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Jul 30, 2012

The Cosmic-Rays-versus-White-Dwarfs Safety Argument

Posted by in categories: existential risks, particle physics

Tom Kerwick challenged my warnings by claiming that the observed longevity of white dwarfs, in spite of the constant bombardment by cosmic rays, provides a convincing safety argument regarding the currently running nuclear collisions experiment at CERN. This claim is important but, unfortunately, inconclusive as I shall try to demonstrate.

It is true that the collisions performed at CERN are relatively meager compared to cosmic-ray energies. The current, approximately 10 TeV collisions between equal-momentum particles at CERN correspond to 10.000 TeV cosmic ray protons hitting a stationary proton on earth or a white dwarf. The thousand-fold increase is a consequence of the relativistic energy-momentum law being applicable.

If 10.000 TeV (= 10 to the 16 electron volt) look like much, cosmic ray energies up to 10 to the 22 electron volt (a million times more) have been measured. However, if the latter are translated back into symmetric collisions of the CERN type, they are “only” a thousand times more energetic than CERN’s (owing to the square-root rule implicit in the mentioned law).

The fact that white dwarfs appear to be resilient to this bombardment is living proof that the cross section of CERN-generated miniature black holes (as well as their up to a thousand times more massive cosmic-ray generated analogs) must be minuscule. Specifically, their diameter must lie below that of a lepton (electron or quark). While an electron’s diameter is often supposed to be zero, neutrino absorption in solid matter yields a finite value (about ten to the negative 24 meter). In addition, the Telemach theorem guarantees a non-zero electron diameter.

So far, the cosmic rays cannot be shown not to be generating ultra-fast miniature black holes. When generated, the latter need to be rare enough not to leave a black hole get stuck inside the white dwarf in question. Otherwise white dwarf stars would no longer exist, as Tom stresses. The difference between earth and a white dwarf lies in the latter’s by 5 orders of magnitude higher density. It renders the white dwarf by so many orders of magnitude more vulnerable to ultra-fast natural black holes. Hence we have 3 numbers which jointly limit the lifespan of white dwarfs: The collision rate of CERN-like (or stronger) cosmic rays impinging on their surface; the fraction of these events leading to the formation of a black hole; and the free path length of an ultrafast miniature black hole inside white-dwarf matter.

None of these three parameters is currently known. Nevertheless as long as the black hole is markedly smaller than a lepton, it is the latter’s diameter alone that determines the cross section. Therefore, it is possible to draw a conclusion: White-dwarf longevity is limited by cosmic rays if the energy of the latter (CERN size or larger) suffices to generate black holes. In this case, “very old” white dwarfs cannot exist. This is a testable prediction.

The cooling rate of white dwarfs happens to be very low owing to their minuscule surface-to-mass ratio. Our cosmos is currently assumed to be only 14 billion years old (about the age of globular star cluster in our galaxy). Ultra-old white dwarfs should not be observable for that reason alone. As it happens, the new prediction is theory-independent, however. Ultra-old cold white dwarfs are therefore worth looking for empirically. If they are found, two important implications follow: (i) our universe is older than generally anticipated; (ii) the LHC experiment is safe. If, on the other hand, ultra-old white dwarfs prove empirically absent, this fact confirms the big bang theory at face value. However, if the recent theory of cryodynamics holds true (which implies a very much larger age of the universe), a measured absence of ultra-old white dwarfs implies that cosmic rays produce white-dwarf eating black holes. In that case, there is a high probability that the LHC is currently producing earth-eating black holes.

Therefore an astronomical test of the safety of the LHC experiment, based on white dwarf longevity, exists. The same claim was made by Tom. The difference lies alone in the fact that he assumes that the collision rate of micro black holes with leptons is much higher (due to a higher lepton diameter being apparently assumed). This difference led him to predict a very much shorter lifespan for white dwarfs. Since that prediction is defied by observation, his conclusion was that CERN is safe.

It will be important for everyone to learn if Tom Kerwick (perhaps in conjunction with Giddings and Mangano whom he quotes) can defend his prediction of a much higher collision rate with leptons for ultrafast natural mini-black holes inside white dwarfs. If so, CERN can perhaps be exculpated for its public refusal to update its 4-year-old safety report while continuing at a nonlinearly increased collision rate.

I thank Henry Gebhardt, Boris Hagel and Tobias Muller for discussions. For J.O.R.

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Comments — comments are now closed.


  1. Tom Kerwick says:

    Otto — thanks for getting back on this. I’m putting together an informal white paper on this at present on a case study of Sirius B. Would you be ok with me appending this and extracts from our earlier WD discussion in an appendix? — let me know.

  2. It is my pleasure, Tom.

  3. Eric says:

    Otto and Tom

    I’m not clear that this statement considering electron accretion according to CERN’s Mangano and Giddings has been addressed as yet:

    ‘we will largely neglect separate capture of electrons since their capture rates
    are much smaller due to their smaller masses and higher velocities.‘
    (p16).

    At least there are reasons given there. In a similar but contrary way that attaining escape velocities on earth results in non earth re-capture , the electron velocity (at least where the black hole is at rest) could well then become a significant factor reducing the capturability of electrons compared to nucleons.

    Perhaps the idea discussed on this blog is to consider the electron diameter as that of the Compton electron wavelength which is around 1000 times wider than that of a nucleon. But i’m not clear should that be relevant:

    If a small black hole is to capture a larger object than itself it would want its capture radius (itself depending on both Schwarzschild radius and the relative velocities) to reach through into the centre of mass of that object — but not to be concerned with what the width of that object is. If this black hole was larger than the object the situation seems similar.

    So I think there are other issues that need to be brought to the Mangano & Giddings analysis of white dwarf vs earth accretion.

    One of interest to me is a neglected factor by M & G for the accretion phase when the black hole’s extra-dimensional Schwarzschild radius (Rs below) has grown to that of the radius of a white dwarf’s atom / or an earth atom. By this time the black hole is likely to be more or less at rest at the core of the white dwarf or earth (LHC). This issue concerns how the above capture radius (influencing the accretion rate) would be more greatly inhibited — compared to M & G’s calculation — within the core of a white dwarf than it would in the core of the earth. This is because of the respective thermal velocities relating to those temperatures 10mil K (M&G) and 5700K (inner core wikipedia) for white dwarf and earth core respectively.

    The capture radius is given (M& G again — applied for white dwarf accretion but before this particular accretion phase is reached) as:

    Rc = Rs/vT where vT is the thermal velocity.

    The result of this is to reduce the capture radius Rc of white dwarf’s black hole to be 70 x less than that of an earth’s black hole even though both would have the same Rs (thermal velocities: 110 km/s in white dwarf and 1.5 km/s in earth).

    The effect of that on further enhancing the time for full accretion of white dwarf compared to that of earth beyond M& G’s esimate? I haven’t got that far, but I think such a calculation is worth it.

    Eric

  4. Eric says:

    Of course — in my analogy it seems I should have been thinking of the small black hole accreting the larger — or smaller object atom by atom, nevertheless, I think my argument could be applied analogously where the large object represents the larger or smaller particle — location of the ’ centre of mass’ or more likely — probabiliity distribution of a smaller point within that wavelength distance. As far as M& G are concerned they consider parton’s within a nucleus being captured — these having 100MeV or so mass themselves (gluons presumably)- so that gets very narrow.

    Eric

  5. Otto E. Rossler says:

    It is perhaps not only my own impression that, given such deep thoughts, the world has won a right to expect the for 4 years silent safety officials of CERN’s to shed off the political umbrella that forbids them to respond to the detriment of everyone.

  6. Tom Kerwick says:

    Eric — good point on thermal velocities, though not sure about your value of 70 x less. Dividing the equations for Vt for a fixed m simplifies to sqrt(10mil K)/sqrt(5700K) = approx 40 so the Rc of an MBH in a WD is 40 x less than the Rc of an equivalent MBH in Earth — correct me if I’ve made an oversight here. I must apply this back to the Sirius B case, though I believe for early phases of accretion slowdown where the MBH radius is much smaller than that of the captured particles, the mass density near the capture radius is more significant than the capture radius itself.

  7. Eric says:

    Your calculation assumes the same mass of the particles undergoing thermal motion for both cases — which isn’t the case here. Unfortunately not all white dwarfs have same constituents. I’ll check back with what M & G did (I perhaps was just using their result for WD thermal velocity anyway). As was stated this only concerns the phase from rS atomic radius upwards — but that seems the dominant phase anyway. Just using the revised ‘Bondi phase’ capture radius isn’t enough — that has to be processed itself. I’ll get back to where I was getting with that.
    Eric

  8. Amanda says:

    Peter, thank you for the link but, as you probably read aladrey, my shift in the CMS control room got canceled late yesterday evening, because they wanted experts on site for each subdetector. For my own shift, which is attending the tracker, this is hilarious, since the tracker has been kept off for the entire day, given the unstable beam conditions one expects at startup. Sorry for the disappointment of your readers I tried to post some useful information anyway today. Your link alone brought to my site about 500 people Cheers,T.

  9. Eric says:

    Tom I don’t know how you were going to apply this to Sirius B scenario .. it’s not so direct, but anyway I’ll post about where I get with it (which will probably still have to be rather provisional).

    Eric

  10. Tom Kerwick says:

    Eric — yes I apply a reduction factor of 41.92 to the mass density ratio on a casual approximation of relative accretion estimates. Perhaps it should be closer to your estimate of 702 which considers constituents particles. Amanda- if you are referring to Otto’s remark on lepton diameters affecting accretion slowdown, this is not something I concur with as the mass density near the capture radius is more significant at this phase — perhaps you are not intimate with the G&M analysis. The issue I raise in my paper relates to accuracy of magnetic field estimates of cold white dwarfs — not something you can measure for us in the CMS control room, but perhaps requiring a re-look at the spectroscopic and polarimetric surveys for a confidence figure more to an industrial safety standard — a 99% confidence in a safety report doesn’t really cut it.

  11. Otto E. Rossler says:

    The posting by Amanda from CERN is very strange:
    Is this the first sign that CERN is taking seriously our concerns?

  12. Tom Kerwick says:

    Unlikely — I checked it out this morning and the IP 206.223.185.25 attributed to one Amanda Pereira above is a known spammer IP address. It sources to Ontario Canada — most likely Toronto. Quite a distance from Geneva & the CMS control room…

  13. Otto E. Rossler says:

    ——————————————————————————–

    THE “COSMIC-RAYS-STRIKING-WHITE-DWARFS” SAFETY ARGUMENT

    Otto E. Rossler, Faculty of Science, University of Tubingen, Auf der Morgenstelle 8, 72076 Tubingen, Germany

    (Revised August 20, 2012)

    Tom Kerwick challenged my warnings that CERN is risking the short-term survival of planet earth by claiming that the observed longevity of white dwarfs, in spite of the constant bombardment by cosmic rays, provides a convincing safety argument regarding the currently running nuclear collisions experiment at CERN. This claim is highly important but, unfortunately, inconclusive as I shall demonstrate.

    It is true that the collisions performed at CERN do not quite match the highest cosmic-ray energies. Specifically, the current 8 TeV collisions between equal-momentum particles at CERN correspond to about 34.000 TeV cosmic ray protons hitting a stationary proton on earth or a white dwarf. The scaling factor of four thousand is a consequence of the relativistic energy-momentum law being applicable.

    If 34.000 TeV (= 10 to the 16.5 eV) look like much, cosmic ray energies up to 10 to the 20.5 eV (ten thousand times more) have still been measured. However, if the latter are translated back into symmetric collisions of the CERN type as necessary, they are “only” a hundred times more energetic than CERN’s (owing to the square-root rule implicit in the mentioned law).

    While the fact that white dwarfs appear resilient to this bombardment, is potentially related to their strong magnetic fields deviating almost all charged particles, uncharged cosmic rays would not be shielded-off. The latter cannot be definitively excluded to exist up until now. In this case, one would have to conclude that the cross section of CERN-generated miniature black holes (as well as their by an order of magnitude more massive cosmic-ray borne analogs) must be very small: their diameter needs to lie below that of a lepton (electron or quark).

    While a lepton’s diameter is often supposed to be zero, neutrino absorption in solid matter yields a finite value (about ten to the negative 24 meter) as is well known. Independently, the Telemach theorem (published in the African Journal of Mathematics) guarantees a non-zero lepton diameter.

    So far, the cosmic rays cannot be shown not to be generating ultra-fast miniature black holes. If generated, the latter need to be rare enough not to leave a black hole get stuck inside the white dwarf in question during the lifetime of the latter. Otherwise white dwarf stars would no longer exist (as Tom correctly stresses).

    The difference between earth and a white dwarf lies in the latter’s by 5 orders of magnitude higher density. The latter renders the white dwarf by so many orders of magnitude more vulnerable to ultra-fast natural black holes. Hence we have 3 numbers which jointly limit the lifespan of white dwarfs: (i) The collision rate of CERN-like or stronger cosmic rays impinging on their surface, (ii) the fraction of these events leading to the formation of a black hole, and (iii) the free path length of an ultrafast miniature black hole inside white-dwarf matter.

    None of these three parameters is currently known. Nevertheless, as long as the black hole is markedly smaller than a lepton (even though not as small as a neutrino, of course), it is the leptons’ diameter alone that determines the cross section. Therefore, it is possible to draw a conclusion: White-dwarf longevity is limited by cosmic rays if the energy of the latter (CERN size or somewhat larger) suffices to generate black holes. In this case, “very old” white dwarfs cannot exist. Although their maximum age is unknown at present, their survival cannot be used as an argument against the hypothesis that dangerous miniature black holes are generated at the LHC:

    The cooling rate of white dwarfs happens to be very low owing to their minuscule surface-to-mass ratio. Our cosmos is currently assumed to be only 14 billion years old (about the age of globular star cluster in our galaxy) so that ultra-old white dwarfs should not be observable for that reason alone. If they are nonetheless found empirically, two alternative implications follow: (i) our universe is older than generally assumed; (ii) the LHC experiment is safe. If on the other hand ultra-old white dwarfs prove empirically absent, this fact only confirms the big bang theory at first sight. However, the recent theory of cryodynamics (sister of thermodynamics) implies a much larger age of the universe – so that in this case, a measured absence of ultra-old white dwarfs suggests that cosmic rays do produce white-dwarf eating black holes.

    Therefore, an astronomical test of the safety of the LHC experiment based on white dwarf longevity may exist in the long run – as claimed by Tom Kerwick. A difference lies only in his assumption that the collision rate of micro black holes with leptons is much higher (due to a higher lepton diameter implicitly assumed). This difference caused him to predict a very much shorter lifespan for white dwarfs. Since the latter apparently contradicts observation, his conclusion was that CERN is safe.

    It will be important for every earthling to learn if Tom Kerwick (perhaps in conjunction with Giddings and Mangano whom he quotes) can defend his prediction of a much higher collision rate with leptons for ultrafast natural mini-black holes inside white dwarfs. If this is the case, CERN can perhaps be exculpated for its continuing at an exploding collision rate.

    A reviewer has noted, however, that aside from the scientific question of whether or not there exists a white dwarf-derived safety argument, there remains the procedural and ethical obligation of CERN to respond to existing criticisms and to update its 4-years-old safety report using the latest available information.

    I thank Henry Gebhardt, Boris Hagel and Tobias Muller for discussions. For J.O.R.

    ——————————————————————————-

  14. Tom Kerwick says:

    Otto — about a ‘prediction of a much higher collision rate with leptons for ultrafast natural mini-black holes inside white dwarfs’ — the G&M derivation on capture rates determine the accretion slowdown to be proportional to the mass density near the capture radius, and not the size of the capture radius. As we know the mass density in WD is much higher than in Earth, therefore so will the collision rates.

    Also I should clarify that I believe the case of WD safety assurance is more concerned with the magnetic field estimates of distant WD, not of the MBH size.

    As for uncharged CR, it is my understanding that these would not have been accelerated to sufficient energy levels to compare with LHC energies, or at least not have a known sufficiently high flux, to be considered in the safety debate — though if you know of some research which suggests otherwise please let me know, as it would endorse the safety assurances — in overcoming said magnetic field concerns.

  15. Otto E. Rossler says:

    The first point I do not understand — forgive me. Can you explain?

    The second point also deserves clarification to be integrated into the above text.

    The third point is intriguing. I happen to believe in a new source for cosmic rays existing — black hole mergers. Here the unfinished smaller one’s infalling particles would be “recycled” through the formation of a “separatrix in spacetime” near the horizon of the larger one inside the latter’s Reeb foliation in spacetime (unpublished work with Dieter Fröhlich).

    So the possibility of a sub-population in cosmic rays of ultra-fast neutrons is not entirely excluded so far, I feel. Cosmic-ray observatories should soon reveal whether identifiable “straight sources” exist apart from gamma ray sources.

  16. Tom Kerwick says:

    OK — about your last point — so there may be theoretical scenarios where high energy cosmic rays could include neutrons, and so be immune to WD magnetic fields, though there is no strong evidence of such as yet, so not useful in terms of safety assurance — no more than HR Theory is useful as a safety assurance.

    About the first point — G&M derive the stopping distances within WD, caused by both a Coulomb effect where collisions result in a particle scattering and by accretion slow-down where the MBH absorbs particles, to be inversely proportional, not to the capture radius, but to the mass density near the capture radius. Therefore debating a smaller size MBH radius does not change the proposed stopping distance unless you can also find a weakness/oversight in the G&M derived eq for MBH stopping distances (see second half of G&M paper section 5.2.3 page 33).

  17. Otto E. Rossler says:

    I asked you to explain what you meant: you seem to talk about quite sizeable black-hole radiuses here, right? And you seem to assume charged black holes already, right?

  18. Tom Kerwick says:

    http://www.vixra.org/pdf/1208.0005v4.pdf

    Otto — no I do not assume charged black holes — I assume uncharged back holes as this is the criteria you set. Please read my paper which references your concerns linked above — it is just five pages excluding the appendices.

  19. Otto E. Rossler says:

    Dear Tom:

    Is it too much of a nuisance if I ask you to answer my point above rather than referring to a maximally complicated and not yet very enlightening set of texts that in part are said to have been removed violently?

    Making simple statements is required in cases of an un-disproved danger. Such statements I tried to make in the above updated text. Please, say where you disagree.

    Even better: Please, use your good contacts to Giddings and Mangano to entice them to write an update on their for 4 years un-updated safety report? The whole planet is waiting as you know. Their firm’s continuing without any public justification given is nothing the public can accept.

    Time is running out. Please, be so kind as to help us all, Otto

  20. Tom Kerwick says:

    Otto — there has been no violence on my part — I find such a statement from you bizarre in the extreme — are you referring to my webadmin duties here on Lifeboat? Back to the subject matter — The paper above which I referred you to is maximally simplified. If there is a point you do not understand, we can discuss. What is the question I did not answer?

  21. Otto E. Rossler says:

    Dear Tom:
    Policing is never a kind activity, as you will no doubt concede.
    You are definitely impeding the chances for CERN’s responding to its critics by uncritically picking bits and pieces out of their by more than 4 years outdated “safety report” as if they were scientific facts (especially their lepton radius of 10^−17 meters).
    Please, make a statement as to whether you think the safety issue has the infinite weight I am attributing to it, or not.
    Thank you, Otto

  22. Tom Kerwick says:

    Otto — if one writes a paper on the subject, it will reference previous relevant papers, and if you bothered to read my recent paper you would find that it is actually critical of the old safety report, though not on the same grounds that you are critical of the old safety report.

    To answer your question as to whether I would attach the infinite weight you attribute to it, the answer would be No — but I do believe the report needs to be revisited — and updated.

  23. I appreciate your frankness, Tom