CERN and black hole

[sanctus]

Yesterday someone at the weekly juggling meeting asked me what I think about the risk of creating a black hole with the new experiment at CERN (I think he meant LHC). It seems that it was in all newspapers and I missed it. Anyone has any good links to articles?

 

Afterwards I would like to discuss it...

[coldcreation]

Yesterday someone at the weekly juggling meeting asked me what I think about the risk of creating a black hole with the new experiment at CERN (I think he meant LHC). It seems that it was in all newspapers and I missed it. Anyone has any good links to articles?

 

Afterwards I would like to discuss it...

 

Bonjour Sanctus,

 

The story originated from PHYSICS NEWS UPDATE The American Institute of Physics Bulletin of Physics News Number 558 September 26, 2001 by Phillip F. Schewe, Ben Stein, and James Riordon, where it was written:

 

...Physicists hope to bring this whole process down to earth by manufacturing tiny black holes amid the stupendous smashups of protons at the Large Hadron Collider (LHC) being built at CERN. Until recently theorists thought gravity was so weak compared to the other forces that it' date=' and gravitationally bound objects like black holes, could be studied on an equal footing with the other forces like the strong nuclear force only at energies of 10^19 GeV. In the past few years, though, some models featuring extra spatial dimensions hint that the unification of the forces, including gravity, might set in at much more modest energies, even in the TeV realm of the LHC. Thus one can contemplate forming a TeV- mass black hole even as one can imagine creating new particles in that mass range. [...'] A particularly striking signature of the black hole would involve an electron, muon, and photon in the final state of debris particles. Properties of Hawking radiation could tell physicists about the shape of extra spatial dimensions. A possibility of recreating the early moments of the universe in the lab would further unite particle physics and cosmology (Physical Review Letters, 15 October 2001

 

See also American Institue of Physics.

 

If I recall, the story was blown out of proportion, (i.e., there is no way to form a mini-black hole at CERN-LHC or any other future particle accelerator) But I have not yet found an article to that effect (or looked for one).

 

Here is a computer generated image of what it would look like.

 

Computer display of a hypothetical decay of a mini black hole in a collider detector. Collimated "jets" of particles correspond to quark and gluons produced from "Hawking radiation" emitted by the black hole.

.

 

Anyone else find anything more recent?

 

 

A+

 

 

CC

[JTankers]

ColdCreation writes "there is no way to form a mini-black hole at CERN-LHC or any other future particle accelerator"

 

Yes, that is out of date. New theories in physics now predict that micro black holes may be creatable at Large Hadron Collider energies. The CERN Courier in 2004 predicted possible creation of micro black holes at a rate of one per second. (cerncourier.com/cws/article/cern/29199]The case for mini black holes - CERN Courier)

 

But CERN predicted that they would be safe, because a 30 year old theory by Dr. Hawking predicted that micro black holes would decay.

 

But other PHD's in Math, Physics and other theoretical sciences predict that micro black holes may be just as likely to grow, and if they become charged, then grow quickly.

 

Basic arguments:

 

Hawking Radiation is disputed as "no compelling theoretical case for or against radiation by black holes" and cosmic rays striking Earth do not prove safety because if stable neutral micro black holes were created, they would travel through Earth and exit at relativistic speeds.

 

CERN has presented a credible and detailed new safety report with arguments for safety based on Neutron stars and cosmic rays. And while I am very thankful for the creation of this important report, I can not ignore what CERN's SPC Committee writes in their validation report:

 

"A powerful argument applicable also to higher energies is formulated making reference to observed neutron stars, but this argument relies on properties of cosmic rays and neutrinos that, while highly plausible, do require confirmation, as can be expected in the coming years."

 

I suggest that this experiment wait for confirmation from the GLAST space telescope which will attempt to validate Hawking Radiation. If Hawking Radiation can be confirmed, then perhaps we can consider the Large Hadron Collider reasonably safe. If not, then more confirmation is needed.

 

Good links to learn more:

 

Good balanced encyclopedia article, Safety of the Large Hadron Collider on Wikipedia: en.wikipedia.org/wiki/Safety_of_the_Large_Hadron_Collider]Safety of the Large Hadron Collider - Wikipedia, the free encyclopedia

 

Safety arguments in more detail: LHCFacts.org

 

Legal Defense: LHCDefense.org

[Overdog]

Here is the latest I am aware of on the subject...

 

UCSB professor's paper on safety of large hadron collider to be published in Physical Review D

 

Particle colliders creating black holes that could devour the Earth. Sounds like a great Hollywood script.

 

But, according to UC Santa Barbara Physics Professor Steve Giddings, it's pure fiction.

 

Giddings has co-authored a paper, "Astrophysical implications of hypothetical stable TeV-scale black holes," that has been accepted for publication in an upcoming edition of the peer-reviewed journal Physical Review D, documenting his study of the safety of microscopic black holes that might possibly be produced by the Large Hadron Collider (LHC), which is nearing completion in Europe. The paper, co-authored by Michelangelo Mangano of the European Center for Nuclear Research (CERN), which is building the world's largest particle collider, investigates hypothesized behavior of tiny black holes that might be created by high-energy collisions in the CERN particle accelerator.

 

If they appear at all, these black holes would exist for "about a nano-nano-nanosecond," Giddings said, adding that they would have no effect of consequence. However, the paper studies whether there could be any large-scale effects in an extremely hypothetical situation where the black holes don't evaporate.

 

The Giddings/Mangano study concludes that such microscopic black holes would be harmless. In fact, he added, nature is continuously creating LHC-like collisions when much higher-energy cosmic rays collide with the Earth's atmosphere, with the Sun, and with other objects such as white dwarfs and neutron stars. If such collisions posed a danger, the consequences for Earth or these astronomical objects would have become evident already, Giddings said.

 

"The future health of our planet and the safety of its people are of paramount concern to us all," Giddings said. "There were already very strong physics arguments that there is no risk from hypothetical micro black holes, and we've provided additional arguments ruling out risk even under very bizarre hypotheses."

 

The LHC, near Geneva, Switzerland, is expected to begin operations this summer. It will collide proton beams at levels of energy never before produced in a particle accelerator. Those results will then be studied for clues to new forces of nature, and possibly even extra dimensions of space. The first collision of beams is likely to be in September. The $8 billion project has taken 14 years.

 

Two men have filed a federal lawsuit in Hawaii in an attempt to halt the LHC due to their concerns about the safety of black holes. Giddings' study has been cited by CERN as evidence of the safety of the LHC.

[JTankers]

The report above is available here: indico.cern.ch/getFile.py/access?contribId=20&resId=0&materialId=0&confId=35065

 

And quoted in that report under the micro black hole section about the new neutron star and cosmic ray argument is this:

 

"A powerful argument applicable also to higher energies is formulated making reference to observed neutron stars, but this argument relies on properties of cosmic rays and neutrinos that, while highly plausible, do require confirmation, as can be expected in the coming years."

 

An other professors write of the theory that predicts decay "no compelling theoretical case for or against radiation by black holes"

 

As Dr. Paul J. Werbos of the National Science Foundation writes: "stake the very survival of all life on earth on the truth of their ZPE stuff! … a gamble."

 

That may be an understatement, we have not even confirmed whether the deck is stacked against safety or not!

 

LHCFacts.org

[freeztar]

What would be the Swarzchild radius of a TeV black hole? If it did not dissipate, what would be the worst that could happen?

[Little Bang]

I for one am very skeptical of Hawking radiation therefore think that if the energies are great enough to create a black hole it will grow.

[modest]

What would be the Swarzchild radius of a TeV black hole?

 

1 TeV = 10^12 eV = 1.602E-7 joules

 

by e=mc^2 that's 1.783E-24 kg

 

Schwarzschild radius is 2Gm/c^2 which gives:

 

2.65 x 10^-51 meters. by comparison, an electron is about 10^-18 meters. So, it would be 33 orders of magnitude smaller than an electron. I wonder what the chances would be that it would hit anything. I guess it probably would if it didn't evaporate, in which case...

 

If it did not dissipate, what would be the worst that could happen?

 

If it had less than earth's escape velocity of 11 km/s it would stay gravitationally bound to earth - falling through the earth almost out the other side. Then back through again and again until it settled down toward the middle. At first, I imagine it might grow rather slowly. Eating an atom here and there. Eventually though, it would get big enough to grow rapidly at which point the ground would start to fall beneath us.

 

I'm sure it would be loud, painful, debilitating, and confusing. Shock waves and concussive blasts would probably disintegrate the earth's crust killing most everybody from falling or being crushed or accelerated beyond human tolerance. I doubt it would be a gentle descent into the singularity. At the end of the day everything that was your existence would be erased from the universe forever.

 

But, I'm sure that won't happen :hihi:

 

~modest

[Moontanman]

1 TeV = 10^12 eV = 1.602E-7 joules

 

by e=mc^2 that's 1.783E-24 kg

 

Schwarzschild radius is 2Gm/c^2 which gives:

 

2.65 x 10^-51 meters. by comparison, an electron is about 10^-18 meters. So, it would be 33 orders of magnitude smaller than an electron. I wonder what the chances would be that it would hit anything. I guess it probably would if it didn't evaporate, in which case...

 

 

 

If it had less than earth's escape velocity of 11 km/s it would stay gravitationally bound to earth - falling through the earth almost out the other side. Then back through again and again until it settled down toward the middle. At first, I imagine it might grow rather slowly. Eating an atom here and there. Eventually though, it would get big enough to grow rapidly at which point the ground would start to fall beneath us.

 

I'm sure it would be loud, painful, debilitating, and confusing. Shock waves and concussive blasts would probably disintegrate the earth's crust killing most everybody from falling or being crushed or accelerated beyond human tolerance. I doubt it would be a gentle descent into the singularity. At the end of the day everything that was your existence would be erased from the universe forever.

 

But, I'm sure that won't happen :hihi:

 

~modest

 

Could something that much smaller than an electron even eat an electron? Could it compress an electron? It certainly couldn't tear an electron apart, it has no parts. How many millions of years would it take such a small black hole to grow big enough by consuming particles small enough for it drag into it's event horizon. are there any particles small enough for it to drag into it's even horizon? Photons maybe? I'm betting it would take millions if not billions of years for it to grow big enough to consume any thing other than possibly photons.

[freeztar]

1 TeV = 10^12 eV = 1.602E-7 joules

 

by e=mc^2 that's 1.783E-24 kg

 

Schwarzschild radius is 2Gm/c^2 which gives:

 

2.65 x 10^-51 meters. by comparison, an electron is about 10^-18 meters. So, it would be 33 orders of magnitude smaller than an electron.

Thanks Modest. It's funny that when I clicked back on this thread I was scolding myself for not doing the math and just asking the question, and then I saw your post. ;)

 

That seems immeasurably small. Would we even be able to detect that one was created?

 

EDIT: I guess we could indirectly detect them via the presence of muons and such?

 

If it had less than earth's escape velocity of 11 km/s it would stay gravitationally bound to earth - falling through the earth almost out the other side. Then back through again and again until it settled down toward the middle. At first, I imagine it might grow rather slowly. Eating an atom here and there. Eventually though, it would get big enough to grow rapidly at which point the ground would start to fall beneath us.

 

I'm sure it would be loud, painful, debilitating, and confusing. Shock waves and concussive blasts would probably disintegrate the earth's crust killing most everybody from falling or being crushed or accelerated beyond human tolerance. I doubt it would be a gentle descent into the singularity. At the end of the day everything that was your existence would be erased from the universe forever.

 

That doesn't sound that bad. :hihi:

[modest]

Could something that much smaller than an electron even eat an electron? Could it compress an electron? It certainly couldn't tear an electron apart, it has no parts.

 

Yeah, it all seems a bit speculative to me. General relativity being about the big and quantum mechanics being about the small - I don't see how they come up with any answers to this stuff. I know it's way out of my league.

 

The things that get trapped in a black hole are the things inside the Schwarzschild radius If it's not inside that then it's not trapped. Baryonic subatomic particles are too big to fit inside the schwarzschild radius (event horizon) - so could they ever really be inside the black hole? Maybe not.

 

If they do somehow get in there I don't see them sticking around long. Quantum particles aren't known for holding still. Quantum tunneling is well enough established. Anything that gets trapped (including the particle that made it) may evaporate instantly even without hawking radiation

 

How many millions of years would it take such a small black hole to grow big enough by consuming particles small enough for it drag into it's event horizon.

 

Yeah, who could say? If they eat anything that touches them then I can't imagine it taking more than hours to eat the earth. If it's more like a neutrino and hardly wants to interact with anything then It would take a very long time. I don't see how anyone could know for sure.

 

are there any particles small enough for it to drag into it's even horizon? Photons maybe? I'm betting it would take millions if not billions of years for it to grow big enough to consume any thing other than possibly photons.

 

Hey - we were on the same wavelength about the event horizon there :hihi: A photon is a point particle in QM, so maybe. But, in string theory it is 10^-44 meters so maybe not

 

That seems immeasurably small. Would we even be able to detect that one was created? EDIT: I guess we could indirectly detect them via the presence of muons and such?

 

I have no idea, I'll look into it. I honestly need to do that before I start answering ;)

 

I really don't take these threats too seriously considering the energies that cosmic rays bombard earth's atmosphere with regularly. In four and a half billion years that has never been a problem. High speed jets coming off black holes and stars would similarly be filled with tiny black holes which one would imagine would be all around the interstellar medium. If miniature black holes were possible by anything we're going to do at LHC then I'd think nature already would have filled the galaxy with them by now. That not being the case, I think we're safe.

 

~modest

[freeztar]

But, in string theory it is 10^44 meters so maybe not

 

Typo?

[modest]

Typo?

 

alright wise guy 10^-44

[tmm35]

Does anyone know the relative speeds and trajectory of possible MBH created by cosmic rays. If their argument for safety is that cosmic rays may create them and we are still here then should they not mimic the conditions of a cosmic ray collision in LHC rather. Since we are talking about so many unknowns that would seem to be the minimum standard for safety.

[CraigD]

Welcome to hypography, tmm35! :)

Does anyone know the relative speeds and trajectory of possible MBH created by cosmic rays. If their argument for safety is that cosmic rays may create them and we are still here then should they not mimic the conditions of a cosmic ray collision in LHC rather.

The LHC’s most energetic collisions – those involving lead nuclei – are a bit over [math]10^{15}[/math] eV (1150 TeV). It’s max for a proton (hydrogen nuclei) collision is a little over [math]10^{13}[/math] eV (14 TeV).

 

Cosmic rays, the highest energy kind which are mostly protons and helium nuclei – have been detected with energies over [math]10^{20}[/math] eV – that is, over 100,000 times as energetic as the LHC can create.

 

So the LHC can’t mimic the highest energy cosmic ray collisions, because it’s not powerful enough. Though it’s the most powerful accelerator made by humans, it’s still puny by the standards of the cosmos – though much more conveniently located to its detectors. ;)

 

As for trajectories – ie angle of impact – any other than a head-on, 180°, simply results in a lower-energy collision, so are not a significant factor.

 

Though physicists usually don’t, you can convert from a particle energy to a velocity by algebraically manipulating the mass dilation formula

[math]m = \frac{m_0}{\sqrt{1- \left(\frac{v}{c} \right)^2}}[/math]

into

[math]v = c \sqrt{1 - \left(\frac{m_0}{m} \right)^2}[/math]

 

The mass of a proton is about [math]10^9[/math] eV (938 MeV), So the speed of a [math]10^{13}[/math] eV proton is about 0.999999995 c. The mass of a lead atom is about 200 times (208.76) that of a proton, so a [math]10^{15}[/math] eV lead nucleus has about the same speed as a [math]10^{13}[/math] eV proton. The speed of a [math]10^{20}[/math] eV proton is about 0.99999999999999999999995 c (if I haven’t miscounted a 9 – now you can see why physicists usually prefer to use the energies of high-speed particles, rather than their speeds. :edizzy:

[tmm35]

Thanks for calculations of input paticle velocity and trajectory but the main issue is output paticle (i.e. potential black hole) velocity and trajectory. I havent seen any calculations on this but my understanding of physics say that a LHC collision of particles of equal mass traveling in opposite directions would yeild output particles of nearly zero velocity realtive to earth and trajectory of input particles. A CR collision of simillar particles would yeild output particles of much higher velocity relative to original trajectory and earth. This would mean that potential dangerous objects output from LHC collision would remain here on earth whereas those from a CR collision would fly away into vacum of space where there is no other objects to interact with and those would have no affect to earth. CR having higher energies only makes the CR velocities higher and less risk to earth since.

 

So if LHC is claiming we are safe since CR collisions havent created output particles that have damaged the earth then they need to make sure the output particles of LHC collisions mimic simillar output velocities as CR collision. Has LHC published or has anybody taken the time to calculate the velocity of output particles ?

 

p.s. I do understand that meeting the criteria of ensuring output particles are ejected into space rather then remain on earth means limiting energy level LHC collisions. If that is minimal thing to do though to ensure safety of countires in locality of LHC and possibly the entire planet LHC and all there representatives should be taking that responsability for ensuring safety.