There is absolutely, positively, definitely no chance of the LHC destroying the planet when it eventually switches on some time later this year. Right?
Err, yep. And yet a few niggling doubts are persuading some scientists to run through their figures again. And the new calculations are throwing up some surprises.
One potential method of destruction is that the LHC will create tiny black holes that could swallow everything in their path including the planet. In 2002, Roberto Casadio at the Universita di Bologna in Italy and a few pals reassured the world that this was not possible because the black holes would decay before they got the chance to do any damage.
Now they’re not so sure. The question is not simply how quickly a mini-black hole decays but whether this decay always outpaces any growth.
Casadio have reworked the figures and now say that: ” the growth of black holes to catastrophic size does not seem possible.”
Does not seem possible? That’s not the unequivocal reassurance that particle physicists have been giving us up till now.
What’s more, the new calculations throw up a tricky new prediction. In the past, it had always been assumed that black holes would decay in the blink of an eye.
Not any more. Casadio and co say: “the expected decay times are much longer (and possibly ≫ 1 sec) than is typically predicted by other models”
Whoa, let’s have that again: these mini black holes will be hanging around for seconds, possibly minutes?
That doesn’t sound good. Anybody at CERN care to clarify?
Ref: arxiv.org/abs/0901.2948: On the Possibility of Catastrophic Black Hole Growth in the Warped Brane-World Scenario at the LHC
Folks – the scientists involved are proceeding cautiously. LHC will not be run at full power from day one. Rather it will be increased incrementally.
Thus if any black holes are produced, assuming they can exist at all, they will be formed at the lowest energy first where they can be studied before moving to higher energies. This allows us to maintain a safe system in spite of the uncertainties.
The drake equation underestimates the chance of advanced civilizations destroying themselves with technology which is why we are never visited by advanced aliens.
@ Nathan
Please have a look at the following video to get a feeling of phase transitions, criticality and thresholds in physics:
http://www.youtube.com/watch?v=NKxgG2LUG8M
I understand why you think in the way you are going here, Because as a young person I was also wondering: Why does water not become tenacious before freezing? It is a bit more complicated!!
@ Geo
What you are reasoning seems plausible to me… there might be other reasons (strict locality, finite velocities and more…)
Best wishes to both of you
… but in principle Nathan is right: Often it is very helpful to advance taking small steps. Unfortunately not necessarily in this case!!
Generally the small steps are useful because we are acting more or less as full blinds being born without any knowledge and not attended by higher intelligence (?) for the reasons Geo mentioned. Due to this it is extremely inappropriate and unprofessional what CERN is doing at the moment in my judgement – especially because the colleagues have been warned by many concerned citizens and other academics for years! An accurate public revision (never suggested by CERN or the participating states to my knowledge) to clarify the situation is urgently needed!
Hello,
here are further results of my enquiries concerning LHC experiments:
In the following key arguments against the cosmic ray argument are presented. The citations from the field of astrophysics can be found and studied further in the following expert’s review about the search for LIV and related topics by W. Bietenholz: http://arxiv.org/abs/0806.3713
The comparison of the LHC collisions with cosmic ray events is problematic according to my enquiries because
- The composition of cosmic rays even at our time is not entirely clear:”[…], but many aspects of the energy dependent composition are controversial” and “the identification is not easy at all, and in practice the criteria are not always consistent”. Also ultra high energy cosmic rays are rare events: “Note that the flux above 10^12 eV is around 10 primary particles per minute and m², but above 10^18.5 eV it drops to O(1) particle/(km² year) […], so the search for UHECR takes patience”. The reason for construction of colliders is the imprecise configuration in observing natural cosmic rays. Only limited insight into the physics of cosmic rays is possible up to now – experiments for further clarification are currently prepared!
- The boost (the momentum / the velocity) of the products in a cosmic collision might be higher in the rest frame of the earth than the minimum momentum of the collider products (whatever heavy products). This results in other cross sections of these products with the matter of earth (or the atmosphere or moon) and other subsequent reactions due to the different energies. Not only are the products important but also their momentum when further reactions have to be considered. I do not cite here the literature because this correlation is canon in particle physics.
- The conditions in the collider (collision in the vacuum near to a solid) are different from the environment in the atmosphere (collision in gas) or on the moon (collision in a solid). Respective implications (reactions, life times, …) have to be analyzed in detail.
- To be able to compare the reactions a Lorentz transformation has to be applied: In the LHC two protons with equal velocities shall collide head on in the lab – in the cosmic case an extremely fast proton is assumed to meet a resting proton (relative to the earth). Up to now no violation of this transformation (LIV) is known and precise laboratory experiments for small energies (gamma at 10^5) are available. However, at extremely high energies (10^17 eV of LHC after transformation or more) experimental evidence is rare (Auger, HiRes, neutrinos) and neither fully exact nor unambiguous: “This observation [AGASA] disagrees, however, with the data of the HiRes (High Resolution Fly’s Eye) observatory”. Lorentz invariance violation in this context is discussed in the literature: “On the other hand, the sizable number of super-GZK cosmic rays asks for an explanation and keeps the door open for speculations” and “This is a very active field of research with exciting open questions. We may expect enlightening new data in the near future. They could lead to new insight in outstanding issues like LIV — or to new puzzles and perhaps to evidence for new physics.” More than 100 physical parameters subjected to the transformation are discussed: “Kostelecky et al. have identified more than 100 LIV parameters in this way, including CPT breaking terms”. Not all are checked by the cutoff seen in Auger but could play a role in LHC experiments.
- Known physics might change drastically at energy densities making micro black holes possible as academically discussed in the meantime [Plaga 2009 http://arxiv.org/abs/0808.1415 ]. W. Bietenholz: “Based on the uncertainty relations (3.14), the identification of a as the Planck length now leads to a consistent picture of the space-time uncertainty range as the event horizon of a mini black hole [142]. In fact, a (hypothetical) measurement of a length of O(LPlanck) requires (according to the Heisenberg uncertainty) an enormous energy density, which gives rise to such an event horizon — the notion of detectable events then requires inequalities (3.14) to hold with a ∼ LPlanck . This Gedankenexperiment suggests that points should indeed be washed out over a range of O(LPlanck ). If several directions are involved, as in relation (3.14), this is practically equivalent to non-commutativity. […] Thus we have the case of an “active LIV”” Within this context – possible micro black hole production in colliders and the discussed effects at the Planck length – the comparison of the LHC collisions with cosmic ray events is additionally extremely questionable.
Concluding these arguments against operation and the calculations and considerations of even possibly dangerous scenarios of other academic colleagues are absolutely sufficient to enforce an independent, careful, public revision of the experiment and its discussed dangers before new experiments of any kind! The academic opinion clearly is not unambiguous as it would have to be the case amongst others for admissible operation.
In the following some more considerations – only preliminary – but presented here with the aim to draw others attention to this important topic (real head ons in our universe):
To compare particle experiments with natural cosmic events we want to calculate the probability for a head on collision of two protons (or other ions) with energies above 10^12 eV in the entire known universe (we take for simplicity a cube with a length of 10 Gigaparsec). The probability for such particles to occur is around 10 particles per minute and square meter. Conservatively we take for the cross section of proton proton interaction 10^-28 m^2, realistically we can assume maybe 10^-40 m^2 (picobarn) for subnuclear reactions. The first calculations are (partly wrong – please be careful and try to find out) sketches which are refined until at the end a consistent result is found. It stems from diffusion theory (biophysics) and is comparable with the standard formula in astrophysics.
10 particles per minute and square meter (neglecting the other directions which just add) with speed c results in a density of (10/60)/(10^8) = ca. 10^-10 particles per cubic meter. In the entire known universe (ca. 10^75 m^3) there might be (assuming for simplicity same intragalactic and extragalactic flux) 10^65 particles with a volume of (strict case) 10^-60 * 10^65 = 10^5 m^3. The density of interest is therefore 10^-70. The volume of the trace after a flight of one second is 10^8 * 10^-40 = 10^-32 m^3. One subnuclear structure with a density of 10^-28 would be detected during this flight per average (10^20 * 10^8) assuming a sphere like subnuclear structure. If the density is only 10^-70 this case will not occur in 10^10 years (ca. 10^17 seconds or flights) may it be head on or not.
I forgot the overwhelming number of such particles in our known universe: 10^65 like I calculated amply. If we multiply we get 10^28 * 10^17 * 10^65 = 10^110. This will happen often, let’s go to good head on and reduce to 10^105. Let’s further reduce, leave intergalactic space and go inside the galaxies – resulting in about 10^100. And we need only 10^70 to reach the low density! Now we want to know it exactly and ask: Do we get it near moon-like objects to incorporate secondaries and their reactions? The surface volume (thickness around 10 cm) of moon like objects inside the solar system is difficult to be estimated – we ask for simplicity whether it happened near to the moon of the earth – a volume of about 10^12 m^3. Compared with the volume of the solar system including outer space of around 1 cubic parsec (ca. 10^45 m3). The result is even more tiny if we remember that the particles have to meet tangential to the surface of the moon – let’s assume three or more orders. The difference is more than thirty orders of magnitude. This is too much even for the 10^100. The result will change if we incorporate the other moons and the asteroid belt – but I do not know how. So including secondary reactions with other matter the head on result is hardly to find as far as I see. Comments are welcome!
verification:
… if one takes the classical formula flux2 * cross section / c and uses the chosen values the result is similar. For picobarn the head on for energies > 10^12 eV is found often in the entire universe over 10^10 years. Near to objects like the moon however the result is not clear. Here one has to rely on Lorentz Transformation.
… and last refinement (up to now):
… if we take into consideration the occurence of the particles (number per (m² second sr GeV)) scales nearly with the inverse of the third power (-2.7) of the energy – then the 10^13 eV collisions at LHC are of course more seldom than the ones at 10^12 eV. The integral should be also 10^-3 times smaller than for the lower energies (correct? -> please countercheck). So the occurence should fall with a factor of 10^6. This results in a density of 10^-16. The number of particles reduces to 10^59. The volume of interest is therefore only 10^-1 m^3 and the density 10^-76. The 10^110 become 10^104 and (after head on correction and look inside the galaxies) 10^94. Let’s also take a strict head on and win additional maybe three orders of magnitude. Conservatively we can also use attobarn instead of picobarn and win again 10^6 (smaller volume but more particles during flight). We come closer now… especially if we consider that about 10^9 events may have happened so far – how high is the rate in the LHC?
The calculations of the head on probabilities are preliminary and currently refined by the author – please all experts available comment on that! The counterarguments concerning the comparison with cosmic rays are however based on current academic opinion.
The review by W. Bietenholz is written to give a summary of current research for cosmic rays and LIV – it is not intended to assess the LHC. My items against the argumention of CERN can be based on this review to a large extent.
Why is the head on not discussed in the safety paper of CERN!? Correct this and show your results!! Move….!!!!
Watch Anime, Online Anime Episodes. You can watch the best animes in the world, English dubbed Anime. Watch Anime . Watch Anime Episodes, our site to watch animes. Best online animes series here. English dubbed anime episodes. watch english dubbed and subbed anime episodes. Free anime series and chapters online and free.
i dont understand how i found your weblog as a result of i was searching information about politics, but anyway, i had a nice time studying it, keep write it
Download FAST 3.47MB
Yet again you come out with terrific piece of work. would anyone that kind of information and written speech to make next week, and always looking for.
Best, asian blowjob, [url= http://boards.sonypictures.com/boards/member.php?u=80017 ]asian blowjob[/url], nphb,
can you do thi for me, All about exotic g string bikini, [url= http://exoticgstringbikini.yolasite.com/ ]All about exotic g string bikini[/url], dvh,
Im havin’ some difficulty trying 2 load your blog. I have been read it(blog) many times before & never gotten something like this, but now when i try 2 load something it just takes a little while (8-15 minutes) & then just stop. I have tried with www or not. Does anyone know what the trouble could be? Ask your support at hoster..And, yes, thanks a lot for your job!
I’m a huge lover of your weblog! Look at my website, You can submit your weblog there!
Great post thanks for the nice read!
Great article Thank
would anyone that kind of information and written speech to make next week, and always looking for.
Hi and thanks. I’m constantly looking into posts and info about web-site search engine optimization. You can’t predict where you’ll find a brand-new tactic (well, new to me at least). Even though there are always classic Seo strategies, a tiny adjustment here and there, and your site will get significantly better search rankings. If you use Wordpress getting the proper plug ins and / or an effective premium theme can help your Search engine optimization. It’s also extremely important to keep up to date with the modifications in search engine algorithms.All the best
I have had this unit for 5 years. I bought it as a result of my basement smelled so musty, all you may smell as quickly as you walked into my home was the basement. I used to be terribly embarassed by the scent and concerned in regards to the health effects. The basement had been damp for the first few years after we constructed it, and I was concerned the scent was toxic mold.
I feel that the IQAir HEPA filters saved my life. Had persistent bronchitis in 2008 that would not go away. The doctor that launched me from the hospital advised that I get a HEPA filter (said that a Sharper Picture kind air filter would make me worse because of the ozone it creates). Searched on line and located the IQAir and all of the nice reviews, bought (1 for every stage of our townhouse) and love them. I can inform as quickly as I stroll into the home the difference that they make.
I adore your blog – super job!
Great, http://www.wearediabetic.org/vodkalimesugarices/bio vodka lime sugar ice, xzgyyo,
Everybody has their passions in everyday life and everybody has their expertise. Your own information has surely offered me a few completely new thoughts. Thankyou.
Hello,
in the formula presented in the paper by Hut/Rees (HOW STABLE… ) and in the paper by de Rujula/Heinz/Dar (WILL RELATIVISTIC…) both modelling head on collisions it is wrong to multiply with c (speed of light) – we have to divide by c, because the particles will leave the cube faster!!
An important result for the safety of us all – please countercheck it and spread it!
Hello again,
sorry in the above comment I was wrong. In the paper densities are used. This means indeed one has to multiply with c but I miss:
- careful discussion of reasonable cross sections at respective energies showing respective widths
- careful discussion of reasonable astronomical objects which give clear evidence
- careful discussion of the cosmic volume appropriate to allow the comparison with collider events
- careful discussion of experimental and theoretical know-how concerning cosmic rays and underlying physics to justify the discussions mentioned before
- discussion of the small angle the particles meet head on- they have to be on one line
A public revision and immediate stop of the engine is urgently necessary
Please find below my (Alf Pretzell, biophysicist) communication with Dr. Ellis, CERN LSAG member. The email-discussion took place in April 2010 and was subsequent evaluation of a discussion I had with CERN members including Dr. Ellis in March before the new 7 TeV center of mass collisions took place. I give the public here account of the substantials, for reasons of privacy I do not directly cite from our discussion. My comments are originals however.
I want to emphasize I am not an expert and try to confine my argumentation and discussion to the comparison with cosmic rays. Here I have limited insight and hope to solve the problem already without detailed analysis of dangerous scenarios. Those in my opinion belong to technology and knowledge impact assessment following the comparison with natural events. I try to “attack” already this comparison, call my colleagues for a large public revision including population of earth and think if black holes or strangelets are discussed academically this revision would be necessary even more. Inside brackets you find additional information not part of the discussion.
Fundamental research is necessary and I acknowledge the work of my colleagues in general.
Pretzell: (item 1) You are convinced by your experience with colliders nothing serious will happen
Dr. Ellis agreed.
Pretzell: (item 2) You are convinced of the safety due to the analysis of Dr. Mangano and others of the black hole scenario
Dr. Ellis agreed.
Pretzell: (item 3) For you the remaining possible risk is too small to be worth thinking about
Dr. Ellis replied the comsic-ray argument would exclude any conceivable risk
Pretzell: (item 4) For you my argumentation – doubting the cosmic event with the collider one – lacks to incorporate the slow down of the boosted secondaries due to interaction with matter of earth, moon, white dwarfs etc.
Dr. Ellis replied especially white dwarfs and neutron stars discussed by Giddings and Mangano would be an argument.
Pretzell: (item 5) Especially by the recent results of Auger you feel safe with respect to reliability of Lorentz and other invariances
Dr. Ellis agreed.
Pretzell continued this scholastic like discussion and uttered:
(Item 1) Experience is very useful and important but with respect to the research “on edge” CERN is doing, the awaited new physics and other imagined surprises not a good argument. You are at CERN at the limits of our knowledge and have to take responsibility to be be extremely careful for this reason!
Dr. Ellis replied this is why CERN would emphasize the empirical cosmic-ray argument and not so much purely ‘theoretical’ arguments.
Pretzell: This is in principle very good like I already commented – a precious argument we should keep. But where is an exact treatment of the comparison? The de Rujula, Dar 1999 paper is interesting, but not sufficient from my point of view. Nuclear cross section are taken for the strangelet case. A thorough analysis of the fluxes and resonances is missing, as well as for the probabilities of the reactions near to matter. The paper is interesting because of the symmetric case considered here, really like in the collider. If you would strengthen this analysis and show you are comparable you will loose me as criticist. Exact numerical results are missing here. Then it would be possible as well to fix the risk (using this model) and say: This is our result for the risk: 10^-23 with a standard deviation of two orders of magnitude or anything like that. CERN can not provide this to my knowledge.
Pretzell acknowledged he would be not able to comment on the analysis of Dr. Mangano in a professional way as biophysicist and uttered on a more epistemic level:
(item 2) Please be aware of the many discussed MBH scenarios in brane worlds by particle physicist like Suranyi, Yoshino, Nambu and others. In this case – concrete possibility of these objects – a radical revision of all collider physics WAS already necessary – Hawking radiation is pure theory and has never been observed.
Dr. Ellis defended CERN uttering the theories which would predict MBH production also would predict MBH decay via Hawking radiation.
Pretzell replied: Yes I remember you pointed out this argument when I was at your room. As far as I know in the regime MBH are possible you are near to the Planck length. Is it not in this regime the standard model will not work anymore reliably? Look for example at the Bietenholz paper I cite in my briefing. This means in my opinion one has to take extreme care if any cases are extrapolated. This is the case for MBH, but this is also the case for Hawking to work in this context. So with bad luck MBH’s will be generated, Hawking will fail. What is in this case – then we have bad luck and I am not such a hasardeur (Pretzell wanted to point to the fact possibly unsafe experiments in science not only at CERN would resemble gambling in a fully inadequate context) and you neither I guess.
Pretzell: (item 3) It could be the remaining risk is indeed very small – but where are the calculations – in the sense of Dr. Mangano’s paper – for the comparison with cosmic events?
The discussion continued but not with respect to the comparison with cosmic rays.
Pretzell: (item 4) The interaction can be calculated only if the forces are known – this is maybe impossible for new particles which might be produced and were not observed in cosmic showers.
Dr. Ellis replied the power of the cosmic-ray argument would be that it is applicable whatever interactions of the MBH one can think of.
Pretzell was not content: Yes but in general you rely for the comparison to work on known particles knowing also forces, knowing interactions. Let’s assume a new SUSY? particle is generated. How will it interact – you do not know you have to measure you want to measure!! Cross sections for certain reactions depend on momenta of the particles – you can not deny that! Like I said, maybe before slowed down a reaction at fast momentum has taken place already and you are not anymore comparable!! You will hardly be able to refute this argument of the different boost.
Pretzell: (item 5) Auger is only one – very impressive – experiment. It is by far not enough to justify the LHC, the most powerful engine on earth and not comparable to any other processes in our solar system – cosmic rays are single events and due to the reasons I mentioned only indirectly comparable
Ellis was not content and appealed to my understanding LHC collisions would have much lower energies than Auger collisions. He made me aware LHC collisions would be independent of each other like cosmic-ray events.
Pretzell replied here: I know Auger is ca. 1000 times higher, but there are many parameters to be tested for invariance – by far not all I suppose are comprised by the GZK-cutoff. And like I said, main results of Auger appeared after LSAG 2008 and an ex post argumentation is not allowed in a safety context. You see I am quite strict, but this in the context of LHC is necessary. And like I said it is not the task for five CERN people to do this job but for a whole institution outside CERN because “the community has the right to expect CERN to demonstrate the validity of the safety arguments”! I think you agree here (Pretzell meant here CERN should care for precise analysis – Pretzell’s opinion is to let an independent board do this analysis and not CERN involved in the experiments)
Pretzell thanked Dr. Ellis, closed the discussion and does not think his arguments have been refuted fundamentally.
If you guys are interested in Starcraft 2, you should check out this SC2 website.
… it’s strange to me no one reacts to my comments – starcraft2 and exotic g string bikini now talk about different things:
clothes and computer games…
well – think I leave this place!! Give room to
vodka lime sugar ice
and friends
Best wishes to you – you understand my language and comments – last question if you allow – just for my imagination and education!? In case we meet again… earth is not so big awak (as we all know)!!
Hey blogger, I was browsing the internet looking for some info and came accross this blog. I was pleased by the details that you have on this post. It just shows how great you understand this article. I just bookmarked your article and am going to come back for more. You, blogger, RULE!!!