CERN's Black Hole that can eat the earth

[Klaynos]

wait, i thought that black holes were just super dense gravity wells, so dense that not even light could escape. so, how can there be micro-black holes? i thought they needed alot of mass to colapse onto itself?

 

Any mass with all it's mass within the schwarzschild radius.

 

I blogged about it...

[CaptainPanic]

I think the interesting thing is that most of you agree that the chance that experiments in the LHC go catastrophically wrong is very very small, but not zero. (And it might in fact be zero, but lack of information means we cannot guarantee this yet).

 

Which leads to an interesting problem... and risk assessment is the tool.

 

Risk = chance * effects

 

Chance = very very small, but not zero

Effects = the end of life

 

It is something like multiplying infinity by zero...

 

I will not speculate how it exactly could go wrong, I'll just get myself flamed here. Some people on this forum seem to think that experts should only be allowed to post on threads of their expertise (which is kinda naive on an open internet forum).

[ydoaPs]

I'm not sure your effects term is correct.

[D H]

Effects = the end of life

 

It is something like multiplying infinity by zero...

The cost of "the end of life" is very high, but not infinite. It is not "something like multiplying infinity by zero". It is something like multiplying a very large number by a very very small number. The result is a very small number. The result becomes even smaller if you do a proper risk assessment and account for the time value of money.

 

Even if the LHC creates a quantum black hole and even if Hawkings is wrong about black holes evaporating (and these are two very, very big ifs), there remains another unknown, which is the amount of time it would take for the purported black hole to gobble up the Earth. A time span that measures in the millions of years reduces the effective risk to almost nothing. A small number times a very very small number is a very, very, very small number.

[Phi for All]

Some people on this forum seem to think that experts should only be allowed to post on threads of their expertise (which is kinda naive on an open internet forum).

Don't mistake skepticism for snobbery. Forums are for tossing ideas around, and in science forums, those ideas are going to be pulled apart and analyzed, critiqued and either thrown away or pushed upward on the ladder of viability.

 

Ideas are like biological units; if they don't have what it takes to survive, they die off without producing anything. If they're strong and their flaws don't stop them, they will live to spawn and continue evolving.

[Daecon]

Any effects can't be as bad as anything the Universe itself couldn't have already created.

[Royston]

Any effects can't be as bad as anything the Universe itself couldn't have already created.

 

It's odd you use that as an example as to why the LHC isn't dangerous, because that's exactly the kind of reasoning that has lead to the scaremongering nonsense surrounding the LHC.

[Severian]

Even though every physicist "knows" that the photon has zero rest mass, you will never get a physicist to say unequivocally that photon's rest mass is identically zero.

 

The photon's rest mass is identically zero.

[D H]

The photon's rest mass is identically zero.

Note well: I was not being a crackpot when I wrote the referenced post. The photon's rest mass is identically zero according to both the standard model and relativity. Every experiment to date has yielded results consonant with theory. The photon's mass is identically zero as far as I am concerned.

 

Severian, can you truly say that the photon's rest mass is identically zero with absolutely no equivocation? Theories have been overturned in the past, and no experiment has (or ever will) be able to unequivocally reject the hypothesis of a non-zero rest mass. Scientific fact, like law, always has some doubt. Our standards tend to be higher than the "beyond a reasonable doubt" standard legal profession, but there remains some doubt. Theories are occasionally overturned and experimentation can never yield absolute certainty.

 

The media is looking for 100% certainty here. That is not how science works. It is how crackpots and religion work ... until proven wrong. Then they do it all over again, with 100% certainty.

[iNow]

Isn't it impossible, by definition, for a photon to be at rest, and hence rest mass is a meaningless concept when applied to the photon?

[D H]

Picky, picky, picky. Some other terms are intrinsic mass, invariant mass, proper mass, or just mass. Rest mass is yet another name for the same concept.

[markamerica]

evidence. So let's see if I can sum this up.

 

It(the creation of a black hole at LHC that grows and consumes the earth) can't happen because:

 

1. CERN said so.

2. It would contradict some part(s) of the standard model.

3. Hawking radiation would have to fail either to materialize at all, or operate at too slow a rate.

4. The energies involved at the LHC are too small to create one in any case.

5. Cosmic particles with higher energies ought to be creating them all the time, and the Earth is still here at something around 4.5 billion years old

6. EVEN if it does happen, the accretion rate would take far too long to matter to mankind(millions of years.)

7. This is the paranoid fantasy of evangelicals and media hype of disaster pimping journalists.

 

I've seen other dismissals of the doomsday scenarios, on other sites, but if I missed any here, please feel free to remind me. I'm going to play devil's advocate for a little bit, because I notice nobody is doing that much, and that seems extraordinarily unscientific:

 

1. "CERN said so." Well, assuming we generally trust the authority of CERN, this might still be a problem, because after all, they and their partners have spent in excess of $8billion getting this puppy ready. The USDOE, one of its partners, has contributed a pretty large share of that total, around 1/7th or 1/8th. I have never, in my entire life, seen a single large bureaucracy admit that it might be doing something foolish and/or dangerous, reverse course, and hold a press conference to say "Gee, we re-ran our numbers, and lo and behold, we goofed. This experiment is far too dangerous to ever actually perform." As a veteran of several large bureaucracies, governmental and private sector, I can promise you that having spent $8 billion, they're pretty much inclined to run this thing whether it might send the universe into oblivion or not. Can anybody say "NASA", "Shuttle," "O-Rings," and "Challenger" with a straight face and seriously contend that bureaucracies do not frequently create calamities by exactly this sort of "bureaucratic inertia?"

 

2. "It would contradict some part(s) of the standard model." So? Prior to Galileo, or Copernicus, the notion of a non-geocentric universe violated some part(s) of the "standard model" of the time. Every time we think we have it all figured out, the universe reaches out and slaps us a bit. Or a lot. Assuming the universe and everything in it must follow the precepts of our "standard model" because otherwise, the model is broken, is a bit like arguing that if the pants I ordered on Ebay won't zip up in front around my girth, there must be something wrong with the pants or the size measurements of the manufacturer of the pants. It couldn't possibly be that I "misunderestimated" the size of my waist, now could it?

 

Heck, it wasn't long ago that the accelerating rate of the expansion of the universe didn't fit the "standard model." So, rather than trying to cram reality into the confines of our model, we modified it, and called the process to blame "dark energy." Well, bully for the standard model. Of course, the standard model really doesn't have much clue about what causes "vacuum energy." And until this was discovered, every scientist on the planet would have told you, with something approaching certainty, that the expansion was slowing, "or at least, it ought to be."

 

3. "Hawking radiation would have to fail either to materialize at all, or operate at too slow a rate." You mean, sacred cow Stephen Hawking would have to be wrong [again]? Heck, he's as much as admitted that he may be very wrong about this, although he shades it in uncertainty. The truth is, and it's probably somewhat uncomfortable for most to consider, we assign far too much credibility to Hawking because he's an affable, sympathetic character. He's a very smart guy, but I think we assign a certain affirmative action to his theories because we feel bad for his physical predicament. That's certainly understandable, but it isn't science. At present, Hawking radiation has never been observed or demonstrated anywhere, and the first real experiment that has a chance of detecting it "in the wild" happens with the launch of GLAST in May.

 

4. "The energies involved at the LHC are too small to create one in any case."

This is a guess. The most frequently publicized estimates of the energy to be released by collisions at the LHC are around 7-14 TeV. This, we are told, is too small to create a stable black hole. Estimates for how much energy it would take to create a micro black hole of the stable, potentially accreting variety are around 1000 TeV. With all this in mind, it is therefore interesting to note that the top energies to be produced at the LHC will result from the collision of heavy ions, lead(Pb), and they will be in the range of 1150 TeV. Uh-oh.

 

5. "Cosmic particles with higher energies ought to be creating them all the time, and the Earth is still here at something around 4.5 billion years old."

 

Interestingly, I just read an article about this very thing today:

 

Study confirms 1966 prediction: The most energetic particles in the universe are not from the neighborhood

 

Also interesting, to me, is the fact that the LHC will be using dual beams. I wonder how often heavy ions have head-on collisions at speeds approaching c, in nature, and where that's likely to happen. Surely, it happens in supernovae, but where else?

 

6. "EVEN if it does happen, the accretion rate would take far too long to matter to mankind(millions of years.)" I have seen estimates as high as 6 billion years, which is likely to be long beyond the end of the earth, having been consumed by the red giant sun on its way to ignominious death. I've seen estimates in the millions of years, which is a little less comforting, since there is some chance humans will still be running around then. I've seen estimates in the thousands, and the hundreds of years. All of these are based on a relatively slow initial accretion rate due to the effects of Hawking radiation(see above). The proposed accretion rates might well be a good bit faster if Hawking radiation fails to step in to save the day, and those estimates run from a few decades to 50 months of terror, down to four minutes and thirty seconds. Well, in the latter case, at least it will be fast, and CERN will be indemnified against lawsuits.

 

7. "This is the paranoid fantasy of evangelicals and media hype of disaster pimping journalists." To address the first half, I am aware of some people of an atheistic mindset(self included) who are not so certain about all of this. The assumption that only the stupid or the religious(and apparently, to some here, the latter is a reasonable substitute for the former,) have such concerns is troubling to me. The sort of people who tend to follow these issues with enough interest to make any sort of judgment aren't generally stupid, and may or may not be religiously guided. This thesis seems like an altogether unscientific assertion: "Only stupid people are concerned about micro black holes." As for media types, sure, they love a good disaster-in-the-making, but they also know their audience, and they know that few in their audience pay any attention to much beyond the sports or entertainment pages. Okay, a few probably read the comic strips, and the want ads. The truth is, however, that too few people even know what the LHC is, let alone what it may or may not be capable of producing. I would be willing to bet that even with the lawsuit story of recent weeks, less than 2% of the adult population of the United States has ever heard of the LHC or CERN. Half of those who may have caught a snippet or two about it will either dismiss fears out of hand, trusting in their government to protect them from "lunatic europeans with destructive machines" or simply never follow it up. All in all, however, I'm not so convinced as some here that there is nothing about which to be concerned, and neither am I willing to categorically state that photons have no at-rest mass.

 

Regards,

 

Mark

[iNow]

It's always easier to believe a conspiracy than the science...

[SkepticLance]

To Mark

 

That was a very nice, comprehensive and informative post. I think it is very good to see someone playing Devil's advocate. Thank you.

 

I am not keen on conspiracies or catastrophes. Thus, what I am about to say is not something I really take too seriously.

 

One of the great puzzles has been called the Fermi Paradox. This is the query as to why no civilised star travelling alien species has visited Earth, and left traces of that visit. It does not take much to calculate that, if such species are common, one would have visited Earth before now. Lot's of different explanations for the Fermi Paradox have been suggested, but few are really very tenable.

 

It occurred to me a while back, that one reason might be that all intelligent life gets killed off by a booby trap set by Mother Nature, before they can become star travellers. All developing intelligences are likely to follow a similar path to scientific understanding. For example ; they are all likely to invent prisms for splitting light into colours before they make different coloured lasers.

 

If all such development follows more or less the same path, perhaps one step on that path is lethal, but not able to be predicted. An all devouring black hole that inevitably appears for a certain size particle accelerator might be such a booby trap that inevitably kills off the developing species.

 

As I said, I do not really believe that, but it is probably worth thinking about.

[markamerica]

iNow,

 

Neither am I much on conspiracies. I tend to think in terms of coincidental, contemporaneous failures... Or what I suppose one could call a conspiracy of stupidity born of hubris. To briefly continue the analogy, do I believe that anybody at NASA wanted the Challenger to explode during its boost phase? Hardly. I doubt seriously that any two people were conscious of the concerns the other might have about the o-rings and the cool temps expected at launch. Institutionally, I am sure there was no edict that "We shall not make noise over potential o-ring problems." That said, nobody wanted to be the fly in the ointment, either. In this way, there was no conspiracy... It was just a lack of courage multiplied by the number of people who did not express doubts, concerns, and reservations. This is what happens in large bureaucracies, and I've yet to see a single one in which it doesn't occur. There needn't be any conspiracy... Just an environment that tends toward the discounting of risks when weighed against sticking one's own neck out.

Creatures of any bureaucracy are terribly risk-averse, but this applies to their lives and careers, personally. It says nothing of the result this garners from the bureaucracy at large.

 

SkepticLance,

 

Like you, I have my doubts about doomsday scenarios, but at the same time, I notice a generally non-critical attitude among those who ought to be doing the most thoroughly critical evaluations. Of course, that may be my perception, and my bias, but that's how I see it. More bothersome to me is that CERN did issue an advisory to staff to stop talking about micro black holes in terms of exceedingly low risk, and instead stick to the idea of zero risk. Now, I understand from a PR standpoint why they might say that, but it's exceedingly bad PR to ever let anybody know they said that... For those who see a conspiracy behind every collider, that's just way too much ammunition.

 

As for your "Fermi Paradox," I've seen it stated in various forms in a number of places. As you probably do, I am more prone to apply Occam's Razor and merely suggest that the reason we've no evidence of more advanced societies having visited is simply because they don't exist, or if they do, are no more able to overcome the obstacles of space travel over interstellar distances than are we. Nevertheless, it is an interesting premise, and provides at least a pause for introspection.

 

Playing "Devil's advocate" can be fun. I'm not nearly an advanced enough student of this field to offer theories about all of this, but I am a curious bugger and seldom run out of questions. One of the things I do with my fellows at work is to play devil's advocate, and they do the same for me. While sometimes, it all comes out fairly simply, on occasion, somebody hits upon a question, or points out a contradiction, or otherwise brings to light some flaw that poses a serious threat to our goal. When this happens, the value of the exercise becomes clear.

 

Besides, if I counted all the times a newcomer to my field asked a question that was so simple, and yet so probing, and absolutely demolished somebody or other's great idea, I'd be busy for a good long while, and would surely run out of fingers and toes. One of those "out of the mouthes of babes" kind of things...

 

Cheers!

 

Mark

[iNow]

It does not take much to calculate that, if such species are common, one would have visited Earth before now.

 

<...>

 

All developing intelligences are likely to follow a similar path to scientific understanding.

 

<...>

 

An all devouring black hole that inevitably appears for a certain size particle accelerator might be such a booby trap that inevitably kills off the developing species.

 

Ah... Yeah... That. Sorry, I need a napkin. I just squirted milk through my nostrils.

[John Cuthber]

Playing devil's advocate is all very well, but ...

There's still the scientific observation that colisions with higher energies than this happen in the atmosphere all the time and they haven't eaten the earth.

The fact that those particles are not made in our nieghbourhood isn't important. They only need to exist to show that the LHC is safe.

The dual beam bit isn't important either, one of the particles is sationary from it's point of view when the other hits it.

While the earth's atmosphere means that most cosmic rays interact with relatively light elemnts the same can't be said of the moon, which is also still there.

[SkepticLance]

To John

 

Both Mark and I agree that the probability of that kind of disaster is small. The point is that it is not zero.

 

Cosmic rays are not the same as colliding streams of high energy particles. In all probability, there will be no catastrophe. However, as said, it is not zero probability.

[markamerica]

John,

 

You know, I wondered about this, so maybe you can help me understand it, as it's a bit confusing to me. What is the point of dual beams? After all, if relativity says that c is the max possible speed of the collision, why build this thing with dual beams at all? Why not simply use a single beam and a fixed target? Seems to me like a whole lot of expense if in fact it makes no difference relative to the collision energies. Or am I missing something very elementary here?

 

Further, if you read the entirety of the article I linked, it seems there is some cutoff point, and that space (and everything in it) acts as a giant filter to some of the higher energy particles moving about, and that at certain energies, many fewer than expected ever arrive here due to this effect. It seems to me as though the "garden variety" cosmic particles probably don't represent much danger, and it may be that even the higher energy particles that arrive aren't very dangerous either, but the question that rings out in my mind is: What about the conditions of such naturally occurring collisions would make them different from what will occur in the LHC?

 

When I ask it this way, the only things I can come up with are:

a.) the mass of the particles(?)

b.) the relative velocity of the particles(?)

c.) the relative angle of the collision of the particles(?)

 

Now, in a sense, I've already covered b+c with the question about dual beams, more or less. Why bother with that, if it makes no difference to b, particularly?

 

As for the notion that playing devil's advocate is "all well and good," of course it is all well and good. One of the problems I notice with CERN is that they don't want anybody playing devil's advocate, seemingly.

 

I should think all scientists would welcome those sorts of examinations of their theories and experiments, but hey, maybe not.

 

Lance,

 

Thanks, yes indeed. It's all rather interesting, and yes, such catastrophes seem rather remote, but as you point out, it is not zero. That being the case, it raises ethical issues, and while I think the subject of ethics is too easily dismissed by some in science, this is probably not the forum for that discussion(which is part of why I think ethical considerations are too easily dismissed by science.) Experiments may happen in a vacuum, but not an ethical one.

 

Cheers!

 

Mark

[Klaynos]

I'm a bit tired so I'm just going to answer the first question.

 

Under c is the limit, c is unachiveable by massive particles.

 

You use two beams because the speed is not what you're trying to maximise but the energy (which is related to speed but it's not a linear or quadratic relationship), so you have 2 beams not double the speed but alot higher energy.

[Mr Skeptic]

To John

 

Both Mark and I agree that the probability of that kind of disaster is small. The point is that it is not zero.

 

Cosmic rays are not the same as colliding streams of high energy particles. In all probability, there will be no catastrophe. However, as said, it is not zero probability.

 

That's what we're trying to tell you. They're not the same; the cosmic rays are more powerful.

 

Unless you're saying that cosmic rays are not highly accelerated ions, then I would have to disagree that they're not the same in that sense.

[Cap'n Refsmmat]

Cosmic rays are high-energy particles -- some of them ludicrously high-energy.

[swansont]

Klaynos has already pointed out that you are trying to maximize energy; this is because you are trying to create massive particles from this energy.

 

Center-of-mass collisions means the KE afterwards is zero, so you can convert all of the KE into mass of any particles you create. There are limiting factors to beam energy, like how much synchrotron radiation you can accept. And there is the added advantage of collisions in the center-of-mass frame allowing you to detect emitted particles in all directions, instead of having them limited to a forward-scattered cone of much smaller extent.

[John Cuthber]

SkepticLance,

What's the difference between a cosmic ray high energy ion and a cyclotron produced high energy ion?

[insane_alien]

i'm not skepticlance but i'll answer, cosmic rays have been observed with higher energies than the LHC is able to produce.