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| Author | Topic: CERN - Large Hadron Collider and the Very Early Universe | ||||||||||||||||||||||||
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DevilsAdvocate Member (Idle past 3131 days)  Posts: 1548 Joined: |
LOL, that's pretty funny. Actually not if it really happened!  Shh, don't tell the doomsdayers! Edited by DevilsAdvocate, : No reason given. For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring. Dr. Carl Sagan
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DevilsAdvocate Member (Idle past 3131 days) Posts: 1548 Joined: |
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DevilsAdvocate Member (Idle past 3131 days) Posts: 1548 Joined: |
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DevilsAdvocate Member (Idle past 3131 days) Posts: 1548 Joined: |
What, can't I have some fun watching sci fi? Your critique of my posted video is like a critique of star trek. LOL. Yes, but there a lot of people out there that take Star Trek seriously and think Star Trek is real or at least really, really want it to be.  For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring. Dr. Carl Sagan
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DevilsAdvocate Member (Idle past 3131 days) Posts: 1548 Joined: |
Yes. Those are some of the most powerful rays ever measured, but this comparison is a bit unfair. What is more fair is to look at it from the perspective of one of the protons in the LHC collision. From the proton's perspective it is at rest, and the beam striking it is enormously higher in energy than when it is considered in the lab frame. If you do the proper transformation your factor of 1 million is really closer to a factor of 100. Can you site your source on this, because I believe the 7 TeV energy level is taking into consideration the kinetic energy of the each beam of protons at top energy levels accelerating at 0.999999991 the speed of light, not at rest. The combined kinetic energy of these two beams colliding at near light speeds is 14 TeV as shown here: LHC Machine Outreach. The below illustration depicts this:
You are right in that the center-of-mass collisions for cosmic rays are more on the par of 100+ TeV as shown here: Astrophysical implications of hypothetical stable TeV-scale black holes. However, with the Earth's 4.5 billion year lifespan and the nonexistence of astrophysical data indicating mini-black growing into super massive black holes elsewhere in the cosmos, how likely is it that humans could at less than 1/10th the energy create a quantum-black hole that would instead of evaporating will rather increase in size and threaten the planet, when this hasn't occur once with a constant barrage of cosmic particles during the Earth's 4.5 billion year history? The following quote illustrates the logic behind the defense for the LHC (and other particle accelerators) well:
Review of the Safety of LHC Collisions, ''Journal of Physics G: Nuclear and Particle Physics. 35, 115004 writes: Other astronomical bodies are even larger. For example, the radius of Jupiter is about ten times that of the Earth, and the radius of the Sun is a factor of ten larger still. The surface area of the Sun is therefore 10,000 times that of the Earth, and Nature has therefore already conducted the LHC experimental programme about one billion times via the collisions of cosmic rays with the Sun - and the Sun still exists. Moreover, our Milky Way galaxy contains about 1011 stars with sizes similar to ourSun, and there are about 1011 similar galaxies in the visible Universe. Cosmic rays have been hitting all these stars at rates similar to collisions with our own Sun. This means that Nature has already completed about 1031 LHC experimental programmes since the beginning of the Universe. Moreover, each second, the Universe is continuing to repeat about 3x1013 complete LHC experiments. There is no indication that any of these previous “LHC experiments” has ever had any large-scale consequences. The stars in our galaxy and others still exist, and conventional astrophysics can explain all the astrophysical black holes detected. Secondly, you can argue that the cosmic rays are not a good model for the heavy ions that the LHC will occasionally collide. I guess you are talking about the ALICE (A Large Ion Collider Experiment) component/detector part of the LHC which is measuring the less energetic lead ion collisions. Also, we have been doing ion collisions for the past 20+ years now without any significant problems. For example, the Relativistic Heavy Ion Collider (RHIC) at the Brookhaven National Laboratory in NY is the most powerful heavy ion accelerator in the world and has been operating for nearly 8 years. BTW, it had the same doom and gloom cloud as the LHC project. Guess what, there have been no problems. This paper discusses some of the same objections given for the RHIC which are also being brought up again for the LHC: Review of Speculative "Disaster Scenarios" at RHIC.
These collisions of clusters of hundreds of particles, each individual one of which is at a lower energy, could conceivably lead to something dangerous that cosmic rays and proton collisions do not produce. Such as? Are you talking about stranglets? Or something different? As far as stranglets, the less energy being used to combine large conglomerates of particles i.e. ions, the greater likelihood they have of producing a stable stranglet particle. Since the LHC will smash ions together at higher energies than that of the RHIC any potential issues with creating stable stranglets would have already raised its ugly head in the 10+ years other ion colliders have been online. Again we are only replicating at lower energy levels what is already happening elsewhere in the cosmos.
Thirdly, and perhaps importantly, what if dangerous particles (black holes or whatever) are produced in super-high energy cosmic rays all the time. They would be traveling at the speed of light relative to the earth. It's crazy to think about, but what if their cross section for interaction with the earth becomes tiny at these high speeds, and they pass through it just like a neutrino. For an electrically neutral stable black hole, this seems quite likely. In contrast, a similar black hole (or whatever) produced at the LHC could conceivably be produced with less than escape velocity, and so it would be caught by the earth's gravity, perhaps in an orbit that is inside of the earth itself. This could possibly provide it with time to behave dangerously. However, particle physicists state that these quantum black holes will dissipate rapidly due to the Hawking radiation and into the component particles from which they originally were converted from as shown here: Review of the Safety of LHC Collisions . Also since neutron stars and other sources of high energy cosmic radiation due not have this issue of stable black holes consuming them than this is an indicator that our much less energetic particle beams are not going to be a danger.
In the end, we can't rely on experiments or observations to be 100% sure this is safe. Nothing in life much less science is 100% but it is pretty close to 99.999999999 ad infinitim % safe.
We have to trust the calculations and theory at some level, which I for one, am not trained to understand. I have been informed that it is theoretically impossible to conceive of stable mini black holes. And that even if black holes are stable, the cosmic rays would produce them, there would be some which are charged, and they would have already been captured by the earth and destroyed it. Indeed, the latest safety reports suggest that if there were a black hole trapped in the earth, and we assume that they consume material at a rate slow enough for astronomical bodies to have the observed lifetimes, then there is no way it could take less than billions of years to grow large enough to become dangerous. True.
Well, I hope the theorists have done their homework properly ... and about strangelets as well as black holes. These guys are humans just like us. You really think they would not do there homework on this? You think they want the Earth to be swallowed up by some engulfing micro-black hole or become a supermasive stranglet? 
As an experimentalist who does not have a year+ available to go out and learn quantum gravity, etc, I will just have to take their word that the LHC is safe. Or maybe I don't ... I'm fine with taking a tiny risk of catastrophe in the name of big science. I could imagine others might disagree though. I think we can all be rest assured from the mere existence of our planet, solar system, galaxy and universe over past 14 billion years that if anything like this could happen i.e. Murphy's Law that it would have already happened. Just my 2 cents. Edited by DevilsAdvocate, : No reason given. Edited by DevilsAdvocate, : No reason given. For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring. Dr. Carl Sagan
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DevilsAdvocate Member (Idle past 3131 days) Posts: 1548 Joined: |
Myself writes: I think we can all be rest assured from the mere existence of our planet, solar system, galaxy and universe over past 14 billion years that if anything like this could happen i.e. Murphy's Law that it would have already happened. Of course that might be why we have'nt found any ET life out in the rest of the cosmos. Maybe they built a LHC type device once they reached a certain phase in the evolution of there civilization and wiped themselves out. Oooh, cool theme for a sci-fi book!  For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring. Dr. Carl Sagan
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DevilsAdvocate Member (Idle past 3131 days) Posts: 1548 Joined: |
I think we are pretty close to agreeing here.
I guess I am just more worried about dying by getting hit by some insane driver during my 75 mile commute back and forth to work every day, than by getting gobbled up by a self-induced black hole or some other world destroying science project. Of course we are talking about the fate of the entire planet and mankind so I can see where an abundant amount of caution is important here. Edited by DevilsAdvocate, : No reason given. For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring. Dr. Carl Sagan
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DevilsAdvocate Member (Idle past 3131 days) Posts: 1548 Joined: |
As an agnostic, I would prefer not to speculate on what will happen when we study the new conditions created at the LHC. There is no reason to think anything dangerous would happen, and cosmic rays do give some reassurance, along with the calculations of the theorists. I predict we will open up a worm hole to the Restaurant at the End of the Universe For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring. Dr. Carl Sagan
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