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Concern Over Creating Black Holes
Maria Williams writes to tell us about worry surrounding the impending startup of CERN's Large Hadron Collider. Some fear that the device, in creating mini black holes, could jeopardize Life As We Know It. While the tiny black holes should evaporate quickly — throwing off so-called Hawking radiation that can be detected — CERN software developer Ran Livneh reminds us that "Any physicist will tell you that there is no way to prove that generated black holes will decay." The LHC site assures us there's nothing to worry about. The flap is reminiscent of the time the Relativistic Heavy Ion Collider went live. The worry then was that "negative strangelets" could gobble up the world.
As long as Gordon Freeman is there to watch over the experiment, I think we'll all be okay. Maybe.
I hear the Vortigaunts are our allies.
....Hard On Collider? I think I'd prefer an earth swallowing black hole.
Being cautious about a potentially real issue is one thing, but of course the big issue here is that collisions of similar energy happen, if not commonly, at least not entirely rarely due to cosmic rays. If the world could be destroyed by the side-effects of such a collision, we wouldn't be here to be nervous about it.
I've had this sig for three days.
Of course there's a way. Empirical research, just like they're doing. First you make a black hole, then you see if it expands until it destroys all life on earth. Simple, straight forwards, effective.
Where are they? Gone.
Civilizations routinely destroy their home planet by creating miniature black holes thereupon whilst trying to figure out what makes them tick. Technology advances faster than democracy, and it has never yet in the long history of the universe been put to a vote.
If you mod me down, I shall become more powerful than you could possibly imagine.
You see, the problem is that we could all get sucked off before we know what's going on.
I meant sucked in.
Summation 2
...Yet
Make sure you buy your SpeedPass at your local church.
I think microscopic black holes couldn't eat up the earth due to the three stooges problem. They are so small that only an atom at a time can get in, but the gravity is strong enough to try to suck in more, so all the atoms get bunched up around the event horizon like the three stooges all trying to get through a door at the same time. Problem nullified. Whoop hoop oop! Nyuck nyuck, why I oughta!
- None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
Primary cosmic rays impact the earth all the time, and these often have far higher energies than even our largest particle accelerators are capable of producing. For any experiment we attempt, we can be reasonably sure that colliding cosmic rays have already produced the same results, sometime within the past few billions years. If we could create massively destructive black holes through our particle accelerators, one would expect that stray cosmic rays would have already done so.
This type of fear occurred many times during the nuclear physics history, when higher and higher energies were explored. The answer against fears of unknown catastrophic effect has been that some cosmic rays are much more energetic than any artificially accelerated particles (10^21 eV for some cosmic rays in comparison to the feeble 10^12 eV in today accelerators such as LHC). For sure the Earth and the Sun did already receive zillons of cosmic rays without disappearing...
For example, there are as yet little-understood phenomena that can accelerate particles six orders of magnitude faster than anything achievable in a lab. Try reading about Ultra-high-energy cosmic rays.
More specifically read the story of the Oh-My-God Particle. This was a proton detected in October of 1991 that had an energy of 3.2 * 10^20 eV. The equivalent energy of a baseball thrown at 55 mph... all in a single proton travelling at 99.99999999999999999999951% the speed of light!
While something travelling that fast has little probability of interacting with anything you could imagine the surprise if one of those hit you! I think that the fact we are alive with such powerful forces already at work in our universe means we have little to fear.
I work one of the LHC expirements (low-level grad student, no one important), and this is utter crap.
Yes, there are physicists who are concerned. There is a chance that this could happen - one of those "if everything we know about high energy physics is completely wrong, this could happen". There is an approximately equal chance that Pat Buchanan will be nominated as the Democrat candidate for president in 2008. No physicist can prove that this won't happen - just like no physicist can actually prove that Superman doesn't exist.
Unfortunately, it's about the only way a reporter can "sexy up" a story about a particle accelerator. I can't wait to see the headlines in 2007 - "Will the Earth end tomorrow?" (subheading: "Respectable scientists say 'No'").
What will happen?
We'll all die. Simultaneously. Noone will feel anything.
What's the big problem aside from the end of the earth?
On November 3rd, 2004, civil war was narrowly averted when Kerry supporters realized that only 0.03% of them owned a gun.
Dark Reflection
working in a small cubicle, doing nothing that will ever even change the world, while these guys are working on a project that could destroy the world! I'm so jealous... I've made bad choices.
See Doomsday Fears at RHIC in particular the reference Review of Speculative "Disaster Scenarios" at RHIC
i\hbar\dot{\psi}=\hat{H}\psi
There is an assumption in all of this, that the singularity is a point in space/time. This is how it is normally considered, but it is by no means the only interpretation that would be valid. Evaporation only applies within this assumption because entropy can only ever increase and the entropy of a physical point singularity that did not evaporate would be a constant. If a singularity does not exist as a point (there are other solutions, such as a "Kerr Ring Singularity") or doesn't actually exist as a physical entity at all (see below for a trivial theory where that would work), then all bets are off.
This is a "just for amusement" theory, for the sole purpose of illustrating a singularity that would not violate the second law of thermodynamics and still not evaporate. Let us say that a singularity does have infinite gravity at the point at which it "exists", and that the curvature of space/time is a direct function of gravity, then what we call a singularity would not actually exist as an object. At all. What you would have is a "well" of essentially zero diameter where the sides were orthogonal to space and along the axis of time in a negative direction. The notion that "space and time end at a singularity" would not be true to an observer within the Universe, as they would not experience the well as anything other than a continuation of space. However, space would then not be simply-connected and it would be mathematically possible to show that there were mathematically definable points within an otherwise well-defined region that could not be reached.
Now for the well itself. It cannot stop within the universe, because there are no forces along that axis. F=ma, so if F=0, then a=0. Nor can it continue forever, because it's going along the axis of time and time does not continue forever. There is exactly one place such a well could terminate, that being the moment of the Big Bang. (It stops there because there's nothing more to travel along.) It would be an express trip, there would be no possibility of getting off anywhere else. So it's just as well that, if this correct, anything that fell in would be crushed into quantum foam. Nothing else is going to fit in a well of zero diameter. Hawking's theory of imaginary time becoming real time would certainly fit this description.
This theory would require that (a) black holes can only ever expand, (b) hawking radiation would contain equal numbers of particles and anti-particles (which would explain why we have such trouble finding any), (c) the recently-proved Poincare hypothesis does NOT apply to space/time, as it is no longer simply-connected, and therefore the Universe is NOT topologically equivalent to a hypersphere (which is going to upset the Chinese and Russians no end), and (d) the Hubble constant absolutely must be below 1.
(That last one might not be obvious, so I'll explain. This theory recycles matter and energy through time to the big bang. Since you have a Universe's worth of matter/energy, you would not need inflation theory - which is "good" because inflation is an ugly hack whose chief benefit is that it works vastly better than every other mainstream theory in existance. But you can't guarantee that the whole Universe is recycled if the Universe is open. You can only guarantee 100% recycling if every possible photon and every possible particle is absolutely
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)