February 12, 2012 3:56 pm

    @ But anyway there was probably never a cosmic ray collision with two equally fast protons or lead ions with LHC-design energy on Earth since its existence.

    But what about the number of such collisions over the volume of the Solar System — which is 1012 times greater? If the odds of these collisions on earth during its history is one in a billion, it should have ahppened a thousand times in the history of the solar system — 10000 times larger radius and a trillion times greater volume.

    How many of the resulting black holes would orbit stars as they expand into red giants? How many would be sucked into protostellar cores as huge volumes of gas collapse to form stars?

    Someone needs to calculate this!

    P. Conant

  • Niccolò Tottoli on February 12, 2012 6:04 pm

    Dear Mr. Conant
    Very interesting questions!
    Yes, calculations…
    I will try to send you an adequate answer tomorrow.
    Thank you very much.
    Niccolò Tottoli

  • Niccolò Tottoli on February 14, 2012 7:43 pm

    Dear Mr. Conant

    Sorry for delay. It was not so easy for me to write you an adequate answer, because I am not a physicist and because my English is bad — but I think it should be worth to read for various reasons.

    To your questions.
    You are talking about infinitely stable micro black holes.
    Generally it is true, that there are collisions with LHC-design energy or greater, high up in the atmosphere on earth or on other celestial bodies, but:
    Higher velocities of primary cosmic ray particles, colliding with nearly stationary particles on celestial bodies do result in faster secondary particles too.
    To be reasonable many points have to be considered. The shadow of Earth, the velocity of the cosmic ray protons, the escape velocity, the cosmic ray flux (and perhaps I forgot something).

    “MAC” has once made some calculations concerning the theme and Marc Fasnacht has made the conclusion of 0,000’000’0045 natural collisions which would have resulted in a micro black hole, since the existence of Earth (4’500’000’000 years), slow enough to be entrapped on Earth by gravity (or 0,000’000’000’000’000’0001 collisions per year).
    Here:
    http://www.relativ-kritisch.net/forum/viewtopic.php?p=33281#33281
    (It seems that MAC starts with his explanations and calculations on page 10, 24.03.2009, 24.03.2009, 16:24)
    And here are two links leading to calculations of a person named “Peter” (coincidence?), who has made calculations too, but I have not taken a closer look yet. He tells for example that LHC-like frontal collisions (the hit rate in the empty space) are very rare and negligible (see 2nd link):

    http://forum.astronomie.de/phpapps/ubbthreads/ubbthreads.php…Post531795
    http://forum.astronomie.de/phpapps/ubbthreads/ubbthreads.php…Post531917

    It seems that LHC-like frontal collisions (in the range of 14TeV collision energy or more) with both collision partner having nearly the same speed relative to the astronomic object, near (1m or less) the surface of celestial bodies do never happen at all.

    You told about the volume of the solar system and consider orbits around stars. Good points. To calculate all paths and escape velocities of (infinitely stable) micro black holes in the solar system is perhaps not very easy, computer programs would be probably the best.

    I have an other link in German from a critical scientist. Others should double check all:
    http://www.achtphasen.net/index.php/plasmaether/2011/09/02/h.….uido#c5903
    It has been roughly calculated that in the entire volume(!) of the Milky Way there would be only every 10 seconds a frontal collision with energies like at the LHC.
    But if the (dangerous) products would be metastable, they would probably decay after a while, because most of the Milky Way is empty space. And it gets more complicating if we do not know the accretion rate or the half-life too.
    At the LHC it is very different, because collisions are near dense objects.
    It has been calculated that in the last 10‘000‘000‘000 years there was never a LHC-like collision in our solar system also.

    As you see, to have safe collider experiments it does not suffice to make such calculations just with respect to infinitely stable micro black holes.
    The question is: What are all possible reactions and islands of stability of all possible particles, compound particles and fields, also in terms of their velocity and growth rate and similar things, when passing through space-time and matter? An example could be metastable micro black holes. What could be possible? Scientists should calculate all.

    Again: I only call a particle collision “LHC-like” if it is a proton-proton collision or a lead-lead collision, with LHC (-design) energy or greater. Important is that just at the LHC both particles have (relative to the celestial body) almost the same velocity and that they collide almost frontal. To call a collision LHC-like, the center of the collision must have the same distance (or less) to an equal dense material (or better: equal material) as in the detectors of the LHC.

    Fast particles do not equally interact with matter like slow particles. Examples are the decreased decay rate of very fast particles or the increased reactivity of slowed neutrons in uranium.
    New kinds of (exotic) particles have been detected with each new collision energy record.

    Therefore the hypothesis of a dangerous particle or field:
    Could it lead to a chain reaction if half-life, reactivity and velocity “coincide” while crossing matter and space-time and could dangerous thresholds be exceeded?

    Lead-lead collisions with energies like at the LHC are even more rare than proton-proton collisions. Just negligible, because they probably never happen in the entire Milky Way. And also without considering all important differences between natural collisions and collisions at the LHC, the following phrase has been told by some scientists:
    “Because of the much larger mass number, Pb-Pb events can be expected to show exotic phenomena that is beyond the reach of cosmic rays.“ Please see the argument at the end of the abstract here:
    http://cdsweb.cern.ch/record/1046330

    As you see various calculations are a little bit different but all lead to a similar conclusion – that CERNs cosmic ray argument that “nature has already conducted about a hundred thousand LHC experimental programs on Earth” (and similar) is just invalid, because important points and differences have not been considered.

    Please let me know your opinion or if you have some more information with respect to the theme.

    Thank you.

    Sincerely yours,

    Niccolò Tottoli
    —————

  • Niccolò Tottoli on February 15, 2012 10:16 am

    Remind that a cosmic ray proton which collides with a (relative to earth) stationary proton needs 100‘000TeV to match the collision energy of 14TeV.

  • Peter Conant on February 15, 2012 11:10 am

    Mr. Tottoli,

    Interesting. Based on your (admittedly preliminary, but it makes sense) analysis, we can’t use a “Cosmic Ray 3″ argument based on head on collisions to dismiss LHC risks.

    And it looks like even if the case of “permanent” mini black holes is ruled out (I personally don’t think non-evaporating, uncharged black holes are likely), there might still be some risk from other phenomena…what they sometimes call “unknown unknowns” due to concentrations of energies, proximity to matter, etc.

    Probably not much likelihood, but still worth investigating in detail.

  • Niccolò Tottoli on February 17, 2012 1:51 pm

    Dear Mr. Conant

    Great if you find it interesting, thank you.
    “Unknowns due to energy concentrations…” — this is absolutely my point.
    Risk is probability multiplied by the damage factor.
    If the probability estimate given by an argument is dwarfed by the chance that the argument itself is flawed, then the estimate is suspect.
    Safety standards should be based on specific values rather than hypothetical estimations of risks.
    Risk exposures of the public or the planet from controllable sources should be maintained as low as reasonably achievable and the risks should be quantified.
    Therefore an independent safety conference is required, open to CERN and the critical scientists.

    Please, what does “Cosmic Ray 3″ mean?

    Sincerely yours, Niccolò Tottoli

  • Niccolò Tottoli on February 17, 2012 1:59 pm

    It is not clear whether cosmic rays with LHC-design energy or more are protons or not. It seems that such rare and high energetic particles have never been observed directly. Just the rare secondary “events” have been measured.

  • Niccolò Tottoli on February 17, 2012 2:07 pm

    Regarding the references in CERNs LSAG-report, they have not had a sound basis to say that cosmic rays with LHC-design energy or greater would be protons. But at the LHC we have accelerated protons or lead ions producing exotic particles…

  • Niccolò Tottoli on February 17, 2012 2:15 pm

    All in a nutshell: too many differences between collisions at the LHC and cosmic ray collisions and too many uncertainties!

  • Niccolò Tottoli on February 17, 2012 5:13 pm

    Dear Mr. Conant

    You say: “Probably not much likelihood, but still worth investigating in detail.“
    I think the main problem is, that the “LSAG safety report” and the “SPC report on LSAG documents” (both of CERN) and G./M.‘s black hole safety paper too are all based on the invalid cosmic ray argument and that some risks (micro black holes and strangelets for example) have not been fully investigated nor disproven because of the flawed cr-argument.

    Sincerely yours, Niccolò Tottoli

  • Eric on February 20, 2012 8:04 pm

    While I would very much doubt about the calculation result relating to number of cosmic ray collisions on earth at relativ-kritisch.net from energies comparable to LHC’s, the mentioned lack of direct evidence for cosmic ray particles at energies comparable to LHC is well worth taking into account: even that calculation would have to assume at least some proportion of such ordinary nuclei cosmic rays.

    For the front-on or head to head cosmic ray collisions — which I would understand to be what was meant by ‘cosmic ray 3′ — there are calculations made within the paper by Dar et al (http://arxiv.org/abs/hep-ph/9910471v1) about RHIC and LHC safety. Perhaps this was used in the other calculations at relativ-kritik but I don’t know the German.

    I’ve been looking again at the calculations and formulae used in Sections 3–4 of the Dar paper dealing specifically with head to head collision as the basis for their central safety argument.

    A result I obtain from there (end of section 3) — actually this relates to the fairly similar RHIC colllisions — is that within the volume of the milky way, (assuming a disk radius 55000 light years and depth 1000 light years), there would have been around 2500 strangelets created from relevant lead- lead collision resulting in the slow moving — thereby undestructible –strangelets becoming harboured within the protostellar interstellar medium — gas clouds.

    But the basic part of this argument itself was criticised by Wilczek et al in another RHIC (approximately pro safety) review — with this problem acknowleged even in the LSAG report — because Dar et al. assume the initial strangelets created by head to head cosmic ray collisions would be stable enough to survive the first phase of their argument. But there seems to be other problems where this fully stable initial strangelet assumption is accepted:

    The argument relies on a colosally vast 1×1051 cubic metre interstellar medium volume to eventually create a one solar mass star. This works out as 4 trillion times the volume within our galaxy and this assumption of the involvement of the interstellar medium, itself having a density below that of artificial vacuums, is supposed to be involved for the smaller phase of the universe before 4.5 billion years ago. While there is an estimated 10million x this volume in the universe as observed today there is also the vastly greater estimated accumulating mass within it of between 2.5 x10^22 and 8 x10^22 solar mass stars (these values based on wikipedia ‘Observable universe’: ‘Size’ and ‘Matter content’).

    How then could there be so have been so much interstellar medium volumes in the universe to enable the stars of today to have been created by such a mechanism?

    From the only source I could find from google that includes phrase “origin of interstellar gas clouds”, in Soviet Astronomy, Vol. 9, p.408 (1965), it is stated:
    “The problem of the origin of interstellar gas clouds
    is a very complicated one and a method of solving it has not yet even been worked out.” That doesn’t look surprising to me, but I don’t believe Dar et al. have resolved this either — and no reference by Dar et al. for their mechanism of the creation of interstellar gas clouds.

    Eric

  • Eric on February 20, 2012 8:46 pm

    Clarification about my first comment regarding number of relevant cosmic ray collisions on earth — one in 600million of these could lead to a 1 TeV black hole (if the relevant theories are correct), so I am doubtful of the mentioned calculated number of black hole producing collisions involving (presumably) proton cosmic rays.
    Eric

  • Eric on February 20, 2012 8:52 pm

    Another thing — the number of strangelets within the volume of our milky way should actually refer to ‘a volume equivalent to that of the disk of our milky way’.

  • Niccolò Tottoli on February 23, 2012 1:50 pm

    Dear Eric
    Interesting points. I will send you an answer soon.
    Thank you.

  • Eric on February 24, 2012 6:14 am

    Dear Niccolo/ all

    Worst mistake to make is to have to correct a correction back to original! Unfortunately my last comment requires that. The volume of strangelets produced by this mechanism would be for within the volume of our milky way — though from a vastly greater initial volume of contracted interstellar medium. The vastness of that initial volume per solar mass star is given in the Dar et al. paper in section 3 or 4 (1x10^-57cm^3).

    Eric

  • Niccolò Tottoli on February 25, 2012 8:11 am

    Clarification:
    4th line of my comment (Niccolò Tottoli on February 17, 2012 1:51 pm):
    Not: “If the probability estimate given by an argument is dwarfed by the chance that the argument itself is flawed, then the estimate is suspect.”

    Better: “If the probability estimate (that there would be absolutely no risk) given by an argument (the cosmic ray argument) is enlarged by the chance that the argument itself is flawed, then the estimate is suspect.“
    —–

    Dear Eric

    Now to your comment.
    Thank you for your argument: “the mentioned lack of direct evidence for cosmic ray particles at energies comparable to LHC is well worth taking into account”.
    Then you wrote: “even that calculation would have to assume at least some proportion of such ordinary nuclei cosmic rays.” The question is: how many? For example I have read that only cosmic rays with 2TeV have directly been measured. Please see the very interesting comment (regarding other points too) of LHC Kritik on February 16, 2012 1:25 pm on lifeboat in the following blog theme (11th paragraph):
    http://lifeboat.com/blog/2012/02/lhc-critique-press-release-…ent-102017

    I just found it remarkably that all people in the various links that I have shown in my answer to Mr. Conant have come to a similar conclusion — that natural head-on collisions with LHC-design energy or more, with two (with respect to neighboring celestial bodies) equally fast particles are very seldom and do usually not happen near celestial bodies, because of various reasons (for example the shadow of the body and so on).

    You say that you would doubt about the calculation result relating to number of cosmic ray collisions on Earth at “relativ-kritisch” from LHC-design energy but I have shown other links too. One point is that it seems they have not considered the different distribution of matter in the young universe. Perhaps you can tell us an other value? Formulas are often too difficult for me but I collect them, read the words and compare the results. If you have additional links or calculations then it would be great to have them. Physicists should double check them.

    The difference it makes. One thing are frontal collisions of pairs of protons or lead ions in the (nearly) empty space of our solar system or the Milky Way. But it is an other thing if both collision partner have an equal velocity with respect to the celestial body near to the collision. To avoid confusion one has to tell these parameters in all safety arguments regarding cosmic rays. Obviously they have often been not so precise in the LSAG-report. Why?

    Strangelets could be produced in the “empty” space of the Milky Way. But it depends on the speed. If a strangelet is smashed very fast into matter, the strangelet could be destroyed. How slow must a strangelet be, to survive if it strikes matter?

    Strangelets are hypothetical particles and nobody knows the collision energy at which they might be produced. The higher the required collision energy the rarer the natural strangelets. Perhaps slow natural strangelets have never (or very seldom) been produced enough near celestial bodies to pose a risk and have had time to decay to their ground state, which is predicted by most models to be positively charged, so they are electrostatically repelled by nuclei, and would rarely merge with them. But high-energy collisions could produce negatively charged strangelet states which would live long enough to interact with the nuclei of ordinary matter, because they would be produced very near the surface of Earth (respectively at the LHC).
    http://en.wikipedia.org/wiki/Strangelet#Dangers

    Ok, you have told about the gas clouds in the young Milky Way. I can not find the value of 2500 strangelets, which would have been produced by cosmic rays (heavy nuclei) so please can you tell me the time-span? But then, what about the decay to their ground state? Could strangelets or micro black holes be part of dark matter? Scientists tell that there is much more dark matter in the universe than ordinary matter.
    Why is this so? Should we not be more careful?

    The LSAG-report makes many assumptions, estimations and often tells not the complete truth (I could show you various examples), therefore it is great if people like you do research and try to find “holes” in such safety papers, to show risks. We know both that the strangelet issue is a very contradictory one. I am sure that you could show a link or tell some facts here with respect to it…

    Micro black holes are hypothetical particles too and we do not know at which collision energy they will be produced. They say it depends on the fundamental Planck scale. The higher the required collision energy for MBH-production, the rarer the MBHs.
    Calculations and variable computer models should be made, to see whether there could be a risk in certain circumstances and within certain parameters.
    Your point regarding the creation of the universe is a very good one and all parameters of such aspects should be included into these proposed computer models too, to evaluate “LHC-like” cosmic ray collisions or the natural production of all hypothetical dangerous particles over the required period of time.
    For the moment very long periods (as the evolution of the Milky Way) may only tell something about infinitely stable hypothetical particles like micro black holes.
    But one more time: It is very important to consider metastable dangerous particles too. To be absolutely safe, all possible reactions and islands of stability of all possible particles and fields have to be theoretically considered, also in terms of their velocity, growth rate, penetration depth and similar things, when they traverse space-time and different densities of matter.

    I often say a bit provocative that there was never a frontal collision, with two equally fast protons or lead ions with LHC design energy 1 meter or less above the surface of dense celestial bodies in our entire solar system and probably not too in the Milky Way since the existence of Earth. Nobody has shown me the contrary yet. Can you?

    We can be obviously glad that the planet has not yet be blown up by men but how can we be sure that nothing dangerous will happen at higher energies?

    I am sure that a continuous interdisciplinary and independent safety assessment between CERN and the scientists referring to risks would help much more to be safe than discussions in blogs between laymen like me and critical minds like you.

    Thank you for the interesting discussion and for your great research.

    Sincerely yours,

    Niccolò
    ——-

  • Niccolò Tottoli on February 25, 2012 8:40 am

    Clarification (3rd-last paragraph):
    Not: “I often say a bit provocative that there was never a frontal collision, with two equally fast protons or lead ions with LHC design energy 1 meter…”

    Better: “I often say a bit provocative that there was never a frontal collision, with two equally fast protons or lead ions with LHC design energy or more 1 meter…”

  • Niccolò Tottoli on February 27, 2012 5:17 am

    Dear readers

    A friend told me that the 4th link in my long answer to Peter Conant (Niccolò Tottoli on February 14, 2012 7:43 pm) does not work.
    Here is it:
    http://www.achtphasen.net/index.php/plasmaether/2011/09/02/h…uido#c5903
    My intention was to show that different people came to a similar result which leads to the conclusion that the cosmic ray argument (CERN´s No.1 repeated safety argument) is flawed.

    Thank you for your interest.

  • Eric Penrose on March 5, 2012 5:47 pm

    Niccolo

    High energy cosmic ray constituents — I haven’t followed up the question of what the range of view actually is in astrophysics about what the possible proportions of proton to iron cosmic rays would be, but within the LSAG report — and with the references that the report relies on — seems to given as between 10% and 90% for protons cosmic rays at these LHC comparable collision energies (with other nuclei being supposedly much less likely).

    Cosmic ray to earth collisions — ie rate of cosmic rays hitting particles in the atmosphere of the earth. I don’t see a particular reason to doubt the estimate of Mangano and Giddings in their paper http://arxiv.org/abs/0806.3381 given at end of page 28 (including formulae) : 1/A x 1022 (which is 1 x 1022 for proton or 1.8x 1020 for iron nuclei cosmic rays) during the time of the earth’s existence. (Actually that value doesn’t include the very highest energy cosmic rays whose flux is difficult to estimate).

    That’s not to say that these sorts of statistics provide a reliable safety assurance.

    LSAG and two –way collisions — they didn’t deal with this as they rely on the following couple of questionable arguments dependent on only nuclei cosmic ray to ‘stationary’ nuclei collisions — which you may be aware of. One of these tenuous assumption relates to strangelets — if there is a strangelet danger there would be enough undestructible, slow moving strangelet by products of collisions to have anyway led to higher than observed rates of supernovae. In the black hole case they effectively rely on the conclusion of Mangano and Giddings paper that the survival of 8 identified white dwarfs couldn’t have occurred if there was a risk from micro black holes. For the first argument no evidence, even of a very indirect and thereby unsatisfactory sort — from RHIC data — is actually presented to support it even though this is claimed. The second avoids any statistical analysis comparison in relation to any unobserved massive black holes that could have emerged subsequently from white dwarfs of the relevant vulnerable type if they were afflicted by micro black holes. But there are better arguments against this second assurance. One would be that high energy cosmic rays may actually emerge from only certain specific locations- as has been suggested in the relevant literature — and that furthermore their angular range of emission from these sources could be limited — something accepted in an email communication to me from an astrophysicist. Also various neglected factors in the calculations of accretion rates are involved in Mangano and Giddings paper along with their neglect of the slow decaying black hole scenario.

    The maximum speed for a strangelet — this is estimated by Dar et al.s paper on RHIC/ LHC safety (1999) to be 1/10 of light speed. This seems to me could be significantly too slow as it is based on the speed for disruption of mult-nucleon nuclei — which themselves are not singly bound while strangelets are. But it can nevertheless be used within either pro-risk or pro-safety assessments.

    Threshold energy for strangelet production — I think it is more likely the collision energy needs to be above a certain threshold than below (but possibly both). There is some indication for a minimum threshold at just above RHIC’s collision energy from cosmic ray detector results that are discussed in papers by team members of CERN’s own not so publicised strangelet search project at LHC — CASTOR.

    Strangelets as dark matter. Don’t think I’ve come across that — doubtful I think.

    Two way collisions and strangelets. Yes, it seems to make a lot more sense to talk about the starting point for stars being simply interstellar gas clouds not initially empty space (which would alledgedly be subsequently much contracted after supernovae shock waves) where the problems I mentioned in my last posts emerge.

    Two-way collisions in the vicinity of compact stars/ stars/ planets or their satellites without atmospheres would be a good comparison to make certainly better than what LSAG report relies on. Would be better even there though if we have direct knowledge of the constituents of these high energy cosmic rays for the comparison.

    Metastable particles — Yes possibility applies to both micro black holes and to collision induced strangelets and I think makes reliability of safety arguments more difficult again.

    Higher energies and risk. The two issues for the longer term I think are the prospect of a minimum energy for black hole creation being from above the 8TeV to be achieved this year and also the total number of collisions [awkwardly given conventionally in terms of ‘anti femto barns’} that would be achieved by the end of this year. The value by then would still be very much lower than would be achieved some time after the highest/ design energy collisions have started in a few years — magnifying both the chances of creating dangerous stranglelets or micro black holes and of the number of any of them which itself increases the rate by which any catastrophe would occur.

    Eric

  • Tom Kerwick on March 6, 2012 10:32 am

    Eric — about the window for BH creation, it should be noted that the lower bound of this window — which we are tentatively approaching — is where the greatest risk is — as the higher the collision energy the less likely derivative products will have low enough velocities for gravity-capture… though one could argue this could be offset by the rate at which they are created as energies increase thereon. I understand the strangelet debate was similar there was a lower bound of the window in which they theorised these were most likely to form, though you are more intimate with the strangelet debate than I am…

  • JP on March 12, 2012 6:08 am

    Prior to about a year ago I hadn’t given the LHC safety much thought, but now I feel the same concerns as in the header of this thread. If you are concerned about the LHC, I think you are missing a very easy and obvious angle, the cosmological constant problem. The equations and empirical evidence of accelerating expansion do not work the way we have them. If one solely takes into consideration a constant of integration from the fundamental theorem of calculus from the point of Einstein’s curvature tensor and the cosmological constant, then it all works out. But this does not bode well for the opinions of those who examined the safety of high velocity particle experiments, such as the LHC. I have a post up at the link if you are interested.

  • kasser on March 16, 2012 2:50 pm

    Nice and great post.

    Thanks & regards.