Register to reply 
Black hole in LHC? 
Share this thread: 
#37
Aug608, 06:32 AM

P: 5

than energy of a single particle in LHC, it calms. But there remains a concern. Namely intensity of cosmic rays is incomparably less than in LHC. In LHC very many particles will hit the unit area of target in one second, and as result much more energy will hit the unit area in unit of time. So, there could be unknown nonlinear effect, which will give a BH. 


#38
Aug608, 06:44 AM

Mentor
P: 16,321

First, there is no target at the LHC. There are colliding beams. That's why it's called the Large Hadron Collider. Next, there are a series of discrete interactions, occurring every 25 ns. Are you trying to tell us that somehow space "remembers" that previously there was a collision there? 


#39
Aug608, 07:33 AM

Emeritus
Sci Advisor
PF Gold
P: 29,238

Zz. 


#40
Aug608, 02:34 PM

P: 77

Particle collisions like those in the LHC happen naturally, they just aren't observed by huge detectors. Thus, if the LHC were likely to produce dangerous black holes, we would have seen this naturally occurring, no?



#41
Aug608, 03:36 PM

P: 55

The energy levels produced in the LHC are only going to be a fraction of those energies produced in nature everyday from events such as gamma ray bursts and cosmic ray collisions. In a very real sense, we already use the universe as a veritable collider whose vast size amplifies the effects of cosmic events, and observe the effects of extraordinarly high energy occurances, to which the LHC pales in comparison. The fact of our continued existence is a strong confirmation of LHC's safety. However, additional safety concerns have been probed and reviewed in the CERN safety report which is exceptionally comprehensive.



#42
Aug608, 08:48 PM

P: 539

For the LHC I would imagine that the colliding protons have a greater probability of creating a black hole whose velocity is less than earth's escape velocity, since the colliding protons will have momenta of about the same magnitude and approach from nearly opposite directions in terms of the stationary LHC frame. I think the probabilities of such a result would be very small, but possible. Does this make sense? If this is true, I am not too concerned since the black hole would be extremely tiny and will have little gravitational effect on its immediate surroundings; its essentially a black hole with total mass no more than two protons. 


#43
Aug608, 09:00 PM

P: 32

Well suppose many small black holes are created and collide. Could that pose a problem? Also couldn't it be beneficial if the LHC created microscopic black holes. That way they could be studied with very little risk.



#44
Aug608, 09:07 PM

Emeritus
Sci Advisor
PF Gold
P: 29,238

http://physicsandphysicists.blogspot...omeatlas.html http://physicsandphysicists.blogspot...atlas_21.html In the second part, he addressed my question if such blackholes can be identified if created at Atlas. Zz. 


#45
Aug708, 11:49 AM

P: 1,672

Are black holes really thought of actually existing? I always thought of them as still being theory, although a highly supported theory. After all do we really have any cognitive proof that black holes really do exist other than mathematics based on empirical assumptions?



#46
Aug708, 11:56 AM

Mentor
P: 16,321

Do you mean microBHs? No, nobody knows if they exist. Odds are they don't.
If you mean astronomical BHs, there are a number of objects that are known to be too heavy to be neutron stars or too dense to be anything but a BH. 


#47
Aug2208, 01:06 PM

P: 1

Hello, I understand that our equations have demonstrated that the microscopic black holes capable of being created at the LHC would quickly evaporate, but I was curious as to whether or not those conclusions were strongly based on the assumption that black holes are infinitely dense. If black holes happen to NOT be infinitely dense, would the results be much different??



#48
Aug2208, 01:58 PM

P: 989

I have already calculated how much time is required for a classical 'stable' microsingularity to consume one Iron nucleus in Terra's core at 1 Tev: [tex]\boxed{\tau_b = \frac{4 m_{Fe}}{3} \left(\frac{E_b}{\hbar c} \right)^2 \sqrt{\frac{r_e^7}{2 G m_e^3}}}[/tex] [tex]\tau_b = 12331.540 \; \text{s}[/tex] = 3.425 hrs. Time required for a classical 'stable' microsingularity to consume one proton in Sol's core at 1 Tev: [tex]\boxed{\tau_b = \frac{4 m_p}{3} \left(\frac{E_b}{\hbar c} \right)^2 \sqrt{\frac{r_{\odot}^7}{2 G m_{\odot}^3}}}[/tex] [tex]\tau_b = 15.722 \; \text{s}[/tex] Based upon this particle rate, and presuming this rate is constant, how much time would be required for a single quantum black hole to consume Terra? [tex]\boxed{t_e = \frac{4}{3} \left(\frac{E_b}{\hbar c} \right)^2 \sqrt{\frac{r_e^7}{2 G m_e}}}[/tex] [tex]t_e = 7.951 \cdot 10^{53} \; \text{s}[/tex]  2.521*10^46 years BH horizon radius as function of energy: [tex]r_h(E_b) = \frac{\hbar c}{E_b}[/tex] Theoretical upper limit: [tex]\boxed{t_e = \frac{4m_p}{3} \sqrt{\frac{(m_e c)^3 r_e^7}{2 \hbar^5}}}[/tex] [tex]t_e = 6.874 \cdot 10^{131} \; \text{s}[/tex]  2.180*10^124 years [tex]\boxed{t_a = \frac{c^4}{4 \pi} \sqrt{\frac{r_e}{2 G^5 m_e^3}}}[/tex] Time required to absorb 1 m^3 of Terra: [tex]t_a = 6.844 \cdot 10^{16} \; \text{years}[/tex] Note that if such an event were possible, the Universe would have generated trillions of such particles. Reference: classical stable microsingularity absorption crosssection  Orion1 #75 classical stable microsingularity absorption crosssection  Orion1 #83 classical stable microsingularity absorption crosssection  Orion1 #90 classical stable microsingularity absorption crosssection  Orion1 #104 


#49
Aug2608, 02:02 AM

P: 3

Hey everyone. Sorry if this topic has been played to death, but like many, I'm having pretty high anxiety about the start up of the LHC in a few weeks. Just got engaged, new job, life is really starting for me. I'm afraid it might be cut short cause of this thing. Theres so much speculation about what this machine can bring, and I'm actually seeing more doomsdayers on the internet then people with faith in the project. So, I decided to come to the most rational message board I could think of. A Physic board, since the whole machine is one giant physics experiment. I keep seeing article after article that offers a counterargument to the "its safe" theory. This one specifically caught my attention:
http://arxiv.org/PS_cache/arxiv/pdf/...808.1415v1.pdf If this machine is "so safe" why are all these distinguished scientists fighting so hard against it? Some of these guys ARENT nutballs. So....is this really safe? Like I said, sorry if this has been discussed before but if I could get some reassurance from you guys, it'd be great cause I've definitely been losing lots of sleep over it. 


#50
Aug2608, 02:30 AM

P: 1,133

don't worry...what happens will happen when it happens...life is only life...do not mourn over it...do not obsess over it



#51
Aug2608, 05:23 AM

Mentor
P: 16,321




#52
Aug2608, 06:07 AM

PF Gold
P: 2,907




#53
Aug2708, 03:44 AM

P: 22




#54
Aug2708, 05:51 AM

Mentor
P: 16,321

As far as "arrogance", I marvel at the state of affairs where someone who criticizes a report that they don't understand isn't being arrogant, but where someone who points this out is. 


Register to reply 
Related Discussions  
Black hole vs. Black hole, who wins?  Astronomy & Astrophysics  44  
Black hole inside a larger black hole.  Cosmology  33  
White hole / black hole theory  Astronomy & Astrophysics  26 